Quote from: turbopumpfeedback2 on 05/12/2016 02:08 pmUS and China collaboration....is prohibited by law.
US and China collaboration.
Quote from: sghill on 05/12/2016 04:49 pmQuote from: turbopumpfeedback2 on 05/12/2016 02:08 pmUS and China collaboration....is prohibited by law.Laws can be changed.
Quote from: sanman on 01/23/2016 05:34 amIn what ways could the Moon serve as a convenient testing ground for things that might be used on Mars?What things could be tested on the Moon before trying them out on Mars?What are the differences between the 2 environments that would have to be accounted for?What kind of projects might be beneficial for lunar science even while supporting greater goals for Mars?The moon can be used to test the business case for a Mars colony. Most of the GDP of a colony will be the generation of intellectual property. Much like Antarctica, the vast majority of people there will be researchers who's institutions or governments are paying for their time there. Residents will be a fraction of the total population. A moon outpost let's you try out all your support functions for that economic activity, but without the time, expenses, and danger of a two year trip.
In what ways could the Moon serve as a convenient testing ground for things that might be used on Mars?What things could be tested on the Moon before trying them out on Mars?What are the differences between the 2 environments that would have to be accounted for?What kind of projects might be beneficial for lunar science even while supporting greater goals for Mars?
Quote from: A_M_Swallow on 05/12/2016 05:18 pmQuote from: sghill on 05/12/2016 04:49 pmQuote from: turbopumpfeedback2 on 05/12/2016 02:08 pmUS and China collaboration....is prohibited by law.Laws can be changed.Yes, but not this one as long as the Republicans control Congress.
In what ways could the Moon serve as a convenient testing ground for things that might be used on Mars?
More that a stepping stone to Mars, Moon is it own destination.Very insteresting in long term, because is a very good place for robotic telepresence.
But the biggest reason to go back to the Moon in my opinion is that it can act as a testing ground for TTP (tactics, techniques, and procedures) in a harsh environment with a moderate safety risk.
Quote from: sanman on 01/23/2016 05:34 amIn what ways could the Moon serve as a convenient testing ground for things that might be used on Mars?As many have said before me:The environmental differences between the moon and mars are big enough that you'd have to have specialized solutions for each environment (abrasive lunar dust is a big one).But the biggest reason to go back to the Moon in my opinion is that it can act as a testing ground for TTP (tactics, techniques, and procedures) in a harsh environment with a moderate safety risk.While it takes pretty much the same delta V to go to the moon as Mars...the big advantage is travel time.You can launch to/from the moon pretty commonly and travel times are pretty short:Going to/from the moon (liftoff [earth or lunar] and landing [earth or lunar]) takes 4~ days as opposed to 150 to 300 days for Mars.This short cycle enables you to do a lot of realistic training far away from earth, but not so far away that if something happens, you're pretty much dead.Plus, the short cycle enables a lot of iterativeness, making it possible that in the near-future (25-35 years from now), the career progression for an astronaut/cosmonaut/taikonaut would be:Stage 1: Low Earth Orbit / Space Stations = A few hours away from help if something goes wrong.Stage 2: Lunar Orbit / Lunar Surface = A few days away from help if something goes wrong.Stage 3: Mars = Months away from help if something goes wrong.Allowing the candidate to progress in their training to higher and higher levels.Plus, it provides off-roads for the training system; because even if the person may not be cut out for Mars missions, they're still good for LEO/Lunar missions -- important if we're to move towards a space program with large masses of people living or working off-earth, instead of only a few highly trained and handpicked specialists working off-earth at any one time.
Quote from: RyanC on 05/21/2016 02:07 pmBut the biggest reason to go back to the Moon in my opinion is that it can act as a testing ground for TTP (tactics, techniques, and procedures) in a harsh environment with a moderate safety risk.What advantage does operating a pretend Mars base on the moon have over operating a pretend Mars base in a remote area of Earth?The disadvantage being the extra tens of billions of dollars necessary for NASA to operate a moon base.I mean, if little of the hardware can be common, what benefit is there that is worth the enormous cost?
building up a cislunar infrastructure in no way requires or needs us to take jaunts from there on down the lunar surface. Any surface exploration out of a cislunar station is a separate thing from the development of habs and transit modules for Mars, and can't really help us prepare for Mars. It can only take away funding from a Mars goal.
