Category: Space Sunday

Space Sunday: touching the Sun and Martian organics

Posted on by Inara Pey
Parker Solar Probe. Credit NASA

The Parker Solar Probe has finally reached the atmosphere of the Sun.

The NASA spacecraft has spent more than three years winding its way by planets and creeping gradually closer to our star to learn more about the origin of the solar wind, which pushes charged particles across the solar system.

Since solar activity has a large effect on living on Earth, from generating auroras to threatening infrastructure like satellites, scientists want to know more about how the Sun operates to better make predictions about space weather, and gain a better understanding of the mechanisms at work in and around our star. Over the years, we’ve done this with a number of missions – but the most fascinating of all to date is the Parker Solar Probe, a NASA mission that has literally touched the face of the Sun.

The spacecraft – launched in 2018 – is in a complex dance around the Sun that involves skimming closer and closer to our life-giving star, and they sweeping away again, far enough to cross back over the orbit of Venus – indeed, to use Venus as a means to keep itself looping around the Sun in orbits that allow it to gradually get closer and closer, with the aim of actually diving into and out of the Sun’s corona, what we might regard as the Sun’s seething, broiling atmosphere.

In fact, the probe actually first flew through the corona in April 2021; however, it was a few months before the data to confirm this could be returned to Earth, and a few more months to verify it; hence why the news has only just broken about the probe’s success. One of the aims of pushing the probe into the Sun’s corona was to try to locate the a boundary called the Alfvén critical surface. This is the boundary where the solar atmosphere  – held in check by the Sun’s gravity – end, and the solar wind – energetic particles streaming outwards from the Sun with sufficient velocity to break free of that gravity – begins, creating the outwards flow of radiation from our star.

Up until Parker’s April 2021 passage into the corona, scientists has only been able to estimate where Alfvén critical surface lay, putting it at somewhere between 6.9 million and 13.8 million km from the gaseous surface of the Sun. As it passed through the corona, Parker found these estimates to be fairly accurate: the data it returned to Earth put the outer “peaks” of the boundary at 13 million km above the Sun’s surface – or photosphere; the data also revealed the boundary is not uniform; there are “spikes and valleys” (as NASA termed them) where the boundary stretches away from the photosphere at some points, and collapses down much close to it in others. While it has yet to be confirmed, it is theorised this unevenness is the result of the Sun’s 11-year active cycle and various interactions of the atmosphere and solar wind.

The Parker Solae Probe. Credit: NASA / I. Pey

The April “dip” into the corona lasted for five hours – as the mission goes on, future “dips” will be for longer periods). But give the spacecraft is travelling at 100 kilometres per second, it was able to gather a lot of data as it zipped around the Sun – and even sample the particles within the corona. The probe’s passage revealed that the corona is dustier than expected, the cause of which has yet to be properly determined, as well as revealing more about the magnetic fields within the corona and how they drive the Sun’s “weather”, generating outbursts like solar flares and coronal mass ejections (CREs), both of which can have considerable impact on life here on Earth.

To survive the ordeal of passing through the corona, where temperatures soar to millions of degrees centigrade, far hotter than those found at the Sun’s photosphere.  – Parker relied on its solar shadow-shield: a hexagonal unit 2.3 m across made of reinforced carbon–carbon composite 11.4 cm thick with an outer face is covered in a white reflective alumina surface layer. This shield is so efficient in absorbing / reflecting heat, whilst passing through the corona the sunward face is heated to around 1,370ºC, but the vehicle, sitting inside the shadow cast by the shield never experiences temperatures higher than 30ºC.

In addition to mapping the Alfvén critical surface, Parker’s April 2021 trip into the Sun’s corona, the probe also passed through a “pseudostreamer,” one of the huge, bright structures that rise above the Sun’s surface and are visible from Earth during solar eclipses. This was compared to flying into the eye of a storm the probe recorder calmer, quieter conditions within the streamer, with few energetic particles within it. Exactly what this means is again unclear at this time, but it does point to further incredibly complex actions and interactions occurring with the Sun.

Since April, Parker has dipped back into the corona twice more, with the November 2021 passage bringing it to around 9.5 million km of the Sun’s photosphere – although again, the data from that pass has yet to be received and analysed. The next passage in February 2022 will again be at roughly the same distance from the photosphere, with a further five passes to follow at the same distance in 2022/23, before a flyby of Venus allows Parker to fly even deeper in to corona. By December 2025, and the mission’s final orbits, it will be descending through the corona to just 6.9 million km from the photosphere.

An artist’s depiction of magnetic switchbacks in the solar wind. Credit: NASA Goddard/CIL/Adriana Manrique Gutierrez

But that’s not all. Because Parker is in an elliptical around the Sun, it spends a part of its time much further away. This both allows the craft to dissipate absorbed heat from its shield, and for it to observe the Sun from a distance, giving scientists much broader opportunities to study the Sun, such as allowing them to study the physics of “switchbacks”. These are zig-zag-shaped structures in the solar wind, first witness by the joint ESA-NASA Ulysses mission that occupied a polar orbit around the Sun in the 1990s.

In particular, Parker’s observations suggest that rather then being discrete events, switchbacks occur in patches, and that these “patches” of switchbacks are aligned with magnetic funnels coming from the photosphere called called supergranules. These tunnels are thought to be where fast particles of the solar wind originate; so switchbacks may have something of a role to play in the generation of the solar wind or they may be a by-product of its generation or, given they seem to have a higher percentage of helium than other aspects of the solar wind, may serve a highly specialised role as a part of the solar wind.

Right now, scientists are unclear on what might be the case, or what actually generates switchbacks; but gaining clearer insight into their creation, composition and interaction with other particles in the solar wind, and with the Sun’s magnetic field might provide explanations for a number of solar mechanisms, including just why the corona is so much hotter than the photosphere.

Mars 2020 Mission Update

Scientists with NASA’s Mars 2020 Perseverance rover mission have discovered that the bedrock their six-wheeled explorer has been driving on since landing in February likely formed from red-hot magma. It’s a discovery with implications for our understanding and accurately dating critical events in the history of Jezero Crater – as well as the rest of the planet.

