Category: Space Sunday

China became the first nation to successfully return samples gathered from the Moon’s far side to the Earth on June 25th, when the capsule carrying those samples made a successful soft-landing on the plains of Inner Mongolia.

The capsule had been launched to the Moon on May 3rd as part of the Chang’e 6 mission (see: Space Sunday: Starliners and samples), which targeted an area within the South Pole-Aitken (SPA) basin, where both the United States and China plan to lead separate international projects to establish permanent bases on the Moon. The craft initially entered a distant lunar orbit on May 8th, taking around 12 hours to complete a single pass around the Moon. The orbital was then gradually lowered of a period of several days prior to the mission settling into a period of observation of the landing site from an altitude of just over 200 km, allowing mission planners on Earth the opportunity to further confirm the proposed area of landing was suitable for the lander.

Then, on May 30th, the lander vehicle with is cargo of sample-gathering tools, ascent vehicle with sample canister and mini-rover detached from the orbiter / return craft and gently eased into its own obit some 200 km above the Moon, from which it could make its final descent.

Landing occurred 22:06 UTC, the vehicle using its on-board autonomous landing system to avoid any land minute hazards and bring itself down to just a couple of metres above the lunar surface. At this point, the decent motors were shut off in order to avoid their exhausts containing the surface material from which samples would be obtained, and the lander dropped into a landing, the shock of impact at 22:23 UTC absorbed by cushioning systems in its landing legs.

The surface mission then proceeded relatively rapidly thereafter. The mini-rover, was deployed not long after landing. Described as a “camera platform” rather than a fully-fledged mini-rover like the Yutu vehicles China has previously operated on the Moon. Once deploy, the rover trundled away from the lander to take a series of images to help ensure it was fit for purpose post-landing. The rover was also able to observe the deployment of the lander’s robot arm with its sample-gathering system, and make remote measurements of surface conditions around the lander.

It’s not clear precisely when the samples were gathered, but at 23:38 UTC on June 3rd, the ascender vehicle with just under 2 kg of samples of both surface material and material cored by a drill from up to two metres below the surface, lifted-off from the back of the lander and successfully entered lunar orbit, rendezvousing and docking with the return vehicle at 06:48 UTC on June 6th. The transfer of the sample capsule to the return vehicle took place shortly thereafter, and the ascender was then jettisoned.

Throughout most of the rest of June, China remained largely quiet about the mission. However, based on orbital calculations and observations by amateurs, it appears likely the return vehicle fired its engines to break out of lunar orbit on June 21st, then fired them again to place itself into a trans-Earth injection (TEI) flight path, the vehicle closing on Earth on June 25th. As it did so, the 300 kg Earth Return unit separated and performed a non-ballistic “skip” re-entry.

This is a manoeuvre in which a spacecraft reduces the heating loads placed on it when entering the atmosphere by doing so twice; the fist manoeuvre see it skim just deep enough into the denser atmosphere to shed a good deal of its velocity before it rises back up again, cooling itself in sub-orbital ballistic cruise, at the end of which it drops back into the denser atmosphere for re-entry proper. Doing things in this way means that spacecraft returning from places like the Moon do not have to have hugely mass-intensive heat shields, making them more mass-efficient. For Chang’e 6, the skip was performed over the Atlantic, the ballistic cruise took place over northern Europe and Asia before it re-entered again over China and then dropped to parachute deployment height for a touchdown within the Siziwang Banner spacecraft landing area in Inner Mongolia, the traditional landing zone for Chinese missions returning from space.

Following recovery, the capsule was airlifted to the China Academy of Space Technology (CAST) in Beijing. Then, on June 27th during a live television broadcast, the capsule was opened and sample canister very carefully removed so it could be transferred to a secure and sterile facility for future opening. Afterwards, Chinese officials responsible for the mission gave an international press briefing in which scientists, agencies and research centres from around the world were invited to request samples of the 1.935 kg of material gathered by the probe, the invitation made along much the same lines as made following the rear of the Chang’e 5 samples in 2020.

What makes these samples particularly enticing to scientists is that they are far a part of the Moon very different in terms of morphology and geology to that of the lunar near side, from where all sample of material have thus far been gathered. As such, the Chang’e 6 samples are of significant interest not only because of what they might reveal about the region where humans will – in theory – one day be living and working, but also for what they might reveal about what is currently a genuinely unknown geology and morphology on  the Moon, as thus further reveal secrets about it’s formation.

