Category: Space Sunday

Space Sunday: China’s plans, Hubble and Soyuz

Posted on by Inara Pey
An artist’s rendering of the Tiangong space station is it is at present. but showing a Shenzhou crew vehicle attached to the nadir port of the main docking hub. Any additional core module will be attached to the axial port of the hub (and so would extend to the left of this image). Credit: CCTV

China continues to grow and expand its astronomy and space aspirations. In a series of announcements, the country has indicated its aims for Earth-based astronomy, the expansion of its space station, international co-operation and more on it plans for a presence on the Moon.

With the Tiangong station only having recently been “completed” in terms of its pressurised modules with the arrival of the Mengtian science module in October, China had originally indicated that the only remaining module awaiting delivery to the station was the Xuntian space telescope, capable of docking with the station for maintenance, but designed to operate as a free-flying automated platform to be launched in 2023.

However, Wang Xiang, director of space station systems at the China Academy of Space Technology (CAST), has indicated China is considering adding a second “core” module to Tiangong. If this goes ahead, it will be mated to the axial port of the current docking hub at the forward end of the Tinahe-1 module.

According to Wang, the new module will provide a larger and more comfortable living environment for crews, and would include its own docking hub capable of supporting two further modules as well as accepting vehicles docking at its the axial port. This would allow the station to double in size and support larger crew numbers, as well as allowing it to operate for considerably longer than the planned 10-year time frame.

A breakdown of the current Tiangong space station modules and supporting vehicles. Credit: Shujianyang (via Wikipedia)

In addition, CAST has announced China is working with Saudi Arabia, the United Arab Emirates and other Gulf states to reach partnership agreements which could see these states working alongside China aboard Tiangong, developing a human presence on the Moon and in deep-space astronomy and robotic exploration.

Among other aspects of the agreement is the potential to establish a China-GCC (Gulf Cooperating Council – comprising Saudi Arabia, Qatar, UAE, Bahrain, Oman, and Kuwait) joint centre for lunar exploration, which would also oversee the selection and training of tiakonauts from GCC member states.

In terms of the latter, China is keen to gain international partners in its vision for lunar exploration in order to match the Artemis Accords. The latter is a set of a non-binding agreements that (to date) has seen 23 nations agree to support the US-led return to the Moon with personnel, materiel and scientific endeavours.

China’s lunar aspirations are seen by some as potentially kicking-off a new “space race”, given both it and the United States have identified the Moon’s south polar regions as the most likely location for establishing bases, given the relative accessibility of water ice within craters there. Whether this proves to be the case remains to be seen; certainly, there is a degree of chaffing within China at being excluded from all international space efforts involving the United States; however, the country has been developing its own approach to space exploration for decades without feeling the need to be seen as directly competing with the US in a manner akin to the US / Soviet space race.

A computer generated model of the interior of the EAST observatory showing the competed 8-metre primary mirror on its focusing support mechanism (in deep blue) and the secondary mirror supports (red) complete with the secondary mirror housing at the top (brown). Credit: Peking University

With regards to astronomy, China is also looking to build its own version of the James Webb Space Telescope (JWST), with the first phase of the observatory being operational by 2024, and the completed facility operational by around 2030.

The project is to be led by the Peking University, but rather than being launched into space, this observatory will be Earth-based. Referred to as the  Expanding Aperture Segmented Telescope (EAST), the observatory will have a primary mirror similar to that of JWST, a 6-metre diameter made up of 18 individual hexagonal mirrors which work both individually and collectively to focus the light they gather into the secondary mirror for transfer back into the telescope and its instruments.

The site for the observatory is Saishiteng Mountain within the Qinghai Province on the Tibetan plateau, 4.2 kilometres above sea-level, well above the majority of the denser atmosphere, making it much easier for the telescope to also compensate for the distorting influence of that atmosphere.

But that’s not all; as an Earth-based telescope, EAST will be constructed in two phases. Once the 6-metre primary mirror system has been completed, and as funding allows, the addition of a further 18 mirror segments, increasing the mirror’s diameter to almost 8 metres; 1/3 as big again as JWST.

A drawing showing the initial 6, primary mirror design (to be completed by the end of 2024) and the planned expansion to an 8-metre mirror (r). Note the black hexagon marks the focusing port / tertiary mirror which carries light gather by the primary and scondary mirrors down to the instruments. Credit: Peking University

The cost estimate for the first phase of the observatory’s construction has been put at a mere US $69 million, with the expansion work – to be completed by 2030, as noted, to cost around a further US $20 million, compared to JWST’s estimated US $9 billion construction cost – although in fairness, EAST is an optical, rather than infra-red telescope, and so doesn’t require the need to operate at extremely lower temperatures, making it a lot less complex. When completed, EAST will be the largest optical telescope in the eastern hemisphere.

NASA Issues RFI Regarding Hubble Reboost

Since its launch in to a 540 km orbit above Earth in 1990, the Hubble Space Telescope (HST) has required regular “reboosting” as drag caused by friction contact with the tenuous upper atmosphere caused its orbit to decay. Up until 2009, these operations were completed by the US space shuttle as a part of scheduled HST servicing missions, with the very last mission serving to push HST to its highest orbit in anticipation of the shuttle being retired from active duty in 2011.

However, since then, atmospheric drag has reduced its orbit by some 60 km, and unless countered, it will force NASA to de-orbit HST in 2029/30 to ensure it burns-up safely and any surviving debris falls into the Pacific Ocean. By contrast, a re-boost mission could extend Hubble’s operational life by another 20 years.

In September 2022, NASA joined a study involving SpaceX and the Polaris group examining the feasibility of using a Crew Dragon vehicle in a servicing / reboost mission to the Hubble Space Telescope (HST). This work has now been expanded into a request for information on possible reboost mission options. Credit: NASA

To this end, in September 2022, SpaceX and billionaire Jared Isaacman – who has already funded one private mission to space using a Crew Dragon vehicle (Inspiration4) and is currently planning a further series of flights under the Polaris mission banner – started work on an unofficial mission outline to  rendezvous with HST and then boost its orbit. NASA then joined in these discussions on a non-exclusive basis or commitment to manage any reboost mission.

