# congress tells NASA to go back to the moon. Can we use the water ice there? **URL:** \ **Category:** Factual Questions\ **Created:** [May 25, 2016, 12:14pm UTC](https://boards.straightdope.com/t/congress-tells-nasa-to-go-back-to-the-moon-can-we-use-the-water-ice-there/755649 "2016-05-25T12:14:56Z")\ **Posts on this page:** 19\ **Page:** 2
**Author:** ![davidm](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/davidm/32/225_2.png) [@davidm](https://boards.straightdope.com/u/davidm)\ **Post date:** [May 26, 2016, 8:50pm UTC](https://boards.straightdope.com/t/congress-tells-nasa-to-go-back-to-the-moon-can-we-use-the-water-ice-there/755649/21 "2016-05-26T20:50:14Z")
Oh I love the idea of a crewed Mars landing. I grew up during NASA’S heyday and as a child was totally caught up in the excitement and romance of it. I think humans are hardwired to explore, and there are no more unexplored continents on Earth. Also, reaching for such goals pays off scientifically and economically. Apollo and it’s predecessors contributed greatly towards the modern world we live in. ---
**Author:** ![coremelt](https://avatars.discourse-cdn.com/v4/letter/c/4491bb/32.png) [@coremelt](https://boards.straightdope.com/u/coremelt)\ **Post date:** [May 26, 2016, 11:40pm UTC](https://boards.straightdope.com/t/congress-tells-nasa-to-go-back-to-the-moon-can-we-use-the-water-ice-there/755649/22 "2016-05-26T23:40:14Z")
> [@naita](#): > > I stand corrected. I totally forgot the looney toon “We’re going to Mars!”-project. From Elon Musk’s past record I’d say calling it looney toon is pretty unreasonable. He might not get there on the current announced schedule, and he might be wrong about the technical method they use but I have no doubt they will get there. Falcon Heavy also has plenty of commercial potential, so I don’t see a problem with him getting the funds. Certainly the first private company to put a lander on Mars would be a huge publicity boost and sales pitch for SpaceX. ---
**Author:** ![usedtobe](https://avatars.discourse-cdn.com/v4/letter/u/ec9cab/32.png) [@usedtobe](https://boards.straightdope.com/u/usedtobe)\ **Post date:** [May 27, 2016, 12:41am UTC](https://boards.straightdope.com/t/congress-tells-nasa-to-go-back-to-the-moon-can-we-use-the-water-ice-there/755649/23 "2016-05-27T00:41:42Z")
And, once again, children: It is Looney Tunes Also: Merrie Melodies Happy Harmonies Silly Symphonies They were intended to sell sheet music in a time when you made your own music. Radio came later. ---
**Author:** ![naita](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/naita/32/5862_2.png) [@naita](https://boards.straightdope.com/u/naita)\ **Post date:** [May 27, 2016, 5:47am UTC](https://boards.straightdope.com/t/congress-tells-nasa-to-go-back-to-the-moon-can-we-use-the-water-ice-there/755649/24 "2016-05-27T05:47:14Z")
> [@coremelt](#): > > From Elon Musk’s past record I’d say calling it looney toon is pretty unreasonable. He might not get there on the current announced schedule, and he might be wrong about the technical method they use but I have no doubt they will get there. Falcon Heavy also has plenty of commercial potential, so I don’t see a problem with him getting the funds. Certainly the first private company to put a lander on Mars would be a huge publicity boost and sales pitch for SpaceX. I don’t know if you’re talking about a manned lander or not, but that’s what I mean when I say “we’re going to Mars”. And I’m sure we’re not going to get there. But since I’m not a rocket scientist, psychologist or doctor, that’s just based on other people’s opinions in those fields. ---
**Author:** ![TriPolar](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tripolar/32/3008_2.png) [@TriPolar](https://boards.straightdope.com/u/TriPolar)\ **Post date:** [May 27, 2016, 5:57am UTC](https://boards.straightdope.com/t/congress-tells-nasa-to-go-back-to-the-moon-can-we-use-the-water-ice-there/755649/25 "2016-05-27T05:57:49Z")
We could easily send a human being to Mars right now. The landing will probably kill them, and if it doesn’t they’ll die when their food and/or oxygen supply runs out anyway. ---