However, one agency which may not directly benefit from China’s offer is NASA. The 2011 Wolf Amendment prohibits the US space agency and its research centres to use government funds or resources to engage in direct, bilateral cooperation with agencies of the government of the People’s Republic of China, or any affiliated organisations thereof, without the explicit authorisation from both the FBI and Congress. Such authorisation was not granted in the wake of the Chang’e 5 sample return mission, and so it seems unlikely it will be given for this mission, no matter what the scientific import of the samples.

That said, the Wolf amendment does not prevent non-NASA affiliated US scientists and organisations from being involved in studying samples from the mission. Following Chang’e 5, for example, US scientists joined with colleagues from the UK, Australia and Sweden in a consortium which obtained samples from that mission, allowing several US universities to be involved in studying them. This is something that could happen with regards to the Chang’e 6 samples, once they start being made available by China.

Russian Satellite Break-Up Prompt ISS Shelter In Place – Including Starliner

Despite efforts by NASA, much of the media incorrectly continues to present the idea that two NASA astronauts – Barry “Butch” Wilmore and Sunita “Suni” Williams are “stranded” on the International Space Station (ISS) due to issues with their Boeing CST-100 Starliner Calypso. However, as I noted in my previous Space Sunday article, this is simply not the case (see: Space Sunday: capsules, spaceplanes and missions). Yes, NASA is being cautious around the Starliner vehicle’s issues, but this does not mean the vehicle “cannot” return to Earth.

In fact, practical evidence of NASA’s confidence in the vehicle to make a safe return to Earth came on June 27th, when the entire crew of the ISS were ordered to prepare for s sudden evacuation of the station.

The emergency procedure – referred to as shelter in place – was triggered when the destruction of a decommissioned polar-orbiting Russia satellite was detected by debris-tracking organisation LeoLabs. Producing a cloud of around 180 trackable pieces of debris, the event was traced to the orbit of the 6.5 tonne Russian Resurs P1 spacecraft.

Orbiting at  some 470 km, the orbit of the satellite periodically intersected that of the ISS. As the explosion had caused a new orbital track for the resultant debris, it was necessary for the US Space Command to re-assess the passage of both the ISS and the growing debris cloud to ensure there would be no “conjunction” (that’s “collision” to you and me). As a precaution against this being the case, at 02:00 UTC, the entire Expedition crew were ordered into their spacesuit and then into their vehicles and power them up ready for a rapid departure, but not actually seal hatches and undock – and this included Williams and Wilmore on the Starliner.

While all this sounds dramatic, it is not; shelter in place has been the order on a number of occasions when there has been the risk of a collision with debris. Perhaps the most famous up until now came in 2021, after some idiot in the Kremlin ordered an unannounced test of an anti-satellite (A-SAT) missile, resulting in the destruction of another decommissioned Russian polar-orbiting satellite, this one causing a debris cloud of almost 2,000 trackable fragments at an orbital altitude close to that of the ISS.

As news broke of the June 27th event, there was some short-lived concern the same A-SAT foolishness had occurred with Resurs P1; however, this was quickly ruled out by the United States Space Command, as a review of data showed there was no evidence of any missile firing in the period ahead of the satellite disintegrating. After analysis of the debris cloud’s orbit and period aby both USSC and LeoLab, the New Zealand based debris tracking agency which initially reported the loss of Resurs P1, it was determined there was no threat to the ISS, and the crew were informed they could secure their spacecraft and return to the station after around an hour.

It is currently believed the destruction of the Russian satellite was due to it not undergoing “passivation” when it was decommissioned at the end of 2021. Whilst not mandatory or 100% effective, “passivation” has been common since the 1980s and involves the removal of any potentially energetic elements of a decommissioned satellite to reduce the risk of future break-up as a result of an explosion or similar. Typically, batteries are ejected so they will eventually burn-up in the atmosphere, whilst remaining propellants are vented into space.

Another of the first cadre of humans to visit the Moon and its vicinity was lost to us on June 7th, with the death of William Alison “Bill” Anders at the age of 90.

Born in 1933 in the (then) British Crown Colony of Hong Kong, Anders was the son of a US naval officer on deployment to Hong Kong and China, the family becoming embroiled in the Sino-Japanese War when it broke out in 1937. This forced Anders’ mother to flee Nanjing with her son and survive by wits alone to get them both back to the United States, where they were reunited with Anders’ father, who had been wounded and subsequently rescued by British forces after the Japanese dive-bombed his patrol vessel out from underneath him.