On December 22nd,  NASA issued a formal request for information (RFI) based on those discussions and exercising their non-exclusive nature to invite any interested parties to propose how a reboost mission might be completed, whether or not it expressly uses SpaceX hardware or some other, likely automated, booster vehicle. The RFI period is short, closing on January 24th, 2023, and the information gathered from respondents will be assessed over a further 6-month period and alongside the SpaceX / Polaris study to determine the best means of carrying out such a mission.

In this, there are both challenges and opportunities: HST is primarily designed to be serviced by shuttle, so by default it does have the capability to dock with the likes of SpaceX Dragon or other craft without the risk of damage. However, during the 2009 servicing mission, it was equipped with a Soft Capture Mechanism (SCM), a device primarily designed to allow a small automated vehicle attach itself to Hubble as part of a de-orbit mission. But with a suitable adapter, it might be used by a vehicle the size of Dragon to safely mate with HST and then ease it to a higher orbit.

Soyuz MS-22 Leak Update

The Russian space agency, Roscosmos, has stated it will conclude its investigation in to the status of Soyuz MS-22 towards the end of January 2023.

As I’ve reported in recent Space Sunday updates, the vehicle was used to carry cosmonauts Sergey Prokopyev and Dmitry Petelin and NASA astronaut Francisco Rubio up to the ISS in September 2022, where it has been docked ever since. However, on December 14th, 2022, the vehicle suffered an extensive ammonia coolant leak, potentially crippling it.

The exact cause of the leak has yet to be determined, although Roscosmos remains convinced it was the result of either meteor dust or a tiny piece of space debris impacting the Soyuz coolant radiator, puncturing it. However, their focus has not been on determining the cause of the leak, but in trying to determine whether or not the vehicle is capable of returning the three crew to Earth safely, or if a replacement vehicle will be required.

Video of the Soyuz MS-22 coolant leak, December 14th 2022. Credit: NASA

As I noted in my previous Space Sunday update, should Roscosmos decide a replacement vehicle is required to return Prokopyev, Petelin  and Rubio to Earth, it will likely be Soyuz MS-23, which would be launched in February 2023 to make an automated rendezvous with the space station. However, it is now being reported that NASA has also contacted SpaceX to assess the feasibility of using Crew Dragon to return some or all of the MS-22 crew to Earth.

In this, it is unclear as to precisely what NASA has requested of SpaceX, and neither party is commenting. One theory is that the request is to determine whether the current Crew Dragon vehicle currently docked at ISS could carry additional personnel to Earth, if required. Another is NASA wishes to access the potential of launching an uncrewed Dragon to the station as a means to act as an emergency back-up for evacuation of the station – should it be required – prior to MS-23 being available to launch.

Both options are long-shots; getting Crew Dragon vehicle and its Falcon 9 rocket ready for launch in advance of MS-23 – a mission already in preparation, regardless of whether it flies with its planned crewed or uncrewed – is not an easy task. Further Dragon isn’t equipped to handle Russian space suits, the kind used by Prokopyev, Petelin  and Rubio. As such, to even consider Crew Dragon as temporary lifeboat  – much less a replacement for MS-23 to bring the three crew back to Earth – would require not small modification to its support systems. Similarly, while the Crew 5 vehicle might be able to return one or two of the MS-22 crew to Earth should it be necessary to do so, there is also the no insignificant matter of getting its life support systems to work with the Russian space suits.

One particular area of concern is that a number of experts outside of NASA / Roscosmos have opined that whatever Roscosmos may announce at the end of January, MS-22 is unlikely to be safe to bring its crew home. Therefore, should Roscosmos opt to do so, NASA might opt to look to other means to return astronaut Rubio to Earth as a matter of safety.

 

Space Sunday: Mars missions and the Soyuz leak

Posted on by Inara Pey

NASA’s Mars 2020 Perseverance rover has started preparations to have some of the samples it has gathered to be returned to Earth for extensive analysis.

Since its arrival on Mars in February 2021, the rover has been exploring Jezero Crater and collecting samples of sub-surface rocks in much the same manner as its older sister, Curiosity, which arrived within Gale Crater half a world away on Mars 12 years ago.

Some of these samples have been subject to on-board analysis by the rover’s internal lab, but for the most part they have been sealed in special tubes stored in an on-board cache, part of a total volume of 43 such tubes it carried to Mars tucked within its underside.

The idea behind the tubes – one of which has been used to collect a sample of the Martian atmosphere, and five more contain various materials intended to capture particulates in the ambient environment – is that they would form one or more sample caches Perseverance could deposit at locations where they could later be collected for return to Earth by a European-American sample-return mission.

Thus, on December 21st, 2022, the rover started building the first of these caches with the “drop” of the first tube to be selected for surface caching. The operation involved the rover parking at a recognisable feature within Jezero crater – dubbed “Three Forks” – and then rotating the rotunda of sample tubes so that the selected tube – containing samples of igneous rock collected at the start of 2022 – could be released and dropped to the Martian surface. Then, to confirm the operate had succeeds, and the tube wasn’t snagged somewhere in the mechanism, NASA commanded the rover to use its robot arm to peer down between its wheels and use the camera mounted on the end of the arm to confirm the position of the tube and check its overall condition.

Somewhat resembling a light sabre from the Star Wars franchise, the sample tubes are made up of a mix of materials designed to protect their contents from the rigours of being placed out in the harsh Martian environment and and rick of contamination by solar radiation or by the future process of transferring them to the vehicles that will be used to return them to Earth.

Resembling a Star Wars light sabre, a sample tube dropped by the Mars 2020 rover Perseverance on December 21st marks the start of an operation to place 10 sample tubes in a cache for collection by a future mission which will return them to Earth. Credit: NASA

This resemblance to a light sabre is something that has not been lost on the mission team at NASA’s Jet Propulsion Laboratory.

I’ve been holding out my hand to my computer screen to see if the tube will be transported from Mars, since as director, I’m pretty sure the Force is with me, right? OK, so no joy so far, but I’ll keep trying!

