<p><pre><code> “This is completely against the established common wisdom
of how to go to Mars, which is a straight shot to Mars,
carry everything with you,” de Weck says. “The idea of
taking a detour into the lunar system … it’s very
unintuitive."
</code></pre>
and later...<p><pre><code> “Assuming you can extract these resources, what do you
do with it? Almost nobody has looked at that question.”
</code></pre>
Give me a break. People discuss this sort of approach all the time. They don't necessarily publish their conclusions, though.
We still use chemical propulsion almost everywhere from cars to rocket engines, a breakthrough in propulsion systems will not only make solar system exploration feasible but will be greatly beneficial to our society by reducing pollution and costs.<p>We need the next steam engine for a new industrial revolution, space exploration and our society depends on it.<p>I think that all space resources should be channeled into this, our current approach to solar system exploration is the same as trying to explore the world by foot, expensive an inefficient and no matter how big our ambitions are we don't have the technology to accomplish them.
You can already produce fuel on Mars itself using the Sabatier Reaction with technology available today, you have to bring along a little hydrogen but that's not too big of a deal.<p>Refueling on the moon requires an (almost pointless) web of infrastructure that balloons the cost of a mission, and more importantly, increases the time to carry out the mission.<p>Each US administration has a habit of cancelling the more ambitious NASA/JPL projects of the previous one, so if we really want to go to mars, it has to be a mission doable in as short a time span as possible, such as proposed by Zubrin's Mars Direct plan.
Does anyone writing these papers have any appreciation for the difficulties of producing liquid H2 appropriate for use in manned rockets? This is some seriously tricky stuff. Turning water into liquid H2 is one thing, making it out of dirty moon-frost is another. A little impurity here and there and your rocket engine becomes a bomb.
Asteroids are even better for resource utilization.<p>They might be far away in space but a lot closer by delta vee, and they can be reached, mined and escaped with low maximum thrust, meaning very efficient propulsion methods can be used.<p>This discussion just goes around in the same stupid circles for decades. We know so many better ways of doing things, but they can not be done for political / PR reasons.
If you have one hour if front of you, I highly recommend this documentary: <a href="https://www.youtube.com/watch?v=tcTZvNLL0-w" rel="nofollow">https://www.youtube.com/watch?v=tcTZvNLL0-w</a><p>In it they explain how it would be feasible to be on Mars in ten years with current technology and not so much additional fundings.
Seeing as the title could be a bit misleading, I'm glad the article clarifies:<p>><i>Ishimatsu says the research demonstrates the importance of establishing a resource-producing infrastructure in space. He emphasizes that such infrastructure may not be necessary for a first trip to Mars. But a resource network in space would enable humans to make the journey repeatedly in a sustainable way.</i><p>In other words if we want to get to Mars ASAP, setting up lunar mining and refueling infrastructure probably isn't the fastest way to go about that, even if it is more mass efficient.
This point is key:<p>"assuming the availability of resources and fuel-generating infrastructure on the moon"<p>Sure, if the moon is a gas station, then stopping there to fuel up on the way to mars makes sense. But it's making a big leap of faith that refueling infrastructure and raw materials can be reasonably built on the moon.
Another issue with this would be that a Mars vehicle would probably be big, and to a large extent designed to never land on anything. Getting it down to the Moon safely and back out again would be very complicated. The solution is to do a fuel run with a smaller craft that can disengage from the main craft several times, but then you're doing several landings and takeoffs and that's going to shoot the risk WAY up.<p>I think that we would be wise to invest in a space elevator on the Moon. We can't support one on Earth with currently understood technology, but the Moon is different and it could be done with modern materials. A plan of this sort would seriously reduce the cost of lunar development and increase the viability of the plan in the article.
Another way to "save on weight" is to use the lowest-cost launch from Earth, and rendezvous in orbit. We're going to know what the risk and cost of reusable Falcon 9 and Falcon Heavy is long before we'd start building this lunar base. A 75% reduction in SpaceX's already low launch rates would be a big savings.<p>We even have experience launching fuel to ISS on the Russian and European unmanned supply ships.
Can't find paper but I wonder if he'd taken into account near future technologies, like orbital construction (look at the IIS, that was 'built' in orbit) and fully reusable rockets.<p>Anyway I do believe we need to establish a resource operation on moon just because debugging a resource operation on mars as our first space colony would be all too risky.
I first read about this idea in <a href="http://www.amazon.com/Orthogonal-Galaxy-Book-ebook/dp/B00QD35580/ref=sr_1_1?s=digital-text&ie=UTF8&qid=1445001975&sr=1-1&keywords=Michael+Lewis+Galaxy" rel="nofollow">http://www.amazon.com/Orthogonal-Galaxy-Book-ebook/dp/B00QD3...</a>
Obviously getting a chance to refuel en route is huge for saving dv - the rocket equation is a harsh mistress. Honestly, I'm a little surprised that it isn't more efficient to move the fuel for lunar orbit to LEO.
On a similar note, I do think that best way to get a shot at better and more investments in space would be to build a hotel on the moon.<p>(Maybe I should submit my blogpost about that to a journal to get academic cred.)
But what about the mass depletion to the moon! (<a href="https://en.wikipedia.org/wiki/The_Moon_Is_a_Harsh_Mistress" rel="nofollow">https://en.wikipedia.org/wiki/The_Moon_Is_a_Harsh_Mistress</a>)