The Week in Space and Physics: Back to the Moon
The Week in Space and Physics: Back to the Moon
On Artemis, the Space Launch System, Starship and the next Moon landing
This time, they say, they are going to stay.
When Artemis I roared to life last Wednesday, it did so almost two decades after President George W Bush called for a return to the Moon; and five long decades after the last manned voyage to that barren world.
Bush’s speech, in 2004, charted a new course for NASA. The agency, still reeling from the Columbia disaster, was sorely in need of that vision. Its flagship, the Space Shuttle, was soon to be retired. The International Space Station – still merely half completed – already appeared as something of a dead end. The agency was, as some put it, floundering without a clear purpose.
Two decades on, NASA’s goal – despite many twists and turns along the way – remains firmly fixed on the Moon. It will get there much as Bush had imagined: with an enormously powerful rocket, a direct descent to the surface, and a short foray by the astronauts. That, of course, is how NASA did it last time, when the Apollo astronauts briefly visited the Moon in the 1960s and 70s.
The first few Artemis missions, it is true, will achieve little new. Artemis II, a mission planned for 2024, will replicate the flight of Apollo 8. Artemis III – which will see astronauts walk on the Moon – differs little from Apollo 11 or the missions that followed. But after, if NASA can sustain its course and funding, Artemis will finally begin to break new ground.
Key to NASA’s plans is the Lunar Gateway, a small space station that will soon be built in orbit around the Moon. Artemis IV, and many of the subsequent missions, will use this station to host astronauts for weeks at a time. Humans could then spend extended periods on the Moon, building up infrastructure and carrying out experiments.
That would go far further than Apollo ever did – and, hopefully, avoid a repeat of the extended absence that followed the last moon mission in 1972. Yet it is also worth remembering that NASA was equally ambitious in the 1960s. Wernher von Braun, the architect of the Apollo program, then sketched out plans for humans to build a base on the Moon, to fly past Venus and to explore Mars.
Things, sadly, didn’t work out that way. Von Braun would surely have been disappointed to see, half a century later, that humanity is only slowly retracting the path he boldly outlined. His half-mad visions of flights to Venus would never be seriously contemplated today. Mars, his ultimate goal, remains as distant as ever: a dream relegated to far future decades.
Still, the launch of Artemis I last week represents a chance to change things. It may well mark the beginning of a new era of space exploration: opening a slower but more sustainable expansion of human presence beyond the Earth. Let’s hope NASA, and its funders, mean it when they say this time they plan to stay.
The Space Launch System: More Than a White Elephant?
After two failed efforts and two hurricanes, the successful launch of NASA’s Space Launch System came as a welcome relief. The flight was magnificent, soaring into the sky on a flame of burning orange; placing the uncrewed Orion capsule first in orbit around the Earth and then on a perfect trajectory towards the Moon.
As designed, the Space Launch System now gives NASA a rocket capable of reaching deep in space. It will, probably, send humans to the Moon; but it may also send them to Mars, or even further. It could allow NASA to build a lunar space station and to propel robotic probes to Jupiter, to Neptune, or even to the outer fringes of the Solar System.
All that is welcome. But it is also questionable whether the rocket is capable of delivering the kind of long term and sustainable space program NASA truly needs. In its current form, the SLS is enormously expensive: each flight costs roughly four billion dollars. Even worse, manufacturing constraints limit its production. NASA can probably manage just one launch a year, at best.
If NASA relies on the SLS alone, then, the ambition of future plans will surely be limited. Certainly, it will not be possible to sustain a permanent human presence on the Moon or Mars with just one flight per year: America will instead be forced to stick to short duration trips, each of which will consume a significant proportion of its budget for space exploration. That is no way to run a human space flight program.
Fortunately there are other options. SpaceX’s Falcon Heavy, a rocket surpassed in power only by the SLS, can fly far more regularly and at lower cost. It could conceivably take over much of the work of the Artemis program, helping NASA build a station around the Moon and place infrastructure on its surface. It can also send probes to the outer Solar System – though on slightly slower trajectories – and can send tonnes of cargo to Mars.
A better plan for Artemis, then, would see much greater use of the Falcon Heavy. The SLS may stick around as NASA’s flagship, reserved for high profile missions. But for the rest, NASA and Congress should swallow their pride and turn to SpaceX.
Starship: Both Rival and Ally
No mention of SpaceX, of course, can be complete without mentioning Starship. This spacecraft – larger even than the Apollo-era Saturn V – may one day carry crews of private astronauts to Mars; helping to establish the first settlements on the Red Planet.
In this sense Starship is often mentioned as a rival to the Space Launch System. It could – if what Musk claims is anywhere close to accurate – fly far more often and at a far lower price. That, if true, would render the SLS all but obsolete: a rocket outclassed by its flashier commercial rival.
It is somewhat ironic, then, that NASA has made Starship an integral part of the Artemis project. While the SLS rocket and Orion capsule can carry astronauts to the Moon, they cannot land them there. Instead, as NASA envisions it, astronauts heading to the Moon will rendezvous with a Starship waiting for them in lunar orbit. That will then transport the crew to the lunar surface, before carrying them back up to their capsule.
SpaceX still has some way to go before this happens. Starship still hasn’t reached space, let alone the Moon, and SpaceX will need to be sure they can reach lunar orbit before Artemis III can take place. Even then, NASA wants to see a demonstration that it can touch down safely on the Moon. That, even for SpaceX, will be no easy feat.
A Moon Landing Follows... But When?
Realistically speaking, there is no chance astronauts will walk on the Moon before 2026. Three key things are needed first: a rocket to carry them there, a lander to take them to the surface, and suits for them to wear while they are there.
With the launch of the SLS, NASA now has the first of these three items. But the other two look years away from reality. A contract to develop the space suits was recently awarded to Axiom Space, but NASA has quietly acknowledged they won’t be ready until 2026 at the earliest.
As for the lander, much depends on how fast SpaceX can progress with Starship. The last year has seen little activity, as the company has been forced to wait for regulatory approval before they proceed with test flights. Even once that is done, which could come before the end of this year, flying such a large rocket is fiendishly difficult. Despite SpaceX’s track record, we can expect many more explosions before Starship is ready for the Moon.