Space Sunday: selected spaceflight previews for 2025

Blue Origin’s New Glenn performs a full 7-engine statis fire test at Space launch Complex 36, Cape Canaveral Space Force Station, December 27th, 2024. Credit: Blue Origin

As we’re at the end of 2024, rather than looking back over the year, I thought I’d look ahead to some of the spaceflight events hopefully coming our way in 2025. Note this list intentionally does not include schedule missions to the ISS, SpaceX Starlink launches or test programmes, or similar.

New Glenn Maiden Flight

While Blue Origin didn’t meet their target to fly their new heavy lift launcher, New Glenn, before the end of 2024, the flight now looks set to go ahead in early January 2025. Specifically:

  • On December 27th, 2024, and after some delay, the company finally received a license from the FAA to conduct New Glenn launches out of Canaveral Space Force Station for five years.
  • That same day, the rocket, which has been on the pad for final testing, completely a full static fire test of its core stages engines. The test saw all seven core stage engines run for a total of 24 seconds, over half of which saw them throttle up to 100%.
  • While a launch date has not been disclosed by Blue Origin, an airspace advisory has been released referencing NG-1, the name of the flight, and warning of airspace restrictions around and over Florida’s Space Coast for the period 06:00 through 09:45 UTC on January 6th, 2025, with the option for a second airspace restriction being enforced at the same time on January 7th, 2025.

As I’ve previously noted, the flight will be carrying a prototype Blue Ring satellite platform capable of delivering up to 3 tonnes of payload to different orbits, as well as being able to carry out on-orbit satellite refuelling (as well as being refuelled in orbit itself) and transporting payloads between orbits. However, Blue Ring will not physically detach from the launch vehicle’s upper stage for the flight. Additionally, the flight is seen as the first of two flights required to certify New Glenn to fly United States Space Force national security and related payloads, and will hopefully see the first stage make a safe return to Earth and landing on the company’s Landing Platform Vessel 1, Jacklyn.

Japan Goes Lunar Roving

January is also the target month for Japan’s second attempt at a private lunar landing, in the form of the Hakuto-R Mission 2, developed by ispace. It is a follow-up to the Hakuto-R Mission 1, a technology demonstrator mission also launched by ispace, which took the “long way” to the Moon, covering a total of 1.4 million kilometres in a 5-month journey.

However, the lander and its payloads were lost during it landing attempt on April 23rd, 2023, after a disagreement between the main flight computer and the vehicle’s altimeter resulted in it entering a sustained hover some 5 km above the lunar surface, expending its propellants so it fell uncontrolled to the Moon’s surface.

The Hakuto-R lander Resilience with micro-rover Tenacious visible, undergoing final preparations at a JAXA facility in Tsukuba, Japan prior to being shipped to Kennedy Space Centre. Credit: ispace/JAXA

Like its predecessor, Hakuto-R Mission 2 comprises a lander vehicle some 2.5 metres tall and 2.3 metres wide intended to demonstrate a reliable small-scale lander capability with data transmission and relay capabilities for use as a part of the US-led Project Artemis. The lander will launch atop a SpaceX Falcon 9, but unlike it predecessor will head directly to the Moon, where it will land in Mare Frigoris, the Sea of Cold.

Once there, the lander – called Resilience – will deploy a micro-rover called Tenacious. Weighing just 5 kg, this has been built as a multi-role vehicle by a team in Luxembourg. Once deployed, it will demonstrate autonomous driving capabilities as it explores the area around the lander, and will also partner with the lander in an ISRU (in-situ resource utilisation) demonstration, attempting to extract water from the lunar surface, heating it and splitting the resultant steam into oxygen and hydrogen.

One of the team responsible for Tenacious checks the little rover before the cover is closed on the payload bay containing it. Credit: ispace

The mission will carry a number of additional payloads, perhaps the most unusual of which is Moonhouse, by Swedish artist Mikeal Genberg.

For 25 years, Genberg has had a dream about a little red house (“all house in Sweden are red!” he states) on the Moon; throughout that time he’s visualised it through art installations here on Earth, and has even seen one of his models flown aboard the space shuttle, courtesy of Swedish astronaut Christer Fuglesang. Now, Tenacious will carry one of Genberg’s little houses to the surface of the Moon. It is secured to a platform on the front of the rover, and represents the culmination of Genberg’s 25-year-long dream.

Mikael Genberg’s Moonhouse mounted on the front of the micro-rover Tenacious. Credit: ispace / JAXA

As to its meaning – Genberg notes that it could be many things, depending on who you are. A symbol of life; for the potential for future life; a beacon of hope that anything is possible if we put our minds to it; a commentary on humanity and our treatment of the one home we have; as art, it has the ability to speak to each of us, and to do so differently with each of us.

Fram2 Private Polar Mission

Due to launch in around March 2025, Fram2 is another “all-private” space mission in the mould of Jared Isaacman’s Inspiration4 (2021) and Polaris Dawn (2024) flights. Also utilising SpaceX Crew Dragon Resilience, Fram2 will fly a crew of 4 on a mission of up to 5 days duration in a 90º inclination orbit between 425 and 450 km altitude. It aims to observe and study aurora-like phenomena such as STEVE and green fragments and conduct experiments on the human body, including the first X-ray of a human in space.

The Fram2 mission will utilise SpaceX Crew Dragon Resilience, which will once again be fitted with the panoramic cupola in the vehicle’s nose section, replacing the ISS docking mechanism. Credit: SpaceX

The crew for the mission comprise:

  • Chung Wang, the mission commander and co-bankroller, a Chinese-born Maltese crypto currency entrepreneur who founded f2pool , one of the largest Bitcoin mining pools in the world, and Stakefish, one of the largest Ethereum staking providers.
  • Jannicke Mikkelsen, the vehicle commander, and co-bankroller for the mission, a Scottish-born Norwegian cinematographer and a pioneer of VR cinematography, 3D animation and augmented reality. A skilled speed skater, she will become the first Norwegian astronaut and the first European to command a space vehicle.
  • Eric Philips, a 62-year-old noted Australian polar explorer, who will serve as the vehicle pilot as will be the first Australian national to fly in space (while both Paul Scully-Power and Andy Thomas were born in Australia and flew on space shuttle missions (Thomas flying multiple times), they only did so after becoming US citizens).
  • Rabea Rogge, a German electrical engineer and robotic expert, who will fill the role of Mission Specialist and will become the first German woman to fly in space, beating-out those selected as a part of the privately-funded programme Die Astronautin, specifically set-up to fly a German woman in space by 2023.
The Fram2 crew (l to r): Chun Wang, Jannicke Mikkelsen, Eric Philips and Rabea Rogge

Fram2 is named for the Norwegian polar exploration vessel Fram, a veteran of multiple expeditions to both poles between 1883 and 1912, including Roald Amundsen’s historic 1910-1912 southern polar expedition, is planned to launch in March 2025.

Tianwen-2: Asteroid Sample Return Mission

China will continue its deep-space exploration ambitions with the planned May 2025 launch of Tianwen-2 (“’Heavenly Questions-2”) robotic vehicle. Whilst bearing the same name as the highly-successfully mission to place an orbiter around Mars and a lander and rover on the surface of that planet in 2021 (and covered within past Space Sunday articles), Tianwen-2 is a very different mission: that of rendezvousing with, and landing on, a near-Earth object (NEO) asteroid and gathering up to 100 grams of material for a return to Earth.

A screen cap of the Tianwen-2 vehicle arriving at 469219 Kamoʻoalewa. Credit: CCTV

The target for the mission is a quasi-moon 469219 Kamoʻoalewa, thought to be around 40-100 metres along its longest axis. It orbits the Sun at distance of between 0.9 and 1.0 (the average distance of the Earth from the Sun) and with an orbital period of 365-366 days. This makes it appear as if it moving around the Earth, although it is in fact oscillating around the L1 and L2 and L4 and L5 positions, and not actually gravitationally bound to Earth, never coming closer than some 14 million kilometres.

What is particularly interesting about 469219 Kamoʻoalewa, first identified in 2016, is that spectral analysis suggests it is likely silicate in origin; combined with its orbit, this points to it possibly being a lump of rock ejected from our Moon as a result of an asteroid impact. However, it could equally be an S-type asteroid (which account for around 17% of all known asteroids) or possibly an L-type, which are exceptionally uncommon.

Thus, given the mix of potential heritage, 469219 Kamoʻoalewa has been seen as an intriguing subject for up-close study ever since its identification, and a number of proposals have been put forward up-close study, as well as being the target for observation by numerous Earth-based telescopes. Following launch, Tianwen-2 is expected to intercept the asteroid in 2026, and conduct remote sensing activities which will include identifying locations for sample acquisition. It will also deploy both a nano-orbiter and a nano-lander for independent study of the asteroid.

To collect samples, Tianwen-2 will send down a sample gathering unit which will conduct both touch-and-go operations similar to those used by Japan’s Hayabusa2 probe sent to obtain samples from the near-Earth asteroid 162173 Ryugu (2014-2020), and NASA’s OSIRIS-REx (2016-2023) mission to gather samples from asteroid Bennu, and also anchor-and-attach – the first time such a technique will be attempted.

The two approaches to gathering samples: in touch and go, the sample gathering vehicle will briefly touch the surface of the asteroid to gather a sample, the  spring-loaded arm of the sample gatherer absorbing the vehicle’s downward momentum before pushing it back away from the asteroid. With Anchor-and-attach, the sample vehicle will attempt to use four legs with penetrators to grip the asteroid’s surface, prior to the sample arm being deployed to collect material. Credit: CCTV

After gathering samples, Tianwen-2 will depart 469219 Kamoʻoalewa and make a fly-by of Earth in 2027, which it will use to both drop-off its sample capsule and also complete a gravity assist manoeuvre in order to travel on to rendezvous with active asteroid 311P/PanSTARRS, which orbits the Sun every 3.24 years and exhibits the characteristics of both an asteroid and a comet, including having up to six comet-like tails.

