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 ; Sun, 12 May 91 01:56:06 -0400 (EDT) Message-ID: Precedence: junk Reply-To: space+@Andrew.CMU.EDU From: space-request+@Andrew.CMU.EDU To: space+@Andrew.CMU.EDU Date: Sun, 12 May 91 01:55:59 -0400 (EDT) Subject: SPACE Digest V13 #530 SPACE Digest Volume 13 : Issue 530 Today's Topics: Re: NASP and Aurora Re: Terraforming Venus? 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: 7 May 91 23:02:50 GMT From: littlei!intelhf!ichips!news@uunet.uu.net (Larry Smith) Subject: Re: NASP and Aurora Craig Cole writes: >Any chance anyone out there working on the NASP can post regular updates >on progress with the NASP? > >Scientific/Engineering hurdles & successes, budget concerns, progress >on the prototype when its construction is started... > >I for one am very interested, and can't seem to find enough about >it in magazines, etc. I bet a lot of others are interested too. That's good to hear. I know of people working on a book about NASP (I've even been asked to help), however they are having trouble getting a publisher to sign up. A lot of the publishers are waiting for 1993, when the decision on building 2 vehicles will be made. I believe this is a mistake. Even now, there is a very interesting story here because of the history of this type of aircraft. For example, there was a project called ASP (AeroSpace Plane) back in the 60's, and there have been many government and aerospace company funded looks into this type of aircraft, or its propuslion systems, ever since the early 50's. There is a lot of information that is now declassified and available. This information provides a good background in which to frame the current program. Classic Motorbooks is the only publisher interested in a NASP book now and Bill Sweetman is aledgedly interested, although I have no confirmation of this. We are checking on this now. Michael Kent writes: >Probably not a good idea. Most of NASP is classified. What isn't will prob- >ably be in Henry Spencer's AvWeek summaries. For a peek at the program, check >out the 29 Oct 90 issue of Aviation Week. A lot of the hypersonic technology that will be used to design NASP is NOT classified. In other words the basics are not classified. The advanced application of that technology IS mostly classified, but one can certainly go a long way at educating the public about these systems by using the basics. You can indicate where the hard parts of the design are (all of it), and what the characteristics of the solutions are. Also, some of the foreign teams are talking about their successes, and it is possible to learn a lot from that. You can also talk about some of the unclassified university based research, that the NASP national team may never use now, but nonetheless, is very interesting. You can also infer things about NDVs (NASP Derived Vehicles) which would be highly classified (at least the military ones). Right now Craig Cole is right. The public has only been given very simplistic information about this program. I don't think that the NASP program is against any positive pro-NASP information getting out to the general public. These types of aircraft, to me, are THE most exciting aircraft ever! Also, this program, even in flight test, will be a technology development program. I think the public would easily understand that if they understood the basics. Allen W. Sherzer writes: >Well, I don't work on it but one of my congressional sources is very >interested in it. I'll ask him now and then and post what I can. > >One very interesting thing has happened recently on the political front. >In recent testimony military whitnesses have been very enthusiastic about >NASP. This is a far cry from past years when they saw no need for it. They >now see lost of missions for it now and are interested in funding it. This >is a far cry from years past where they zeroed out their part of the funding. > >If this continues, the large hurdle which NASP needs to cross to get a >vehicle built will be a lot easier. See Aurora comment below. Mary Shafer writes: >I don't want to discourage your interest, but you should be prepared >for a lack of real information. Well if your talking about, for example, the real shape of the inlet on the underside I agree, we will have to wait for rollout in 1996 or whenever. However if you are telling me that I just spent $350 to have Dr. Kevin Bowcutt, head of the NASP nozzle design effort, lie to me and give me and other engineers, disinformation on hypersonic aerodynamics, I will be ticked!! Dr. Bowcutt used an airframe design very similar to the current team NASP design in his lecture on hypersonic vehicle design. He even pointed that out in his lecture. He presented a design methodology for hypersonic accelerators (aircraft). Now I'm not expecting that Dr. Bowcutt told us everything, but the points he did make were VERY interesting, and I think that a lot of people would be very interested. I was even saying to myself during the class, I don't believe this stuff is unclassified! Geee, I wonder what the classified stuff is!! So I guess I'm saying, hey, there is some really great unclassified stuff on this program out there! Doug Mohney writes: >NASP is quite probably liberally building on "Aurora" and other black >hypersonic projects. Phil Fraering writes: >What if it isn't? I get the strong feeling that a lot of duplication >of effort is going on. Yes, this possibility was brought out in a AW&ST story back in Dec, 89. Many NASP people claim no knowledge of what we call Aurora. They even claim that after the AW&ST articles, they tried to