Return-path: X-Andrew-Authenticated-as: 7997;andrew.cmu.edu;Ted Anderson Received: from hogtown.andrew.cmu.edu via trymail for +dist+/afs/andrew.cmu.edu/usr11/tm2b/space/space.dl@andrew.cmu.edu (->+dist+/afs/andrew.cmu.edu/usr11/tm2b/space/space.dl) (->ota+space.digests) ID ; Mon, 29 Apr 91 01:26:01 -0400 (EDT) Message-ID: <0c6utTG00WBwE-3E4d@andrew.cmu.edu> Precedence: junk Reply-To: space+@Andrew.CMU.EDU From: space-request+@Andrew.CMU.EDU To: space+@Andrew.CMU.EDU Date: Mon, 29 Apr 91 01:25:52 -0400 (EDT) Subject: SPACE Digest V13 #477 SPACE Digest Volume 13 : Issue 477 Today's Topics: Re: Saturn V vs ALS Re: Saturn V and the ALS Re: Saturn V and the ALS Galileo works? Re: Saturn V vs. ALS space news from March 11 AW&ST Re: Galileo Solution Re: Saturn V vs. ALS Another Galileo Sulution Administrivia: Submissions to the SPACE Digest/sci.space should be mailed to space+@andrew.cmu.edu. Other mail, esp. [un]subscription requests, should be sent to space-request+@andrew.cmu.edu, or, if urgent, to tm2b+@andrew.cmu.edu ---------------------------------------------------------------------- Date: 28 Apr 91 07:33:27 GMT From: cs.utexas.edu!swrinde!sdd.hp.com!uakari.primate.wisc.edu!dali.cs.montana.edu!milton!hardy.u.washington.edu!brettvs@rutgers.edu (Brett Vansteenwyk) Subject: Re: Saturn V vs ALS Consider the following development pedigree: Saturn V: Return to heavy lift capability Saturn VI: Using what we learned in the '70s and '80s to lighten/improve the basic Saturn V design Saturn VII: A Saturn VI modified so that the first stage is now a flyback booster (the Boeing proposal). The end result (or even a Saturn VI) would probably contain most of the desirable features of modern boosters, including one the "modern" ones don't have: it will be reliable. Making a program where you first try to get operational with a reasonable existing design, then incrementally improve along what would seem to be a well-marked trail, would keep you improving without forcing you to go through no-op phases that last a year or more. You will improve while staying operational--and staying operational seems to be a feature that we have come to appreciate more and more (at least, our gov't opinion leaders are giving more lip service to it). The development trail would be longer, but I think that a flyback Saturn V would have some technical advantages over the ALS, and in the meantime we would have access to orbit at a reasonable cost. I do have one concern--and I admit I have not read all the postings on this subject, so I do not know if this was covered--what would the Saturn V based cargo booster configuration look like? I could see a case for only keeping the first two stages since they are sufficient by themselves for getting into orbit. Unfortunately, if memory serves me, all the smarts of this rocket are in the third stage. Would there be a problem in putting them in a section of the payload canister? Would a third stage the size of the original Saturn V third stage be justified even for geosynchronous orbit delivery? ---Brett Van Steenwyk ------------------------------ Date: 26 Apr 91 15:06:41 GMT From: agate!bionet!uwm.edu!caen!uakari.primate.wisc.edu!crdgw1!gecrdvm1!gipp@ucbvax.Berkeley.EDU Subject: Re: Saturn V and the ALS In article , gaserre@isis.isis.cs.du.edu (Glenn A. Serre) says: > >Indeed, two of ALS goals are to be big and cheap. However, >1) Current ALS designs are cheap only with high launch rates. >2) ALS will be very expensive and time-consuming to develop and build; >starting >over if it turns out not to be cheap doesn't seem very likely. Consider the >shuttle. One of its design goals was to be cheap. It is not cheap, and we >haven't started over, we've built another one. >3) Big and Cheap are only two of ALS design goals. Henry pointed out earlier Maybe the whole trick is to have as an actual goal of being cheap and or big, rather than a "research" program sold on false promises (cheap). methinks that if NASA/US Gov't really wanted a cheap launcher it could build one quite easily, but then there would be no excuse for further research. Besides which, wouldn't the rest of the launch companies go belly up if company X blows them away with a cheap,reliable launcher? ------------------------------ Date: 26 Apr 91 14:16:08 GMT From: crdgw1!gecrdvm1!gipp@uunet.uu.net Subject: Re: Saturn V and the ALS In article , gaserre@isis.isis.cs.du.edu (Glenn A. Serre) says: > > > > *not* have to debug the design significantly. For example, we know the > > engines run reliably without serious combustion instability... and that > > is several years' development bypassed right there. > > BUT, engines could be made that burn less fuel and therefore lift > even more to orbit. Maybe rocketdyne could modify the F-1 to > bring it up to date. > >This is how we got the SSMEs. Increasing performance does not decrease >cost, nor does it increase reliability (neccessarily). The Saturn V could It is my understanding that the SSME and the F-1 are two different beasts a main difference being fuels. Isn't there alsoa difference in the method of fuel delivery/combustion in which the SSME opted for the more risky/tempermental approach (sort o like the difference in a rotary vs piston engine?). Have to cry here for the experts' explaination, and advice: could the F-1 be improved easily, either performance or manufacturability, or is it fine the way it is? >lift plenty of weight (mass, whatever) to orbit: 265,000 pounds. in light of several people asserting that it is the cost of the payload rather than the launcher which defines current launch rate, would a big booster by itself more expensive (but cheaper/kg) reduce overall launch costs by eliminating the need for expensive miniaturi- zation of the payload? > > >and they worked reliably. Maybe if we had been building and using F-1s since >the Apollo days, they would now be somewhat improved, but we scrapped the >tried and true Saturn for the complex, high-performance Shuttle and its >SSMEs. Ah, the wisdom of hindsight. It's about as useful as ifsight. Like, IF the shuttle had been done right (yeah I know I'm in a minority in saying the shuttle could have been built properly. I'm not saying it was the best of ideas, or that its promises were realistic, but I believe that a shuttle could have been built that was more up to spec) there would have been no regret about scrapping Saturn. or IF politics and porkbarreling weren't part of the space program we might actually be getting our money's worth. ------------------------------ Date: 28 Apr 91 14:35:58 GMT From: bionet!uwm.edu!wuarchive!rex!rouge!dlbres10@apple.com (Fraering Philip) Subject: Galileo works? I heard from a friend over here (who I guess heard it on the news) that the moment of inertia for the Galileo probe is totally in agreement with a correctly-performed antenna deployment. In short, the antenna deployed, but the sensor doesn't know (sound familiar to anyone?). Anyway, although more asteroid missions, in my humble opinion, might be a good thing, many thousands of people worked very hard on Galileo for the express purpose of looking at Jupiter and its satellites. It might even be optimized to the task. Moving Galileo to look at asteroids would probrably waste a great deal of the instruments for analyzing the space enviornment unless asteroids have ionospheres and magnetic fields. -- Phil Fraering dlbres10@pc.usl.edu Joke going around: "How many country music singers does it take to change a light bulb? Four. One to change the bulb, and three to sing about the old one." ------------------------------ Date: 28 Apr 91 14:48:15 GMT From: agate!bionet!uwm.edu!wuarchive!rex!rouge!dlbres10@ucbvax.Berkeley.EDU (Fraering Philip) Subject: Re: Saturn V vs. ALS In article <1991Apr27.230512.23682@zoo.toronto.edu> henry@zoo.toronto.edu (Henry Spencer) writes: >It is. Now for the hard part of the assignment: name three more such >investments, to justify the plural in "companies". The OSC/Hercules >Pegasus effort is a rare exception, not the rule. Space related: How about the decision by General Dynamics to go ahead with building the new Atlas-Centaur production line without enough orders in place already to pay for it? The proposed Iridium system? Aerospace related: the decision by Northrup to develop the F-20? They lost a billion dollars or so on that long-term investment thanks to the fact that noone would buy it unless the Air Force bought it, and the Air Force likes the F-16 more, even though the plane had to be totally re-done to get the contract the two planes were competing for... 777? The recent flight-test program for the 747-400, which (or so I gather) went above and beyond the call of duty in testing overloaded planes taking off and landing, among other things? -- Phil Fraering dlbres10@pc.usl.edu Joke going around: "How many country music singers does it take to change a light bulb? Four. One to change the bulb, and three to sing about the old one." ------------------------------ Date: 29 Apr 91 01:10:39 