Estimated to be around 240 metres across and always orbiting the Sun beyond the orbit of Mars, 311P/PanSTARRs was first identified in 2013, and observations in 2018 suggested it might have a companion orbiting it. Tianwen-2 is expected to reach it in 2034.

Two images of 311P/PanSTARRS captured by the Hubble Space Telescope and showing its tail formations. Credit: NASA, ESA, D. Jewitt

Dream Chaser Rises

May is the month that will hopefully see the launch of the newest addition to the fleet of vehicles that help keep the International Space Station (ISS) well-stocked with supplies and operational, when a ULA Vulcan Centaur VC4L lifts-off from Space Launch complex 41 at Canaveral Space Force Station, carrying Tenacity, the first Dream Chaser Cargo vehicle from Sierra Space.

Referred to SSC Demo-1, the mission will see Tenacity and its Shooting Star power and cargo module carry out a check-out mission of up to 45 days duration which will see the combined vehicle rendezvous and dock with the ISS, undergoing check-out by ISS crew and eventually undocking, after which the Shooting Star module will be jettisoned and Tenacity will return to Earth for an aircraft-style landing at the former Space Shuttle Landing Facility, Kennedy Space Centre.

Dream Chaser Tenacity and its cargo module undergoing testing at NASA’s Neil Armstrong Test Facility, Kennedy Space Centre, Florida. Credit: NASA

When operational, Dream Chaser with Shooting Star will have the largest all-up payload capacity of any ISS resupply vehicle: 5.5 tonnes; 5 tonnes of which can be pressurised. However, missions will likely be flown with lesser payload amounts. In addition, Dream Chaser can return to Earth with payloads of up to 1.75 tonnes, comprising equipment, experiments and general waste.

Six Dream Chaser resupply missions to the ISS have been contracted, using at least two Dream Chaser vehicles, Tenacity and Reverence (although construction on the latter is currently suspended). The date of the first operational flight (CRS SSC-1) has yet to be given, but is unlikely to be before 2026.

Space RIDER Flies

The European Space Agency (ESA) is expected to debut its entry into the reusable spaceplane market in the latter half of 2025 with the maiden flight of Space RIDER (Space Reusable Integrated Demonstrator for Europe Return), a two-stage vehicle designed to provide routine and relatively low-cost capabilities to delivery payloads of up to 620 kg to low-Earth orbit.

I’ve covered Space RIDER in the past, but briefly, it is a small-scale reusable lifting body supported by an expendable service module which supplies it with main propulsion and electrical power when in orbit, prior to being jettisoned before the main vehicle re-enters the atmosphere. Payloads are intended to be experiments and science instruments, which the vehicle returns to Earth at the end of a mission, although it will have the ability to deploy smallsats in space as well.

An artist’s impression of ESA’s Space RIDER in orbit. The black module with solar panels to the rear is the vehicle’s expendable service module. Credit: ESA

Massing 4.9 tonnes at launch (including the service module), the lifting body – referred to as the Re-entry module (RM) – masses 2.8 tonnes on landing. The combined craft has a length of just over 8 metres, of which 4.6 metres is that of RM, which includes a payload volume of 1.2 m³.

Designed to be launched atop ESA’s Vega-C rocket, Space RIDER can remain in orbit for up to 2 months at a time conducting experiments. Following re-entry, the RM will use its lifting body shape to drop its speed from Mach 25 to Mach 0.8 (roughly the speed of an commercial airliner) as it descends, prior to deploying a drogue parachute at between 12-15 km altitude, which will slow it to around Mach 0.22. After this, a parafoil is deployed, which allows the vehicle to glide under control to a horizontal landing. It is designed to make up to six flights into space, and has a turnaround time of “less then 6 months”.

The Year of Fly-bys

2025 is going to be a year of fly-bys for several deep space missions, including:

  • January: The ESA / JAXA BepiColumbo mission to Mercury will complete its sixth and final fly-by of the planet as it uses Mercury’s relatively weak gravity to both decelerate and swing it on to a trajectory from which it can establish itself in orbit around the planet. The manoeuvre will mark the end of 9 fly-bys of three planets – Earth (1); Venus (2) and Mercury (6); the next time the probe reaches Mercury (after another passage around the Sun) in November 2026, it will fire its motor and enter orbit ready to commence its primary science mission, over 8 years after its launch.
  • March: ESA’s Hera mission, launched in October 2024, will perform a fly-by of Mars en route to its final destination, the Didymos binary asteroid system, where it will carry out a detailed study of the aftermath of the NASA Double Asteroid Redirection Test (DART) which impacted the asteroid Dimorphos in an attempt to deflect it in its orbit around the larger Didymos.
An artist’s impression of ESA’s Hera mission, complete with its payload of two cubesats as they observe the asteroid Didymos. Credit: ESA
  • March: NASA’s Europa Clipper mission will also fly-by Mars as it makes its way towards Jupiter in order to study the icy world of Europa. The second of two such mission to be launched – the other being ESA’s Juice mission (see below), The NASA mission will make better progress to Jupiter by virtue of being launched atop a more powerful rocket – the SpaceX Falcon Heavy.
  • April: NASA’s Lucy mission will complete its fourth fly-by of a celestial body, and the second of a main belt asteroid – 52246 Donaldjohanson, named for the paleoanthropologist who discovered the famous “Lucy” fossil. This vehicle is on a complex mission to examine eight separate asteroids (2 within the main belt between the orbits of Mars and Jupiter; four more in the L4 Trojan cloud occupying the same orbit a Jupiter, but 60º, which it will reach in 2027; and a pair within the Trojan cloud trailing Jupiter in its orbit by 60º, which it will reach in 2034 after a further fly-by of Earth at the end of 2030.
  • August: ESA’s Jupiter Icy Moons Explorer (Juice) will make a fly-by of Venus as it gathers the momentum it needs to reach Jupiter and start its studies of Europa, Ganymede and Callisto. The fly-by of Venus will be the second of four such manoeuvres, the other three (August 2024, September 2026, January 2029) being around Earth.

Space Sunday: Mars milestones and crash investigations

A natural light image captured by the NASA Mars 2020 rover Perseverance as it is parked on “Lookout Hill” on the rim of Jezero Crater, December 10th, 2024 (mission Sol 1,354). In the middle distance horizon, just right of centre is approx. 10 km from the crater rim while the two hazy peaks on the horizon centre are approx. 60km from the crater rim. Credit: NASA/JPL/MSSS

NASA’s Mars 2020 rover Perseverance reached a milestone in its exploration of the region that includes Jezero Crater, when it was confirmed on December 12th, 2024 that the rover had reached the top of the Crater’s rim, and is now in a position to commence exploration along the edge of the crater as it starts a new science campaign.

For the majority of its time on Mars, Perseverance has been exploring within the crater, looking for evidence of the planet’s potential to have once harboured life and investigating the geological history of the crater itself, which was once home to liquid water. These investigations have comprised four science campaigns thus far:

  • Crater Floor: the first campaign following the rover’s arrival on Mars in February 2021, through to the end of March 2022, as it exploring the floor of the crater and investigated sites of geological interest, making its way towards the outflow delta of a river which once tumbled into the crater.
  • Fan Front: running from April 2022 through March(ish) 2023, this involved explorations of the lower end of the delta’s outflow plain, traversing a transitional region rich in evidence of water having once been free-flowing and comprising rock and material deposited in the crater rather than forming it.
  • Upper Fan: This saw the rover reach the upper limits of the delta fan, where time was spent in further studies which included potential routes up the crater wall, possibly using one of the former river channels, and then starting its initial ascent.
  • Margin Unit: starting in September 2023, this saw the rover enter a “marginal zone”, or lithological boundary between the lower slopes of the crater and its upper walls, and a region of intense geological study.
Perseverance looks back over its shoulder as it traverses “slippery” terrain whilst engaged on the final leg of its climb to the rim of Jezero Crater. Credit: NASA/JPL

Following some 8.5 months of study whilst traversing upwards as part of the Margin Unit campaign, in August the focus switched to the rover just getting up the rest of the “Mandu Wall” and up and over the crater’s rim, using a combination of Earth-based route planning and “driving”, and allowing the rover to steer its own course through hazards and difficult areas using its autonomous driving capabilities.

The rover finally reached the crater rim on December 5th, 2024, where it paused on a rise at the rim the mission team dubbed “lookout hill”, allowing the rover to catch its breath and take a look at its surroundings – and the mission team to identify possible points of exploration as they confirm plans for the next science campaign, which has been dubbed “Northern Rim”.

This is a slightly confusing name given Perseverance has ascended the south-western side Jezero’s rim, but can be explained by the fact it has arrived at the northern end of that part of the rim. It’s a location the mission has long hoped to reach, because it forms a region of significant scientific interest.

The Northern Rim campaign brings us completely new scientific riches as Perseverance roves into fundamentally new geology. It marks our transition from rocks that partially filled Jezero Crater when it was formed by a massive impact about 3.9 billion years ago to rocks from deep down inside Mars that were thrown upward to form the crater rim after impact. These rocks represent pieces of early Martian crust and are among the oldest rocks found anywhere in the solar system. Investigating them could help us understand what Mars — and our own planet — may have looked like in the beginning.