Initially opting to follow his father into the Navy, Anders studied at the US Naval Academy at Annapolis, gaining a degree in electrical engineering. However, enamoured with flying, on graduation he opted to take a commission into the US Air Force and became a fighter pilot. After a series of non-combat operational tours, he sought to become a test pilot – which required he have an MSc. Initially studying aeronautical engineering, he switched to nuclear engineering, gaining his MSc in 1962. However, at that time NASA was recruiting its third astronaut intake and applied and was accepted.

In late 1966, Anders was assigned to the crew of Apollo 9, alongside Frank Borman and Michael Collins. Together, they would carry out the second Earth-orbiting, crewed check-out of the Apollo Lunar Module (LM), following-on from the Apollo 8 mission crewed by James McDivitt, David Scott and Russell “Rusty” Schweickart. However, by mid-1968, and with both flights due before the end of that year, the LM was not fit for supporting astronauts in space. Fearing the Russians were about to fly a crew around the Moon, NASA decided to switch gear: Apollo 8 would become a cislunar mission, flying with just the Apollo Command and Service Modules (CSM), and Apollo 9 would then complete 1 Earth-orbit crewed test of the LM.

Only McDivitt and his crew didn’t want to go around the Moon, feeling their expertise was better suited to the LM test flight. So instead, the crews were swapped – Borman and Anders, now joined by James “Jim” Lovell, Michael Collins having suffered a back injury requiring surgery – became the Moon-orbiting Apollo 8 crew, and McDivitt’s mission was re-designated Apollo 9, to fly in early 1969.

Thus, on December 21st, 1968, Apollo 8 lifted-off for the Moon, racking up a number of firsts along the way: the first crewed flight of the Saturn V rocket, the first crewed spacecraft to leave Earth’s gravitational sphere of influence; the first crewed  spaceflight to reach the Moon; the first crew to broadcast to Earth from lunar orbit – and most famously of all – the first humans to ever witness Earthrise, with Anders capturing what is now regarded as “the most influential environmental photograph ever taken”.

The picture was captured on Christmas Eve 1968, as Anders was using a 70mm Hasselblad camera loaded with a black-and-white film cartridge to image the lunar surface when he happened to look up through the Command Module’s window and see Earth starting to come into view over the Moon’s limb. Calling to Lovell for a colour film cartridge, he quickly re-loaded his camera with it and then took the iconic shot we all now know as Earthrise.

In doing so, he was actually the second human to photograph the Earth rising over the Moon’s limb; the honour of being the first actually goes to Frank Borman – only his camera was also only loaded with black-and-white film. Thus Anders is the first human to capture the sight in the colour image which has come to represent the beauty, loneliness and fragility of the world we call.

If you can imagine yourself in a darkened room with only one clearly visible object, a small blue-green sphere about the size of a Christmas-tree ornament, then you can begin to grasp what the Earth looks like from space. I think that all of us subconsciously think that the Earth is flat … Let me assure you that, rather than a massive giant, it should be thought of as the fragile Christmas-tree ball which we should handle with considerable care.

– Bill Anders describing how he felt when seeing the Earth appearing from behind the limb of the Moon

Bill Anders would only make that one flight in space. In May 1969 he was appointed to the influential position of executive secretary of the National Aeronautics and Space Council (NASC), where he did significant work in developing US space policy. In 1973 he was appointed to one of the five leadership slots of the US Atomic Energy Commission (AEC), transferring to chair the Nuclear Regulatory Commission (NRC) when that was formed in 1975.In mid-1976 he was appointed (at his request) as the US Ambassador to Norway, prior to moving to the private sector and the start of a highly successful career in business in 1977, finally retiring in 1994.

Passionate about flying, Anders, together with his wife Valerie and two of his sons – Alan and Greg – founded the Heritage Flight Museum in 1996, regularly flying the museum’s pistoned-engined aircraft and air shows around the United States. He also owned and operated a T34 Mentor training aircraft, and on June 7th, 2024, he took to the air in this aircraft to fly circuits over Puget Sound, Washington State, where he lived. During this flight it appears – via eye witness video – he attempted a low-altitude loop in a channel between two islands, but the aircraft failed to pull up in time, slamming into the water and breaking up, likely killing Anders instantly. The accident is now under investigation by the US National Transportation Safety Board (NTSB).

Anders is survived by his wife of 67 years, Valerie, and their six children.