Even before the Mars 2020 mission arrived on Mars, there have been much debate about the formation of the rocks in the crater: whether they might be sedimentary in origin, the result compressed accumulation of mineral particles possibly carried to the location by an ancient river system, or whether they might be they igneous, possibly born in lava flows rising to the surface from a now long-extinct Martian volcano. However, whilst studying exposed bedrock at location dubbed “South Séítah” within Jezero, the science team noted a peculiar rock they dubbed “Brac”, selecting it as a location from which to collect further samples of Martian bedrock using the rover’s drill.

When taking samples of this kind, booth Perseverance and her elder sister, Curiosity, operating in Gale Crater half a world away, are both instructed to scour target rocks clean of surface dust and dirt that otherwise might contaminate samples. This is done by using an abrasion tool (think wire brush) mounted alongside the drilling mechanism. However, in checking the work on “Brac”, the mission team realised the abrasion process had revealed the rock was rich in crystalline formations.

Rather than going ahead and drilling the rock for a sample, scientists ordered the rover to study the formations using the Planetary Instrument for X-Ray Lithochemistry (PIXL) instrument  – which is designed to map the elemental composition of rocks. PIXL revealed the formations to be composed of an unusual abundance of large olivine crystals engulfed in pyroxene crystal, indicating the formations grew in slowly cooling magma, offering some confirmation that volcanism has at least be partially involved in Jezero Crater’s history. However, PIXL’s data also suggested the rock, once hardened, has subsequently altered as a result of water action – confirming free-flowing water also had a role to play in the crater’s past..

The crystals within the rock provided the smoking gun … a treasure trove that will allow future scientists to date events in Jezero, better understand the period in which water was more common on its surface, and reveal the early history of the planet. Mars Sample Return is going to have great stuff to choose from.

– Ken Farley, Perseverance Project Scientist

The Sample Return mission has yet to be fully defined, let alone funded, but is being looked at as a mission for the early 2030s, quite possibly with European Space Agency involvement. In the meantime, a question Farley and his colleagues would love to answer is whether the olivine-rich rock formed in a thick lava lake cooling on the surface of Mars, or originated in a subterranean chamber that was later exposed by erosion; knowing the answer to this could determine the early history of Jezero Crater and its surroundings.

This 60-second video pans across an enhanced-color composite image, or mosaic, of the delta at Jezero Crater on Mars. The delta formed billions of years ago from sediment that an ancient river carried to the mouth of the lake that once existed in the crater. Taken by the Mastcam-Z instrument aboard NASA’s Perseverance rover, the video begins looking almost due west of the rover, and sweeps to the right until it faces almost due north.

Also within the latest updates from the Mars 2020 team is the news that Perseverance has found organic compounds within the rocks of Jezero Crater and in the dust that covers them. This discovery was made as a result of a review of findings from the SHERLOC (Scanning Habitable Environments with Raman & Luminescence for Organics & Chemicals) instrument.

This does not mean that the rover has discovered evidence of past microbial life on Mars; these carbon compounds can be created by both organic and inorganic processes. However, the fact that they have been found at a number of locations explored by the rover means that the science team can map their spatial distribution, relate them to minerals found in their locations, and thus both further determine their organic / inorganic origins and trace the distribution of minerals, etc., within the crater.

Further, the fact that compounds like these have been identified by both the Curiosity and Perseverance rovers means that potential biosignatures (signs of life, whether past or present) could be preserved, too. IF so, then assuming they exist, there may come a time when one our other rover might happen upon them.

Continue reading “Space Sunday: touching the Sun and Martian organics” →

Space Sunday: telescopes, wings and exoplanets

Posted on by Inara Pey

The Hubble Space Telescope – operations fully restored. Credit: NASA
NASA has successfully restored the Hubble Space Telescope (HST) to full operations after more than a month with the telescope either being in a “safe” mode, or only able to partially operate its science instruments.

The longest-running space mission in Earth orbit, HST has been subject to a range of issues throughout its career, all of which have been overcome, although this has been only of the more draw-out in getting resolved. It started on October 23rd, when the telescope started sending error codes indicating the loss of a specific synchronisation message that provides timing information used by its instruments use to respond to data requests and commands correctly. Two days later, the same error codes were again issued, prompting Hubble to cease science activities and enter a “safe” mode.

Throughout out the rest of October and early November, mission engineers on Earth worked to diagnose and rectify the issue, and on November 8th, 2021, were able to report a restart of the main computer system and a set of back-ups had allowed science operations to recommence on the telescope’s Advanced Camera for Surveys (ACS). Later in November, operations were restored to the Cosmic Origins Spectrograph (COS) and then the Wide Field Camera 3 (WFC-3), Hubble’s most heavily-used instrument, leaving just one major science instrument out of commission.

That was the Space Telescope Imaging Spectrograph (STIS),  which was finally restored to operational status on Monday, December 6th, marking Hubble’s full return to its science programmes.

However, the October glitch, following on as it does from a systems error that caused the telescope to enter a safe mode in July 2021, serves as a reminder that HST is running on software and systems designed and built in the 1980s.

As a result, the mission team has been evaluating and testing ways and means to refine and update the telescopes software on both its operating systems and its science instruments. This means that mid-December should see the COS gain a significant software update, with the remaining science instruments also being updated early in 2022.

Such upgrades are vital to Hubble’s continued career, given there has been no means to physically service it since the space shuttle was retired in 2011 – and NASA / ESA very much hope to keep the observatory running through until at least the end of the 2030s, consumables permitting.

That said, and if all goes according to plan, Hubble will so no longer be the only large-scale, space-based observatory in operation.

As I’ve frequently reported in these pages, the James Webb Space Telescope (JWST) is due to be launched from the European Spaceport, Kourou, French Guiana, on December 22nd, 2021. This is actually 4 days later than planned, the result of unexpected vibrations passing through the telescope after a clamp unexpected released as JWST was being integrated with the Launch Vehicle Adapter (LVA) – the element that physically connects the telescope to the rocket. This required a period of checks to be carried out to confirm the telescope’s instruments and systems had not been damaged by the vibrations.

However, following confirmation that no damage had been caused, two of the four remaining pre-launch operations for the telescope have now been completed and a third is in progress.

On November 23rd, European Space Agency engineers started the delicate operation to fill JWST’s propellant tanks with 168 kg of highly toxic hydrazine gas and 133 kg of equally toxic dinitrogen tetroxide oxidizer, both of which are needed to power the observatory’s thrusters. So harmful are both of these propellants, the loading took a total of 10 days, during which time engineers working in the same space as the telescope had to wear  Self-Contained Atmospheric Protective Ensemble (SCAPE) suits – essentially space suits for use on Earth that completely isolated them from their surroundings.

