The genius of LOP-G is that it can be converted back to an asteroid intercept platform (its original purpose) should the next president decide to change NASA's mission yet again.
NASA’s Lunar Space Station Is a Great/Terrible Idea
111–120 of 168 posts
Re: NASA’s Lunar Space Station Is a Great/Terrible Idea
#112This might be a radical idea, but after reading that article, my thought was, "At this point, the most merciful thing to do might be to put NASA out of its misery." Specifically, this would entail: - The US government getting out of the business of designing launchers: We'd acquire launchers the same way the Air Force gets airplanes: define requirements and solicit bids. This isn't perfect (see: F-35), but it's a dar…
This is a terrible idea. NASA is still the best agency in the world for moving humanity forward, even with bureaucratic inefficiencies. No other agency will have the funds to do what NASA does for non-military reasons. For every tax dollar spent, the U.S. still gets about 7 times the return.
What do you mean by "7 times the return"? In productivity increases via. technology? In just the fiscal multiplier effect? In keeping decrepit, middle-of-nowhere NASA departments up and running?
Re: NASA’s Lunar Space Station Is a Great/Terrible Idea
#113Earlier quoted context omitted.
I guess Johnson then took the honor of being blamed for getting the country into Vietnam:). And it broke him.
Johnson accomplished a lot and, more importantly, in the correct order to make sure things got done. I think you're right though (and that he probably felt the same way) that he'll always be the Vietnam president. That may be a little unfair but it happened on his watch so that's what history will rightfully focus on.
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Re: NASA’s Lunar Space Station Is a Great/Terrible Idea
#114Earlier quoted context omitted.
I almost down voted you in a knee jerk reaction. I believe that manned space exploration serves a very important purpose in advancing humanity . . . however, from the typical Congress critter's point of view, I suspect you're right.
I suspect GP underestimates the scientific value of Apollo missions. It's so much difference to e.g. study samples brought from the Moon (and taken with reasonable care) in Earth labs than to send robots to do the same. There is a POV that robots are good for scientific missions up to certain price point. After that manned missions become more cost effective.
I would bet good money that when Starship makes its first safe return to Earth after a manned lunar landing mission, there's going to be some serious-as-a-heart-attack talk within the worlds' universities about pooling cash for manned missions.
Re: NASA’s Lunar Space Station Is a Great/Terrible Idea
#115For long time NASA announced a space program after space program only to be canceled at an unfortunate moment. We have to understand that our problems with advancing manned spaceflight are mainly organizational. And because of that, it's beneficial to focus efforts not on a grand goal, which may not survive the next budgetary fight in Congress, but instead on capabilities which can mostly be used for whatever goal we…
The idea of NASA becoming smart enough that it reroutes its plans around administrations is a nice idea. It's pretty hopeful. It also seems wrong: if it were true, NASA would've gotten us somewhere by now.
Re: NASA’s Lunar Space Station Is a Great/Terrible Idea
#116For long time NASA announced a space program after space program only to be canceled at an unfortunate moment. We have to understand that our problems with advancing manned spaceflight are mainly organizational. And because of that, it's beneficial to focus efforts not on a grand goal, which may not survive the next budgetary fight in Congress, but instead on capabilities which can mostly be used for whatever goal we…
You mean... agile?
Sort of. Gateway looks like an example of how could we try to get to the Moon, but to do that not in a single Apollo-sized project, but splitting the task in easier chunks - and yes, incurring some overhead, but also opening up new opportunities.
See, for Gateway we have much better TRL (technology readiness level) than for, say, short trips to the Moon surface, not to say about longer term Moon-surface activities like maintaining a base there. For Gateway we need technologies which are similar to ISS, with main changes being:
1) the modules need to be transported to Moon vicinity. That means that in practice, for example, each module needs to be pushed there - so the module should include its own booster (I think it's not very good, as that spent booster won't be used afterwards) or each module should be mated to a booster temporarily. Then modules should be assembled in Moon vicinity similarly to how they are assembled into ISS.
2) we have worse radioactive environment for Gateway than we have for ISS. That means all habitat modules have to additionally include means of protection - be that extra layer of passive material, or active external plasma generators which would reduce radiation by getting it through a weak layer of particles around the module, or something else. A new and a challenging problem, for sure, but with certain payouts in the future if we will ever want to venture from Earth.