GMT From: bonnie.concordia.ca!news-server.csri.toronto.edu!utzoo!henry@uunet.uu.net (Henry Spencer) Subject: space news from March 11 AW&ST NASA's Precision Segmented Reflector program, aimed at mirrors for space astronomy, will terminate at the end of FY91. The excuse offered is that advances in adaptive optics etc. require some rethinking. The U of Houston Wake Shield project, intended to fly on the end of the orbiter's arm, is being upgraded to a free-flier, separated from the shuttle for a few days during a mission. The intent of the project is to provide an ultra-clean environment in the wake of a conical shield, and concerns about contamination from the orbiter have arisen. NASA decides to launch Atlantis despite minor hinge cracks. The cracks found in Atlantis are actually closer to being scratches, and are not as serious as the ones in Discovery and Columbia. The Ariane mission delayed due to third-stage worries flies; no problem. Launch dates for Cassini and CRAF have been swapped to give CRAF more development time and weight margin. Cassini goes in Nov 1995, CRAF in Feb 1996. The changes also include a Venus gravity assist for CRAF, which will add eight months to the flight time but increase payload and provide better fallback launch windows if CRAF can't make Feb 1996. NASA engineer at Reston, asked by visitor why his office and adjacent hallways lack models, photos, paintings of Fred, comments: "Are you kidding me? This is the Space Station Office. We don't know anything about hardware here!" [Meant humorously, but oh so appropriate...] OSC to get two new NASA contracts: seven Pegasus launches (plus options on three more) for Goddard's Small Explorer series, starting 1993 and running two per year, and five years of data from OSC's proposed SeaStar commercial remote-sensing satellite, starting in Oct 1993. The latter is noteworthy as the first government purchase of such data from a fully private venture. DARA (the German space agency) recommends cutting the size of the Columbus lab for Fred by a factor of two, mostly to cut costs but also to permit a fully-equipped launch. "If NASA is going to reduce their space station, I think we have the right to reduce ours as well." The resulting module will be about the size of Spacelab. The change would also help keep Columbus logistic support within its current allotment of shuttle space. NASA has not reacted officially, but Lenoir has said in the past that the NASA changes might well spark changes in the foreign modules, and that the US:foreign interfaces remain unchanged and the impact thus is minimal. ESA has also asked NASA whether the Columbus man-tended free-flyer can be serviced by the shuttle rather than by docking to Fred. This would be cheaper, but another concern is that docking the free-flyer to the station will be trickier with the more closely-spaced solar arrays of the new Fred design. DARA also thinks that the man-tended free-flyer and Hermes should get a program stretch, as both funding and manpower are tight for doing them, the Columbus Fred module, and Ariane 5 simultaneously. Arianespace is proposing to boost the performance of Ariane 5 [again!] because Hermes keeps gaining weight. -- And the bean-counter replied, | Henry Spencer @ U of Toronto Zoology "beans are more important". | henry@zoo.toronto.edu utzoo!henry ------------------------------ Date: 29 Apr 91 04:20:23 GMT From: agate!lightning.Berkeley.EDU!fcrary@ucbvax.Berkeley.EDU (Frank Crary) Subject: Re: Galileo Solution In article <1991Apr27.221502.21264@cs.rochester.edu> dietz@cs.rochester.edu (Paul Dietz) writes: >Perhaps a more sensible approach would be to jettison the reentry >probe, change the second gravity assist and salvage some science by >abandoning Jupiter and converting to a multiple asteroid flyby >mission. It could repeatedly swing by earth and/or mars to be >directed onto flybys of new asteroids. With luck, we could get >pictures of half a dozen or so, with the data from each encounter >played back over the low gain antenna at the next flyby of earth. While Galileo's scientific return from Jupiter would be much less if its antenna can not be fixed, that does not mean it will return no data at all. Also, Galileo's instruments are not intended for asteroid fly-bys. Since they are on the way, Galileo is looking at two of them, but that does not make Galileo a good platform for this work. In addition, the Jovian atmospheric probe could operate at 100%, even with out a high gain antenna on the