JWST sits within a clean room, folded ready for vehicle integration, and receiving its highly toxic thruster propellants as engineers wear SCAPE suits for their protection. Credit: ESA

With fuelling completed on December 3rd work then commenced on bringing both the telescope, mounted on its LVA, and its Ariane 5 launch vehicle together for the first time, moving both of them into the Final Assembly Building and readying them for mating together. This work was completed on December 7th, 2021, clearing the way for the mating process to commence.

Mating involves lifting JWST and its LVA up to the high bay of the building, and then lowering it on to the top of the Ariane booster. Once this has been done, a final series of tests on telescope, LVA and booster will be carried out and the Ariane payload fairings will be closed around the telescope. After this, a final check-out will take place, and the final pre-launch activity will see booster and payload moved to the launch pad a few days ahead of the launch.

The launch itself will in turn mark the start of the most complex deployment of a space instrument undertaken to date. It will take JWST 16 days to reach its operational halo orbit at the Earth-Sun L2 point, with the entire deployment taking some 29 days, as the video below explains.

Continue reading “Space Sunday: telescopes, wings and exoplanets” →

Space Sunday: the ISS, and commercial launch systems

Posted on by Inara Pey
The International Space Station, November 8th, 2021. Credit. T. Pesquet / ESA / NASA

The International Space Station (ISS) faced further threats from space debris this past week. One December 1st., a planned EVA spacewalk by NASA astronauts Thomas Marshburn and Kayla Barron was pushed back 24 hours over concerns about an unspecified debris threat that might be related to continuing concerns over the recent Russian ASAT missile test that left a cloud of debris orbiting Earth in an orbit that can pass relatively close to the space station.

Then on December 3rd, the ISS had to take more direct action to avoid any risk of collision with a piece of debris designated 39915, a major part of the upper stage of a Pegasus air-launched rocket that flew in 1994, and broke apart two years later.

Tracking the debris showed it would come within 5.5 km of the station, so the decision was taken to use the motors of a Progress re-supply vehicle to lower the station’s orbit to increase the clearance between it and the debris.

The ISS seen from “above” showing the main truss with 8 of the 12 gold solar arrays, the grey thermal radiators, the “international” modules towards the bottom of the picture and the Russian modules extending back between the thermal radiators. Credit; T. Pesquet / ESA / NASA

The motor firing took place at 08:00 UTC on December 3rd, with the thrusters on the Progress vehicle firing for three minutes. The manoeuvre is not expected to impact the December 8th launch of Soyuz MS-20 on Wednesday, December 8th, classified a “space tourism” flight featuring Japanese billionaire Yusaku Maezawa and his assistant, Yozo Hirano on an 18-day trip to the ISS. This will mark the first tourist flight to the space station since 2009. Maezawa is also the name (and money) behind the proposed Dear Moon cislunar mission using a SpaceX Starship vehicle.

All of this excitement blotted the news that NASA’s Office of Inspector General (OIG) has warned that NASA and its partners will potentially be without any Earth orbiting space station for a number of years if the ISS is to be “retired” as may currently be the case.

While NASA awarded US $415.6 million to three U.S. groups to develop designs for new orbit “destinations” – commercially-run space stations that can take over from the ISS from 2030 onwards – OIG has stated concerns any of these plans can be realised by that year – seen as the year in which ISS operations are expected to draw to a close.

One of the groups awarded a NASA contract is lead by Blue Origin and Sierra Space, who are promoting their Orbital Reef space station. Credit: Blue Origin / Sierra Space

In particular, the OIG report questions the ability for any commercial space station to be ready by the end of the decade, given the commercial market for on-orbit activities sans government financial support has yet to be assessed, as have the overall costs of developing space station facilities – or even the amount of funding NASA can provide to help ease development along.

In our judgment, even if early design maturation is achieved in 2025 — a challenging prospect in itself — a commercial platform is not likely to be ready until well after 2030. We found that commercial partners agree that NASA’s current timeframe to design and build a human-rated destination platform is unrealistic.

– NASA OIG report on commercial space stations

The report suggests that a further extension to ISS operations to eliminate any gap. However, doing so requires clearing some significant hurdles. The first is that of finance. The Untied States covers more than 50% of the ISS operational budget, and feelings about continuing to support the project beyond 2030 within Congress are very mixed.

There is also the fact that several of the older modules – notably the Russian Zvezda service module – are approaching the end of their operational life. Zvezda in particular has been suffering numerous leaks that have affected overall atmospheric pressure within the station, and numerous fatigue cracks have been located within the module’s structure, not all of which can be fully repaired.

Finally, Russia has indicated it is unwilling to support ISS operations beyond 2030, and is considering using the recently-delivered Prichal module on the ISS as an initial element of that station – although the loss of the module would not necessarily impede ISS operations if no agreement on extending operations beyond 2030 were to be reached.

ISS from “beneath”, with the damaged thermal radiator clearly visible. The “international” modules are up and to the right, the Russian modules to the lower left. Also visible is the Cygnus automated re-supply vehicle (with the circular blue/gold solar arrays, a Soyuz vehicle just to the left and below it, and a Progress re-supply vehicle beneath the lower left end of the station. Credit: T. Pesquet / ESA / NASA

As it is, the ISS has, since 2000, been visited by 403 individual crewed flights that have delivered 250 people to the station, and it remains a remarkable piece of space engineering and construction.

Just how remarkable was again shown in November 2021, when the Crew 2 mission departed the ISS aboard SpaceX Crew Dragon Endeavour; because as they did so, they took a ride around the ISS taking photos that were released this week.

Captured by ESA astronaut Thomas Pesquet, these images reveal the station in great detail – including what appears to be damage caused by what may have been a debris strike on one of the radiator panels.

They also reveal the stunning complexity of the station’s design from the long truss “keel” that is home to the station’s thermal radiator, vital for carrying away heat, and massive primary solar arrays, vital for providing power, to the “international” modules slung “under” it and focused around the US Harmony module, and the “tail” of the Russian built modules with their own solar arrays. In addition the Soyuz, Progress and Cygnus vehicles docked with the station can also be seen in some of the images.

