In December 2017, President Trump signed Space Policy Directive (SPD)-1, directing NASA to focus on returning human to the Moon. More recently this has seen the White House to direct NASA to achieve this return by 2024, and not 2028, the US space agency’s target year. We’ve also seen the programme gain a name – Project Artemis (Artemis being the sister of Apollo in Greek mythology) and the White House and Congress getting into something of a tussle over NASA’s 2020 budget: the former wants to add US $1.6 billion to NASA’s budget specifically for the lunar effort, the latter wants to give NASA an extra US $1.3 billion for programmes other than a return to the Moon.
However, tussles over budget increases aside (and even if it were granted, US $1.6 billion is merely a splash of the level of financing NASA realistically needs to reach the Moon by 2024), the US space agency has at least had a goal to aim for, until President Trump appeared to rock the boat on June 7th, when he issued a tweet that appeared to suggest NASA shouldn’t be aiming for a return to the Moon, but should be focused on Mars.
The tweet drew a huge amount of backlash from people trying to claim that Trump regards the Moon as “part of Mars”. However, those doing so are somewhat misguided. Anyone with any understanding of NASA’s plans / desires over the last 30 years with regards to Mars know that the Moon has been indelibly linked to that effort; it’s been pretty much the view that the one (Mars) cannot be achieved without the other (a return to the Moon).
The cornerstone of this claim has always been that the Moon can be used as a testing ground for technologies that might assist us in the exploration / settlement of Mars.
The Moon provides an opportunity to test new tools, instruments and equipment that could be used on Mars, including human habitats, life support systems.
– NASA website
But how accurate is this assertion? “Not very” is a not unfair summation. Mars is a very different destination to the Moon. Just landing there requires substantially different capabilities to those required for landing on the Moon.
For example, Mars has an atmosphere and the Moon does not. This can be both an advantage (it can be used to help slow an incoming vehicle down on its way to the surface) and a disadvantage (lander vehicles must be capable of withstanding entry into that atmosphere and making use of it during descent, which adds significant complexity to them). Similarly, the technology needed to get off of Mars is different: more powerful motors are required to counter the greater gravity (twice that of the Moon), these in turn require more fuel, which makes the ascent vehicle more complex – which could also feed back into the decent vehicle as well, if a paired system, such as proposed for use with the Moon, is to be used.
Similarly, how local resources on the Moon and Mars might be used differ substantially. With the Moon, it is proposed water ice in the southern polar regions is leveraged as a means of producing oxygen, water and fuel stocks. This could also be done on Mars – but there is a far more accessible resource on Mars for this: its carbon-dioxide rich atmosphere.
Using a 19th century technique called the Sabatier Reaction, water, oxygen and methane can literally be produced out of the Martian air. The oxygen and methane can be used a fuel stocks, while the air and water have obvious life-support options.
Tests carried out by the Mars Society – and verified in a 2003 joint NASA / ESA study – show that an automated lander vehicle carrying just 6 tonnes of hydrogen to the surface of Mars could produce 112 tonnes of methane / oxygen fuel by the time a human crew arrives 18 months later – enough to power their ascent vehicle back to Mars orbit or – depending on the mission architecture used – even all the way back to Earth orbit.
And when it comes to things like life support systems and radiation shielding – do we actually need the Moon to test these for an eventual Mars mission? Actually no. In terms of life support systems, we already have the infrastructure in place for testing them, just 400km from the surface of Earth; we call it the International Space Station. And when it comes to testing technologies to protect against radiation – even GCRs (galactic cosmic rays) – this can be done through other, and potentially less costly, means.
Which is not to say that we shouldn’t be going to the Moon; the potential science returns are as significant as those in going to Mars. However, it’s not unfair to say that for the last 30 years, the constant linking of the Moon and Mars has resulted in NASA being unable to achieve either.
Thus, Trump’s tweet shouldn’t be seen as any kind of belief on his part that the Moon is anyway “a part” of Mars, but rather a reflection (or possibly parroting) of the frustration some space advocates feel in the way NASA constantly links the two, with the emphasis perhaps too closely focused on the Moon, rather than looking at the potential and inspiration humans face in going to Mars.
However, where Trump’s tweet is potentially harmful is in the confusion it might cause. Trump’s spur-of-the-moment tweets have an unfortunate habit of becoming “policy”. As such, it was hard to know if the June 7th tweet was simply parroting something heard, or whether it was signalling a genuine change in direction for US space policy. As such, some, such as the Planetary Society, more correctly sought not to belittle the Moon “a part” of Mars element of Trump’s tweet, but to request a clarification of anticipated goals.
This clarification appeared to come at the National Space Society’s International Space Development Conference in Washington DC on June 8th. At that event, Scott Pace, Executive Secretary of the National Space Council, indirectly referenced Trump’s tweet, stating that while efforts to return humans to the lunar surface by 2024 were ongoing, NASA and the administration should devote more attention to long-term aspirations of human Mars missions.
The president’s comments was a criticism not of going back to the moon but rather not paying more attention to that long-term goal. We’re head down, working on the immediate execution of this [and] I don’t think we always do a good job speaking to the larger vision that this is part of. What he [Trump] is doing is stepping back and expressing, I think, a very understandable impatience with how long all of that takes, and sometimes we miss the bigger picture.
– Scott Pace, Executive Secretary, the National Space Council