Date: Sun, 9 May 93 05:07:52 From: Space Digest maintainer Reply-To: Space-request@isu.isunet.edu Subject: Space Digest V16 #550 To: Space Digest Readers Precedence: bulk Space Digest Sun, 9 May 93 Volume 16 : Issue 550 Today's Topics: landing at Edwards vs. the Cape (4 msgs) Pat and the Big Dan Vandalizing the sky. Will NASA's Mars Observer Image the Fa Will NASA's Mars Observer Image the Face on Mars? Welcome to the Space Digest!! Please send your messages to "space@isu.isunet.edu", and (un)subscription requests of the form "Subscribe Space " to one of these addresses: listserv@uga (BITNET), rice::boyle (SPAN/NSInet), utadnx::utspan::rice::boyle (THENET), or space-REQUEST@isu.isunet.edu (Internet). ---------------------------------------------------------------------- Date: 8 May 1993 18:05:52 -0700 From: Ken Hayashida Subject: landing at Edwards vs. the Cape Newsgroups: sci.space In article henry@zoo.toronto.edu (Henry Spencer) writes: >As for the takeoff and landing... an extra takeoff and landing or two in >a well-proven powered aircraft with substantial operating margins has got >to beat landing an unpowered orbiter with bizarre flying characteristics >and marginal landing gear in a crosswind at a site (the Cape) with only >one runway, solid obstacles to either side, and rapidly-changing weather. >-- | Henry Spencer @ U of Toronto Zoology | henry@zoo.toronto.edu utzoo!henry Henry, I appreciate your usually well-informed opinions. Do I sense disfavor regarding the US space shuttle? If so, why? Space Shuttle is certainly the most successful spacecraft series in the history of mankind. While I understand that the human race can do better, it is all that "the powers that be" have given my generation. I for one am not interested in waiting 10 years for independent corporations to develop SSTO/DC-X/DC-3. ;-) I would rather see us use the orbiter and perhaps derivative heavy lift capacity to serve as a bridge between the difficult access of yesteryear and the hoped for (but as yet unproven) projections of regular access in the future (which DC-X/DC-3 will fill) . Space shuttle- more people, more hardware, more trips than any other space vehicle. Who can argue with the numbers? Don't get me wrong, I like the DC-X idea...its Buck Rogers (recall, "People want Buck Rogers and that's us." from the Right Stuff). In a way, I kind of envy the skunk works mentality of the DC-X effort, and I am really hopeful that it'll be a stunning success because I have got a ton of experiments that I would love to fly in to space. Nevertheless, right now, shuttle is my only ticket into space. So, the old orbiter gets my support. I hope that the shuttle program receives your unwavering support as well. Really now, can we expect to be able to use DC-3/DC-X in space if we can't even automatically rendezvous & dock the orbiter with any target in orbit. DC-X is good, but its unproven. My prediction is that the preliminary phases of the program will go quite well. But, that the US federal government will have insufficient funds to support development of the full DC-3 during the first term of the Clinton Administration. If MacDac can fund a fully orbital vehicle, GO for it! If it works, they should be given hefty profits (like billions). But I'm not holding my breath...I'll just continue to root for them from the sidelines. Meanwhile, I hope the orbiter keeps on truckin'! Ken Hayashida khayash@hsc.usc.edu ------------------------------ Date: Sun, 9 May 1993 01:48:24 GMT From: Henry Spencer Subject: landing at Edwards vs. the Cape Newsgroups: sci.space In article <1shldg$4kt@hsc.usc.edu> khayash@hsc.usc.edu (Ken Hayashida) writes: >>...beat landing an unpowered orbiter with bizarre flying characteristics >>and marginal landing gear in a crosswind... > >I appreciate your usually well-informed opinions. Do I sense disfavor >regarding the US space shuttle? In this particular case, not necessarily. The sentence of mine that I've quoted above is verifiable facts, not opinion. I think we all agree that the orbiter is unpowered. :-) This makes the landing a zero-defects operation, with no ability to go around for another try if the first approach isn't right. This in itself is a big black mark against anything that tries to be an operational transport system, although it is acceptable for low-duty-cycle