SpaceX and Rocket Lab Updates

SpaceX Gear-Up and Problems

SpaceX is gearing-up for Starship  / Super Heavy operations, and also to support further crew flights to / from the ISS.

On Friday, December 3rd, the company indicated it is to resume / start work in earnest on new Starship / Super Heavy launch facilities at Kennedy Space Centre. The new facilities will be at Pad 39A, which SpaceX leased from NASA in 2014 in a 20-year agreement, and which has been the home of Falcon 9 and Falcon Heavy vehicles – and will remain so, despite the construction work.

Work on Starship / Super Heavy launch facilities within the Pad 39A launch pad area  – home of all but two of the Apollo lunar missions – in 2019, but the work was quickly halted in favour of the work being carried out at the company’s Boca Chica facilities. The plan is to build facilities of a similar nature to those at Boca Chica, but with improvements learned as a result of that work.

Kennedy Space Centre Pad 39A showing the SpaceX Falcon / Falcon Heavy launch facilities and the location of the Starship / Super Heavy launch facilities, where construction work has now resumed. Credit: Spacenews.com

The same day as SpaceX confirmed work on the Kennedy Space Centre launch facilities for Starship was resuming, NASA announced it was awarding a further three contracts to SpaceX for crew missions to / from the International Space Station (ISS) in addition to those already assigned to both SpaceX and Boeing, in part as a hedge against Boeing continuing to having issues with their CST-100 Starliner crew vehicle, which has yet to complete its demonstration crewed flight test, now due for some time in 2022.

Neither NASA nor Boeing have issued any update on the status of Starliner since October after valve corrosion problems caused the planned crew flight test to be  scrubbed and the vehicle returned to Boeing’s facilities. As such, it appeared unlikely Boeing would gain any additional contracts for ISS flights when NASA issued a request for information in order to award additional contracts for both entire vehicles for dedicated NASA-ISS flights or individual seats on commercial flights. However, this does not preclude them from further contract extensions once Starliner passes certification.

But it is not all good news for SpaceX. The company is encountering issues in scaling-up production of its Raptor engine – vital for the Starship / Super Heavy vehicles. While it is not clear what the problem(s) is / are, the situation appears dire enough for Musk to issue an e-mail to all SpaceX employs that the company could face bankruptcy if the issue(s) is/are overcome.

How serious his warning is, is not clear – he’s issued similar warnings in the past in order to “motivate” staff – and following the e-mail making headlines, he did start stepping back from some of his comments. However, Raptor production is key to the company’s future: SpaceX is banking on a high cadence of Starship / Super Heavy launches each of which will require a minimum of 35 motors per launch – with periodic swap-outs to be expected, even allowing for their reusability.  As it is, Musk has indicated he would like to hit 26 launches by the end of 2022, although it is not clear if this is combined booster / Starship launches (using a mix of 35 or 39 motors) or a mix of booster / Starship orbital attempts and further Starship high-altitude flight tests (the latter only requiring 3 or 6 motors).

Rocket Labs Provide Neutron Update

SpaceX aren’t the only contender in the US reusable launch vehicle Market. The New Zealand-US based Rocket Lab is already working towards partial reusability with their Electron small payload launcher, and CEO and founder Peter Beck recently provide an update on their Neutron medium-lift vehicle, which includes an entire new look to the vehicle.

The updated vehicle will be made of carbon composite materials (with Beck taking a slight dig at the use of stainless steel as adopted by SpaceX and (now) Blue Origin), and will be of a tapered design with a 7-metre diameter base. This shape is designed to reduce heat loads during re-entry into the atmosphere, with the booster standing on a set of fixed legs on landing.

An artist’s rendering of the Neutron rocket, showing the unique petal-like integrated payload fairings opened to allow for the deployment of the upper stage and payload. Credit: Rocket Lab

Nor does it end there. Neutron’s standard payload to low Earth orbit will be 8 tonnes – marking it as an ideal launcher for the smallsat / constellation / rideshare market. However, this can be extended to 15 tonnes  – although this is in a non-reusable format for the vehicle. But perhaps the most unique aspect of the vehicle is the manner in which it carries payloads when operating as a reusable launcher.

Traditional rockets carry their upper stages and payloads on top, with “throw away” aerodynamic fairings protecting the payload through the ascent through the atmosphere. Neutron, however, features fairings that are integrated into the rocket. These will open like petals around the payload / upper stage to allow them to be deployed, then close again to allow the vehicle to maintain the integrity of its shape through the re-entry phase of its flight through to landing.

An artist’s rendering of Neutron making a return to its launch site. Credit: Rocket Lab

Overall, the hope is that by using 3D printing, carbon composites, reducing the vehicle mass – which reduces the stress placed on the motor systems – and offering a design with a return to launch site capability that does not require complex infrastructure to enable re-use, Neutron will provide Rocket Lab with a significant launch capability at extremely low, high-competitive pricing.

Assuming the original plans for Neutron remain true, the vehicle’s first flight could come in 2024, most likely utilising the facilities Rocket Lab has been developing at NASA’s Wallops Island, Virginia, launch centre.

Space Sunday: a DART plus JWST and TRAPPIST-1 updates

Posted on by Inara Pey
NASA’s Double Asteroid Redirection Test (DART) vehicle under thrust as it closes on the asteroid Dimorphos as it orbits Didymos. Credit: NASA

On November 24th, 2021, NASA launched the Double Asteroid Redirection Test (DART) mission, a vehicle aimed at testing a method of planetary defence against near-Earth objects (NEOs) the pose a real risk of impact.

I’ve covered the risk we face from Earth-crossing NEOs – asteroids and cometary’s fragments that routinely zoom across or graze the Earth’s orbit as they follow their own paths around the Sun. We are currently tracking some 8,000 of these objects to assess the risk of one of them colliding with Earth at some point in the future. This is important, because it is estimated a significant impact can occur roughly every 2,000 years, and we currently don’t have any proven methods of mitigating the threat should it be realised. And that is what DART is all about: demonstrating a potential means of diverting an incoming asteroid threat.

Developed as a joint project between NASA and the Johns Hopkins Applied Physics Laboratory (APL), DART is specifically designed to deflect an asteroid purely through its kinetic energy; or to put it another way, by slamming into it, and without breaking it up. Both are important, because by simply slowing an Earth-crossing NEO along its orbit, we give time for Earth to get out of its way; then, by not causing it to break, then we avoid the risk of it becoming a hail of shotgun pellets striking Earth at some point further into the future.