– Laurie Leshlin, NASA’s Jet Propulsion Laboratory director

A photo of the “Three Forks” cache site in Jezero Crater, Mars, depicting the points at which the ten sample tubes will be dropped by the Perseverance rover. Credit: NASA

In all, ten of the 22 tubes so far used by the rover will be dropped around the “Three Forks” location – each one in its own drop point to facilitate easier pick-up. The second of the ten – containing the longest core sample thus far collected by the rover, comprising sedimentary rock taken from the edge of an ancient outflow delta in the crater – was dropped on December 22nd. A second cache of tubes will be established elsewhere in the crater at a later period in the rover’s mission to offer an alternate collection point for samples.

The current plan for the sample-return mission (July 2022) requires an orbiter / return vehicle to be supplied by the European Space Agency and delivered to Mars orbit in May 2028. At around the same time, a Sample Retrieval Lander built for NASA, will also arrive on Mars relatively close the the selected sample cache and carrying an sample ascent vehicle and two small helicopters similar to Ingenuity, already operating on Mars in concert with Perseverance.

The Mars Sample-Return Mission elements. top: the ESA- built orbiter / return vehicle; right: the sample lander with the ascent vehicle above it, carrying the sample back to the orbiter; left: the Perseverance rover and an Ingenuity-class Mars helicopter, one or other of which will be used to transfer sample tube to the lander vehicle, which will load them into the ascent vehicle. Credit: NASA / ESA.

Perseverance, which will have returned to the cache site in the interim, will then collect the sample tubes and pass them to the lander vehicle, which will then use a special robot arm to stow them in the ascent vehicle. Should Perseverance be unable to carry out the collection and transfer, the two helicopters will do so instead. Once all the samples have been collected, the ascent vehicle will launch to a rendezvous with the orbiter, and the containment unit with the sample transferred to it for the return to Earth, arriving in 2033.

Goodnight, InSight

As one team at NASA’s Jet Propulsion Laboratory were celebrating the success of the latest phase of their mission, another team was saying a final “farewell” to their mission vehicle.

Having operated for a total of four years on Mars – two years longer than its primary mission period – the NASSA InSight lander’s mission was officially brought to an end on December 21st, 2022, its mission team no longer able to communicate with it.

InSight on Mars, December 1 2018, on Flickr
Three images captured by the HiRISE camera on NASA’s Mars Reconnaissance Orbiter, released on December 13th, 2018. Left: the lander’s aeroshell and parachute. Right: the heat shield, discarded after EDL and ahead of parachute deployment on November 26th, 2018. Centre: InSight itself with a surrounding ring of regolith blasted by the lander’s landing motors. The teal colour is not genuine, but the result of sunlight being reflected off of the lander and its parts saturating the HiRSE imaging system. Credit: NASA/JPL

Whilst not as exciting as an ambulating rover mission, InSight – short for  INterior exploration using Seismic Investigations, Geodesy and Heat Transport – was a massively ambitious mission, full details of which can be found in Space Sunday: insight on InSight. As the name suggests, the overall aim of the mission was to gain information on the processes going on deep within Mars.

To achieve this, the lander notably included two experiments it had to transfer from its deck to the surface of Mars, post-landing. One of these experiments, the Heatflow and Physical Properties Package (HP3) and involving a self-propelled “Mole” designed to investigate how much heat is emanating from Mars’ core, did not fare too well, the Mole becoming stuck very early in its attempt to burrow into the ground.

However, the second surface package, SEIS (Seismic Experiment for Interior Structure) – the primary mission element for the lander – proved to be highly successful in its goal of recording details of “marsquakes” and other sound-generating events within and on the planet (such as recording meteor impact later traced to a new 150m diameter crater on the planet), allowing scientists build up a clearer understanding of the planet’s internal structure and activity.

In all, SEIS measured over 1300 seismic events in 4 years, marking Mars as still being geologically active deep below its surface. Fifty of these events were “loud” enough to reveal information about their location on Mars, with a large cluster of them coming from Cerberus Fossae, a region of the planet having been thought to be geologically active relatively recently in its 4.5 billion year history, with many “young” surface features.

SEIS also showed that the Martian core is molten but is larger than thought and less dense than the lower crust. Lighter elements mixed with molten iron in the core lower its density, which explains how the core can still be molten even after cooling considerably.

As a static lander, InSight always had a limited lifespan; as a solar-powered vehicle, its panels would inevitably become so coated in dust and subject to deterioration in the harsh Martian environment that they would no longer be able to generated sufficient power to charge the lander’s batteries.  However, it had been hoped that dust devils, tiny Martian tornadoes created during the changing of the Martian seasons, might help “clean” the panels in much they same way they have with the solar-powered MER rovers. Unfortunately, this was not the case – possibly because the 2m diameter solar arrays used by the lander were simply too big for passing dust devils to effectively blow accumulated dust off of them.

Continue reading “Space Sunday: Mars missions and the Soyuz leak” →

Space Sunday: spaceship leaks, exo-Earths & an ancient solar observatory

Posted on by Inara Pey
Ammonia coolant spews from the Soyuz MS-22 vehicle docked against the Rassvet module of the International Space Station. Credit: NASA TV

A potentially serious issue occurred at the International Space Station this week when Soyuz MS-22 developed a coolant leak in the early hours of Thursday, December 14th, almost 3 months after the vehicle had docked with the station to deliver Russian cosmonauts Sergey Prokopyev and Dmitry Petelin, together with American astronaut Francisco Rubio to commence a 6-month tour of duty.

Named for Konstantin Tsiolkovsky, the father of Russian cosmonautics, the vehicle experienced an uncontrolled leak of ammonia coolant which started at 00:45 UTC and ran for several hours, generating stream of material jetting outwards from the vehicle and causing the station crew to have to stabilise the structure.

At the time the leak was detected, cosmonauts Petelina and Prokopyev were preparing to embark on a spacewalk to carry out maintenance work on the Russian segment of the ISS, where the Soyuz is docked. The EVA was called off due to concerns the cosmonaut’s spacesuits could be contaminated with the hazardous coolant fluid.

A second Russian EVA set for December 21st was also later cancelled over concerns about the leak; however, NASA initially indicated a spacewalk due to talk place on the US / International side of the station would go ahead, later deciding to postpone it in favour of assisting Roscosmos in trying to assess the amount of damage caused to the Soyuz – and possibly to the ISS.