research aircraft like the X-15. The bizarre flying characteristics are well known. Even experienced pilots, trying the shuttle landing simulator for the first time, *invariably* crash it. Apart from the hideous sink rate -- if you jumped out at 30,000ft, the orbiter would reach the ground before you would -- the orbiter's flight characteristics are the wrong way 'round for a pilot used to normal planes. Say you're descending a bit too quickly. The normal pilot's reaction is to pull up a bit... but that makes the orbiter sink *faster*, because the increase in lift is overpowered by the increase in drag. To reduce your rate of descent, you put the nose *down*, and vice versa. This is a very difficult aircraft to fly. The marginal landing gear is a matter of record. The orbiters have gotten substantially heavier since the gear was designed. It's still within spec, *if* nothing goes wrong, but there is little room for error. For example, there is no redundancy in the main-gear tires: if you blow a tire at the wrong time (nose-gear touchdown, when main-gear loads are worst), the other one on that side will probably blow too, which will ruin your whole day. The situation is getting better -- they're adding redundant nosegear steering (avoiding the need for differential braking, which caused the only tire burst so far), the braking chute will reduce both braking loads and the nosegear-touchdown load (by holding the nose up longer), various other hardware improvements are being made, and some realistic gear testing is being planned at Dryden -- but it's still not a happy picture unless everything goes right. Combine all this with a landing site with only a single runway (so you can't escape having crosswinds) in the middle of a swamp (meaning you had better stay on the runway) with big strong manholes sticking up at intervals beside the runway (so you really, really had better stay on the runway), and those landings look like a bit more of a gamble than is normally considered desirable. Even without any pre-existing "disfavor regarding the shuttle". And in any case, I do plead guilty to considerable disfavor regarding the system in question... >Space Shuttle is certainly the most successful spacecraft series in >the history of mankind... This is very much a matter of opinion. It certainly hasn't met *any* of its specifications; that is not normally considered a success. I don't deny that it's a useful craft, and that cries to scrap it are premature, but illusions about it are counterproductive. >... it is all that "the powers that be" have given my generation. >I for one am not interested in waiting 10 years for independent corporations >to develop SSTO/DC-X/DC-3. ;-) Have you talked to your Congressthing about funding for DC-Y? If not, what are you waiting for? SDIO's original schedule called for orbital DC-Y flights starting in 1995. We *can* break out of this trap without waiting a generation, dammit! >...right now, shuttle is my only ticket into space... The shuttle will never be our ticket to space. Never. Ever. We're never going to fly in it. Business-as-usual will never get *us* into space. Delta Clipper just might. >... I hope that the shuttle program receives your >unwavering support as well. Sorry, support that I can arrange for launchers all goes to launchers that I have some hope of riding some day. At the moment, that's DC-X's hoped-for successors. -- SVR4 resembles a high-speed collision | Henry Spencer @ U of Toronto Zoology between SVR3 and SunOS. - Dick Dunn | henry@zoo.toronto.edu utzoo!henry ------------------------------ Date: Sun, 9 May 1993 02:33:35 GMT From: Francois Yergeau Subject: landing at Edwards vs. the Cape Newsgroups: sci.space In article henry@zoo.toronto.edu (Henry Spencer) writes: >In article rcs@cs.arizona.edu (Richard Schroeppel) writes: >> ... I don't think it would cripple the program to land at the Cape >> only when Edwards is unavailable... and that would be a better policy. >> >>Are you including the ferry-back risk in your assessment? >>Moving the vehicle back to the Cape requires a couple of takeoffs and >>landings, and they've had to work around a lot of bad weather in Texas. > > [...] > >As for the takeoff and landing... an extra takeoff and landing or two in >a well-proven powered aircraft with substantial operating margins