The DART mission. Credit: NASA

The target for the mission is a binary asteroid 65803 Didymos (Greek for “twin”), comprising a primary asteroid approximately 780 metres across, and a smaller companion called Dimorphos (Greek: “two forms”) caught in a retrograde orbit around it, with both orbiting the Sun every 2 years 1 month, periodically passing relatively close to Earths, as well as periodically grazing that of Mars.

Discovered in 1996 by the Spacewatch sky survey the pair has been categorised as being potentially hazardous at some point in the future. At some 160m across, Dimorphos is in the broad category of size for many of the Earth-crossing objects we have so far located and are tracking, making it an ideal target.

DART actually started as a dual mission in cooperation with the European Space Agency (ESA) called AIDA – Asteroid Impact & Deflection Assessment. This would have seen ESA launch a mission called AIM in December 2020 to rendezvous with Didymos and enter orbit around it in order to study its composition and that of Dimorphos, and to also be in  position to observe DART’s arrival in September 2022 and its impact with the smaller asteroid.

However, AIM was ultimately cancelled, leaving NASA to go ahead with DART. To reduce costs, NASA initially looked to make it a secondary payload launch on a commercial rocket. But it was ultimately decided to use a dedicated Falcon 9 launch vehicle for the mission, allowing it to make its September 2022 rendezvous with Dimorphos.

An artist’s impression of DART and the LICIACube cubesat, with Dimorphos and Didymos in the background. Credit: NASA

In order to impact the asteroid at a speed sufficient to affect its velocity, DART needs to be under propulsive power. It therefore uses the NEXT ion thruster, a type of solar electric propulsion that will propel it into Dimorphos at a speed of 6.6 km/s – which it is hoped will change the velocity of the asteroid by 0.4 millimetres a second. This may not sound a lot, but in the case of hitting an actual threat whilst it is far enough away from Earth, it is enough to ensure it misses the planet when it crosses our orbit.

This motor is powered by a deployable solar array system first deployed to the International Space Station (ISS). However, what is most interesting about these solar panels is that a portion of them is configured to demonstrate Transformational Solar Array technology that can produce as much as three times more power than current solar array technology and so could be revolutionary should it reach commercial production.

Accompanying DART is Light Italian CubeSat for Imaging of Asteroids (LICIACube), a cubesat developed by the Italian Space Agency, and which  will separate from DART 10 days before impact to acquire images of the impact and ejecta as it drifts past the asteroid. To do this, LICIA Cube will use a pair of cameras dubbed LUKE and LEIA.

As the cubesat is unable to orbit Didymos to continue observations, ESA is developing a follow-up mission called Hera, Comprising a primary vehicle bearing the mission’s name, and two cubesats, Milani and Juventas, this mission will launch in 2024, and arrive at the asteroids in 2027, 5 years after DART’s impact, to complete a detailed assessment of the outcome of that mission.

 ISS Gets a New Module

On November 26th, 2021, a new Russian module arrived at the International Space Station (ISS).

The Prichal, or “Pier,” module had been launched by a Soyuz 2.1b rocket out of the Baikonur Cosmodrome in Kazakhstan two days earlier. Mounted on a modified Progress cargo vehicle, the module was successfully mated with the Nauka module which itself only arrived at the station in July, at 15:19 UTC.

Carried by a Progress vehicle, the Prichal module approaches the ISS. Credit: NASA TV

The four-tonne spherical module has a total of six docking ports, one of which is used to connect it with Nauka, leaving five for other vehicles. However, when first conceived, the module was also intended to be a node for connecting future Russian modules.

But since that time, the Russian space agency, Roscosmos, has abandoned plans to support the ISS with additional modules. Instead, with relations with the west continuing to cool and the ongoing rise in nationalism in Russia, the agency has indicated it plans to orbit its own space station. This being the case, Prichal is viewed as the final element in the Russian segment of ISS, and potentially the first of the new station.

Unlike the arrival of Nauka in July, Prichal managed to dock with the ISS without the additional “excitement” of any thruster mis-firings. Now, the Progress carrier vehicle will remain attached to the module through until December 21st, allowing time for the Russian cosmonauts on the station to carry out a spacewalk to attach Prichal to the station’s power systems. Once it has been detached, the Progress vehicle will be set on a path to burn-up in the Earth’s atmosphere.

Visible over the top of a Progress resupply vehicle, the Prichal module and its Progress carrier can be seen docked with the nadir port of the Nauka module. Credit: NASA TV

As well as expending the docking facilities at the ISS, Prichal delivered some 2.2 tonnes of cargo and supplies to the station. The module will formally commence operations in its primary role in March 2022 with the arrival Soyuz MS-21.

Continue reading “Space Sunday: a DART plus JWST and TRAPPIST-1 updates” →

Space Sunday: Debris, Artemis delays, SpaceX Plans

Posted on by Inara Pey
The International Space Station. Credit: NASA

Anyone  who follows news on space activities will be aware that on November 15th, Russia carried out the test of an anti-satellite(ASAT) missile system that resulted in the destruction of a defunct Soviet-era electronic signals intelligence (ELINT) satellite – and required the crew of the International Space Station (ISS) to move to their respective Earth return vehicles (Soyuz MS-19 and Crew Dragon Endurance) due to risk of being hit by the debris.

To be clear, ASAT systems are not new. The United States and Russia (/the Soviet Union) have between them spent decades developing and testing such systems (the last successful US test was in 2006, with both the USAF and USN having significant ASAT capabilities), and China and India have also demonstrated ASAT systems as deliberate demonstrations of force.

However, the November 15th test by Russia was somewhat different. Occupying a polar orbit at an average altitude of around 470 km, the 2.2 tonne Kosmos 1408 as both a substantial target risking a massive debris cloud, and routinely “passed over” the orbit of the ISS (ave 420 km), putting it at clear risk.  Nor did Russia give any forewarning of the test.

Instead, the US Space Command only became aware of what had happened after they tracked the missile launch all the way to impact – and then started tracking the cloud of debris. This presented no danger to the ISS in its first orbit, but tracking showed it was a very define threat to the station on its 2nd and 3rd orbits, prompting mission controllers to order the ISS crew to start shutting down non-essential operations and sealing-off hatches between the various science modules.