As the leak curtailed, cosmonaut Anna Kikina – the first Russian to fly to the ISS aboard an American commercial crew vehicle as a part of a seat exchange programme between NASA and Russian space agency Roscosmos – used a European-built robotic arm attached to the Russian Nauka science module delivered to the ISS in 2021 to inspect the Soyuz craft. Further inspections by both the Russians and Americas using their respective robot arms are also being scheduled.

Operated by Anna Kikina, the European- supplied robot arm attached to the Nauka module is extended to image the exterior of Soyuz MS-22 in an attempt to assess the damage caused by the coolant leak. Credit: NASA TV

The exact nature of the leak is unknown. However, the former head of spaceflight safety at the European Space Agency Tommaso Sgobba, believed the leak occurred with the vehicle’s active coolant system, most likely crippling it “beyond repair”. This appeared to be borne out both by the images captured by Kikina using the Nauka module’s robot arm – which shoe extensive damage to the outer skin of the instrument and assembly compartment of the vehicle. Since the leak, Roscosmos has reported the interior temperatures of the vehicle’s pressure modules had risen to 30C which, despite being referred to as being within “acceptable limits”

On Friday, December 16th, 2022, the Russian space agency began remote testing of a number of the vehicle’s systems – including its thrusters – in an attempt to ascertain its space-worthiness.

If the vehicle is unfit to fly, it means Prokopyev, Petelin and Rubio will be unable to use it to make their scheduled return to Earth in March 2023 – although reports that this leaves the three “stranded” in space are somewhat exaggerated. There are a number of ways in which the three can be returned to Earth either individually or collectively:

  • Soyuz is fully capable of automated flight and docking with the ISS (it can use the same system as the Progress re-supply vehicles – themselves essentially uncrewed Soyuz – to reach the ISS and provide the three with a ride home.
  • Failing this and allowing for the necessary crew alterations, both Soyuz and Crew Dragon can fly to the ISS with a vacant seat, which can then be used by one of the MS-22 crew.
  • The Boeing CST-100 Starliner is due to make a crewed flight to the ISS in April / May 2023, a month or two after MS-22 is scheduled to return. It could, with some adjustment to the mission, be used to return one or two of the MS-22 crew as well as the main crew at the end of its week-long stay at the ISS.

Of these three options, the first would appear to be the most likely. For now however, assessments of MS-22’s overall condition are on-going and (for now) leave the door open on a fourth option: if the vehicle is deemed safe to make an immediate return to Earth, the three crew members curtail their mission and come home three months early.

The Artemis 1 mission to cislunar space is a potential watershed moment in space exploration., potentially the first genuine step in a human return to the Moon, with the potential to reach even further into the solar system. It’s a mission I covered in these pages over a number of articles, up to an including the previous piece. However, for those who would like to relive it in a compressed manner NASA has released a video of the mission’s highlight from launch to splash-down.

Running to 24 minutes – just shy of a total reflecting  the duration of the mission in days – the video is a fascinating compression of the mission, presenting many iconic images of the vehicle, the Moon and Earth.

Continue reading “Space Sunday: spaceship leaks, exo-Earths & an ancient solar observatory” →

Space Sunday: 50 years – last and first at the Moon

Posted on by Inara Pey

Apollo 17 lifts off from Launch Complex 39A, Kennedy Space Centre, December 7th, 1972. Credit: NASA
At 05:33 UTC on December 7th, 1972, the last of the Moon-bound Saturn V rockets thundered into the Florida skies from Kennedy Space Centre’s Launch Complex 39A At the start of the Apollo 17 mission.

Looking back at the Apollo era now, it is incredible to think that the entire project was conceived and – in terms of its lunar aspirations –  executed in just 13 years, with the missions to the land humans on the Moon all taking place within a span of just 42 months. It was originally initiated in early 1960 under the Eisenhower administration as a means for the US to expand its space capabilities by providing a vehicle system capable of being used in the construction of a space station and, eventually, of carrying humans to the Moon. But in 1961 the project was co-opted as the best means of achieving President Kennedy’s desire to see America “commit itself to achieving the goal, before this decade is out, of landing a man on the Moon and returning him safely to the Earth”.

In doing so, Apollo set in motion the biggest single increase in NASA’s capabilities ever witnessed, giving rise to the facilities – such as the Merritt Island Launch Operations Centre with its massive VAB and two launch facilities at pad 39A and Pad 39B, and the sprawling mass of the Johnson Space Centre in Texas (often colloquially referred to as “Mission Control”) – people take for granted today as the most public elements of NASA’s infrastructure. Even so, by the time Apollo 11 landed on the Moon, the programme had already started towards closure: Apollo 20 had already been diverted for use in the Skylab project, while Apollo 18 and 19 would be cancelled early in 1971, leaving Apollo 17 as the last Apollo flight to the Moon.

The Apollo 17 crew: seated in the lunar rover replica is Gene Cernan, with Harrison Schmitt to the left behind him, and Ronald Evans to the right
The Apollo 17 crew, 1972: seated in the lunar rover replica is Gene Cernan (Commander), with Harrison Schmitt (Lunar Module pilot) to the left behind him, and Ronald Evans (Command Module pilot) to the right, and the Saturn V launch vehicle on the pad behind them. Credit: NASA

A “J-Class” mission, Apollo 17 was one of only three of the lunar flights designated as being for “extensive scientific investigation”, the missions up to and including Apollo 14 being focused primarily on the task of making precision lunar landings, with all science activities running secondary to that. It was also the only Apollo mission to the Moon to carry a full trained scientist in the form of geologist Harrison H. Schmitt.

Initially, Schmitt had been slated for Apollo 18, but when that mission was cancelled, there was a push from the science community to have him moved to Apollo 17 – a push resisted by mission commander Eugene Cernan, who (understandably) wanted to keep his original team of himself, Ronald Evans and Joe Engle. However, Cernan’s own leadership of the mission was seen as questionable by some at NASA after pilot error on his part caused during a training flight resulted in a helicopter crash; so when it became clear the choice was to replace Engle with Schmitt or have the who crew replaced, Cernan capitulated – and he and Schmitt went on to form a strong working relationship and friendship.

