Two more of the disappointments and delays which I listed in ‘Space Notes’ in October have now been resolved. One is the return of NASA’s Crew-8 from the International Space Station. Crew-9 had been reduced to two astronauts instead of four, in order to bring back the crew of the Boeing Starliner, which returned to Earth unmanned for safety reasons. The rearrangements which that required, and a temporary block on the Falcon 9 boosters which carry the Crew Dragon spacecraft, brought the October return date too close to Hurricane Milton and it finally happened on 25th October, in darkness like most of the recent landings (Fig. 1), but in calm seas in the Gulf of Mexico (Fig. 2).
As soon as the crew disembarked, however, it was announced that one of them had been taken ill (Fig. 3) and flown ashore to the Ascension Sacred Heart Hospital in Pensacola, causing momentary confusion with the British Ascension Island in the Atlantic, where NASA has maintained a tracking station since before Project Apollo (Fig. 4). That might have meant that the case was serious enough for total isolation, as happens in Martin McInnes’s novel In Ascension (Atlantic Books, 2023), but would have been a false alarm. There were conflicting reports that one, two or three astronauts had been affected, but it turns out that all four were flown to Pensacola as a precaution, three were released and flew on to Houston, one was kept overnight for observation (NASA declines to say which one) and then was released to follow them.
Crew 9 is now fully settled in on the ISS and getting on with the experiment schedule, and is already being described in the media as ‘stranded’ although their Crew Dragon is firmly attached to the ISS and should bring them back with the Starliner astronauts in February.
It’s just possible that they might have to come back sooner, because NASA is looking at evacuation if a problem of leaks on the ISS gets seriously worse. Hitherto the Russian Soyuz has been the designated escape vehicle (Fig. 5), but now that Crew Dragons are attached to the station at all times, for US astronauts it’s the preferred option (Fig. 6). A transfer tunnel attached to one of the oldest parts of the station, the Russian Service Module, has been leaking air since 2020, and it’s getting worse although more than 50 seals have been applied. The problem is that these aren’t punctures, which would be easy to patch, but microscopic cracks which are propagating in the aluminium hull. The problem is at least partly due to flexing of the complicated structure (Fig. 7), as spacecraft dock and undock with it, and use their motors to raise the station’s orbit, and as the astronauts and cargo move around inside. The possible problem was foreseen as far back as the 1970s, and there were strong recommendations that space stations should have large core modules (modified Space Shuttle External Tanks would have been ideal), and dockings should be axial rather than radial to reduce transverse stresses. Although the Russian design which was adopted is more robust than the original US proposals, the problem has finally caught up with it, and the only wonder is that it has taken 24 years to do so. How long fixing it will take, if it can be when the station has just 6 remaining years of life, we must wait to find out.
There’s mixed news about the commercial space stations which are to replace it, supposedly. In ‘Axiom Attic and Orbital Reef’ (ON, 11th February 2024), I described the stations planned by Axiom Space, Blue Origin, and Voyager Space, all under contract with NASA to produce commercial stations, with Axiom looking most promising, although the first proposal under contract was with VAST Space, the only one which had yet to produce detailed designs. That was remedied at October’s International Astronautical Congress, when VAST revealed the design of a first orbital module, HAVEN-1, intended to be launched next year, and to be followed in 2028 by a 4-module HAVEN-2 design (Figs. 8 & 9), and later expanded into a cross shape (Fig. 10). As Axiom is said to have major financial problems, VAST Space may take the lead, as SpaceX has in the crew transfer stakes.
China has already achieved a successful cross-shaped space station, Tiangong-2 (Fig. 11), without the elaborate truss structure which holds the ISS together (Figs. 7 & 12), and is planning to expand it.
The Shenzhou-19 flight to it lifted off on October 19th to great celebration at the Jiuquan Satellite Launch Center (Fig. 13), carrying the youngest taikonauts to date, and they have joined the Shenzhou-18 crew in orbit before the latter returns to Earth (Fig. 14).
China has definitely learned from Western experience in one respect: Tiangong-2 will be joined in orbit by a Space Telescope, as large as the Hubble one but with a much wider field of view (Fig. 15).