Quote from: the_other_Doug on 05/21/2016 05:51 pmbuilding up a cislunar infrastructure in no way requires or needs us to take jaunts from there on down the lunar surface. Any surface exploration out of a cislunar station is a separate thing from the development of habs and transit modules for Mars, and can't really help us prepare for Mars. It can only take away funding from a Mars goal. That's not necessarily true. Beefed-up versions of the Moon landers that ULA proposed based on their ACES platform could land on Mars; albeit you'd have to do it mostly fully propulsively. This was discussed here years ago. Basically you'd be trading the cost of propellant for the cost of developing a brand new Mars lander that would require a fancy EDL system where you'd use aerobraking to shed the vast majority of Mars orbit delta v. Also, it's hard to imagine what a single stage, reusable Mars lander would be like based on the latter design because the TPS is going to weigh a lot, and the delta v for taking off is going to be basically the same as that required for a fully propulsive descent. Maybe you could have a SpaceX-style returnable 1st stage, so the actual capsule would be able to land on its own, but then it could be mated to the reusable first stage for relaunch. Sounds good, but when contemplating such monsters, the concern for lunar missions sucking away Mars funds then becomes real.This points out two very different mind-sets when it comes to Mars exploration. There are those who prefer the Apollo-on-steroids, flags 'n' footprints, mass-starved architecture, and there are those that prefer a sustainable, long-term presence that will make evolutionary use of existing architectures, as well as space resources to ensure that something as simple as rocket propellant will always be available in an abundant supply.As for habs, if one would suffice for the surface of the Moon, I don't see how it would not also work on Mars. If anything, it'd be a bit overengineered. But so what. The idea that brand new architectures have to be designed for Mars missions is a guarantee of massive cost overruns. According to Doug's logic, a 3rd-stage designed to boost communications satellites to GEO has no business being included in the design for a manned lunar lander. After all, satellites don't require pressurized chambers and life support systems, and the Moon's surface is a very different environment compared to LEO or GEO. In reality, a Mars architecture based on a lunar architecture based on ULA's ACES combined with Bigelow-style habs would work admirably IMHO.YMMV
And in its entire existence ESA hasn't even done a lunar orbiter.
That ease of teleoperation of robotic rovers demonstrates the lack of scientific interest in the moon by major agencies.In 40 years, NASA hasn't put a single lander or rover on the moon. They've flown a small number of low-funded orbiters, but not followed up on the interesting findings of those orbiters. Even during Constellation, which Bush justified as lowering the cost to Mars, there was no serious proposal for a lunar lander or rover, not even to do a ground assay of the supposed polar ice deposits.
Supposedly, SpaceX is proposing non-mass-starved architecture. If true, and if achievable, then a lot of what we're talking about here really stops being applicable...
Quote from: the_other_Doug on 05/21/2016 08:54 pmSupposedly, SpaceX is proposing non-mass-starved architecture. If true, and if achievable, then a lot of what we're talking about here really stops being applicable...If the plan is to get everything from the Earth, it's going to be mass starved no matter what they say.
Quote from: Warren Platts on 05/24/2016 02:32 pmQuote from: the_other_Doug on 05/21/2016 08:54 pmSupposedly, SpaceX is proposing non-mass-starved architecture. If true, and if achievable, then a lot of what we're talking about here really stops being applicable...If the plan is to get everything from the Earth, it's going to be mass starved no matter what they say.Mars.
Propellantless launch isn't necessary if you have lots of reaction mass available. On Earth and Mars, that's not really a problem. This thread's author seems to claim it's not a problem on the Moon, either (though I'm skeptical).
If NASA wants to go to Mars, it'd be a huge waste for NASA to go to the Moon just for propellant. I guarantee FAR more money will be spent by stopping off at the Moon first.
Now if private companies think they can deliver lunar water or propellant to orbit for cheaper than you can get from Earth, then they should offer it to NASA for a fixed price. NASA ought to have mechanisms in place to allow that. Same for alt-launch from Earth or atmospheric scooping or asteroid resources, etc. But I guarantee NASA will explode the costs and there's simply no way it'd be cheaper for NASA to go to the Moon first.
Quote from: Robotbeat on 05/24/2016 05:15 pmPropellantless launch isn't necessary if you have lots of reaction mass available. On Earth and Mars, that's not really a problem. This thread's author seems to claim it's not a problem on the Moon, either (though I'm skeptical).Propellantless launch, when practical (it's tons more practical on the moon than either Mars or Earth) dramatically cuts down on the amount of mining and infrastructure you need in order to support a given rate of propellant export. ...
I'd say propellantless launch options are usually more infrastructure-intensive than reusable chemical launch. Again, if reaction mass is easily available, you don't need or even necessarily want propellantless launch (though useful for assists, maybe).
CO/O2