– Ken Farley, Mars 2020 mission project scientist, JPL

The first point of interest due for in-depth study as a part of the Northern Rim campaign is a mound outside of the crater dubbed “Witch Hazel Hill”. Standing on the outside of the crater’s rim, the mound is around 100m tall, and comprises layered materials that likely date from a time when Mars had a very different climate than today; thus as it will be able to gather “snapshots” of the ancient geological history of Mars going back potentially billions of years.

In this image the route of the rover’s passage up through the outflow plain delta and the wall of the crater (white line) is overlaid onto a orbital image of the portion of Jezero Crater Perseverance has been exploring. This image covers (right to left) the Fan Front, Upper Fan and Margin Unit science campaigns.  False colour is used to try to help highlight the rover’s track, with the position of the rover (December 4th, 2024), to the left of the highlighted area. Click the image for a larger view, if required. Credit: NASA/JPL

From here, the rover is expected to make its way to “Lac de Charmes”, a region roughly 3.2 km from the crater rim, and believed to have not been greatly affected by the crater’s impact formation and thus likely to reveal more about the composition of the ancient crust of Mars.

Once the studies of “Lac de Charmes” have been completely, Perseverance is expected to make its way back towards the crater rim to a location dubbed “Singing Canyon”. Here it will examine megabreccia, or huge blocks of bedrock thought to have been hurled clear of the impact zone which gave rise to the 1,900 km wide depression of Isidis Planitia, on the edge of which Jezero Crater sits. The basin of Isidis forms the third largest impact structure on Mars, and was created some 3.9 billion years ago when an object estimated to be some 200 km across slammed into Mars.

This impact occurred during the Noachian Period on Mars, the epoch which saw free-flowing water on the planet and the time when the great volcanoes of the Tharsis Bulge are thought to have formed. Thus, the study of the megabreccia could unlock insights into how the Isidis impact many have both reshaped the surface of Mars, affecting things like the outflow of water and the general atmospheric environment, and so potentially impacted conditions suitable for the evolution of life on the planet.

The journeys to (and down) “Witch Hazel Hill” and then back to the crater rim via “Lac de Charmes” is likely to take Perseverance around a year to complete, during which time it will cover some 6.4 km in total, with four points of geologic interests thus far identified for scientific study as it does so. As the new science campaign opens, the mission tam also hope it will see the rover encounter much improved driving conditions when compared to the climb out and out of the crater.

Ingenuity Crash Investigation

One aspect of the Mars 2020 which will continue to be missed is that of Perseverance’s airborne companion, the little helicopter drone – and first powered vehicle from Earth to fly in the atmosphere of another world – Ingenuity.

As I reported at the start of the year (Space Sunday: a helicopter that could; a lander on its head) the helicopter, which had been designed with just 5 flights in mind but went on to make a total of 72, becoming an invaluable aid in scouting potential routes of exploration for the Mar 2020 rover, was “grounded” and “retired” at the start of 2024, following a mishap at the end of its 72nd flight on January 18th, 2024.

Images taken of the grounded drone and its surroundings later revealed not only had one or more of its rotor tips been broken (as revealed by Ingenuity taking pictures of its own shadow a few days after the incident), it had completely shed an blade.

NASA’s Ingenuity Mars Helicopter, right, stands near the apex of a sand ripple in an image taken by the Perseverance rover on February 24th, 2024, some 5 weeks after the rotorcraft’s final flight. Part of one of Ingenuity’s rotor blades lies on the surface approx. 5 metres west (far left of the image), after its mounting failed. NASA/JPL / LANL / CNES / CNRS

Since the accident, NASA personnel at the Jet Propulsion Laboratory have been carrying a long-distance investigation into what may have caused the accident that resulted in Ingenuity’s effect loss. At the time of the mishap, Ingenuity was involved in efforts to help Perseverance navigate the upper slopes of Jezero Crater’s rim, which was proving difficult In particular the little helicopter was overflying a field of sand dunes in the hope of finding a route by which Perseverance could traverse them safely. However the lack of clearly definable surface features within the dune field was affecting Ingenuity’s ability to navigate / maintain its correct velocity.

To explain: in order to maintain both its horizontal and vertical velocity within safe parameters when descending, Ingenuity uses a downward-pointing camera to track surface features.: boulders, rocks, shadows, etc. However, the dune field it was overflying was almost uniformly bland and without significant features. This had already proven to be an issue on the helicopter’s 71st flight, when what appears to have been a light brush with the sand of a dune on landing caused a very slight deformation in one root.

Ironically, it as because of this incident that the mission team slotted-in the 72nd flight: they wanted to test Ingenuity’s capabilities to see if their were any abnormalities in flying as a result of the deformation. As such, it was intended to be a straight-up, hover, traverse a short distance a and flight, they kind performed multiple times in the past. So what went wrong?

Following extensive study of high-resolution images gathered by Perseverance of the damaged helicopter in February 2024, together with a careful review of data from the flight and images recorded by Ingenuity whilst flying, the JPL investigators and engineers from AeroVironment, who built the drone for NASA/JPL, now conclude Ingenuity suffered a similar issue as the 71st flight: it simply could not discern surface details via the navigation camera that could help it properly verify its vertical and horizontal motion.

As a result, investigators believe that Ingenuity approached the ground at the end of the planned20-second flight with a high horizontal velocity, resulting in a hard impact with the back slope of a sand ripple. The force of the impact, coupled with the slope, was enough to pitch the helicopter sideways and roll it forward. However, rather than bringing the blades in contact with the ground as had been thought, the combination of pitch and roll overstressed all four blades at a point of structural weakness roughly one-third of the way back from their tips, snapping them. This instantly caused both severe rotor vibration and imbalance, causing the mounting for one blade to fail completely, with the remnant of the blade hurled some 15 metres from the landing point.

This graphic depicts the most likely scenario for the hard landing of NASA’s Ingenuity Mars Helicopter during its 72nd and final flight on Jan. 18, 2024. High horizontal velocities at touchdown resulted in a hard impact on a sand ripple, which caused Ingenuity to pitch and roll, damaging its rotor blades. NASA/JPL

This act additionally caused a power surge, which in turn caused the loss of communications at the end of the flight as the helicopter temporarily placed itself in a safe mode to protect its electronics.

Whilst it has remained unable to fly, Ingenuity has been far from silent in the months since its January 2024 accident: elements of its electronics – some of which are off-the-shelf components used in cell phones and table devices – are still operational, enabling it to continue to monitor the atmosphere and environment at its crash site and send that data on a roughly weekly basis to Perseverance for onward transmission to Earth.

In addition, all of the data gathered from Ingenuity is being used to directly inform the design and capabilities of the next generation helicopter JPL hopes to build with AeroVironment. This is a more complex vehicle which perhaps more closely resembles rotary drones as used here than was the case with Ingenuity. Comprising a central body with (as currently envisaged) six electrical motors each powering a four-bladed rotor, the craft has been dubbed the Mars Science Helicopter (MSH) or simply “Mars Chopper”.

A key aim of the MSH project is to develop a craft capable of deploying and recovering science packages between 0.5 and 2.0 kg mass as it autonomously explores Mars.

Space Sunday: of Artemis and Administrators

November 16th, 2022: the Space Launch System (SLS) rocket lifts-off on its maiden flight, lifting an uncrewed Orion MPCV capsule on the Artemis 1 mission to test the latter on an extended flight to cislunar space and back to Earth. Credit: Joel Kowsky

NASA has announced the push-back of Project Artemis missions in the continuing efforts to return to the Moon with human missions, and with the announcement has come renewed calls for the cancellation of the Space Launch System rocket.

During a December 5th, 2024 briefing, NASA management confirmed that Artemis 2 – the mission to fly a crew of four around the Moon and return them to Earth – will now not occur until April 2026, slipping from the target launch month of September 2025. As a result, the first attempt at a crewed landing under the project – Artemis 3 – has been rescheduled for a mid-2027 launch.

The most significant reason for delaying the missions relates to issues with the primary heat shield on the Orion MPCV (multi-purpose crew vehicle). As I’ve reported in these pages, this heat shield suffered greater than expected wear and tear during the unscrewed test of Orion on a flight around the Moon in December 2022 – something first release to the public in detail in May 2024.

The Artemis 2 crew (l to r: Canadian Space Agency astronaut Jeremy Hansen and NASA astronauts Christina Koch, Victor Glover, and Reid Wiseman) outside the Astronaut Crew Quarters inside the Neil Armstrong Operations and Checkout Building during an integrated ground systems test at Kennedy Space Centre, September 20th, 2023. Credit: Kim Shiflett

More recently, NASA has indicated that it has identified the root cause of the issues, with comments at that time appearing to suggest part of the solution might involve charges in the construction of the heat shield itself, particularly as the October 2024 update on the issues, Lori Glaze, acting deputy associate administrator, NASA Exploration Systems Development Mission Directorate indicated that while NASA were confident about the cause, as the heat shield for this mission “is already built”, the agency was at that time unsure as to how best to protect the crew during the critical re-entry into the Earth’s atmosphere at the end of the mission.

For assorted reasons, the Orion capsule operates differently to the Apollo Command Module capsule. As it returns to Earth at a high velocity than Apollo, the Orion vehicle does not perform a single re-entry into the atmosphere as Apollo did; instead, it performs what is called “skip guidance”. This involved dipping briefly into the upper atmosphere and using it to reduce speed, prior to making a final re-entry.

The overall goal of this approach is to allow the Orion vehicle to experience somewhat lower temperatures (although still in the order of around 2,700oC) during its “proper” re-entry, than would otherwise be the case were it to simply slam into the atmosphere a-la Apollo and use the friction of that re-entry to slow itself.