**Author:** ![coremelt](https://avatars.discourse-cdn.com/v4/letter/c/4491bb/32.png) [@coremelt](https://boards.straightdope.com/u/coremelt)\ **Post date:** [May 27, 2016, 9:35am UTC](https://boards.straightdope.com/t/congress-tells-nasa-to-go-back-to-the-moon-can-we-use-the-water-ice-there/755649/26 "2016-05-27T09:35:22Z")
> [@naita](#): > > I don’t know if you’re talking about a manned lander or not, but that’s what I mean when I say “we’re going to Mars”. And I’m sure we’re not going to get there. But since I’m not a rocket scientist, psychologist or doctor, that’s just based on other people’s opinions in those fields. The current announced goal of SpaceX is to put an unmanned Dragon capsule there. That in itself would be an achievement because it would be heavier than any previous lander on Mars. Their long term goal for manned missions to Mars is the Mars Colonial Transporter, which they are saying could possibly be operational sometime in the late 2020’s. Elon Musk is only 44 and he seems to be very successful at selling his vision in order to obtain the private funding he needs. It’s far too early to say if he’s going to succeed or fail on sending manned vehicles to Mars. > **[SpaceX Starship design history](https://en.wikipedia.org/wiki/Mars_Colonial_Transporter)** > > Before settling on the 2018 Starship design, SpaceX successively presented a number of reusable super-heavy lift vehicle proposals. These preliminary spacecraft designs were known under various names (Mars Colonial Transporter, Interplanetary Transport System, BFR). > In November 2005, before SpaceX had launched its first rocket, the Falcon 1, CEO Elon Musk first mentioned a high-capacity rocket concept able to launch 100 t (220,000 lb) to low Earth orbit, dubbed the BFR. Later in 2012, Elon Musk... ---
**Author:** ![carnivorousplant](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/carnivorousplant/32/3563_2.png) [@carnivorousplant](https://boards.straightdope.com/u/carnivorousplant)\ **Post date:** [May 27, 2016, 2:37pm UTC](https://boards.straightdope.com/t/congress-tells-nasa-to-go-back-to-the-moon-can-we-use-the-water-ice-there/755649/27 "2016-05-27T14:37:15Z")
> [@Stranger\_On\_A\_Train](#): > > There are other objectives that may benefit or even require a human presence on the surface, such as planting flags and putting down footprints, testing methods for future human occupation, et cetera. > > Stranger Such as using a j[ack on Spirit.](http://www.space.com/11773-nasa-mars-rover-spirit-mission-ends.html) Controlling from orbit without a time delay would be very advantageous. ---
**Author:** ![scr4](https://avatars.discourse-cdn.com/v4/letter/s/59ef9b/32.png) [@scr4](https://boards.straightdope.com/u/scr4)\ **Post date:** [May 27, 2016, 2:55pm UTC](https://boards.straightdope.com/t/congress-tells-nasa-to-go-back-to-the-moon-can-we-use-the-water-ice-there/755649/28 "2016-05-27T14:55:21Z")
> [@carnivorousplant](#): > > Such as using a j[ack on Spirit.](http://www.space.com/11773-nasa-mars-rover-spirit-mission-ends.html) Sending a replacement rover is _much_ cheaper than sending people to fix one. In fact, sending a [_much better_ rover](https://en.wikipedia.org/wiki/Curiosity_(rover)) was a lot cheaper than sending someone to fix an obsolete one. > [@](#): > > Controlling from orbit without a time delay would be very advantageous. Except autonomous driving technology is advancing much faster than low-cost space launch technology. ---
**Author:** ![Stranger\_On\_A\_Train](https://avatars.discourse-cdn.com/v4/letter/s/13edae/32.png) [@Stranger\_On\_A\_Train](https://boards.straightdope.com/u/Stranger_On_A_Train)\ **Post date:** [May 27, 2016, 3:53pm UTC](https://boards.straightdope.com/t/congress-tells-nasa-to-go-back-to-the-moon-can-we-use-the-water-ice-there/755649/29 "2016-05-27T15:53:45Z")
> [@scr4](#): > > Except autonomous driving technology is advancing much faster than low-cost space launch technology. That is certainly true, but there are decisions and issues that need to be evaluated by a human mission team; for instance, [the unanticipated erosion experienced by _Curiosity_ during its sojourn toward Mt. Sharp](http://www.planetary.org/blogs/emily-lakdawalla/2014/08190630-curiosity-wheel-damage.html). Because of the communication delay time (typically 20-40 