There are other differences, like navigation, space debris environment, communications, ways of getting there-and-back etc. but that all seem to be much more attainable than direct Moon missions. And after having Gateway in such a shape, subsequent Moon missions can obviously employ those existing capabilities - i.e. missions would start from Gateway, which is much closer to the Moon, not from Earth, as the path to Gateway would be already well developed.
And we have better hopes of actually having that built before critical changes will happen - so we'll have taken at least some steps forward.
Re: NASA’s Lunar Space Station Is a Great/Terrible Idea
#117Earlier quoted context omitted.
Early warning satellites would be a heck of a lot easier to install than the missiles. Basically once someone started building such a plant it would be impossible to hide what you're doing. You'd never get first strike launching from the Moon, regular ICBMs would be all over you long before the moon IPBMs made the 1 day journey back to Earth. Even with the faster travel speed from only having to accelerate out of the…
It doesn't have to be a one day journey. With a 3 ton payload the Atlas B seems to have > 8000km/s delta-v. Getting from moon to earth took Apollo about 4800km/s delta-v, leaving our little Atlas 3200km/s spare fuel. If you use that to accelerate to 3200km/s travel speed you arrive on earth after about 2 minutes (if we ignore the time it takes to accelerate).
Besides acceleration at the moon side, wouldn't there need to be deceleration before entering the atmosphere? I'm thinking an IPBM traveling that fast would rip apart in the upper atmosphere and/or explode too high to cause any real damage.
Re: NASA’s Lunar Space Station Is a Great/Terrible Idea
#118Given the exponential nature of Tsiolkovsky's rocket equation, I don't understand why its not common to perform multiple launches from the ground to LEO, and then rendezvous in orbit and go to the moon, or mars, or whereever.
If I'm understanding the mechanics properly (informed mostly by kerbal space program!) the biggest "expense" in traveling most places is getting into LEO. And every doubling of payload requires more than doubling of fuel. All of which requires significantly larger and more complex rockets.
Either I'm misunderstanding the true costs of launches (I know the fuel itself is relatively cheap) or I'm underestimating the complexity of linking two spacecraft in a robust and rigid connection while in orbit.
Re: NASA’s Lunar Space Station Is a Great/Terrible Idea
#119Earlier quoted context omitted.
Early warning satellites would be a heck of a lot easier to install than the missiles. Basically once someone started building such a plant it would be impossible to hide what you're doing. You'd never get first strike launching from the Moon, regular ICBMs would be all over you long before the moon IPBMs made the 1 day journey back to Earth. Even with the faster travel speed from only having to accelerate out of the…
It doesn't have to be a one day journey. With a 3 ton payload the Atlas B seems to have > 8000km/s delta-v. Getting from moon to earth took Apollo about 4800km/s delta-v, leaving our little Atlas 3200km/s spare fuel. If you use that to accelerate to 3200km/s travel speed you arrive on earth after about 2 minutes (if we ignore the time it takes to accelerate).
Can a missile survive reentry at 3200km/s? From https://www.grc.nasa.gov/WWW/BGH/hihyper.html LEO reentry speed is 17500 mph = 28000 km/h = 7.7 km/s. It's 415 times the speed.
I didn't do the math but at that speed you don't need a warhead to destroy a target. Let's try with 1000 kg steel or whatever won't melt down
1/2 mv^2 = 500 * (3200 * 3600)^2 = 345,500,000,000 J
1 J lifts about 100 g mass by 1 m on the surface of Earth. That energy would lift 345,500,000 kg by 100 m.
Re: NASA’s Lunar Space Station Is a Great/Terrible Idea
#120The thing about the original moon landing programme was that it had a great clarity of outcome and timeline. What: Land a man on the moon and return him safely When: Before the decade is out That meant NASA could really focus and throw out everything that wasn't directly on that path. Reusability - take too long, we'll build each craft from scratch. Permanent mission - Too complicated, keep the missions very short. M…
Yes, though a lot of the Apollo infrastructure was in retrospect massively over-engineered, based on a very high estimate of required numbers of launches. This was partly because they needed to start the infrastructure before settling the mission mode but still, the plans were ambitions beyond what was strictly required to get to the moon by the end of the decade.