A view of the heat shield used on the Orion vehicle during the Artemis 1 mission. The scoring and surface damage to the surface of the heat shield was expected as a part of the ablative process during atmospheric re-entry. However, the large areas of deeper pitting and cratering – called “char loss” – were not. Credit: NASA

However, following the investigations into the excessive pitting (called “char loss”) seen with the heat shield used with Orion on Artemis 1, was an unforeseen result of the skip guidance approach.

While the capsule was dipping in and out of the atmosphere as part of that planned skip entry, heat accumulated inside the heat shield outer layer, leading to gases forming and becoming trapped inside the heat shield. This caused internal pressure to build up and led to cracking and uneven shedding of that outer layer.

– NASA Deputy Administrator Pam Melroy, December 5th, 2024

During the briefing, it was confirmed that no significant redesign of the heat shield is required to overcome this problem; rather the re-entry trajectory for all Artemis crewed missions must be altered in order to minimise the char loss seen with Artemis 1 (remembering that while severe, the damage done to the heat shield in that mission did not reach a point of threatening the overall integrity of the Orion capsule).

For Artemis 2, engineers will limit how long Orion spends in the temperature range in which the Artemis 1 heat shield phenomenon occurred by modifying how far Orion can fly between when it enters Earth atmosphere and lands.

– NASA Artemis FAQ, December 5th, 2024

While an adjustment to the mission parameters is not as drastic as having to build an updated version of the heat shield, it does still require significant computer modelling, updates to flight software on Orion and a re-training of the Artemis 2 crew so they are familiar with the new flight envelope, control protocol and dealing with any alarms / emergencies during the revised re-entry phases of the mission. Hence pushing back Artemis 2 until early-to-mid 2026.

While this does have a knock-on effect for Artemis 3, other factors have come into play which have also contributed to the delay in that mission; some of which many observing Artemis and the choices made (myself included) have long anticipated.

Whilst announced on December 5th, 2024, slippage of the Artemis 3 mission to land a crew of two on the surface of the Moon was seen as inevitable by many thanks to the slow development of the SpaceX HLS vehicle the sheer complexities of the launch system on which it depends. Credit: SpaceX

Chief among these is the fact that the SpaceX Human Landing System (HLS) vehicle – a modified SpaceX Starship just wasn’t going to be ready for use in 2026; in fact, there is much to suggest the vehicle will not be ready for any planned 2027 launch of Artemis 3, and that a more reasonable expectation for any Artemis 3 launch would be late 2028, earliest.

However, there are some other factors involved in the Artemis 3 delay; given the changing dynamics and plans for Artemis lunar missions, there is a requirement to make improvements to Orion’s on-board environmental systems. These will not take as long as getting the SpaceX Starship system to the point where it can properly carry out the roughly 12-16 launches required just to get the HLS vehicle to the Moon (leave alone actually construction and testing of the lunar landing vehicle ahead of and use by the crew), but they are a issue which need to be factored into the mission delays.

“Scrap SLS”

The December 5th Artemis announcement saw a further renewed expectation of, and calls for, the cancellation of NASA’s Space Launch System (SLS).

The largest calls for this have come from the SpaceX fan community who frequently (and unfairly) compare the cost of SLS to that of the SpaceX Starship, although there have also been repeated concerns raised from within the US government, such as buy the Government Accountability Office (GAO) and NASA’s own Office of Inspector General (OIG) that the overall cost of SLS is entirely unsustainable.

The core stage of the first SLS rocket to fly being moved between facilities at NASA’s Michoud Assembly Facility in New Orleans in January 2020, as part of preparation for it to be loaded onto a shipping barge for transport to Kennedy Space Centre, Florida. Credit: NASA

In particular, the latter offices note that SLS launches will cost around US $2.5 billion each. This includes all elements of a vehicle and the facilities required to launch it – the rocket, its boosters, the re-usable Orion crew vehicle + its service module, the cost of all launch support facilities, etc., together with the cost of future enhancement to the system, such as the Exploration Upper Stage (EUS) which will allow SLS to carry even heavier payloads to orbit. The cost per launch also takes into account the on-going expenditure in developing the system (US $26.4 billion, 2011-2023). As such, and while by no means cheap, its high cost is perhaps better understood.

However, cost isn’t actually the issue here. Rather it is capability. Simply put, there is no other launch system available that is either capable of launching a crewed Orion vehicle to the Moon or rated to do so.

To get to the Moon, the 26.52-tonne Orion and its European Service Module require an additional booster to send them on their way to the Moon. Currently, this booster is the 32.74 tonne Interim Cryogenic Propulsion System (ICPS) for the Space Launch System. It is the only human-rated upper stage capable of boosting the Orion+ESM mass to the Moon and it is only designed to be used by SLS.

The Interim Cryogenic Propulsion Stage (ICPS) of the SLS – a crucial component in getting Orion to the Moon. Credit: NASA

And therein lies the rub; whilst people have been bandying ideas of “alternatives” to SLS around like sending human-rated payloads to the Moon is akin to playing with Lego  – just stick the bits together you need and away you go, this just isn’t the case.

For example, Falcon Heavy might well be able to lob Orion+ESM+ICPS to LEO off its own back when used in fully expendable mode, a) it must be rated for human flight first; b) it will require significant, potentially costly, and certainly time-consuming, modifications to its core stage and (likely) to the ICPS. These latter points remain true even if the launch is split (e.g. one vehicle to launch Orion+ESM and a second to launch ICPS), which would allow the core and booster stages of Falcon Heavy to be recovered.

And while a split launch might also allow the use of Blue Origin’s New Glenn as an alternative to Flacon Heavy, (a) and (b) remain constraining factors. This is also true of another idea: launching Orion + ESM on New Glenn and then use the Centaur stage of ULA’s Vulcan-Centaur as the kick stage to send them on to the Moon after a rendezvous and docking. But again, again, Centaur is not human rated, and Orion+ESM are not designed to be used with Centaur off-the-shelf. Also, Neither system (nor the ICPS for that matter) are designed for the necessary kind of on-orbit rendezvous and docking, thus, these proposals all add complexity to each and every mission.

An artist’s impression of an Orion vehicle and its European Service Module attached to the ICPS of a Space Launch System, as they orbit Earth. Credit: NASA

This is not to say such alternatives cannot be made possible; it isn’t even necessarily (in the face of SLS launch costs) how much they will cost to bring about; it is the time they would require in order to become feasible, particularly in adapting the disparate system (Orion+ESM (and possibly the ICPS) and Falcon Heavy and/ or New Glenn, and / or the Centaur upper stage) to all play nicely together and reach a point where human missions using them can start. I would venture to suggest reaching such a point in the 2-2.5 years between now and the launch of any Artemis 3 mission (the SLS for Artemis 2 having already been fabricated + currently undergoing assembly / stacking at Kennedy Space Centre) probably isn’t that realistic.

And time is the critical issue here; no programme or project is really “too big to fail”; the more the time frame for Artemis and getting humans back onto the surface of the Moon get repeatedly drawn out (+ the more it is seen to be sucking up available budgets), then the greater the risk an administration and / or Congress could pull the plug to cut losses.

Which is not to say NASA and its incoming new Administrator shouldn’t take a good look at alternate strategies over SLS (and potentially even Orion); rather, they should have a very good game-plan and very realistic numbers on how to proceed and make good on their lunar aspirations before they simply yank out the plug on SLS.

Isaacman Nominated as New NASA Administrator

On December 4th, 2024, the incoming Trump administration announced its choice for the post of NASA Administrator: Billionaire Jared Isaacman, the founder of Shift4, a Payment financial technology company he founded whilst just 16 and which he turned into a multi-billion dollar success.

Jared Isaacman in the cockpit of one of his just fighters

Passionate about flying and (at least) the human exploration of space, Isaacman is a qualified jet fighter pilot (although has not served in the US military), operating one of the largest fleeting of privately-held jet fighters through another of his ventures, Draken International, a company contracted to provide pilot training to the United States armed forces. He also flies as a part of the Black Diamond Jet Team air display team, and as a solo air show pilot flying a MiG-29UB. And if that weren’t enough, he set a world record in 2009 for circumnavigating the world in a light jet (a Cessna Citation), taking just less than 62 hours to complete the flight, operating the aircraft with two others.

In terms of space activities, his is best known for leading the Inspiration4 private mission to space in 2021, and more recently, the first in a series of planned Polaris missions to orbit, Polaris Dawn, which saw him become the first private citizen to complete what is called a SEVA – or stand-up EVA -, partially-exiting the Crew Dragon space vehicle, a feat also completed by SpaceX employee Sarah Gillis in the same mission.

All of this has resulted in many responding to his nomination as positive movet – and again, some circles see it as a sign that SLS will likely be cancelled: Isaacman has been a strong critic of the system, and clearly leans towards more partnerships such as the one directly benefiting SpaceX. Indeed, his closeness to SpaceX and the fact he has consistently refused to reveal his own financial ties to he company has already caused some concern on Capitol Hill.

Isaacman has also used his position as an “independent space entrepreneur” to call into question NASA pursuing similar deals it has made with SpaceX with other commercial entities, such as Blue Origin. In particular, he is highly critical of NASA working with Blue Origin to develop the latter’s alternative – and potentially more practical / cost-effective and certainly more sustainable – Blue Moon family of lunar landing vehicles, openly stated he “doesn’t like” the fact NASA awarded a second contract for reusable human and cargo lunar landing systems.

Given this, some senators are concerned over questions of Isaacman’s overall neutrality when it comes to NASA contracts, and have indicated this is liable to factor into any confirmation hearings involving him.