En-route to the Moon: Harrison Schmitt catches a cheeky-looking Eugene Cernan (l) and Ronald Evans (r). Credit: NASA

The only night-time launch for an Apollo lunar surface mission, Apollo 17 proceeded precisely on schedule despite a brief launch-pad delay. Planned as the longest of the Apollo missions at 12 days and 14 hours, it would also become the most successful of the three lunar science flights for Apollo, with the science work commencing whist en route to the Moon, with the crew carrying out observations of Earth and its weather patterns. Also carried aboard the Command Module were 5 additional crew members: pocket mice the crew unofficially named Fe, Fi, Fo, Fum and Phooey. Carried in their own self-contain life support unit, they were part of an experiment to investigate exposure to cosmic rays in interplanetary space, although the findings of the experiment were ultimately inconclusive.

This science work took a further turn when, as the CSM and LM combination approached the Moon, a panel on the side of the Service Module was jettisoned to expose the contents of the Scientific Instruments Module (SIM), a battery of lunar science packages Evans would monitor whilst his crewmates were on the Moon’s surface.

America’s exposed Science Instruments Module (SIM) imaged from the Lunar Module Challenger. Credit: NASA
These experiments comprised a lunar sounder designed to map the interior geology of the Moon to a depth of 1.3 km; an infra-red scanning radiometer intended to obtain a temperature  map of the Moon’s surface to assist in understanding structural differences in the lunar crust; and a far-ultraviolet spectrometer to obtain data on the composition, density, and constituency of the lunar atmosphere and detect far-UV radiation emitted by the Sun that had been reflected off the lunar surface. Also in the SIM bay were a pair of cameras for imaging the Moon and a laser altimeter.

twenty-four hours after entering orbit around the Moon, Schmitt and Cernan boarded the Lunar Module Challenger, departing the Command Module America on December 11th, 1972 to touch down within the Taurus-Littrow valley at 19:54:58 UTC that day. The landing marked the start of some 75 hours on the lunar surface. During this time, Cernan and Schmitt carried out 3 EVAs, two of them making use of the third Lunar Rover vehicle to the carried to the Moon.

Challenger orients itself ready to start its descent to the lunar surface, as captured by Ronald Evans aboard America. Credit: NASA

The rover was deployed during the first EVA, with Cernan managing to repeat an error made by John Young on Apollo 16, accidentally ripping off one of the dust guards over the rover’s wheels such that both he and Schmitt would be showered in lunar “fines” (dust) kicked up by the wheel when the rover was in motion despite efforts to make repairs under Young’s supervision. In addition, this EVA also saw the two men deploy the surface experiments designed to be used within the vicinity of the Lunar Module.

The second EVA, on December 12th set a series of records for lunar surface operations: the furthest distance travelled from the LM (7.6 km), the longest distance travelled in a single EVA overall, the most time spent of the surface of the Moon in a single EVA (7 hours, 37 minutes) and the largest haul of samples from a single EVA to that point – 34 Kg. Along the way they visited several sites – Nansen Crater, at the foot of the South Massif; Shorty crater, and Camelot crater,

This EVA would go down in history for other reasons as well. At Shorty Crater, Schmitt came across orange soil, never before seen on the Moon. Initially it was thought he’d come across a volcanic vent in the lunar crust, but subsequent analysis of the material’s tiny volcanic beads revealed it has been formed some 3.5 billion years ago during the Moon’s volcanic period, and was exposed when a small asteroid slammed into the Moon to form Shorty a mere 20 million years ago.

Between Nansen and Shorty, the crew also stopped at a then-unnamed crater where Schmitt stumbled and fell in an awkward pirouette. While the fall left him uninjured, it prompted duty CapCom Robert Parker to quip to the crew that the Houston Ballet had called, requesting Schmitt audition for them on his return to Earth (in 2019, the crater was officially named Ballet Crater in honour of Schmitt’s tumble). Also during the EVA, both men (led by Schmitt) offered their own take on the popular song I Was Strolling in the Park One Day, which more than anything else revealed the bond that had grown between them.

The final Apollo era lunar EVA began at 22:35 UTC on December 13th, 1972, carrying out surveys of three “stations”: the North Massif and the Sculptured Hills; a house-sized boulder Cernan dubbed “Tracy’s Rock” after his daughter; and Van Serg crater. Whilst short in distance that the second EVA, this one set a further new record for samples collected – 66 Kg, including the 8 Kg sample designated 70215, a small part of which is now displayed at the Smithsonian Institution as one of the few samples of lunar rock the general public can touch.

At the end of the EVA, Schmitt and Cernan unveiled a plaque mounted on the side of the Lunar Module’s descent stage, commemorating both their own time on the Moon and the Apollo mission as a whole. Schmitt then climbed back into the LM, leaving Cernan as The Last Man On the Moon, expressing some of his thoughts thus:

I’m on the surface; and, as I take man’s last step from the surface, back home for some time to come – but we believe not too long into the future … And, as we leave the Moon at Taurus-Littrow, we leave as we came and, God willing, as we shall return, with peace and hope for all mankind.

– Eugene Cernan, December 13th, 1972

A composite image of Harrison Schmitt alongside of “Tracy Rock”, taken by Eugene Cernan. Credit: NASA

Cernan and Schmitt successfully lifted off from the lunar surface in the ascent stage of the LM on December 14th, 1972 at 22:54 UTC. Following a 7-minute ascent, they entered lunar orbit and coasted to a rendezvous with America, where Evans had been busy with his own work. Following docking and transfer, Challenger was jettisoned at 04:51 UTC on December 15th, 1972, to be successful de-orbited to crash on the Moon’s surface where seismometers left by several Apollo mission recorded the impact.

While en route back to Earth, Evans completed one of only three “deep space” EVAs so far performed, and the last EVA of the Apollo missions to the Moon. At 296,000 km from Earth, he departed the Command Module, watched over by Harrison Schmitt, and retrieved the film cassettes from the cameras in the SIM on the Service Module.