Some 15 minutes before the second pass of the debris field across the station’s orbit, controllers called the station to order the US / European astronauts in the “US section” of the station to secure all remaining hatches to minimise the risk of explosive decompression in the event of a hit, and evacuate to Crew Dragon Endurance both in case an emergency undock was required, and because it presented a significantly smaller target for any stray debris travelling at 28,000 km. The controllers also noted the Russia cosmonauts on the station were engaged in similar actions, and would be retiring to their Soyuz MS-19 vehicle.

In all, the crews were restricted to their Earth return vehicles for somewhere in the region of 3-3.5 hours before it was considered the most significant risk of and impacts had for the most part passed. Even so, it was not until November 17th that all hatches on the ISS were unsealed to allow normal operations to resume throughout all modules. Currently, NASA is still monitoring the situation and may postpone  a spacewalk planned for November 30th as a result of the debris risk.

Ironically, on November 11th, the ISS had to raise its orbit somewhat using the thrust from a docked Progress re-supply vehicle in order to completely remove the risk of debris from 2007 Chinese ASAT weapon test striking it, 14 years after the test.

In these images, Kosmos 1408 can be seen ringed on the left. The image on the right highlights some of the larger clumps and pieces of debris left after the kinetic “kill” by the Russian ASAT weapon. Credit: Numerica and Slingshot Aerospace

Following the test, Russia attempted to play down the risk, stating it posed “no threat” to other orbital vehicle, crewed or uncrewed – a less than accurate statement. Analysis of the debris cloud by both US Space Command and civilian debris tracking organisations reveals much of the cloud will remain a threat for the next several years – if not decades – as the convoluted nature of orbital mechanics and impact velocity gradually increases the cloud’s orbital altitude for a time as it continues to disperse, putting satellites in higher orbits at risk – particularly the likes of the SpaceX Starlink and the OneWeb constellations.

Russia has demonstrated a deliberate disregard for the security, safety, stability, and long-term sustainability of the space domain for all nations. The debris created by Russia’s DA-ASAT will continue to pose a threat to activities in outer space for years to come, putting satellites and space missions at risk, as well as forcing more collision avoidance manoeuvres.

– U.S. Army General James Dickinson, Space Command.

Some 1500 individual pieces of debris from the test are of a trackable size, with potentially tens of thousands more that are too small to be identified. Tim Flohrer, head of the European Space Agency’s (ESA) Space Debris Office noted that the test means that debris avoidance manoeuvres made by satellites in the 400-500 km orbit range may increase by as much as 100% for the next couple of years before the threat is sufficiently dissipated. One of the biggest risks posed by this kind of action is the Kessler Effect (or Kessler Syndrome), wherein debris from one impact causes a second impact, generating more debris, and so setting off a chain reaction.

Given its size and orbit, there is simply no way Russia was unaware of the threat posed by Kosmos 1408 to low-orbit vehicles – particularly crewed vehicles and facilities – if the test was successful. As such, some have seen it as irresponsible due to the impact it could have on general orbital space operations, while others see it as a sign of aggressive intent on Vladimir Putin’s part.

Currently, Russia has not indicated as to whether this was a one-off incident (a previous test in 2020 missed its target), as has been the case in the US, Chinese and Indian tests, or if it could be a part of a wide series of tests. If the latter, then international relationships are liable to be further strained.

NASA OIG: No Moon Landing Before 2026

Following NASA’s indication that the first Artemis lunar laying won’t come “earlier” that 2025, the agency’s own Office of Inspector General (OIG) has thrown a bucket of realism over the entire project, pretty much confirming comments made in this blog concerning vehicle development timelines, whilst also questioning the sustainability of the programme.

Having carried out an extensive audit of the programme, OIG has issued a 73-page report which critiques the current Artemis programme and time frames, although it can only offer suggestions on what might be done, not instigated changes.

Artemis 3 mission (1): the OIG report outlines the first mission to return 2 humans to the Moon – Artemis 3 – as designed by NASA / SpaceX. This uses the SpaceX Starship HLS – which will now be supported by a SpaceX “fuel depot” (a modified Starship hull) sitting in Earth orbit, and frequently refuelled by between 4 and 8 additional Starship vehicles – and the Orion MPCV for transporting a crew of 4 forth and back between Earth and the Moon. Credit: NASA / NASA OIG

It terms of the development of the Human Landing System (HLS), required to get crews to / from the surface of the Moon, the report follows what has been noted in Space Sunday: the 4-year development time frame is simply unrealistic. In particular, the report notes that even in partnerships such as the Commercial Crew Programme, NASA tends to require around 8.5 years to develop a new spaceflight capability – more than double that allocated for HLS (in fact, NASA / SpaceX believed Crew Dragon could be developed and ready for operation in 6 years – it took 10). It also indicates that while a reliance on a single vehicle design / contractors (currently SpaceX) reduces costs, it also places further risk on the entire programme time fame and operations.

Further, the OIG report states that realistically, the first flight of the first Space Launch System (SLS) rocket is unlikely to take place until mid-2022; somewhat later than NASA is still projecting (early 2022). It goes on to point of that given the delays on Artemis 1, it is unlikely that the Artemis 2 mission scheduled for 2023 and which will fly a crew around the Moon and back to Earth in a manner akin to Apollo 8 is unlikely to be ready until mid-2024, simply because NASA plan to re-use elements from the Artemis 1 Orion vehicle in the Artemis 2 Orion, and these will need a comprehensive post-flight examination and refurbishment.

Artemis 3 (2): The report shows the rendezvous with the HLS for the surface mission (2 crew), and leaps ahead to future missions and the establishment of the Lunar Gateway station. What is left unclear is whether the HLS vehicle will be reused (returning it to be refuelled) or simply abandoned (marking it as a waste). Credit: NASA / NASA OIG

Beyond this, the report also raises concerns whether the space suit required for lunar operations – the Exploration Extravehicular Mobility Unit (xEMU) – will actually be ready for operations in 2025, issues in technical development, and in NASA flip-flopping between in-house and commercial contract development of the suit being pointed to as reasons for the delays.