Space Sunday: A Dragonfly for a moon

An artist’s impression of the Dragonfly vehicle operating over Saturn’s Moon Titan. Credit: JHU/APL

For the last few years, and as news arises, I’ve been covering the ambitious plans developed by a team at the Applied Physics Laboratory (APL) of Johns Hopkins University (JHU) to send a flying rover vehicle to Saturn’s largest moon, Titan.

The mission, using a octocopter called Dragonfly has been in development for several years, being formally greenlit for full-scale development by NASA earlier in 2024 (see: Space Sunday: flying on Titan; bringing home samples from Mars), after initially selecting it for evaluation and conceptual development as a part of the space agency’s Frontiers programme in 2019.

The idea of sending a flying – or at least floating, as proposals have also included the potential use of balloons to explore Titan from within it dense atmosphere – has been around for some time. In fact,  Ralph Lorenz, of JHU/APL, one of the proposers of the mission, first considered using rotary craft on Titan back in 2000. His idea then was to use a battery-powered rotor craft equipped with a radioisotope power source.

Montgolfiere balloon and ESA lake lander – a European Space Agency (ESA) concept mission for Titan

That vehicle would spend the daylight hours on Titan (equivalent to 8 terrestrial days) in flight or carrying out surface science. during the hours of darkness (again, lasting the equivalent of 8 terrestrial days), the vehicle would sit on the ground and use the radioisotope to both keep itself warm and recharge the batteries.

It is to this idea that Lorenz returned whilst having dinner with Jason W. Barnes of University of Idaho in 2017, with the two of them agreeing to work on a baseline proposal for a large rotorcraft capable of  flying on Titan. Together, they formed a nucleus of a team of scientists largely from APL’s staff of space scientists, including Elizabeth “Zibi” Turtle, who would be the mission’s principal investigator, as well as expertise from both NASA and other universities and space science institutes such as Malin Space Science Systems (MSSS), another long-time NASA partner.

Their initial proposal was published in 2018, and pretty much laid out the entire concept. Put before NASA for consideration, the proposal went through a series of changes prior to acceptance as a Frontiers mission. Initially targeting a 2027 launch, the mission was hit (like most things) by the COVID 19 pandemic, with all parties agreeing to push back the launch until July 2028.

These delays actually pushed the Dragonfly mission outside of the parameters of the Frontiers guidelines – missions under its auspices are supposed to be developed and flown for no more that US $1 billion (including all launch operator costs); currently, Dragonfly is expected to hit a total cost of around $3.35 billion throughout its lifetime. In all, the primary mission is expected to last some 10 years, 3.3 years of which will by at Titan.

But why go so far and at such cost in the first place? Well, as I noted back in April:

Titan is a unique target for extended study for a number of reasons. Most notably, and as confirmed by ESA’s Huygens lander and NASA’s Cassini mission, it has an abundant, complex, and diverse carbon-rich chemistry, while its surface includes liquid hydrocarbon lakes and “seas”, together with (admittedly transient) liquid water and water ice, and likely has an interior liquid water ocean. All of this means it is an ideal focus for astrobiology and origin of life studies – the lakes of water / hydrocarbons potentially forming a prebiotic primordial soup similar to that which may have helped kick-start life here on Earth.

As both the Huygens lander and Cassini probe showed, Titan is similar to the very early Earth and can provide clues to how life may have arisen on Earth; it is also an aerodynamically benign world. Its dense atmosphere (around 1.45 times that of Earth’s) is ideally suited to the use of rotary vehicles – considered superior to balloons, dirigibles and aircraft because their ability to hover in place whilst carrying out ground observations and their VTOL (vertical take-off and landing) capabilities mean that can easily set down for surface science activities / at the onset of night. Further, Titan has low gravity (around 13.8% that of Earth) and little wind, making automated flight a lot easier.

Titan, lower left, compared to Earth and the Moon. A composite image comprising an Apollo 17 picture of the whole Earth; a NASA Telescopic image of the full Moon, a Gregory H. Revera image of Titan: NASA/JPL/Space Science Institute. Via Wikimedia

Most crucially of all, flight allows the vehicle to move with relative ease between locations of interest for study, even if they are geographically widespread, separated by distances (and potential obstacles) a surface rover might find insurmountable.

Of course, we’re all now familiar with the idea of helicopter drones flying on other worlds, courtesy of NASA’s plucky little Ingenuity on Mars. However, The Dragonfly vehicle is something else all together. For a start, it is the size of a small car, and is expected to have an all-up mass of  around 450kg. A good portion of that will be taken up by its Multi-Mission Radioisotope Thermoelectric Generator (MMRTG), its large lithium-ion battery system and its four electric motors, each driving two pairs of 1.4 metre diameter contra-rotating rotor blades.  When flying, the vehicle will be able to reach speeds of up to 36 km/h, with a maximum airborne time of 30 minutes at that speed.

Initial descent. After release from the entry system and parachute, the vehicle can traverse many kilometres at low altitude using sensors to identify the safest landing site. This schematic from the original proposal uses an aerial image of the Namib sand sea, a geomorphological analogue of the Titan landing site, with ~100-m-high dunes spaced by several kilometres. Credit: Lorenz, Barnes, et al

Obviously, given the distances between Earth and Saturn / Titan render two-way real-time communications impossible without considerable lag, the vehicle will be equipped with a fully autonomous flight and navigation system capable of flying it along a selected flight path, making its own adjustments to account for local conditions whilst in flight, and with sensors capable of recording potential points of scientific interest along or to either side of its flight path, so the information can be relayed to Earth and factored into planning for future excursions. Flights over new terrain will likely be of an “out and back” scouting nature, the craft returning to its point of origin, allowing controllers on Earth to plan follow-up flights to locations where they might wish to set down and carry out ground-based science studies.

In terms of the latter, the vehicle will carry a number of science instruments, including two coring drills and hoses mounted within is landing skids, allowing it to gather tailings from the moon’s regolith and surface for on-board analysis by the vehicle’s on-board laboratory.

Most recently, as well a working on the full-scale development of the vehicle, APL has also been carrying out further tests with a half-scale flight-capable model, which has been used for the last year to help test and refine flight systems and avionics.  This has seen the vehicle put through its paces at near-to-ground flight tests and at reasonable altitudes (but not as high as the four kilometres maximum ceiling the full-size version is expected to operate at during deployment!

In particular, this works builds on work carried out inside a special wind tunnel at NASA’s Langley Research Centre during 2023, which was used to simulate the aerodynamic loads that would likely be placed on the vehicle’s rotors and motors during a wide range of flight operations – ascending, descending, hovering – allowing engineers to determine things like the amount of rotor pitch required during different types of flight operations, providing data which can be fed into the final design requirements for the actual vehicle.

Much of this testing has been around flight hardware redundancy – APL plan to have the vehicle capable of sustained flight even if one set of rotors fails  or even a motor supplying power to two sets of rotors dies. These tested have also allowed for direct assessment of the vehicle’s handling and determining where the centre of mass / centre of gravity should be placed (remembering that the drum-like thing at the back of the vehicle is a nuclear generator and all its associated shielding) to ensure good flight handling across a range of dynamic flight situations.

Also, on November 25th, 2024, NASA confirmed that  SpaceX Falcon Heavy launch vehicle will be used to send Dragonfly on its way to Saturn. This caused some mis-reporting (notably among SpaceX fans) that the mission is somewhat a NASA / SpaceX venture, or has only been made possible by SpaceX, with some SpaceX-biased commentators going to so far as to call the decision “unexpected”. However, Falcon Heavy is the only launch vehicle currently certified for launching NASA high-value missions – particularly those carrying an MMRTG; United Launch Alliance (ULA) having retired both of its certified launch vehicles – Atlas and Delta –  and have yet to achieve the required NASA certification with their Vulcan-Centaur (as is the case with Blue Origin’s New Glenn). As such, and with the prohibitive cost of using NASA’s own SLS rocket, Falcon Heavy has been the only real contender for the job.

At a cost of US $256.6 million, the contract to launch Dragonfly is significantly more than the $178 million NASA paid for the launch of the equally complex Europa Clipper, and the $117 million for the launch of the Psyche mission (although admittedly, that was agreed in 2020), both of which utilised Falcon Heavy. What was new with the announcement was the selected launch window and flight trajectory. The mission is slated to launch some time between July 5th and July 25th, 2028 (inclusive), in a window that will require the vehicle to make a fly-by of Earth in order to acquire the velocity required to reach Saturn in 2034. In this, the flight does differ from the originally planned 2027, which would likely have included a flyby of Jupiter, rather than Earth; however, for the 2028 launch, Jupiter will not be in a position to provide a gravity assist, hence the use of Earth, marking the mission as the first dedicated mission to the outer solar system to not use Jupiter in this way.

Progress MS-29 Update

In my previous Space Sunday update, I covered the detection of a “toxic smells” within the Russian section of the International Space Station (ISS), requiring the atmosphere throughout the station to be scrubbed. The first outlet to cover the news – as it was breaking – was the  highly-reliable Russian Space Web, operated by respected space journalist and author, Anatoly Zak, and it was through that source I first read of the situation.

During the past week other outlets have taken up the story, but it is Anatoly who continues to lead with updates. While there was no immediate danger to any of the ISS crew, the hatches to the Progress vehicle were sealed and the atmosphere throughout the station scrubbed – on the international side of the station, the use of the Trace Contaminant Control Sub-assembly (TCCS) system was imitated after NASA astronaut Don Petit reported a “spray paint-like” smell in the Node 3 module of he station.