find out, with no luck. The Air Force claims no knowledge of it either. As Allen W. Sherzer wrote earlier, the Air Force's sudden appreciation of the program is interesting (actually they have always been interested, they were just never officially interested). I have a recent technical document (not with me) written by an Air Force officer on NASP stability and control. He says something very interesting at the end of the document. He says that hypersonic cruisers are already possible. NASP's goal is to develop hypersonic accelerator technology. Maybe in that context, the Air Force can now feel good that there isn't a duplication of effort going on. In other words, Aurora would provide hypersonic cruiser technology, and NASP would provide hypersonic accelerator (SSTO) technology. Ever wonder why the NASP team design isn't a waverider type design? That's why. For hypersonic accelerators, you don't need the high hypersonic L/D that you need on a cruiser. Waveriders currently have the highest known hypersonic L/D's (on-design). There is controversy about their off-design capabilities. That is still being researched. It is not necessarily true though that an existing hypersonic cruiser would be a waverider. Larry Smith larry@ichips.intel.com ------------------------------ Date: 8 May 91 16:01:01 GMT From: stanford.edu!agate!tornado.Berkeley.EDU!gunter@decwrl.dec.com (Michial Gunter) Subject: Re: Terraforming Venus? Disclaimer: I'm temporalily using my friend's account. Please do not reply to this article by mail. In article <11990@jarthur.Claremont.EDU> jhuyghe@jarthur.Claremont.EDU (Julien David Huyghe) writes: >Could a couple of HUGE fusion bombs (in the 1000 gigaton range) blast away >99% of Venus' atmosphere, leaving us with a manageable situation? Or is >it just too much trouble launching a couple of aircraft-carrier-sized >bombs? Many suggest using thermonuclear explosion for terraforming for obvious reason: Enomous energy required for terraforming. Let me discuss this issue in detail. I'm not sure if H-bomb has enough energy and more importantly, controllability to get rid of enough CO2-rich atmosphere. But this is not the only thing we need enomous energy. Do you remember that Venus has very long sidereal period (i.e. day), which is actually longer than the rotation period w/ respect to the Sun (i.e. year). This causes a lot of problem in its atmosphere. Longer day means more temperature difference between day and night. And/Or stronger wind from day resion to night resion. To control the Venusian climete, we have to do something to it. We can either adapt Venus to us or vise versa. 1st solution doesn't deserve the name of terraforming: We are to adapt the environment to us, not us to the environment. So we have to increase the rotational period of venus. And window-of-an-DA calculation (90's way of saying "back-of-the-enverope") says we just don't have enough energy at our disposal. Venus has mass of 4.87e24 kg. And its radius (equatorial) is 6052km. Thus the moment of inertia, provided its mass is distributed evenly is: I = 2/5 MR^2 = 7.21e+37 kgm^2. Thus in order to accerarate its day to one earth sidereal day (= 23h 56m 04s), Energy it takes would be: K = 1/2 Iw^2 (sorry no small omega in ascii) = 1.92e+29 kgm^2s^-2 (J). In mass, divide it with c^2 and we get 2.13e+12kg! Of course this is just a WOADA calculation. But I think this figure is correct by magnitude. We don't know how fast is fast enough (Slower the better, of course: By factor of the square of its angular velocity). But we don't have 1 trillion tons of antimatter or alternate energy source, much less how to apply that much energy properly. I don't know how much energy 1 megaton of TNT releases (Anyone?) But you got the point. In this respect, Mars is much easier to terraform for it already has fast enough day (almost 1 Earth Day). Probably it takes "Vacuum Energy Drive" used in the A.C. Clarke's great novel "The Song of Distant Earth". In that novel it first decomposes polar cap of Sagan 2--planet the last people of Earth abord Magellan would colonize--to oxygen and hydrogen using its infinite energy from the "Quantum Drive" (Alias "Vacuum Energy Drive"). Then Magellan lands on Sagan 2 and with its omnipotent Quantum Drive to push Sagan 2 inward to its sun up to the habitable zone. With something like Quantum Drive terraforming Venus would be as easy as, say, constructing English Channel Tunnel. But we don't even have fusion for terraformer's sake!!! From economical point of view, terraforming in general, perticularily venus, takes too much work for too little gain compared to such alternatives as Space Colony--Even O'nell's Island 3--A 6km in diameter and 32km long--is just a Barby's house compared to terraforming any planet. I can bet (even though I know I can't live long enough to collect my wager) all my fortune and organ that terraforming will not come before we move most of us humankind up to Space Colony. And with Colony I wounder if our future government has any need for terraformed planets--Study alone would cost many magitudes more than the Gloss Global Product. Still, I dream of terraforming. Especially Venus. Venus is just so close to Earth. Venus never made children like its sister Gaia did. Isn't it really impossible to "convince" her to adopt some of her sister's children which are us? I am sorry for myself being born couple of millenia too early--late enough to know of terraforming, too early to see it come true. It's not life that sucks. Gravity sucks life. ------------------------------ End of SPACE Digest V13 #530 *******************