The biggest critique in the report, however, is related to costs. The OIG report notes that at current levels of expenditure, Artemis will cost US $93 billion by 2025/26, with the first four Artemis SLS / Orion launches (Artemis 1 through 4) alone costing US $4.1 each – and this estimate does not include the development of the actual HLS system or the costs to launch / operate it.

NASA OIG estimates the Space Launch system will cost US $4.1 billion per launch for the 1st four flights, with total Artemis development and infrastructure costs (excluding HLS) being some US $93 billion by 2026. Credit: NASA

To reduce these costs, OIG suggests looking to alternate launch vehicles  to deliver crews to lunar orbit, but NASA management has already rejected such ideas and had refuted OIG’s cost analysis and call for most closely accounting for expenditure. However, it has accepted the report’s other concerns; although it will take time to see if this translates into any form of re-assessment of the programme as a whole.

Continue reading “Space Sunday: Debris, Artemis delays, SpaceX Plans” →

Space Sunday: throwing things into space; NASA & SpaceX round-ups

Posted on by Inara Pey
A conceptual model of a SpinLaunch coastal launch facility with the vacuum accelerator exposed – the launch vehicle is located at the outer end of the black rotating arm. Credit: SpinLaunch

Up until now, the only means to get payload into space has been through chemical propulsion – rockets. And while they are not entirely efficient, they do work. However, if an American company gets its way, launching small payload into orbit could see the core part of their rocket replaced by a vacuum accelerator. Think of whirling an object around at speed on the end of a piece of string and then releasing it vertically, and you’ll get the picture.

The idea may sound bonkers, but it is precisely what US company SpinLaunch is planning to do.

They propose building a 100-metre diameter vacuum accelerator that, over the course of 90 minutes can accelerate an 11.2 tonne launch system up to a speed of Mach 5 before releasing it to travel along a launch tube and into the air. This velocity should be sufficient to propel the launch vehicle – comprising an aerodynamic aeroshell within which is placed a two-stage rocket carrying a 200 Kg payload.

The SpinLaunch payload vehicle, showing the outer dynamic shell, the two-stage rocket vehicle, and a pair of small satellites as the payload. Credit: SpinLaunch

On reaching a altitude matching that of a Falcon 9 first stage, the aeroshell would then split open, releasing the rocket to power itself and its payload on to orbit. Sound this work, it could reduce the cost of placing small payloads into space by around 80%, and allow for multiple launches from a single facility per day, if required.

To prove the idea works, SpinLaunch has constructed a one-third scale version of the accelerator, and on October 22nd, used it – operating at around 20% of rated output – to propel a 3-metre long ballistic projectile “tens of thousand of feet” into the atmosphere. According to SpinLaunch, the test was the first of 30 to take place over the next 6 months before they start work on construction on what they claim will be the first of a number of full-scale launch facilities at various points on the American coast.

That said, there are some significant technical challenges. Spinning at a maximum speed of 450 rpm, the system will subject the launcher and its payload to a peak dynamic load of 10,000 G; that’s a lot for the more sensitive part of the rocket motor to handle. More particularly, when it breaks the vacuum seal at the end of the launch tube, it will be travelling at Mach 5 – and slamming straight into the densest part of the atmosphere, again placing a massive load on it and its payload, as well as generating a lot of frictional heat as a result of its passage through the air. And that’s without considering the challenges in translating the spin of the accelerator into linear motion for the launch vehicle such that it can smoothly and successfully exit the launch tube, etc.

Even so, SpinLaunch appear to be carrying out the right amount of research – even if they are somewhat circumspect in addressing specific technical questions. As such, it will be interesting to see where things lead.

SpaceX Starship Update

With the public phase of the FAA’s Programmatic Environmental Assessment (PEA) of the Starbase facilities at Boca Chica now closed and the agency putting together its final version of the report, SpaceX has been moving ahead with site and vehicle development.

Most notably with the former has been work on erecting the framework of the new Wide Bay facility that could allow work to progress on up to four Super Heavy / Starship vehicles at a time, massively increasing the ability for the company to stack vehicles elements together. At the same time, in the current 2-vehicle High Bay, Booster 5 is nearing stack completion, and work has resumed on Starship 21.

The nose cone section of Starship 21, due to be the second orbit-capable test vehicle, is mounted onto the upper section of the vehicle. Note the thermal protection system already installed on both sections. Credit: BocaChicaGal / NASASpacelfight.com
Booster 5 includes significant differences to Booster 4, which is now sitting on a hard stand at the launch facilities as work continues on the launch platform there. Most notably, elements of the booster are emerging from the fabrication facilities in a completed state than was the case with Booster 4 – which even now, is still awaiting various elements of aerodynamic casing, etc., to protect various parts during its ascent and decent through the atmosphere. Similarly, Starship 21 is showing differences in construction to Starship 20, most notably in having sections fitted with their thermal protection blankets and tiles prior to being stacked together.

At the launch site, work has continued in getting the catching mechanism on the launch support tower properly rigged to the cable system and massive winches that will allow it to move up and down the tower for eventual stacking and catching operations. A short distance away, Booster 4 has started to receive the protective skirting around its base to keep the more sensitive parts of its ring of outer engines safe from the flames and heat of ignition, as well receiving the last of its 29 Raptor engines.

However, the biggest new in recent weeks came with the pre-burn and static fire test of all six Raptor motors on Starship 20. These came almost back-to-back on November 12th, with the pre-burn (a kind of clearing the rocket engines’ throats) coming first and lasting just under a second. Then, around an hour later came a 2-second firing of the vehicles’ 3 sea-level engines and the 3 vacuum rated engines.

As with the last static fire test (with just 3 motors), some of the vehicle’s thermal protection tiles were blown clear, with a good number coming off lower down the vehicle when compared to the 3-engine test. Although brief, the static fire gave a small taste of the amount of noise that will be generated when Booster 4 ignites all 29 of its motors and then sustains their thrust through an actual launch.

Whether or not this launch, which will hopefully carry Starship 20 aloft, will come before the end of the year still hangs in the balance, with a lot riding on the outcome of the FAA’s final version of their PEA.

NASA Updates

Hubble Partially Recovered

On October 25th, the Hubble Space Telescope (HST) entered a “safe” mode, shutting down all science operations, the result of “multiple losses of synchronisation messages” – messages designed to coordinate how the various science instruments on HST receive and transmit data to / from the telescope’s primary computer system. While of concern, and possibly a little more frequent than initially diagnosed, the issue left Hubble in good health and engineers confident science operations could be recovered.