Progress MS-29 approaching the ISS, November 23rd, 2024. Credit: Roscosmos

In Anatoly’s most recent update in the story, he confirmed that after recycling the atmosphere in the Progress vehicle, the hatches had been reopened between it and the Poisk module against which its docked and off-loading of supplies had commenced. Anatoly also noted the the current working hypothesis from Roscosmos is that the smell did not originate from within the Progress MS-29 vehicle.

Instead, the Russian space agency believe the smell came from within the docking mechanism on the Poisk module. The Russian docking mechanisms include fuel lines for both off-loading hypergolic propellant supplies from a newly-arrived resupply vehicle carrying them, and to transfer propellants to Soyuz vehicles to “top off” the tanks of their thrusters prior to making a return to Earth.

Because of this, and while docking operations involving Progress and Soyuz are automated, after any departure from the Russian section of the ISS, ground control should perform a purging of the inner chamber of a docking mechanism to ensure any leak of hypergolic propellant that have been in the feed lines at the time which might otherwise be contained within the chamber is removed. This appears not to have been done following the departure of the last vehicle to use this particular docking port, Progress MS-27, potentially leaving traces of highly toxic propellant caught between the newly-arrived MS-29 and the interior of the Poisk module, releasing them into the latter when the inner hatch was opened.

Space Sunday: big rockets and (possible) ISS troubles

A shot from the “flap cam” on Starship, showing the Super Heavy immediately after separation during IFT6. Note the residual gases burning within the hot staging ring. Credit: SpaceX

The sixth integrated flight test (IFT-6) of the SpaceX Starship / Super Heavy behemoth took place on Tuesday, November 19th, 2024, and proved to be perhaps the most successful test yet of the system, even though the core aspect of the first part of the flight didn’t occur.

The vehicle lifted-off from the SpaceX Starbase facility at Boca Chica, Texas at 22:00 UTC. All 33 Raptor-2 engines on the Super Heavy booster ignited, and the massive vehicle lifted-off smoothly. All continued to run, and the initial phases of the flight passed without incident: the vehicle passed through Max-Q, reached Most Engines Cut-Off (MECO) at 2 minutes 35 seconds, leaving it with just three motors running.  Seven second later, hot staging occurred, Starship firing all 6 of its engines and then separating from the booster.

Starship IFT6 rising from the launch facilities, November 19th, 2024. Credit: Redline Helicopter Tours

This was followed by the booster flipping itself onto a divergent trajectory to Starship and re-igniting the ring of 10 inner fixed motors to commence its “boost back”: gradually killing it ascent velocity and bringing it to a point where it could commence a controlled fall back to Earth, and then a powered final descent into being caught b the Mechazilla system on the launch tower, as seen during the October flight.

However, during the boost-back, the call was made to abort the attempt at capture, and to instead direct the booster to splashdown in the Gulf of Mexico. The booster then went through a nominal descent, dropping engines first (and causing them to glow red-hot during the compression of air inside their nozzles, despite the fact none were firing).

Booster in the water: seconds after splashdown, a single motor still running, the Super Heavy booster sits in the Gulf of Mexico. Credit: SpaceX

At just over 1 km altitude, the 13 inner motors did right, all of them firing for some 7 seconds and reducing the rocket’s descent from 1,278 km/h to just 205 km/h. At this point nine of the ten motors on the inner fixed ring shut down, with one appearing to run a second or so longer. When it shut down, there was a belch of flame of the base of the booster, which might indicate an issue.

Nevertheless, the three central motors continued to operate, gimballing to bring the booster to a vertical position and a brief hover right above the water before cutting off and allowing the rocket to drop end-first into the sea. Remaining upright for a moment, the booster then started to topple over. However, as the live stream cut away at that point, it was down to other camera to capture the subsequent explosion due to water ingress around the super-hot engines, etc., which destroyed the rocket.

“There’s the kaboom!” Shots from onlookers demonstrating that 13 super-heated engines and their plumbing and residual gases in propellant tanks don’t play nice with cold sea water, as the Super Heavy booster explodes

The Starship vehicle, meanwhile, made it to orbit and continued on over the Atlantic and Africa to  the Indian Ocean, where it went through its de-orbit manoeuvres.

Whilst in the coast phase of the flight, the vehicle had been due to re-ignite one of its vacuum engines to demonstrate this could be done in space. This occurred at 37 minutes 46 seconds into the flight, the motor running for about 4 seconds. Although brief, the re-light was a milestone – Starship will need the capability while on orbit in the future.

A camera in Starship’s engine bay captures the steady firing of one of its vacuum Raptor-2 motors during the flight’s orbital coast phase. Credit: SpaceX

The Starship’s return to Earth was anticipated as being potentially “whackadoodle”, and subject to possible vehicle loss. This was because SpaceX had removed elements of the thermal protection system designed to protect the vehicle from burning-up during atmospheric re-entry.

The purpose in removing tiles from the vehicle was to expose parts of the hull where, if Starship is also to be “caught” by the Mechazilla system on its return to Earth, it will need exposed elements on the side bearing the brunt of the heat generated by re-entry into the atmosphere, and SpaceX wanted data on how the metal of the vehicle held-up to being exposed to plasma heat, particularly given the previous two flights had seen plasma burn-through of at least one of the exposes hinges on the vehicle’s aerodynamic flaps.

The leading edge of a flap show clear signs of impending burn-through during re-entry – but the damage is a lot less than previous flights. Credit: SpaceX

As it turned out, the vehicle managed very well during re-entry; there was a significant amount of very visible over-heating on the leading edge of a flap, but even this was less than seen in IFT4 and IFT 5. It’s not clear as to how much damage the exposed areas of the vehicle suffered were TPS tiles had been removed, but given the vehicle survived, any damage caused was clearly not sufficient to compromise its overall integrity.

The drop through the atmosphere was visually impressive, the flight so accurate that as the vehicle flips itself upright at less than 1 km above the ocean, the landing zone camera buoy anchored ready to record the splashdown can clearly be seen. Immediately after entering the water, the Starship toppled, bursting into flame – but this time not immediately exploding.

After fling half-way around the world, the Starship vehicle is about to splashdown just a handful of metres from the camera buoy (arrowed, top right)at the landing zone. Credit: SpaceX

Whilst a booster catch might not have been achieved, IFT6 can be classified a success. All criteria but the catch of the booster was achieved, and even though the later was lost as a result of a forced splashdown, the successful diversion of the booster to do so demonstrates an ability for SpaceX to divert a vehicle away from a landing tower in the event of an issues with the tower – providing said issues are spotted earl enough.

The flip side of this is that it exposes an inherent weakness in the system; the reason for the abort was that the actual launch of the vehicle had caused damage to the launch tower and its communications systems, calling into question its ability to make the catch. Tower / launch stand damage has been a recurring theme with Super Heavy launches, although the degree of damage caused has been dramatically reduced.

The moment before splashdown, as seen from the Starship flap cam (l) and the remote camera buoy (r). Credit: SpaceX

Even so, the fact that comms systems could be KO’d reveals how vulnerable the system is to a potential loss of vehicle (and the knock-on impact in terms of “rapid reusability”), particularly if there is no close-at-hand and available launch / catch tower available to take over the role. And while this abort was called when the vehicle was still 87 km altitude, with lots of time to bring it safely into a splashdown, can the same be said if an issue occurs when the vehicle is just 13 km above ground? Or ten? Or two? Or if the malfunction occurs in the final engine burn?

ISS Reports “Toxic Smell” and Atmosphere Scrubbed

Update: Several hours after this article was published, NASA issued a statement on the event described below.

Reports are surfacing of possible toxic contamination board a resupply vehicle at the International Space Station (ISS). Initial news on the situation was broken by the highly-reliable Russian Space Web, operated by respected space journalist and author, Anatoly Zak, but that the time of writing this piece, western outlets had not reported the story, which is still breaking.

On November 21st Russia launched the automated Progress MS-29 resupply vehicle to the International Space Station (ISS), carrying some 2.487 tonnes of supplies, including 1.155 tonnes of pressurised supplies, 869 Kg of propellants; 420 kg of water and 43 kg of nitrogen gas.

Cosmonauts Ivan Vagner and Alexei Ovchinin monitor the automated approach and docking of Progress MS-29 at the Poisk module of the Russian section of the ISS. The majority of Progress dockings are automated, but members of the crew are on hand to manually intervene if required. Credit: Roscosmos / NASA

After being placed in an initial parking orbit, the vehicle rendezvoused with the ISS on November 23rd, manoeuvring to dock with the zenith port of the Poisk module (mini research module – MSM 2), attached to the Zvezda main module of the Russian section of the station. Following docking, the vehicle was secured and the pressure between the module and Progress vehicle pressurised to allow the hatches between the two to be opened.

However, the hatch to the Progress has to be immediately closed due to a “toxic smell” and a potential contamination hazard in the form of free-floating droplets. Following the securing of the hatches, NASA’s flight controllers apparently ordered the activation of the Trace Contaminant Control Sub-assembly (TCCS) in the International section of the ISS, a system designed to remove traces of potential airborne contaminants, effectively scrubbing the atmosphere in the ISS, with the Russian crew activating a similar system within the Russian section for around 30 minutes, with the cosmonauts themselves donning protective equipment (as reported last week, the main hatch between the two sections of the station is now kept shut due to a continuous leak of air through the Russian Zvezda module).

Progress MS-29 approaching the ISS, November 23rd, 2024. Credit: Roscosmos

The cause of the smell and the overall status of the MS-29 vehicle have yet to be determined; this is a developing story.

New Glenn Gets Ready

Blue Origin is approaching a readiness to launch their new heavy lift launch vehicle (HLLV), the New Glen rocket.

