Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!henry From: henry@utzoo.UUCP (Henry Spencer) Newsgroups: net.space Subject: Re: Manned Mars Trip Message-ID: <6218@utzoo.UUCP> Date: Wed, 11-Dec-85 20:33:48 EST Article-I.D.: utzoo.6218 Posted: Wed Dec 11 20:33:48 1985 Date-Received: Wed, 11-Dec-85 20:33:48 EST References: <8512071719.AA10364@s1-b.arpa>, <489@iham1.UUCP> Organization: U of Toronto Zoology Lines: 93 > (To get back to the subject line): A Mars project may be the way to > get Americans as excited as they were for the Apollo project. If this > happens then we may just get the funding we need. Funding for a Mars > project may necessarily include many of the programs that we feel > are necessary. Unfortunately, the analogy to Apollo may be all too apt. What happens after the First Mars Expedition returns? How long before the budget starts getting cut back, back, back, on the grounds that "you've finished your job"? Take a tour of KSC, and be sure you look at the Saturn V lying on its side rusting: that was FLIGHT-READY HARDWARE, scheduled to launch Apollo 18 or 19. Or visit the Air & Space Museum in Washington: that's a real Skylab, intended to fly as a followon to the original; that's a real Lunar Module, meant for Apollo 18 I believe; that's a real Viking lander and orbiter, which many people wanted to fly as Viking 3. The people who are pushing for a Mars mission are setting us up for the same thing, on a much more massive scale. Yes, a Mars mission would require building many capabilities that would be useful for other things. And they might well get thrown away afterward. The US had *no* man-rated launch system in the half-decade between Apollo-Soyuz and STS-1! In 1970, the US could put a man on the moon; it can't today. We are *farther* from the moon now, in most ways, than we were in 1961: all the specialized hardware is gone, the tools and plans for building it are gone, and NASA has gotten older and more bureaucratized. (Does anyone really believe that today's NASA could mount a lunar mission within 8 years of being told to do it? The Space Station is a much simpler job, if you carefully avoid adding unnecessary frills like AI and other high-tech fads, and last I heard NASA had given up on having it operational within TEN years.) It's been pointed out recently that putting cargo into orbit with the shuttle is no cheaper, per kilo, than doing it with the Saturn V... and the Saturn V prices were based on a total production run of 15! How much cheaper would a modernized, volume-production Saturn be? We'll never know; that capability was thrown away. Apollo/Saturn technology could have sent a small manned expedition to an Earth-approaching asteroid at closest approach, given minor improvements in power and life-support to permit a longer stay in space. When Apollos 18 and 19 were scrubbed, all the major hardware needed for such a mission was *on* *hand*. Anybody want to guess when we get even an *unmanned* sample-return mission to an asteroid? Probably not in this century. The capability was thrown away. If you want a more modern example, a year or two ago it would have been relatively cheap to commit to assembling a backup Galileo, with an eye on sending it to Saturn if the original's Jupiter mission succeeded. This option is getting steadily more expensive as Galileo work teams disperse; the opportunity has probably been lost. Thrown away. Given the realities of funding, a major Mars mission is the last thing we need. Effort and funding *must* go towards building ongoing capabilities that will outlast individual projects. It is important to aim high when conceiving those capabilities, so that they will be *useful* for mounting exciting projects, but the capabilities must be justified on their own merits so we don't lose them afterwards! What capabilities do we need? First and most important, we need cheaper transport to low Earth orbit. Shuttle launch costs will dominate the operational price tag of almost everything else we do right now. Launch costs must come down, if only by the order of magnitude that the Shuttle was originally aimed at. (Many people think that a pretty unambitious goal; we could do better.) Second, we need an orbital staging point, where missions can be assembled. Life gets much simpler if an assembled system doesn't have to survive a noisy, bouncy Shuttle launch, or fold to fit the Shuttle cargo bay. The Space Station is a good approximation to this, although it could be done a good deal sooner and more cheaply than it actually will. Third, we need cryogenic propellant storage in orbit. This lets us mount high-energy missions without tight time constraints, and lets us use high- energy upper stages for space-assembled missions. We also need some minor related items of technology, like free-fall fuel transfer and a Centaur variant that can be fueled in space. The Centaur already has engine-restart capability, so in-space fueling at the Station gives us a good approximation to a reusable OTV. A hefty one. (Who cares if it's unnecessarily big for some missions? It can still fly them, and it doesn't have to be developed from scratch!) In the longer run, we should re-engine the Centaur, and examine larger Centaur variants with bigger tanks and/or more engines. Fourth, we need aerobraking technology. It's decidedly useful even for advanced OTVs working to GEO, and it's very important for lunar and planetary missions. Furthermore, it doesn't look that hard. It would be moderately useful to have partially-recycling life-support systems, to reduce the cost of manned operations in orbit, although Skylab demonstrated consumables-per-man-day figures low enough that the complexity may be hard to justify. Given the above, mounting a Mars mission, or an asteroid mission, or a lunar mission, or any number of other interesting things, becomes vastly easier. And all of these things are justifiable on their own (although aerobraking may be a marginal case), and will survive the success (!) of any particular mission.