The Week in Space and Physics: Starliner's Humiliation
On the failure of Starliner, JUICE, Mars' underground ocean and the most ambitious private spaceflight ever attempted.
On Saturday NASA made a humiliating admission. The two astronauts they sent to the space station on Starliner, Boeing’s crew capsule, will not be returning on the same spacecraft. They will instead wait for six more months at the station, after which SpaceX’s Dragon capsule will bring them back to Earth.
The decision is an embarrassment for NASA, which must now face questions about how Starliner was ever cleared to carry astronauts to the station and why it took so long to acknowledge the spacecraft wasn’t safe for them to return on. For Boeing it is a humiliation. The company, which once saw itself as the professional and reliable alternative to a fast-moving and reckless SpaceX, now seems incapable of building safe spacecraft.
The story of Starliner began with a NASA effort to ensure American access to orbit. Back in 2011, as the space shuttle retired, America faced the question of how to get its astronauts to the space station it had spent billions building. For a decade the answer lay in Russia: NASA was forced to buy seats on the Soyuz under an expensive and geopolitically awkward deal.
To remedy that, NASA turned to America’s aerospace industry. Two companies, Boeing and SpaceX, were selected to build capsules capable of bringing astronauts to the station. SpaceX delivered in 2020, and has been reliably sending crew and supplies ever since.
Boeing, by contrast, suffered a series of disastrous flights. The first test flight of Starliner, at the end of 2019, ran into critical errors soon after reaching orbit. Instead of approaching the space station, Starliner instead returned to Earth early. It was a humiliating flight, and it was clear - despite some contrary murmurings from NASA - that another test flight would be needed before astronauts could fly.
That test came in 2022, and seems to have mostly gone to plan. But a crewed flight was then delayed for years, after problems were found with wiring in the capsule and with its parachutes. Even when it finally came, liftoff was delayed for weeks as engineers struggled with leaks in Starliner’s propulsion system.
The problems that doomed Starliner, however, emerged as the capsule approached the space station. Several of its thrusters failed, forcing Starliner to wait for hours before it was able to dock with the station. The problems with those thrusters - which engineers have now traced to teflon seals - are too serious to allow astronauts to return to Earth.
Starliner should now attempt an automatic return and reentry, without any crew onboard. But the questions will, and should, remain even if it does return safely. The Starliner program is likely to continue - if only because NASA is determined to have an alternative to Dragon. But faith in Boeing has been badly damaged, and their ability to ever restore trust in Starliner is in severe doubt.
Questions should also be asked of NASA. Their efforts to foster commercial spaceflight have paid off, but only in the shape of SpaceX. Other commercial projects, from moon landers to future space stations, have so far had mixed results. Whether the agency is really capable of the ambitious future it has planned, including the Artemis moon landings and a successor to the International Space Station, now looks like a good question to ask.
JUICE Returns
In the strange world of orbital mechanics, the straightest path is not always the best. To get from Earth to Jupiter, for example, the simplest route is a “Hohmann Transfer”, under which a spacecraft fires its engines, raises the high point of its orbit to match the orbit of Jupiter, and then spends about three years voyaging through space to reach the giant planet.
Simple, perhaps, but not always efficient. Getting to Jupiter in this way means adding a lot of speed to a spacecraft, and that means carrying a lot of fuel. The more fuel a spacecraft carries, the heavier it is, and so the less mass is available for useful things like scientific instruments.
Instead, then, mission planners look for other ways to reach the outer solar system. Instead of flying directly to Jupiter, a probe might first head inwards towards Venus. That doesn’t take much fuel, and Venus, as planets go, is relatively close. Get the timing right, and the encounter with Venus can fling the probe back towards Earth. That, thanks to a manoeuvre known as a “gravity assist” can speed a spacecraft up for free, boosting its velocity towards the gas giants at the cost of spending a few years bouncing around the inner solar system.
So it was, then, that Europe’s Jupiter-bound probe JUICE recently found itself heading back to Earth. Sixteen months after it launched, JUICE last week swung past the Moon, making use of a gravity assist to push it towards Venus. Over the next few years JUICE will fly past Venus, back to the Earth, then back to the Earth again, after which it will finally have the speed to reach Jupiter around the end of the decade.
A second Jupiter probe, Europa Clipper, will follow a slightly different path when it launches later this year. Clipper will first head out to Mars, which it should reach next year, before coming back to Earth at the end of 2026. That sequence will give it enough speed to reach Jupiter by 2030.
The pair of probes promise to reveal much about Jupiter and its moons after they arrive. Speculation has arisen over those moons in recent years, and about whether liquid oceans might exist under their icy surfaces. If life exists anywhere else in the solar system, researchers now say, Jupiter’s moons might be where we find it.
An Ocean Under Mars
Long ago Mars was a wet planet. How wet is debatable: some think an ocean stretched across its northern surface, others think the water was limited to scattered seas and rivers. Nevertheless, the evidence is clear. Water once flowed across the Martian landscape, until, about three billion years ago, it vanished.
Where did it all go? The obvious, and long held, answer argues it was lost to space, stripped away as the Martian atmosphere eroded. But losing an ocean’s worth of water in this way is hard, and so researchers think some, or perhaps most, of that ancient water must still be on Mars somewhere.
A small amount lingers in Mars’ polar ice caps. But the rest must be in the interior of the planet. Some might therefore be found in Martian rocks, which could have soaked up and then locked away a lot of water. Without the active geological cycle found on Earth - which pulls rocks down into the mantle and then recycles them in volcanic eruptions - that process may have slowly killed the Martian water cycle.
New evidence now hints at another possibility. Data from NASA’s Insight lander, which monitored “marsquakes” echoing through the planet between 2018 and 2022, shows a layer of water lying several miles under the Martian surface. This water - enough to fill an ocean - is trapped amidst fractured volcanic rock.
That, then, could explain what happened to Mars’ lost oceans. And - more excitingly - it hints that if Martian life ever got started, it could linger on deep under the surface. We know, after all, that life can thrive in deep underground lakes on Earth. There is no reason it could not do the same on Mars.
Polaris Readies For Launch
Over the weekend SpaceX prepared for the launch of Polaris Dawn, the most ambitious private spaceflight yet attempted. SpaceX will launch a crew of four astronauts to an orbit fourteen hundred kilometres high. That will be the furthest point any human has travelled to since the days of Apollo.
Once in orbit the crew will step out of their Dragon capsule, and attempt to complete the first private spacewalk. This, undoubtedly, carries an element of risk. Spacewalks are inherently dangerous, exposing astronauts almost directly to the vacuum of space. Even worse, the Dragon capsule will be fully depressurised to allow the spacewalk, so all four crew members will need to don spacesuits during the exercise.
Assuming all goes well, the flight will be followed by a second Polaris mission in the coming years. Few details about the mission have been released: one mooted idea was to visit the Hubble Space Telescope, but NASA deemed the idea too risky. The third Polaris flight, also undated, will take place on SpaceX’s Starship. It will thus be one of the first crewed flights of that game-changing rocket.
Very cool how the probe heading to Jupiter is slingshotting the inner solar system for a for years. Loved the discussions, thanks!
Everybody at Boeing involved with that fiasco should be extensively interviewed and some kind of "lessons learned" product published and be made required reading for both managers and engineers.
JUICE and Clipper are both exciting but we'll just have to be patient. At my advanced age, not easy.
Mars deep ocean is an exciting speculation. But at two miles down, will be directly inaccessible to us for, at minimum, the remainder of this decade. More patience called for.
The private EVA is a very bad idea for a number of engineering reasons. Don't do it folks!