Earlier in November I reported on the new rocket’s first stage being rolled from the Blue Origin manufacturing facilities at Kennedy Space Centre to the launch preparation facilities at Space Launch Complex 36 (SLC-36), Cape Canaveral Space Force Station. These facilities already held the rocket’s upper stage, which had undergone a series of static fire tests of its motors whilst on a test stand at the pad earlier in the year.

Integrating the first and upper stages of the first New Glenn rocket to fly. Credit: Blue Origin

Since the arrival of the 57.5 metre long first stage at the integration facility at SLC-36, Blue Origin engineers have been preparing the vehicle for launch. By November 14th, the first and second stages of the rocket has been integrated with each other, and worked moved to integrating the payload and its protective fairings to the rocket.

Originally, the inaugural flight for the massive rocket – capable of lifting up to 45 tonnes to low Earth orbit (LEO) – was to have been the NASA EscaPADE mission to Mars. However, due to complications, the flight will now be the first of two planned launches designed to certify the system for the United States Space Force’s National Security Space Launch (NSSL) programme. The payload for the flight will be a prototype of Blue Origin’s Blue Ring satellite platform, a vehicle capable of delivering satellites to orbit, moving them to different orbits and refuelling them.

The fully assemble rocket, two stages plus the payload and its protective fairings, backs towards launch pad SLC-36, Cape Canaveral Space Force Station, November 21st, 2024. Credit: Blue Origin

On November 21st, the completed rocket – over 80 metres in length – rolled out of the integration facility and delivered to SLC-36, where it was raised to a vertical position, mounted on the 476-tonne launch table designed to support it and keep it clamped to the pad.

The actual launch date for the mission has yet to be confirmed, but it will see the company both launch the rocket and attempt to recover the reusable first stage, called So You Think There’s a Chance? Following separation from  the upper stage of the rocket, the first stage will attempted to make and controlled / power decent to and landing on the Blue Origin’s Landing Platform Vessel 1 (LPV-1) Jacklyn.

The New Glenn rocket mounted on its 476-tonne launch table at SLC-26, November 21st, 2024. Credit: Blue Origin

Artemis 2 Vehicle Progress

Even as NASA’s Space Launch System (SLS) continues to face a potentially uncertain future due to its per-launch cost, the second fully flight-ready vehicle continues to come together at NASA’s Kenned Space Centre in readiness for the Artemis II mission.

The mission, which is targeting a launch in late 2025, is due to carry a crew of four – Reid Wiseman (Commander); Victor Glover Pilot; Christina Koch, flight engineer and Jeremy Hansen (Canada), mission specialist – on an extended flight of up to 21 days, commencing with the crew aboard their Orion Multi-Purpose Crew Vehicle (MPCV), being placed in low Earth orbit, prior to transiting to a high Earth orbit with a period of 24 hours.

The Artemis II mission profile – click for full size, if required. Credit: NASA

Once there, they will carry out a series of system checks on the Orion and its European Service Module (ESM), as well as performing rendezvous and proximity flight tests with the rocket’s Interim Cryogenic Propulsion Stage (ICPS), simulating the kind of rendezvous operations future crews will have to do in order to dock with the vehicles that will actually carry them down to the surface of the Moon and back. After this, the crew will make a trip out and around the Moon and back to Earth.

The Orion capsule for the mission is nearing completion, with core assembly completed and the internal fixtures, fittings and systems on-going. Earlier in November 2024, and sans its outer protection shell and heat shield, it was subjected to a series of pressure tests to simulate both the upper atmosphere and space to ensure it had no structural integrity issues.

The core stage of the Artemis II SLS rocket, complete with its four main engines, inside NASA’s gigantic Vehicle Assembly Building (VAB). One of the base segments of a solid rocket booster (SRB) can be seen in the background. Credit: NASA

Meanwhile, the SLS vehicle itself has commenced stacking. The core stage, with is massive propellant tanks and four RS-25 “shuttle” engines, arrived at the Vehicle Assembly Building (VAB), Kennedy Space Centre, in July 2024, and since this has been undergoing much work whilst still lying on its side.

More recently, work on stacking the two solid rocket boosters (SRBs) developed from those used with the space shuttle, that will help power it up through the atmosphere has also commenced.

A crane inside the VAB prepares to lift one of the SRB motor sections and its assembly gantry, ready to place it on the back of a transport vehicle. November 13th, 2024. Credit: NASA

The SRBs comprise 5 individual segments which need to be manufactured and then bolted together, prior to being filled with their wet cement-like solid propellant mix. The base segments of these boosters include the rocket motor and guidance controls, and on November 13th, these were rolled into the Vehicle Assembly Building on special transport / stacking gantries. Over the next several months, the two SRBs will be assembled vertically in one of the bays within the VAB, and then loaded with their propellant and capped off.

Once the SRBs are ready and their avionics, etc., checked out, the core stage of the SLS will be hoisted up into one of the VAB’s high bays, moving to a vertical orientation as it does so. It will then be lowered between the two SRBs so that they can all be joined together. After this the ICPS will be moved up into position and mated to the top of the core stage of the rocket, and then work can commence stacking the Orion and its ESM and their launch fairings.

The SRB motor and its mounting gantry on the transporter, ready to be moved to the VAB bay where stacking can commence, November 13th, 2024. Credit: NASA

Whether or not Artemis II makes its planned late 2025 launch (no earlier than September) is open to question; currently, NASA has yet to fully complete the work on ensuring the already manufactured heat shield for the mission’s Orion vehicle is fit for purpose, per my previous report on heat shield issues.

Space Sunday: more from China, Skylon and an air leak

An artist’s impression of the Haolong automated resupply vehicle, intended to support China’s Tiangong space station. Credit: CCTV

China’s space programme is perhaps the most aggressive in the world in terms of ambitions and speed of development. In the last two decades, the country has been embarked on one of the most forward-thinking human spaceflight programmes, quickly moving from two small orbital laboratories to a fully-fledged space station whilst setting its eyes firmly on the Moon. At the same time, it has shown itself to be the equal of both the United States and Europe in the field of robotic exploration of the Moon and Mars, whilst also seeking to match the United States in pioneering the use of uncrewed reusable vehicles.

Most notably in this latter regard has been the Shenlong orbital vehicle, which I first wrote about in 2023, and which completed its second 200+ day orbital mission September 2024. Whilst not as long in duration as those of America’s X-37B, which it matches in terms of size and secrecy, Shenlong could be broadly as capable. And it will soon be joined by a second Chinese automated spaceplane, one with a similar purpose to America’s upcoming Dream Chaser vehicle.

Called Haolong, this new vehicle is one of two finalists in an 18-month selection process initiated by the China Manned Space Engineering Office (CMSEO) to determine the next generation of resupply vehicles intended to support the country’s Tiangong space station. In May 2023, CMSEO sought proposals from government agencies and China’s growing private sector space industry for vehicles capable of delivering a minimum of 1.8 tonnes of materiel to the Tiangong space station at a cost of no more than US$172 million per tonne. From the 10, in September 2023 four were selected to move forward to a more intensive design and review phase lasting just over a year, with the potential for two of them to be picked for full vehicle development.

A model of the Haolong automated cargo vehicle displayed at the Zhuhai Air Show, November 2024. Credit: China News Agency

On October 29th, 2024, the winning proposals were announced, with the Haolong spaceplane immediately gaining the the most interest due to its nature and the fact it was heavily promoted at China’s annual Zhuhai Air Show, complete with videos showing it in operation and images showing the full-size proof-of-concept development model.

Haolong’s development is being undertaken by an unlikely source: the Chengdu Aircraft Design and Research Institute, operated by the state-owned Aviation Industry Corporation of China (AVIC). Neither Chengdu, which is largely responsible for military aircraft development, nor AVIC has been involved in space vehicle development until now. At a length of 10 metres and a span of 8 metres with its wings deployed, Haolong is very slightly longer and wider than America’s Dream Chaser (9 metres long with a 7-metre span). Like the American vehicle, Haolong is designed to be vertically launched via a rocket, its wings folded to fit within a payload fairing, ready to be deployed once it reaches orbit and separates from its carrier rocket.

Haolong docked at Tiangong, note the open doors with the solar arrays and thermal radiators. Credit: CCTV

Exactly what to overall payload capability for the vehicle might be is unclear; Chengdu have only confirmed it will be able to lift the required 1.8 tonnes to orbit. This is less than one-third the total load carried by the current automated (and completely expendable) Tianzhou resupply vehicle, which can carry up to 6 tonnes to orbit – a capacity Dream Chaser can match.

However, given Haolong’s size and pressurised cargo space – coupled with the fact that the CMSEO requirement included a provision the new resupply vehicles can dispose of / return to Earth up to 2 tonnes of waste / materiel – it would seem likely Haolong’s all-up payload capability is liable to be above the 1.8 tonne minimum should it ever be required to fly heavier loads. 

A rendering of the Tianzhou automated resupply vehicle used to support China’s Tiangong space station. Fully expendable, the 14-tonne Tianzhou is itself based on China’s first two orbital laboratories, also confusingly called Tiangong (1 and 2). Credit: Shujianyang

But even if this isn’t the case, Haolong still scores over Tianzhou, as it’s all-up mass is expected to be less than half that of the older vehicle, potentially enabling it to be launched by a selection of Chinese rockets rather than being restricted to the expensive Long March 7. It could, for example even come to be launched atop the semi-reusable Long March 2F (if this enters production), or the rumoured semi-reusable variants of either the Long March 8 or long March 12B, as well as the expendable versions of Long March 2.