America re-entered Earth’s atmosphere and splashed down safely in the Pacific Ocean at 19:25 UTC, December 19th, 1972 just 6.4 km from the recovery ship USS Ticonderoga. The splashdown brought the Apollo lunar missions to a close. However, 5 more missions would fly under the Apollo banner: the four Skylab missions between 1973 and 1974 (which included the final flight of an Apollo Saturn V rocket), and the lS half of the Apollo-Soyuz Test Project (ASTP) in 1975.

Apollo 17 marked the last time Cernan flew into space, and the first and last times Schmitt and Evans did likewise. In 1976, Cernan departed NASA for the private sector, but maintained strong views on the direction of the US space programme, being highly critical of the Obama administration’s cancellation of the Constellation Programme and NASA’s move to rely on private sector resources. He passed away in January 2017, and is the subject of an obituary in these pages,

Ronald Evans remained at NASA until March 1977, performing key roles in both the ASTP mission and in the development of the space shuttle system. He passed away in 1990 after suffering a heart attack in his sleep. Harrison Schmitt was the first of the three to depart NASA, doing so in 1975 to pursue his political aspirations as a Republican Senator for New Mexico (1976-82). He became chair of the NASA advisory council in 2005  but then abruptly resigned 2008, clashing with NASA on the subject of climate change – of which he is a fervent denier (going so far as to state in 2013 that rising CO2 levels in the atmosphere are “good” because they allow us “to grow more crops”). He has also aligned himself with extremist conspiracy theorists such as Alex Jones.

Artemis 1 Comes Home

While it was not planned this way, fate determined that the 50th anniversary of Apollo17 landing on the Moon would be shared with the return to Earth of the first of NASA’s next generation of crew-carrying, lunar orbit capable vehicles, the Orion Multi-Purpose Crew Vehicle (MPCV).

I’ve covered the 26-day mission of Artemis 1 over the last few editions of Space Sunday. In many respects, it is the “reverse book-end” of Apollo 17; while the latter brought America’s first forays to the Moon to an end, Artemis 1 opens the door to a far more ambitious, international, and potentially far-reaching return to the Moon.

Perhaps the most iconic image of the Artemis 1 mission. Captured on December 5th, 2022 as the vehicle swings around the Moon, it shows the crescent Earth in the distance, the shadow of the Moon partially covering it. Credit: NASA

The mission, launched on November 16th, 2022, sent the Orion vehicle on a wide, slow cruise out to the Moon, which it transited past on November 21st, to enter a distant retrograde orbit (DRO), where it remained until December 5th, when a second close pass by the Moon allowed it to fire its main engine and start its way back to Earth.

The extended nature of the mission was to allow the systems on Orion to be thoroughly checked out over the duration of a typical mission duration, and to gather data on how well the vehicle protects the crew from radiation in the interplanetary medium – and the likely impact of exposure to the likes of cosmic radiation on humans who will spend 20-30+ days away from the protection of Earth’s magnetic fields.

December 11, 2022: Artemis 1 approaches Earth ahead of the Orion capsule separating from the Service Module. Credit: NASA

Approaching Earth on December 11th, 2022, the Orion capsule separated from is its European-built Service Module at 17:00 UTC, immediately performing a “skip” re-entry. This saw the capsule descend to around 60 km above the Earth before rising once more to 90 km to start its “full” re-entry. This “skip” manoeuvre allowed the vehicle to shave off its huge velocity – 40,000 km/h – in stages, both reducing  the over G-load the vehicle would face in a single go whilst also offering a greater flexibility in selecting a  splashdown location should there be an issue with the primary.

Splashdown came at 17:40 UTC bringing to an end a test flight covering a total distance of 2.3 million km. Prior to striking the water, the last of the vehicle’s velocity was reduced through the use of no fewer than 11 parachutes, opened in groups during its descent through the denser atmosphere.

Splashdown! 17:40 UTC, December 11th, 2022: the flight of Artemis 1 concludes as the Orion capsule splashes down safely off the coast of California. Credit: NASA / US Navy

While the mission will be subject to an extensive post-flight analysis, the general consensus is that SLS rocket and the Orion vehicle passed the test with more-or-less flying colours, helping to ensure things remain on course for the crewed mission of Artemis 2, due to take place in May 2024 over 10 days, head of the first planned lunar landing for Artemis 3, currently planned for launch in 2025.

Space Sunday: more Artemis, JWST, China and SpaceX

Posted on by Inara Pey
Captured from a camera mounted on one of the service module’s solar arrays, this shot show the Artemis 1 Orion vehicle heading back to the Moon on November 29th, 2022, with both the Moon (44,949 km distant from the vehicle) and Earth (435,230 km from the vehicle) visible. Credit: NASA
NASA’s uncrewed Artemis 1 mission has started its return to Earth. Having reached the furthest distance on November 28th, the vehicle started back towards the Moon as it travels along its distant retrograde orbit (DRO).  Along the way it completed a further series of flight tests of both its manoeuvring systems and flights systems, including Callisto, NASA’s voice recognition software (based on Amazon Alexa) designed to assist crews during flight operations. On Wednesday, November 30th, the vehicle completed the first of three engine burns to start it on it way back to Earth. This was an “orbit maintenance burn” designed to maintain Orion’s trajectory as it headed back to the Moon, and to decrease its velocity, allowing the Moon’s gravity play a greater role in the craft’s trajectory. At 95 seconds, this burn ran for slightly longer than originally planned, allowing mission engineers gather  additional data to characterise the impact of the vehicle’s thrusters and their radiative heating on the spacecraft’s solar array wings to help inform Orion’s operational constraints.
Created using NASA’s AROW – The Artemis Real-time Orbit Website – this image shows a view of the Artemis vehicle as it heads back towards the Moon on November 29th, 2022. Credit: NASA
On Thursday, December 1st, Orion completed the more critical DRO exit burn, slowing it further and “bending” its trajectory so it make a close passage around the Moon, bringing it to 127 km above the lunar surface, a point it will reach on Monday, December 5th.. At this point Orion’s service module will fire its main engine to exit lunar orbit to move into a trans-Earth Injection (TEI) flight path that will see it reach Earth on December 11th, when it will enter the atmosphere for a splashdown in the Pacific Ocean. As well as testing the flight system, NASA has used the flight back towards the Moon to capture further stunning images and video, with the agency also releasing a high-speed “mission highlights” video covering the mission’s launch and flight to the Moon and into DRO.