orbiter. The orbiter could store the probe's data and slowly send it back to Earth. Even if the high-gain antenna cannot be deployed (why are you assming this by the way), Galileo would, in my mind, still be more usefull as a partially successful Juptier mission, instead of an improvised asteroid observer. Frank Crary UC Berkeley ------------------------------ Date: 29 Apr 91 04:09:30 GMT From: agate!lightning.Berkeley.EDU!fcrary@ucbvax.Berkeley.EDU (Frank Crary) Subject: Re: Saturn V vs. ALS In article rjc@cstr.ed.ac.uk (Richard Caley) writes: >The shuttle is really only a first stage and given that they won't use >a decent second stage for safety reasons, it might be nice to have >something bigger. >For instance, how long would Galleleo have taken to get to Jupiter if >launched on something with an engine under it? Would it be so much >more expensive when things like the ground support for all that time >are costed in? Yes, if Galileo had been launched on a liquid fuel upper stage, it would get to Jupiter in only a fraction of the time it will actually take. But this is an issue of crew (and orbiter) safty, not of payload size. The shuttle could (if one wanted to take the risk) have sent Galileo on a direct transfer. An unmanned rocket only slightly larger than a Titan could have. Such a launch would not have required a heavy lift launch vehicle. >Besides, there is nothing sacred about one payload per rocket. If you >have reasonable reliability, put two or three on it and have some >capacity left to be able to design heavier, cheaper payloads. While it is possible to launch several payloads on a single vehicle, this is not always possible. All of the launched payloads must want to go into more or less the same orbit. The builders must have all the payloads ready for launch at the same time (unless one company is willing to wait, and delay their launch for the benifit of another.) These things can be done, but you should not count on them when figuring launch costs. In reality, about half of the time, the launcher will have only a single payload, even if it is only half the maximum launchable mass. Frank Crary UC Berkeley ------------------------------ Date: Sun, 28 Apr 1991 18:16 CDT From: RDBROWN@UALR.BITNET Subject: Another Galileo Sulution Although putting a communications relay satellite in orbit around Jupiter is a good idea, one must remember that Jupiter's position changes during it's year, sometimes making it even further away from Galileo than Earth would be. Another possibility would be to launch a relay station into a trajectory aimed directly at Galileo, thus the relative position between it and Galileo remain unchanged. Relay-1 can then take on the task of tracking Earth. Later, as Relay-1 gets far enough away from Earth, Relay-2 can be launched to follow behind Relay-1 making it theoretically possible to follow Galileo as long as we keep launching relay probes. This approach would be ideal for following either Voyager 1 or 2, since both are far enough away from here to make their 22 watt signals increasing difficult and unreliable to receive. Just how much would it cost to design, build, launch and maintain a probe who's sole purpose would be to follow another probe, relaying transmissions from it to Earth (or another relay in the chain) and back again? Just how much payback would there be for such a simple probe if we are able to collect scientific data from increasing distances away from the Sun's influence, possible even as far away as the Oort cloud and further? As long as we are hypothetically sending another probe to act as relay to the first, we need to remember that the original satellites are going to run out of power someday. If each successive probe were fitted with it's own set of scientific measuring instruments, as the lead probe was finally shut down the next probe could be "powered up" so to speak to take over the responsibility of the mission. Any thoughts on this approach? Has this already been considered by JPL personnel? I would think that with the advances in our technology since the original Voyager probes were launched, fitting a new satellite to perform the basic task of relay station (plus having a good compliment it's own scietific equipment) would mae for a smaller, more cost-effective probe that could bring about a new level of scietific understanding of the extended solar environment. Robert Brown RDBROWN@UALR.BITNET ------------------------------ End of SPACE Digest V13 #477 *******************