minutes round trip) there is no way to perform any real-time direction, and so once damage was discovered evaluating and recommending a path for _Curiosity_ was a frusratingly halting task requiring essentially around the clock mission surveillance to get the best distance made good while protecting the wheels from further damage. A controller in orbit, on the other hand, could make near-real-time adjustments to the vehicle path to evaluate and avoid unexpected hazards, or to inspect intersting geological structures (something _Curiosity_ has occasionally had to backtrack to do when they were discovered after the fact). The ability to detect and avoid hazards autonomously will of course improve as we better characterize the hazards and develop better synthetic intelligence capability, but we are going to want actual human scientists and engineers in the decision loop to make the kind of multi-varied evaluations that only people are suited to do now and for the foreseeable future. And frankly, the EDL and ascent phases of a crewed mission are the most difficult, risky, and carry the largest fraction of cost and engineering effort for their given mission time, far out of proportion with the rest of the mission. Sending people in a spacecraft on an interplanetary trajectory, while by no means trivial, is fairly straightforward, and the basic hazards (solar radiation, cosmic radiation, physiological degradation in free fall, et cetera) are reasonably well understood. Lofting large payloads into orbit and injecting them into an interplanetary trajectory certainly requires the development of larger and more powerful propulsion systems, but the path to do so is straightforward (insofar as anything in space can be described as “straightforward”). Integration of a multi-component spacecraft is a substantial challenge but we have experience with the ISS to learn from. But the landing and ascent of a heavy payload to Mars is going to be expensive, challenging, and inevitably risky, with limited public and political tolerance for a failure measured in the tens of billions of dollars for even a test payload. It would be more sensible to send a crewed mission to Mars to remain in orbit controlling ground probes and rovers while maturing the technology and building an infrastructure to support sustainable long term space habitation. Stranger ---
**Author:** ![carnivorousplant](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/carnivorousplant/32/3563_2.png) [@carnivorousplant](https://boards.straightdope.com/u/carnivorousplant)\ **Post date:** [May 27, 2016, 4:50pm UTC](https://boards.straightdope.com/t/congress-tells-nasa-to-go-back-to-the-moon-can-we-use-the-water-ice-there/755649/30 "2016-05-27T16:50:12Z")
> [@scr4](#): > > Sending a replacement rover is _much_ cheaper than sending people to fix one. In fact, sending a [_much better_ rover](https://en.wikipedia.org/wiki/Curiosity_(rover)) was a lot cheaper than sending someone to fix an obsolete one. > Except autonomous driving technology is advancing much faster than low-cost space launch technology. True, my point being that a human is more versatile than a rover. ---
**Author:** ![AK84](https://avatars.discourse-cdn.com/v4/letter/a/85e7bf/32.png) [@AK84](https://boards.straightdope.com/u/AK84)\ **Post date:** [May 27, 2016, 4:53pm UTC](https://boards.straightdope.com/t/congress-tells-nasa-to-go-back-to-the-moon-can-we-use-the-water-ice-there/755649/31 "2016-05-27T16:53:25Z")
I often wonder if the astronauts will even be physically able walk for days after a Martian landing. Having, spent 9 months in zero gravity they’ll be pretty weak; and if the Apollo missions are anything to go by, the EVA on the surface will be pretty physically taxing. ---
**Author:** ![Earl\_Snake-Hips\_Tucker](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/earl_snake-hips_tucker/32/3269_2.png) [@Earl\_Snake-Hips\_Tucker](https://boards.straightdope.com/u/Earl_Snake-Hips_Tucker)\ **Post date:** [May 27, 2016, 5:05pm UTC](https://boards.straightdope.com/t/congress-tells-nasa-to-go-back-to-the-moon-can-we-use-the-water-ice-there/755649/32 "2016-05-27T17:05:33Z")
Sample soil return mission first. If we can’t do that (and so far, we’ve never lifted off Mars), not much point in talking about a manned mission. (Not that I think there’s much point in one anyway at least for the forseeable future.) ---