JWST and Keck Continue to Reveal Titan

In my previous Space Sunday update, I noted that the James Webb Space Telescope (JWST) has returned to full operations following the correction of an issue with its Mid-Infrared Instrument. The event was marked by the release of images captured by the instrument of Saturn’s largest moon, Titan. Since then, NASA, the space Telescope Science institute and the Keck observatory have released further stunning images of the moon, these taken with JWST’s Near Infrared Camera (NIRCam). In the first, two images of the moon are placed side-by-side captured using different filters. They reveal both the lower reaches of the moon’s methane-heavy atmosphere. The second reveals how NIRCam can look through the murk of such an atmosphere to see the surface of the moon. Both images reveal intriguing aspects of the moon.
Titan, as images by JWST’s NIRCam, showing (l) the lower atmosphere and (r) the surface. Credit: NASA
On the first, NIRCam reveals two clouds, labelled “A” and “B”, whilst the second reveals some of the known surface details of the moon including Kraken Mare, believed to be a methane / hydrocarbon sea, and above which, intriguingly, “cloud A” had formed, suggesting it might be a weather system. Also imaged was Belet, a range of dark dunes and a bright albedo feature of uncertain nature, called Adiri. The clouds were of particular interest because they can validate long-held predictions from computer models about Titan’s climate: that clouds would form readily in the mid-northern hemisphere during its late summertime when the surface is warmed by the Sun. Further, observing how the clouds move or change shape might reveal information about the air flow in Titan’s atmosphere. To this end the JWST team observing Titan contacted colleagues at the Keck Observatory, Hawai’i who were about to start their own infra-red observations of Titan. They agreed to carry out a similar series of observations of the moon to allow for comparative science studies to be carried out.
On the left, the James Webb Space Telescope Nov. 4, 2022, observations of Titan; on the right, Keck Observatory’s view two days later. Credit: NASA / Webb Titan GTO Team and Keck Observatory
The result is a series of images which appear to show the formation, movement and dissipation of the same cloud formations over the course of several days (November 4th-7th), offering the potential for those promised insights into climate and weather around Titan – although astronomers caution the clouds seen by Keck might be of different origin. NIRCam isn’t the only JWST instrument which gathered data on Titan during the observation period. The Near-Infrared Spectrograph (NIRSpec) examined the light reflected by Titan’s atmosphere to gather its spectra, which will allow scientists map what compounds are present in the lower atmosphere — including a strange bright spot over the moon’s South Pole, which has been a source of puzzlement for astronomers and planetary scientists.
On the left, the James Webb Space Telescope Nov. 4, 2022, observations of Titan; in the middle, Keck Observatory’s view two days later; on the right Keck’s view Nov. 7, 2022. Credit: NASA / Webb Titan GTO Team and Keck Observatory

China Sets a National Record for Taikonauts in Orbit

China had six tiakonauts in orbit for the first time this week as the crew of Shenzhou  15 joined their colleagues of the Shenzhou 14 mission aboard the nation’s new space station of a handover of station operations. Fei Junlong, Deng Qingming and Zhang Lu departed Earth on 29th November 2022 atop a Long March 2F rocket at around 15:08 UTC on November 29th. The vehicle docked with the forward docking port on Tiangong’s docking hub 6.5 hours later. Following the required post-docking checks, the hatches between station and vehicle were undogged and opened a 23:33 UTC,  allowing the Shenzhou 14 crew welcome their colleagues onto the station.
The Shenzhou 14 crew and their newly-arrived Shenzhou 15 crew members, November 29th, 2022. Credit: CMSE
The new crew will be aboard the station for 6 months, and after their welcome and a rest period, they joined Shenzhou 14 team is preparing the station for their stay, carrying out a range of small but essential maintenance work using equipment flown to the station aboard the Tianzhou 5 resupply mission in November. With the hand-over work completed by Sunday December 4th, the Shenzhou 14 crew departed the station aboard their vehicle at 03:01 UTC. Once clear of the station, they performed a series of fast return de-orbit procedures, allowing them to soft-land within the Dongfeng landing area in the Gobi Desert in the Inner Mongolia Autonomous Region nine hours later at 12:00 noon UTC. Their return marked the most successful crewed mission to date for China, with 180 days spent in orbit, three spacewalks, a space lecture and overseeing multiple tests of the station, the arrival of both the the station’s science modules, the manoeuvring (and eventual undocking) of the Tinazhou 4 automated resupply vehicle and the arrival of Tianzhou 5.
A recovery team as the crew return capsule of Shenzhou 14, after it soft-landed in the Dongfeng landing area in the Gobi Desert. Credit: CMSE
The Shenzhou 15 crew are liable to be even busier. Among their tasks, they will be expected to carry out or monitor over 100 experiments both within the science modules and outside, across the six months of their stay. They will also be carrying out three or four EVAs (spacewalks) which will bring new challenges, including “parallel operations” each taikonaut outside the station working independently to the other, with the crew member aboard the station balancing the needs of both EVA crew. Then are scheduled to return to Earth in May 2023.

SpaceX Starship Update

On November 29th, SpaceX completed a second static fire test on its Super Heavy Booster 7, the booster earmarked to try to carry one of the company’s Staship vehicles to orbit – and once again things did not go as quite as planned. Lasting 13 seconds, the test was 3 seconds longer that the first static fire test, performed on November 14th, although it involved three fewer engines: 11 compared to the 14 used in the November 14th test. However, like the first test the firing resulted in damage to the orbital launch facility, gouging clunks of concrete from under the base of the launch table, hurling them into the air where they might strike the vehicle or the launch facilities.