Starliner Launches; Issues Persist

Boeing’s much-troubled CST-100 Starliner finally lifted-off on its first crewed test flight at 14:52 UTC on Wednesday, June 5th, finally sending astronauts Barry “Butch” Wilmore and Sunita “Suni” Williams on their way to the International Space Station (ISS) in a flight intended to help clear the Starliner capsule for use in ferrying up to four crew at a time to the ISS, and in an emergency (and depending on available seating), returning up to 7 to Earth.

As I’ve reported in past Space Sundays, the Crew Flight Test of the vehicle has been plagued by problems – many with Starliner itself, but also extending to launch systems on the ground and systems within its launch vehicle, the Atlas-Centaur V-N22. However, the launch on June 5th was flawless, and marked both the first time in history that humans have flown atop the veritable Atlas V, which is more usually employed for cargo carrying launches, and the first time since Apollo 7 in 1967 that a crewed vehicle has lifted-off from facilities at Cape Canaveral Space Force station (then called the Cape Kennedy Air Force Station).

Fifteen minutes after launch the Starliner separated from the Centaur upper stage, entering a sub-orbital trajectory around the Earth, allowing for a preliminary vehicle check-out and a rapid return to Earth in the event of issues. With the crew and ground personnel satisfied all was well, Wilmore and Williams used the vehicle’s propulsion system to increase its altitude and velocity, enabling it to enter orbit 31 minutes after lift-off.

The rest of June 5th saw the crew carry out a series of tests with the vehicle as it climbed towards the ISS, putting it through various manoeuvres and testing communications and other systems. During this time further helium leaks were detected in the vehicle’s thruster system – a known leak having been the cause of one of the delays to the mission’s launch – and 6 of the vehicle’s 28 thrusters were shut down. This did not impact vehicle performance, but the fact that four further helium leaks were detected on top of the known leak indicates there may be a systematic issue within the design of the propulsion system.

Further issues occurred during the vehicle’s approach to the ISS on June 6th, when five of the reaction control system (RCS) thrusters were automatically deactivated, forcing the actual docking to be delayed, Starliner held in a station-keeping position by Wilmore and Williams some 200 metres from the station whilst a team on the ground recovered four of the recalcitrant thrusters, enabling the vehicle to dock with the Harmony module on the station. Hatches between vehicle and station being opened 2 hours after docking, to allow for further post-flight checks on the dock seal within the vehicle and for Williams and Wilmore to change out of their pressure suits.

The vehicle will remain docked at the ISS for several more days prior to departure with Wilmore and Williams for a return to Earth and a soft landing in New Mexico on June 14th.

Continue reading “Space Sunday: Bill Anders; Starliner & Starship” →

Curiosity, NASA’s Mars Science Laboratory (MSL) rover, arrived on Mars in 2012 – and helped kick-off Space Sunday in this blog. Since then, the mission has been a resounding success; even now the rover continues climbing the flank of “Mount Sharp” (officially designated Aeolis Mons), the 5km high mound of sedimentary and other material towards the centre of Gale Crater where it landed, revealing more and more of the planet’s secrets.

However, there has been one long-running mystery about Curiosity’s findings as it has traversed Gale Crater and climbed “Mount Sharp”. As it has been exploring, the rover has at times been sensing methane in the immediate atmosphere around it. Methane can be produced by both organic (life-related) and inorganic means – so understanding its origins is an important area of study. Unfortunately, Curiosity is ill-equipped to easily detect and investigate potential sources of the gas; that’s more a job for its sibling, Perseverance. As such, the overall cause of the methane Curiosity has detected remains a mystery.

And it is a mystery compounded in several ways. For example: the methane often only seems to “come out” at night; the amount being detected seems to fluctuate with the seasons, suggesting it might be linked to the local environmental changes; but then, and for no apparent reason, Curiosity can sometimes sniff it in concentrations up to 40 times greater than it had a short time before – or after. A further mystery is that whilst Curiosity detects methane in the atmosphere around it, it is the only vehicle on Mars to thus far do so to any significant extent.

Further, the European Space Agency’s (ESA) ExoMars Trace Gas Orbiter (TGO), a vehicle specifically designed to sniff out trace gases like methane throughout the Martian atmosphere has, since 2018 when it started operations, almost totally failed to do so. All of which suggests that whatever Curiosity is encountering is unique to the environment of Gale Crater – and possibly to “Mount Sharp” itself.