**Author:** ![carnivorousplant](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/carnivorousplant/32/3563_2.png) [@carnivorousplant](https://boards.straightdope.com/u/carnivorousplant)\ **Post date:** [May 27, 2016, 5:25pm UTC](https://boards.straightdope.com/t/congress-tells-nasa-to-go-back-to-the-moon-can-we-use-the-water-ice-there/755649/33 "2016-05-27T17:25:19Z")
> [@Earl\_Snake-Hips\_Tucker](#): > > Sample soil return mission first. If we can’t do that (and so far, we’ve never lifted off Mars), not much point in talking about a manned mission. Why not? ---
**Author:** ![davidm](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/davidm/32/225_2.png) [@davidm](https://boards.straightdope.com/u/davidm)\ **Post date:** [May 28, 2016, 5:22am UTC](https://boards.straightdope.com/t/congress-tells-nasa-to-go-back-to-the-moon-can-we-use-the-water-ice-there/755649/34 "2016-05-28T05:22:31Z")
Maybe first we should send an unmanned mission that includes an automated descent / ascent vehicle that is the weight and dimensions of a manned lander to test whether it can successfully leave the surface and dock with an orbiter. As long as we’re doing that then we might as well make it a sample return mission also. ---
**Author:** ![Stranger\_On\_A\_Train](https://avatars.discourse-cdn.com/v4/letter/s/13edae/32.png) [@Stranger\_On\_A\_Train](https://boards.straightdope.com/u/Stranger_On_A_Train)\ **Post date:** [May 28, 2016, 5:33am UTC](https://boards.straightdope.com/t/congress-tells-nasa-to-go-back-to-the-moon-can-we-use-the-water-ice-there/755649/35 "2016-05-28T05:33:04Z")
Well, ideally that would be the way to go (all up testing through EDL and ascent) but it adds substantial cost to the mission. Practially speaking, proofing out the EDL portion and simulating the less challenging ascent is probably sufficient. A sample return mission is desireable from a number of fronts but not part of any current baseline plan (although DRM 5.0 assumes one or more sample return missions have occurred, albeit without any specific mission objectives). Stranger ---
**Author:** ![lazybratsche](https://avatars.discourse-cdn.com/v4/letter/l/ba8739/32.png) [@lazybratsche](https://boards.straightdope.com/u/lazybratsche)\ **Post date:** [June 10, 2016, 5:45pm UTC](https://boards.straightdope.com/t/congress-tells-nasa-to-go-back-to-the-moon-can-we-use-the-water-ice-there/755649/36 "2016-06-10T17:45:39Z")
This is a bit of an off-topic bump, but after the latest bolus of [Elon Musk Hype](https://www.washingtonpost.com/news/the-switch/wp/2016/06/10/elon-musk-provides-new-details-on-his-mind-blowing-mission-to-mars/)\*, I’d love to hear more of a skeptic’s take on the Red Dragon mission. > [@Stranger\_On\_A\_Train](#): > > If those are the estimates for landing a 6200 kg (dry mass) spacecraft on Mars using aerodynamic drag of a blunt base capsule and supersonic retropropulsion with 3200 kg of propellant for a total of about 7.4M N･s of total impulse, the claim is farcical on the face. For even the best theoretical chemical propulsion systems at I[SUB]sp[/SUB] ~450 s in a direct entry, high base drag EDL mode, a propellant mass fraction of \>0.5 is required. Realistically, landed masses in the multiple ton range will require propellant mass fractions \>0.6, and practically speaking the general assumption is that least a single stage inflatable decelerator will be required to achieve both good targeting and high landed mass fraction, which is an important cost driver in minimizing the number of ground-to-orbit launches and on-orbit integration and fueling operations. > > In the 'Eighties and early 'Nineties, it was assumed in many studies that a broad base biconic vehicle would be able to fly aerobraking and supersonic aerolift entry trajectories with good precision and a high landed mass, requiring only terminal-phase propulsion to land. However, once we got more data about the atmosphere of Mars the aerothermal analysts started taking a hard look at aeroheating and realized that the thermal protection system requirements would