During the week, further tests were carried out that gave NASA the confidence to return the Advanced Camera for Surveys (ACS) to operational status on November 7th. The coming week will see the completion of additional tests with the hope that the more sensitive instruments on the telescope can be returned to operational status.

Artemis 3 Moon Landing Now “No Earlier” Than 2025

In a move that should have surprised no-one interested in space exploration, NASA has pushed back their return to the Moon to at least 2025, citing four reasons: the disagreement with Blue Origin over the contract for the Human Landing System (HLS), delays due to COVID working restrictions in 2020, Congress “failing” to fund HLS development and the Trump Administration placing unrealistic time frames on the programme.

Of the four reasons, the last is perhaps the most accurate: you simply cannot lop 4 years off of a programme and expect it to succeed (simply so you can take the credit as theoretically still be in office), without a commensurate increase in budget to allow NASA to achieve the required goals in the reduced time frame. On the other hand, blaming Congress isn’t entirely honest. In 2019, NASA stated they need $5+ billion for HLS development – but only requested less than $2 billion – hoping they could take money from the infrastructure bill and put into HLS – which Congress refused to allow.

The Artemis 1 mission profile. Credit: NASA – click for full size

As it is, the “no earlier” statement is standard NASA parlance when they do not wish to commit to a specific data as yet, in this instance it is perhaps indicative that Artemis 3 could slip to 2026. A lot is riding on the Artemis 1 mission, which has already slipped to February 2022, being the first flight of the Space Launch System (SLS) rocket critical in getting crews to the Moon. Should this first (uncrewed) flight reveal issues with either SLS or the Orion crew vehicle, then it is likely to seriously impact the entire Artemis timeline.

Similarly, while Elon Musk claims SpaceX will be able to land a crewed Starship HLS vehicle on the Moon in 2023, his time-frames tend to be over-optimistic. Also, there are some major questions around the Starship HLS that have yet to be answered; plus SpaceX are working to NASA’s crew safety requirements, not their own, which can (rightly, given crew safety is at stake) cause additional overheads on a development programme.

Crew Dragon: 4 Down, 4 Up

After uncooperative weather mixed things up, and caused delays, SpaceX Crew Dragon Endeavour has returned to Earth, bringing with it NASA astronauts Shane Kimbrough and Megan McArthur, ESA astronaut Thomas Pesquet and JAXA astronaut Aki Hoshide, who were all just a few hours short of spending 200 days aboard the space station.

Departure and splashdown took place on November 8th, with only the late-opening of one of the 4 main parachutes preventing the return from being perfectly textbook.

A remarkable shot captured by the NASASpaceflight.com team showing Crew Dragon Endeavour forming a bright star as it flies through re-entry high above the SpaceX Starbase at Boca Chica. In the foreground is the launch support tower for Super Heavy / Starship. Credit: NASASpaceflight.com

The departure left a lone US astronaut on the ISS along with two Russian cosmonauts. Mark Vende Hei arrived on the station aboard Soyuz MS-18 in April 2021. In September he and cosmonaut Pyotr Dubrov, who also flew to the station on MS-18, had their stay on the station extended through until March 2022. This means that Vende Hei will take the record for the longest individual space flight by an American – 353 days.

However, on Thursday, November 11th, he was joined by NASA colleagues Raja Chari, Tom Marshburn, and Kayla Barron, who arrived at the ISS along with ESA astronaut Matthias Maurer aboard Crew Dragon Endurance as the Crew 3 mission. They had launched earlier on Thursday, November 11th (Late on Wednesday, November 10th, US time), marking the maiden flight of the third Crew Dragon vehicle to enter service. They will remain aboard the station for 6 months.

Further Push to Retire SOFIA

NASA’s Stratospheric Observatory for Infrared Astronomy (SOFIA), the 2.5 metre telescope flown aboard a converted 747 SP aircraft has been recommended for “termination” by the committee that originally prioritised it.

The astrophysics decadal survey committee, which originally pushed for the airborne observatory in both 1990 (when it was not funded) and 2000 (when it was, although technical issues meant it did not enter service until 2014), now believe it is not worth the annual US $85 million cost of operating it and a “lack” of “scientific productivity”.

SOFIA: the Stratospheric Observatory for Infrared Astronomy, a flying observatory, capable of flying high enough to put it above the majority of atmospheric interference – but again threatened with cancellation. Credit: NASA

The “lack of productivity” references the fact that in its first 6 years, SOFIA has only generated 178 scientific papers that were cited 1,242 times, far less than other, more specialised observatories like the Transiting Exoplanet Survey Satellite (TESS); however, supporters of SOFIA note that the figures ignore the fact that in the last 12 months there has been a 59% increase in SOFIA papers, and the observatory is gaining more use in a variety of roles.

NASA has twice tried to cancel SOFIA, but in 2020 Congress provided sufficient funding for operations to through 2021 and into 2022. Currently, the House has also provided funding for the observatory until the end of 2023, although the Senate has yet to make a determination on funding.

Blue Origin Space Tourist Killed

Glen de Vries, who flew with William Shatner, Chris Boshuizen and Audrey Powers, a Blue Origin vice president on the second passenger-carrying Blue Origin New Shepard sub-orbital flight, was one of two people on a Cessna 172 aircraft that crashed in New Jersey on November 11th.

Glen De Vries aboard New Shepard NS-18 capsule prior to launch

De Vries, a biomedical entrepreneur and self-described “space nerd”, paid an undisclosed sum for the flight, and had been giving talks and presentations on his experience since his return to Earth.

At the time of his death, he had been flying with Thomas Fischer from Essex County Airport in Caldwell, N.J. Both men were well-qualified pilots – Fischer also being a flight instructor – but it is not clear who was flying the aircraft. Emergency services were alerted after the pair failed to arrive at their destination, and the wreckage of the aircraft were subsequently found  in a heavily wooded area near Hampton Township, about 64 kilometres northwest of New York City. At the time of writing, the cause of the crash remains undetermined.

We are devastated to hear of the sudden passing of Glen de Vries.  He brought so much life and energy to the entire Blue Origin team and to his fellow crewmates. His passion for aviation, his charitable work, and his dedication to his craft will long be revered and admired.

Blue Origin statement on the death of Glen de Vries