Given this, scientists have been trying to determine the source of methane, but so far, they haven’t come up with a specific answer. However, current thinking is that it has something to do with subsurface geological processes involving water – with one avenue of research suggesting that it is curiosity itself that is in part responsible for its release, particularly when it comes to the sudden bursts of methane it detects.

A recent study by planetary scientist at NASA’s Goddard Space Flight Centre has demonstrated that any methane within Gale Crater, whether produced by organic or inorganic means, might actually be following the path outlined in the diagram above – but is getting trapped within the regolith by salt deposits before it can ever be outgassed. However, this was not the original intent of the study, which first started in 2017.

At that time, a team of researchers at NASA’s Goddard Research Centre led by Alexander Pavlov, were investigating whether or not bacteria could survive in an analogue of the kind of regolith Curiosity has encountered across Gale Crater and within environmental conditions the rover has recorded. Their results were inclusive in terms of organic survivability, but they did find that the processes thought to be at work within Gale Crater could lead to the formation of solidified salty lumps within their analogue of Martian regolith.

And there the matter might have rested, but for a report Pavlov read in 2019, as he noted in discussing the results of his team’s more recent work.

We didn’t think much of it at the moment. But then MSL Curiosity detected unexplained bursts of methane on Mars in 2019. That’s when it clicked in my mind. We began testing conditions that could form the hardened salt seals and then break them open to see what might happen.

– Alexander Pavlov, Planetary Scientist, NASA Goddard Research Centre

As a result, Pavlov and his team went back to their work, looking at the nature of the sedimentary layers of “Mount Sharp”, the amount of water ice they might contain, etc., and started testing more regolith analogues to see what might happen with different concentrations of perchlorates within the water ice. Starting with around a 10% suspension (much hight than has ever been found on Mars), the team gradually worked down to under 5% (closer to Curiosity’s findings, but still admittedly high). In all cases, they found that not only did the perchlorates leach out of the escaping water vapour as it passed through the reoglith analogue to form frozen lumps, it tended to do so at a fairly uniform depth the lumps combining over time  – an average of 10 days – to form what is called a “duricrust” layer.

Duricrusts are extensive (in terms of the area they might cover) layers of frozen minerals trapped within the Martian regolith. They were first noted in detail during the NASA InSight lander mission (operational on the surface of Mars between November 2018 and December 2022), significantly impacting the effectiveness of the lander’s HP3 science instrument, which included a tethered “mole” designed to burrow down into the Martian regolith. However, the “mole” kept encountering duricrust layers which, as it broke through, would surround its pencil-like body with a cushion of very loose, fine material which completely absorbed the spring-loaded action of its burrowing mechanism, preventing it from driving itself forward.

In their tests, Pavlov and his team found that the perchlorate duricrust formed in their tests would not only spread across a sample container, it was very effective in trapping neon gas (their methane analogue). Further, when the samples were exposed to the kind of natural expansion and contraction regolith on Mars would experience during a day / night cycle, they found the gas could indeed escape through cracks in the duricrust into the chamber’s atmosphere and be detected – just as with the methane around Curiosity. They also found that if a sample were subject to a pressure analogous to that of the wheel of a 1-tonne rover passing over it, it could be crushed and allow a sudden concentrated venting of any gas under it – again in the manner Curiosity has sometimes encountered.

Whether or not this is what is happening in Gale Crater, however, is open to question – as Pavlov notes. Firm conclusions cannot be drawn from his team’s work simply because scientist have no idea how much methane might actually be trapped within Gale Crater’s regolith, or whether it is being renewed by some source. As already noted, Curiosity is ill-quipped to study methane concentrations in the regolith and rock samples it gathers, because when the one instrument which could do so – the Sample Analysis at Mars (SAM) instrument – was designed, it was believed any methane trapped within Mars would be so deep as to be beyond the rover’s reach, and it thus wasn’t considered as something that would require analysis. While SAM can be configured for the work, it takes considerable time and effort to do so – and that is time and effort taken away from its primary science work, which is more-or-less constant as it handles both rock and atmospheric samples gathered by the rover.

Even so, the Goddard work is compelling for a number of reasons; it points to the fact that howsoever any methane within Gale Crater might be produced (organically or minerally), there is a good chance it is becoming mostly trapped within the regolith, and possibly in concentrated pockets. If this can be shown to be the case, and if these pockets could be localised and reached by a future mission, they might some day give up the secret to their formation – including the potential they are the result of colonies of tiny Martian microbes munching and farting (so so speak!).

Continue reading “Space Sunday(ish!): Mars methane mysteries” →