result in either a really heavy ablative heat shield or complex active cooling that would not be capable of being made redundant, and was therefore a critical failure mode with minimal margins. Since that time, Mars mission studies have recognized that base drag aerodynamics can only provide modest deceleration capability and supersonic retropropulsion, while technically possible, required a lot of technical development to sufficient maturity (TRL\>7) and had extreme propellant mass fraction requirements. The proposed “Red Dragon” mission is of course a smaller landed mass than anything that would be considered for a crewed mission but the challenges of landing even a multi-single-ton mass are substantial, and I’ll believe Musk’s claims when I see them demonstrated in reality versus PowerPoint. > > Stranger Part of the basis for the Red Dragon mission comes from a series of studies by NASA Ames researchers. In particular, the “farcical” figures on propellant mass fraction and landed payload come from [this 2014 study on the EDL capabilities of the Dragon spacecraft](http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=6836422) (though the numbers I quoted are slightly different from the paper). Indeed, it invokes hypersonic lift and what appear to be some fairly aggressive maneuvers during the entry phase, as well as supersonic retropropulsion for the descent. What’s your take? - One Red Dragon mission to Mars launched in 2018, two in 2020, unmanned Mars Colonial Transporter in 2022, manned in 2024… ---
**Author:** ![Lemur866](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lemur866/32/434_2.png) [@Lemur866](https://boards.straightdope.com/u/Lemur866)\ **Post date:** [June 10, 2016, 6:23pm UTC](https://boards.straightdope.com/t/congress-tells-nasa-to-go-back-to-the-moon-can-we-use-the-water-ice-there/755649/37 "2016-06-10T18:23:32Z")
> [@Earl\_Snake-Hips\_Tucker](#): > > Sample soil return mission first. If we can’t do that (and so far, we’ve never lifted off Mars), not much point in talking about a manned mission. (Not that I think there’s much point in one anyway at least for the forseeable future.) > [@carnivorousplant](#): > > Why not? Because if we can’t return a couple dozen kilograms of inert Mars rocks to Earth, how can we expect to return a team of living astronauts? ---
**Author:** ![coremelt](https://avatars.discourse-cdn.com/v4/letter/c/4491bb/32.png) [@coremelt](https://boards.straightdope.com/u/coremelt)\ **Post date:** [June 10, 2016, 6:49pm UTC](https://boards.straightdope.com/t/congress-tells-nasa-to-go-back-to-the-moon-can-we-use-the-water-ice-there/755649/38 "2016-06-10T18:49:34Z")
> [@Lemur866](#): > > Because if we can’t return a couple dozen kilograms of inert Mars rocks to Earth, how can we expect to return a team of living astronauts? I presume he is referring to the various “one way” mars ideas to send people there and not bring them back. Forget Mars One, there are other options, certainly you could find volunteers to be the first people on Mars even if there was no prospect of bringing them back, or them surviving more than a year. US public sentiment might make that unrealistic but I’m not sure the same would be true of China or India, I can see them sending off one way missions and I am pretty sure they’d have not much trouble finding (genuine) volunteers. ---
**Author:** ![carnivorousplant](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/carnivorousplant/32/3563_2.png) [@carnivorousplant](https://boards.straightdope.com/u/carnivorousplant)\ **Post date:** [June 10, 2016, 7:50pm UTC](https://boards.straightdope.com/t/congress-tells-nasa-to-go-back-to-the-moon-can-we-use-the-water-ice-there/755649/39 "2016-06-10T19:50:36Z")
> [@Lemur866](#): > > Because if we can’t return a couple dozen kilograms of inert Mars rocks to Earth, how can we expect to return a team of living astronauts? Not with this craft. We’d have to have a tanker to bring enough fuel. Coal burning ships initially could not steam across the Atlantic for they could not carry enough coal. Better engines fixed that. [Previous page](https://boards.straightdope.com/t/congress-tells-nasa-to-go-back-to-the-moon-can-we-use-the-water-ice-there/755649.md?page=1)