Robert Zubrin: How to build a lunar base

[nacnud]

there were payloads for the energa system, normal satelites on the zeniths and the building blocks for MIR2, Buran, Polyuos etc on the full energa<br /><br />(yes I know I can't spell <img src="/images/icons/tongue.gif" /> <img src="/images/icons/smile.gif" /> )

 

[shyningnight]

You seem to be under the mistaken impression that just becuase many mission profiles require considerable tonnage to orbit, that we would somehow be "doing it the same as Apollo"...<br /><br />Nothing could be further from the truth!<br /><br />You really need to wrap your brain around this concept;<br />Many times, the CHEAPEST, and most EFFICIENT way to launch complex hardware (that, by the way, weighs more than 20, or 50, or 100 or more tons) is in ONE PIECE rather than several.<br /><br />I am at something of a loss as to why you equate this with "doing it the same as Apollo", and assume that there is something inherently "bad" about having the capability to put large payloads in orbit (or on track for the moon, mars, or other points)...<br /><br />Many older HLV's (such as Saturn) are not cost effective enough to ressurect. That doesn't mean the capability is not needed. It also doesn't mean that EVERY payload needs an HLV. Some do, and you can't reasonably enter into a mission profile that requires (for example) 400 tons of ship, equipment, landers, fuel, food, air, and people, in 20 ton "bites"...<br />You better be able to put that 400 ton mission together in less than 20 launches! <br /><br />Paul F.<br /><br />

 

[gofer]

OK, fine. But do we indeed have these "...large payloads..." planned, and in the pipeline? I've read not only the Zubrin's piece, but also the NASA's requirements for the Spiral 1 of the CEV program. Those don't need an HLV.

 

[shyningnight]

It's a catch-22...<br />Those missions don't NEED an HLV because we don't HAVE an HLV, so they were designed in little pieces (which may NOT be the cheapest, most efficent, or best way to do it).<br /><br />If NASA (and the industry as a whole) would pull their heads out of the sand, and design an HLV... a MODERN one, more cost effective than the likes of the Saturn V (good as it was, it wasn't cheap!)... that opens up SO many other ways to do things!<br /><br />This is just my opinion (but I'm not the only one that shares it!).<br />Paul F.

 

[scottb50]

The problem boils down to how big do you want this thing to be. Figuring the most efficient propulsion systems existing there has to be a point where a single vehicle reaches it's maximum size. Can you imagine the size of a vehicle that could take a Mars mission from Earth to Mars in one shot? With the technology we have available, because that's all we have. <br /><br />Get rid of the Shuttle orbiter and you could put, maybe 250,000 pounds into orbit, the Shuttle C. The problem starts with wanting more payload, because that's about a quarter of what you would need to go to Mars. Add more engines. Then you have to add more propellant, another engine would give you maybe another 10,000 pounds of payload.<br /><br />The problem is the Moon and Mars absolutely need a HLV, however you want to define it. <div class="Discussion_UserSignature"> </div>

 

[gofer]

Whoa..., I'm just gonna say what I still think holds: The view that "the first thing we need is a NASA operated big-a$$ HLV launch rocket 'cause we gonna need it, and 'cause it's cool, and because we can salvage the bits for this from the Shuttle " (a la some of the early Mike Griffin's statements) is going to create another big-time boondoggle on the scale of the ISS and the Shuttle and doom the whole VSE thing to an early grave. Too bad.

 

[shyningnight]

No offense intended...<br />But you're STILL not getting it..<br />What's more expensive (this is not a trick question...);<br />ONE launch of a 350 million dollar HLV, or 15 launches of a 100 million dollar "medium" lift rocket?<br /><br />Would NASA mis-manage and over-spend on building an HLV?<br />Yeah.. almost for sure.<br />That doesn't mean we don't need one.<br />What we are trying to say is; there are some things that CANNOT BE DONE without an HLV. If they CAN be done, they will be 10 times more expensive by virtue of having to be designed for grossly inadequate launchers.<br /><br />

 

[crossovermaniac]

Not if we can take the back seats out of an SUV making it into a makeshift pick-up trick. The Shuttle C or shuttle-derived HLLV would be the cheapest and fastest route to a HLLV.

 

[trailrider]

CrossoverManiac-<br />Meaning NO disrespect to your analogy, which IS VALID to a certain point, the problem is that the SUV/pickup truck is only valid for a certain range of payloads. Attempting to make a single design and size do everything for all purposes is almost a guarrantee that it will do little well. For moving furniture that fills a 3000 sq. ft. house across country you need an 18-wheeler. The SUV/pickup could do the job eventually, it is true! But it would take a huge number of trips, and in some cases, you probably couldn't get a full-size couch with the doors and windows closed!<br /><br />By the same token, it makes no sense to run the kids to school or to go to the corner for a gallon of milk using an 18-wheeler with the trailer attached. With rising fuel costs, plus, if we had to build all of them from scratch, the cost would be prohibitive! Only in a very few instances in aerospace history have we turned out vehicles that were widely versitile. And in most instances that was serendipity, rather than by intent! Nor did the reign of such successes last forever...though some HAVE lasted a long time through modification and update. (The ones that come to mind are the DC-2/3 series transports, the KC135/B-707, the F-4 Phantom II, the C-130 and the B-52 are the best examples.)<br /><br />I agree it would be best to have the types of payloads defined and then design and build the boosters to launch them. While it may seem that we are re-inventing Apollo, form generally follows function. While a winged vehicle design HAS validity for return to Earth from LEO, and to allow for greater crossrange capability, we do not have the technology build one that will successfully return from the moon on a direct descent. Neither are the wings of use in trans-lunar or interplanetary space. (To land on Mars or Titan they might be useful, but now the mass penalty is way too high.)<br /><br />By the same token, whether is worthwhile to attempt to use aerobraking to se

 

[scottb50]

If wings are only needed on returning to the Earths surface, why not have a vehicle that is specifically designed to go from the Earth's surface to orbit and back?<br /><br />From LEO to LLO, or LMO, you need vehicles specific to that task. The same with a vehicle to go from the Moon to LLO and back to the Moon, or Mars to LMO and back. It would be a lot simpler to maintain systems and do refueling in a gravity environment.<br /><br />I also think using aerobraking just won't work, it takes too long. Go to the Moon 3 days, come back 3 months? The only thing that will do it is the motors we already use and a lot of LH and LOX. Fortunately, we have a lot of water on Earth to use.<br /><br />If I read your part about Lunar Orbital Rendevous right we should go directly from the Earths surface to the surface of the Moon? That would be some undertaking. <br /><br />The only way to do it is to break it into components and specialize them for their purpose. If you try to make a one-size-fits-all vehicle it might do everything, but it wouldn't do any of them all that well. Like the Shuttle. The first 20 missions should have been the ISS. <br /><br />It breaks down to five basic areas; launch, LEO routing, Transfer, delivery and Surface Facilities. They all need to devote the maximun attention to their specific job, not be multi-tasked to death.<br /><br />Also, I would love to own a Cessna 180, older than all but the DC-3, and don't forget the DC-9, it's been in production since the 60's, or 50's it is derived from the DC-8. <div class="Discussion_UserSignature"> </div>