Details of the second vehicle to be selected, the Qingzhou cargo spacecraft, are somewhat scant, including its overall reusability. However, it will be launched via the upcoming Lijian-2 rocket being developed by CAS Space. The latter is commercial off-shoot of the Chinese Academy of Sciences, so technically its use as the launch vehicle for a space station resupply craft marks the first time a commercial entity will participate directly in China’s national space programme.

Long March 9: China’s Answer to Starship / Super Heavy?

Also present at the Zhuhai Air Show were further models of China’s in-development super heavy launch vehicle, the Long March 9 (Changzheng 9 or CZ-9) booster, together with the first models of China’s answer to (or near-clone of, if you prefer) the SpaceX Starship vehicle.

First announced in 2011, Long March 9 has been through a number of iterations and design overhauls. As first envisaged, the vehicle would comprise a 10-metre diameter core stage supported by up to four 5-metre diameter liquid-fuelled boosters (essentially Long March 10 first stages), giving it the ability to lift an upper stage with a payload capacity up to 140 tonnes to low-Earth orbit (LEO). With minor variations, this remained pretty much the baseline design until around 2019.

The Long March 9 super heavy launch vehicle as originally envisioned in 2016, to scale with other launch system, notable the SpaceX BFR, the precursor to Starship / Super Heavy. Credit: Wikipedia (2018)

A substantial redesign then appeared in 2021. This saw the elimination of the strap-on boosters and the first stage diameter increased 10.6 metres. To compensate for the loss of the strap-on boosters, the first stage of the vehicle had its original four engines replaced by 16 kerosene / liquid oxygen (LOX) motors, each one generating some 300 tonnes of thrust at sea level, allowing it to haul up to 160 tonnes of payload up to LEO.

Then in 2022, the decision was made to make the first stage of the rocket reusable. The LOX / kerosene motors were swapped for 26 of the more efficient YF-135 methane / LOX motors, the exact number compensating for the reduction in overall thrust. However, as 26 main engines required an 11-metre diameter first stage to fit them and their additional propellants, the design was then scaled back to keep the 10.6 metre diameter, and the number of motors reduced to 24 first stage engines. A further change at this point small the vehicle’s optional third stage increased in diameter from 7.5 metres to 10.6 metre as well, unifying all three stages.

This design carried over to 2023, where it was displayed at that year’s Zhuhai Air Show. However, the engine configuration had again changed for the first stage, with 30 of the more compact YF-215 motors now being used. In this configuration, Long March 9 was touted as being capable of delivering somewhere over 100 tonnes but less than 160 tonnes of payload to LEO in a two-stage variant and between 35 and 50 tonnes of payload to the Moon in a 3-stage version.

A drawing of the 2023 version of Long March 9 from the 2023 Zhuhai  Air Show, showing the 30-stage variant, said to be capable of delivering up to 53 tonne to the surface of the Moon; the 2- stage version with 100-160 lift capability and the proposed “Starship” variant with a 100-tonne capability to LEO and full reusability. Credit: CALT / CCTV

Also revealed at the 2023 Air Show were drawings of CALT’s take on the SpaceX Starship. At the time, the idea was defined as a “possible” iteration of the Long March 9 design, and unlikely to be ready for use – if pursued – until the 2040s. However, at the 2024 Air Show held in early November, it was clear CALT is invested in making a fully reusable Long March 9 launch system; on display were a set of models, one showing the Long March reusable first stage with the “starship” vehicle sitting on top of it, with two smaller models showing the “starship” vehicle on the lunar surface and a Long March 9 first stage resting on its “catch gantry” at the end of a flight.

According to CALT representatives at the show, work has now commenced on fabricating the first Long March 9 test vehicle, indicating the core design for the rocket’s first stage is now largely finalised, and the focus will initially be on developing this and the expendable second and third stages, with the first launch of an integrated rocket targeted for 2030. However, the representatives also indicated that the development of the reusable upper stage vehicle is seen as more integral to China’s lunar aspirations, and that they are looking to introduce it possibly as soon as the mid-to-late 2030s.

Scale models of the proposed “starship” upper stage of the Long March 9 sitting on the Moon (l) and the first stage booster resting on its landing gantry’s movable arms. Note how the deployable grid fins are used to support the mass of the booster on the gantry arms. Credit: CCTV

While making no secret of the fact they are directly emulating SpaceX with their design, CALT noted their vehicle would be more flexible in its application. As well as being able to deliver 100 tonnes to LEO, it was suggested it will be able to deliver smaller payloads to other orbits – such as MEO, GEO, GTO and SSO, and deliver as much as 50 tonnes to TLI, all apparently without the need for on-orbit refuelling (which Starship currently requires in all these cases).

If the lack of refuelling is accurate, then it suggests CALT are considering different internal layouts for their “starship”, such as utilising payload space for additional propellant tanks to enable their vehicle a wider range of operational capabilities; however, until CALT are more forthcoming on exactly how they envisage vehicle operations to work, this is purely speculative.

Reaction Engines in Administration

Reaching orbit using rockets – even reusable ones – is a costly business.  Rockets require complex, high-performance (and costly) motors, have to carry a lot of propellants to feed them, and require a lot of specialised infrastructure to operate them. Because of this, one of the holy grails of access to space has been the SSTO – single stage to orbit – vehicle; a craft capable of taking off in a manner akin to that of an aircraft, reaching orbit and then returning to Earth and again landing like a conventional aircraft.

In the 1980s, Britain in particular worked on an SSTO concept called HOTOL (Horizontal Take-Off and Landing), an uncrewed vehicle roughly the size of an MD-80 airliner. It would have utilised a unique air-breathing engine underdevelopment by Rolls Royce (the RB-545) to carry up to 8 tonnes of payload to orbit , using the air around it as an oxidiser for its rocket motors, mixing it with on-board supplies of liquid hydrogen until the atmosphere became too rarefied for this, and the engines would switch to using on-board LOX with the liquid hydrogen. But despite initial government backing, interest from the European Space Agency and the United States, HOTOL floundered and ultimately died in 1989, and Rolls Royce shelved development of the RB-545.

A cutaway diagram of REL’s Skylon vehicle. Credit: Reaction Engines Ltd

Undeterred by this, one of HOTOL’s originators, Alan Bond, co-founded Reaction Engines Ltd (REL), a company dedicated to developing both a new air-breathing engine to supersede the RB545 and a new SSTO spaceplane to use it. The motor, called SABRE (Synergetic Air Breathing Rocket Engine) and the vehicle, called Skylon, have been in development ever since, with SABRE in particular seeing much progress and both national and international interest. In fact, as recently as 2019, things looked remarkably rosy for SABRE and Reaction Engines.

This is why the announcement that REL had entered administration, with all staff laid-off, is deeply saddening. An eight-week process has commenced to either restructure or sell the company; if neither proves viable, it will enter liquidation and all assets sold-off. No formal reason for the company’s failure to continue to gain funding has been given; however, it has been suggested that the fact SABRE and Skylon would only be able to operate from specially reinforced runways, rather than any suitably-equipped airport facility, may have been a contributing factor.

The SABRE engine. Credit: Reaction engines Ltd

NASA and Roscosmos at Loggerheads over ISS Leak

For the last five years the International Space Station (ISS) has been suffering from an atmospheric leak within one of its oldest modules, the Russian Zvezda Service Module. Launched in 2000 as the third major element of the space station, Zvezda is actually approaching its 40th birthday, the core frame and structure having been completed in 1985 when Russia was still engaged in its Mir space station programme.

As such, the unit is well beyond its operational warranty period, and since 2019, the short airlock tunnel connecting the Zvezda’s primary working space with the aft docking port has been suffering an increasing number of microscopic cracks that have allowed the station’s atmosphere to constantly leak out. Whilst the overall volume of atmosphere lost is small, by April 2024 it had reached a point where attempts to patch some of the cracks were made. While this did reduce the amount of air being lost for a short time, the volume has once again be rising of late.

The Russian Zvezda Module (also called the PrK module), seen from its aft end, with the Progress dock post visible. The airlock tunnel where the leaks are occurring is the cream-white cylinder just inside the module’s main structure, surrounding the docking port. Credit: NASA

Whilst the leaks are still far short of being any risk to the station’s crew, NASA and Roscosmos cannot reach an agreement on either their root cause or their potential to become a significant hazard. Roscosmos remains of the opinion that the cracks are purely down to thermal contraction as the module expands and contracts as it passes in and out of the Sun’s light and heat, and therefore no different to the thermal wear on all other parts of the station.

However, while agreeing agreeing thermal expansion and contraction has a role to play in the leaks, NASA does not agree that it is the only cause. Instead, they see the continued use of the aft docking port – primarily used to receive Progress resupply vehicles – as putting additional stress on the tunnel’s walls, and this, couple with the aging of the module in general and the thermal expansion / contraction is causing the cracks. What’s more, NASA is concerned that if use of the after docking port continues, it is elevating the risk of a high-rick failure within the tunnel which could seriously compromise station operations.

A Progress resupply vehicle docked at the rear end of the Zvezda Module. NASA believes the cracks causing the atmospheric leaks inside the module are in part the result of stresses induced on the module by Progress docking / undocking operations. This image was captured during a station “flyaround” by the shuttle Discovery during STS-102, March 2001. Credit: NASA

Given this, NASA would like to see Roscosmos discontinue the use of the docking port – which Roscosmos argues is not necessary. While both agree the issue is unlikely to result in a complete and catastrophic failure within the tunnel culminating in a lost of the station as a whole; NASA engineers and mission controllers are concerned that any failure within the tunnel could impact operations throughout the station. As such, they have ordered the hatch between the Russian elements of the ISS and the US / international modules to be kept closed other than during crew passage between the two sections of the station.