As I noted following the November 14th test, the flying debris is the result of both an insufficient sound suppression system (SSS) and provision of a flame deflector. The former is best known for deluging a rocket launch platform with thousands of litres of water in order to absorb the sound of the rocket engines which might otherwise be deflected up against the rocket to damage it. However, it has an additional function: to “drown” the launch platform and the area beneath it to protect them from the searing blast of the engine exhausts at lift-off. The flame deflector performs a similar role in protecting launch facilities from rocket engines by deflecting the exhaust plumes out and away from the launch stand (and also carrying the excess water (and steam) from the SSS away from both the platform and rocket, further lessening the risk of damage to either. Part of the sound suppression system used by NASA for Space Launch System rockets is shown being tested in the video below. This element protect the concrete base on the launch facility, with water also being directed down the central flame deflector seen within the trench used to channel heat, steam and sound away from the launch platform. A second suppression system (not seen in this video) is built-in to the mobile launch platform itself, to give it the aforementioned protection from the heat of the SLS four main engines and two SRBs at launch.

However, SpaceX has thus far eschewed and flame deflector and has opted for a spray system of water and nitrogen gas delivered through pipes within the circular launch table on which the super Heavy / Starship combination sits. Already upgraded since its initial installation, this system appears adequate in terms of sound suppression, but does not properly protect the concrete apron directly below the rocket engines from their full fury. Whether this remains the case with all Starship / Super Heavy launch facilities remains to be seen:  this first orbital launch facility is very much a prototype. However, the lack of consideration for any form of flame deflection mirrors a similar decision not to initially equip the launch stand with another basic requirement of a launch facility: burn-off igniters which resulted in the July 11, 2022 spin-start test explosion under Booster 7. Following the November 29th test, two of the booster’s Raptor engines were swapped out at the pad, although it is unclear whether his was the result of damage from the materials flung upwards and outwards from the apron during the test or as a result off other motor issues. After this work had been completed, Booster 7 was disconnected from the launch platform and returned to the production area. This may again be to allow further damage inspections to be carried out, by is likely equally to allow the rest of the booster’s aft skirt to be fitted. At the same time as Booster 7 has been under test, Ship 24, which is due to be mated to it for the launch attempt, has been undergoing repairs at the sub-orbital launch platform where it has been completing its own series of static fire tests. The results of these tests appear to have been fed back into the assembly of Ships 25 and 26, the next vehicles in the series. SpaceX has indicated they are still planning a further 20-sec 33-engine Raptor static fire test prior to any launch attempt, which will also include a further autogenous repressurisation test (feeding cooled gasses from the engines back up into the propellant tanks to maintain their pressure as their contents are used). This coupled with the fact that the Federal Aviation Administration has yet to issue a launch license, means that the launch attempt is unlikely to come before 2023.

Space Sunday: Artemis and JWST updates, solar power from space

Posted on by Inara Pey

A view of Earth taken by a solar array mounted camera on the Orion spacecraft on November 24th, a day before the spacecraft entered a distant retrograde orbit around the moon. Credit: NASA

NASA’s Artemis 1 mission, launched on November 16th, 2022, has become the first vehicle capable of carrying humans that far, to return to the vicinity of the Moon since Apollo 17 in 1972.

The Orion capsule reached the Moon on Monday, November 20th, the fifth flight day of the mission overall. At 12:44 UTC, the vehicle, swinging around the far side of the Moon and so out of communications with Earth, closed to within 130 km of the lunar surface and a velocity of 862 km/h. It then fired the single motor mounted on the vehicle’s service module for 2.5 minutes, the first engine burn designed to push the vehicle into a distant retrograde orbit (DRO).

The DRO is a path that loops the vehicle away from the Moon in the opposite direction to the Moon’s own orbit around the Earth. Confirmation of the manoeuvre’s success came as the vehicle cleared the Moon and resumed communications with Earth – returning a colour image of our home in the process.

The DRO provides a highly stable orbit where little fuel is required to stay for an extended trip in deep space to put Orion’s systems to the test in an extreme environment far from Earth.

– NASA blog post

A portion of the far side of the moon as seen from the Orion spacecraft on November 21st, 2022 during the Artemis 1 mission. Credit: NASA

An hour later, as the vehicle proceeded away from the Moon, it passed over a historic landmark – Tranquillity Base, the landing zone for Apollo 11 in 1969 at a distance of 2,227 km.  It continued outwards from the Moon with all systems functioning as expected. However, on Wednesday, November 23rd, all contact with the vehicle was suddenly lost and remained so for 47 minutes prior to contact being re-established.

The cause of loss-of-contact lay with the reconfiguring of the communications link between the spacecraft and NASA’s Deep Space Network (DSN) – the orbiting and ground-based communications network used to maintain contact with all of NASA’s operational missions. The reconfiguration should have been routine, having been carried out several times during the mission as DSN carried out its multiple duties, and at the time of writing it was not clear what caused the glitch.

looking back at Earth from beyond the Moon, November 2st, 2022. Credit: NASA

At 21:52 GMT on Friday, November 25th, Orion made its second DRO engine burn, one that lasted 82 seconds, sufficient to push the vehicle into its outward loop away from the Moon travelling at 396 km/h. This outbound leg of the flight saw Artemis 1 breaking the record for the for the farthest distance from Earth travelled by a human-rated spacecraft, surpassing the 432,000 km distance set by Apollo 13 in April 1971; Artemis will reach a maximum distance from Earth of 435,000 km on Monday, November 28th, the point marking the start of its return to close proximity to the Moon, which it will reach on December 1st.

The mission has not all been smooth sailing, however. As noted in my previous Space Sunday update, the launch facilities at Kennedy Space Centre suffered damage during the Artemis 1 launch, although at the time of that article, NASA had not confirmed how much damage had occurred on the mobile launch platform.

Immediately following the launch, NASA asked the media not to image or record the launch platform and tower, citing security issues and ITAR (International Traffic in Arms Regulation), sparking speculation (particularly among SpaceX fans) that the Space Launch System rocket have caused considerable damage to its launch facilities and was therefore somehow a “failure”.

The elevator stations at the base of the mobile launch tower used in the launch of Artemis 1, showing the extent of the damage with the protective blast doors entirely blown-in. Credit: NASA

Since then, however, NASA has completed an initial damage assessment exercise and has been more forthcoming. Whilst a more in-depth assessment is required on the internals of the launch tower structure, the initial assessment suggests the launch platform overall faired a lot better than expected, given the huge strain it was under (SLS generates more thrust and heat than either the space shuttle vehicles or the Apollo Saturn V at launch).

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