At the insistence of the scientific community, the HST was placed in an orbit far from the ISS to avoid any contamination of its optics. Five servicing missions to it were conducted by the Space Shuttle in circumstances which came to seem increasingly dangerous, especially after the loss of the Columbia, because in a situation like that the Orbiter would not have enough fuel to rendezvous with the Space Station. NASA cancelled the fifth servicing mission for that reason, but under pressure from the scientific community, was forced to reinstate it, which meant that a second Shuttle had to be prepped for a rescue mission if need be (Fig. 16). China has decided on a robust solution to the issue: their telescope will be alongside their space station, and if it needs repair or refurbishment, the taikonauts will reel it in and do the work in situ.
More details have been revealed about the successful capture of the SpaceX Superheavy booster on October 13th (Fig. 17). There has been much repetition in the media of a senior engineer’s statement that the event came ‘within one second of failure’. But as another engineer pointed out, had it failed, we’d be saying that it came within one second of success. It’s emerged that several struts strengthening the booster popped off in the final moments, but at that stage the booster is basically a big, very lightweight empty tin can, and flexing under stress is to be expected. However, at least one of the struts was protecting essential electronic components which were left exposed. They continued to work perfectly, but Elon Musk won’t want that happening again.
No date has yet been announced for the sixth mission of the Starship/Superheavy combination, but the Starship for it had already had its static fire test on July 26th (see ‘Space Notes, ON, 4th August 2024), and the Superheavy was rolled out on October 22nd (Fig. 18), followed by an immediate static firing on October 24th (Fig. 19). In theory, the Federal Aviation Authority’s clearance for IFT-5 also covers IFT-6, but only if no changes are made to the flight plan. Elon Musk has already hinted he wants to capture the Starship next rather than splash it down at sea (Fig. 20), so it’s to be hoped that another SpaceX/FAA battle isn’t about to slow things up. Elon Musk has now said that he intends to launch two unmanned Starships to Mars two years from now, and two to four crewed missions at the next close opposition with Mars, two years after that, so there’s no time to waste.
A story which was just too late for inclusion in ‘The Sky Above You’ for November (ON, November 1st 2024), is that the Perseverance rover is now half-way up the slope leading to the inner rim of Jezero crater, which it’s intended to reach in December. The dust storm which recently obscured the view back into the crater (see ‘The Sky Above You’, ON, October 2024) has now cleared, and on September 27th Perseverance took a panorama of the crater floor from above (Fig. 21), the right half of which showed all the sites visited there (Fig. 22).
The ascent is proving difficult, with multiple slips and skids (Fig. 23), and one of the team controlling it has previous experience with the Curiosity rover in similar circumstances on the central peak of Gale crater. Various techniques have been tried with Perseverance, including driving it backwards (memories of Ice Cold in Alex, as I’ve mentioned before), but best results seem to be on slightly firmer ground near the rim of the ridge. A video tracing Perseverance’s entire journey since 2021 heads Mike Wall’s report, ‘NASA’s Perseverance rover gets stunning view of big Mars crater from slippery slope (video, photos)’, Space.com, online, 29th October 2024. Meanwhile, also at the 2024 International Astronautical Congress, China has announced plans for its Mars sample return mission, consisting of two spacecraft to be launched by Long March 5 boosters, and simply returning a sample from the landing site (Fig. 24), rather than driving around collecting a range of them, as Perseverance is doing at present – very successfully, but the cost and timescale for the return mission are looking prohibitive.
There’s another piece of good news from the Hera mission, now on its way to the asteroids Didymos and Dimorphos. On arrival there Hera will make a flyby through the double asteroid system, for an overall view of the consequences of the 2022 DART mission impact. Hera’s path will be chosen to minimise the risk of being hit by debris, and two cubesats will be deployed for closer views and attempted landings. Both have now been activated in ‘flight storage mode’ and are in good shape for the rest of the mission.
And finally: the other launch originally planned for October 10th was the return to flight of the Blue Origin New Shepard vehicle, after extensive modifications to both booster and capsule. The launch in New Mexico was far from the coastal regions affected by the hurricane, and the delay was due to a late problem with the rocket. That was resolved and the flight took place successfully on October 23rd (Fig. 25). The first flight of the modified vehicle was unmanned, carrying research payloads for NASA, but Jeff Bezos intends to resume tourist flights to the edge of space by the end of the year. Meanwhile his BE-4 engine has successfully powered two launches of the United Launch Alliance’s Vulcan booster, and his own New Glenn booster is coming up for its first launch on the same engine, taking Blue Origin to a new phase in which it has very ambitious plans, including hopes to provide the Lunar Lander for the US return to the Moon, though the first such mission is supposed to be on a SpaceX Starship. Both companies have a lot to play for.