Why would Elon Musk pivot from Mars to the Moon all of a sudden?(arstechnica.com) |
Why would Elon Musk pivot from Mars to the Moon all of a sudden?(arstechnica.com) |
Bluntly though, the lack of any visible progress with SpaceX-branded Sabatier machines already had me suspicious.
Didn't know about that. That's good insight.
"An uncrewed test flight was planned for 2025 to demonstrate a successful landing on the Moon which has since been delayed. Following that test, a crewed flight is expected to occur as part of the Artemis III mission, no earlier than mid-2027.[3] NASA later contracted for an upgraded version of Starship HLS to be used on the Artemis IV mission." [1]
Unfortunately, I really do mean "dictator" as we'd need to sustain a lot of R&D for a long time (much longer than a two-term US president for example), and even nations can't afford to spend a huge percentage of their economy on long-term projects so it has to be a fairly limited % of the overall money supply for that period. And one needs to be extremely cautious, no speed-running: a nation cannot afford to have a thematic repeat of the Apollo 1 fire with e.g. a 2000 km long Lofstrom launch loop: https://en.wikipedia.org/wiki/Launch_loop
There's three options for that size of economy:
• The US space industry comes in two parts, (1) a jobs program ("Senate Launch System" etc.) whose stated goals change with almost every new president, and (2) New Space (where Musk got the lion's share, but now he showed what is possible the whole world is quite capable of following the same path). Neither half of this lends itself to an R&D program on this scale.
• The EU is not one nation, it's a glorified free trade area. The EU's budget independently of the member states is nowhere near big enough to consider this.
• That leaves China; they could, I think, if they decide they want to. Will they decide that? I have no idea. Fits belt-and-road, but they may consider it a pointless boondoggle.
I believe you might be a bit pessimistic. The USA studied nuclear ramjets in the 1950, as well as thermal nuclear rockets. Russia has a nuclear propelled missile [0].
India is studying nuclear propulsion [1]
[0] https://en.wikipedia.org/wiki/9M730_Burevestnik
[1] https://www.indiandefensenews.in/2025/02/isro-successfully-s...
To live on Mars requires a level of autonomy and self-sufficiency that I don't think we know how to do.
On the Moon we can learn but we have softer requirements, and we can still have near real time comms. Anything further and it's "you're alone, no-one can help you, no-one will even hear you in case of emergency". Faster transportation isn't going to fundamentally change that unless it's near Star Trek level.
IMHO, the rocket is just a small part of the problem.
Even traveling abroad in a developed country carries some risks, if you have some medical issue and are unable to explain yourself because of lack of medical vocabulary, the consequences may be dire.
Mars is colder than Antarctica, drier than the Sahara, has an air pressure much much closer to vacuum than it is to even the top of Mt Everest (and a quarter of it condenses each Martian winter), the air it does have is 95% CO2 and 0.174% oxygen, the soil is as polluted as a superfund* cleanup site, the sunlight is at best 50% of the Moon's due to distance from the sun but planet-spanning dust storms can reduce that, because of the lack of free oxygen there's no free ozone layer and combined with the thin atmosphere in general it has higher ionising surface radiation despite the lower sunlight, and the return time to Earth even for nice options like VASIMR** are 39 days in the best launch window.
To give a toy example: If the water supply suffers a catastrophic loss, everyone dies in almost all circumstances before being able to get help (even if we had/when we get working VASIMR solutions at this scale, right now most discussions assume much slower and more delta-v-efficient Hohmann transfer orbits).
Same incident happens on the moon, emergency evacuation or resupply is possible before death by dehydration.
To get back to Earth from Mars with that kind of time constraint, we'd need an engine that can sustain close to 1g acceleration for about 2 days at closest approach; at maximum separation, unless I've messed up the formula, 1g would still take 4.7 days (with mid-point flip for deceleration). Basically, mytailorisrich is correct to describe this as needing "near Star Trek level" tech, because the closest we have to an inertial dampener right now is a very big magnet pushing on the water inside our bodies***.
* https://en.wikipedia.org/wiki/Superfund
** Claim I last heard was 39 days for a 200 megawatt reactor "with a power-to-mass density of 1,000 watts per kilogram", the good news is we can almost do that power-to-mass density with PV after accounting for Mars-gets-less-sun: https://www.globenewswire.com/news-release/2023/10/25/276652...
*** The difficulty of making this useful is comparable to the difficulty of launching a spaceship with a big magnet on the ship that pushes against Earth's own magnetic field.
As I recall from last time I did the maths, if you did it with copper, the copper would boil before you did much useful.
Basically all the people going "What if 9/11 was done with a flying Chernobyl?"**, some of whom are concerned voters, some of whom are the engineering team, some of whom are the foreign politicians who threaten to put sanctions on you.
Once you get to interplanetary, ion drives take away most of the advantage, because of how many people are willing to put a few extra years on a mission in exchange for not having to care about the risks.
Still, incredibly useful if you can get past all that.
* outside of warfare
** Which is essentially also something that happens in my novel, as the intersection of accident with Newton's first law
> "What if 9/11 was done with a flying Chernobyl?"
I guess it's a PR problem, particularly with the perspective to have dozen of Starship rockets launched every year.
What do people prefer? A rocket that works within reasonable technological limits (a nuclear rocket with chemical first stage) or a monster rocket that works at the edge of what is physically possible (Starship)?
Thanks, I've had similar positive responses from many people… unfortunately, spread over the last decade, because I keep finding it hard to tie all the bits together.
I'm better at world-building than plot, I have discovered.