has got >to beat landing an unpowered orbiter with bizarre flying characteristics >and marginal landing gear in a crosswind at a site (the Cape) with only >one runway, solid obstacles to either side, and rapidly-changing weather. Sounds a bit misleading to me. First, the 747 ferry is a modified aircraft, and thus not so well proven. Furthermore, its operating margins must be substantially reduced when carrying an orbiter on top - a non-negligible aerodynamic load in addition to its weight. Second, you still need to land the shuttle, so the fact that the shuttle is unpowered, has strange flying characteristics and a weak landing gear is irrelevant when comparing KSC and Edwards landing options. Only the disadvantages of the Cape itself remain to be weighted against the risks of the ferry-back trip. Which option wins? From a safety standpoint, Edwards may still win, but by a narrower margin than Henry's assessment implies. From an operational standpoint however, I think KSC wins handsomely: losing a few days per flight may not semm like much, but adding them up over a year probably means losing one flight, with basically no reduction in program costs (the _marginal_ cost of a shuttle flight is about 30M$, right?). That means the cost of each flight, each pound to orbit, each scientific result increases by more than 10%, and the sum total of what can be done with the shuttle (already severely limited by the low flight rate, a major shortcoming of the shuttle program) is reduced by a like amount. Remember, the low flight rate and high cost of the shuttle is what prompts some to call it a failure, despite its achievements. -- Franois Yergeau (yergeau@phy.ulaval.ca) | Qui se fait brebis le loup Centre d'Optique, Photonique et Laser | le mange. Dpartement de Physique | Universit Laval, Ste-Foy, QC, Canada | ------------------------------ Date: Sun, 9 May 1993 05:51:34 GMT From: Henry Spencer Subject: landing at Edwards vs. the Cape Newsgroups: sci.space In article <1993May9.023335.5119@cerberus.ulaval.ca> yergeau@phy.ulaval.ca (Francois Yergeau) writes: >... First, the 747 ferry is a modified >aircraft, and thus not so well proven. Furthermore, its operating >margins must be substantially reduced when carrying an orbiter on top >- a non-negligible aerodynamic load in addition to its weight. As I understand it, the only modification that is actually visible in its handling is the extra tailfins, and those bring the handling back towards normal rather than perturbing it. There are extensive structural modifications internally, but those are not airworthiness issues. The weight is actually not excessive for a 747, as I recall, although it's more concentrated than usual for a civilian freighter (hence the structural work). My understanding is that the aerodynamics don't mess up the handling much, *if* the shuttle tailcone is on -- which it is for all the ferry flights. Landing the 747 is still a whole lot safer than landing the shuttle. Not only is it a much better-handling aircraft, but it has *power* -- it can try again if something goes wrong with a landing. >Second, you still need to land the shuttle, so the fact that the >shuttle is unpowered, has strange flying characteristics and a weak >landing gear is irrelevant when comparing KSC and Edwards landing >options. Only the disadvantages of the Cape itself remain... Yes, but those are substantial when you are dealing with a landing that is difficult and has narrow margins to begin with. Edwards is a *much* better place to make a tricky landing. In fact, ailing military aircraft anywhere in the vicinity will divert to Edwards if they possibly can -- when there's something badly wrong, it's considerably safer than landing at a normal airbase. The shuttle is in that mode all the time. >... losing a >few days per flight may not semm like much, but adding them up over a >year probably means losing one flight... But they don't add! The ferry time for flight N overlaps with the preparations for flights N+1 and N+2 at least. Only the ferry times for *the same orbiter* add. -- SVR4 resembles a high-speed collision | Henry Spencer @ U of Toronto Zoology between SVR3 and SunOS. - Dick Dunn | henry@zoo.toronto.edu utzoo!henry ------------------------------ Date: Sun, 9 May 1993 01:10:20 GMT From: Henry Spencer Subject: Pat and the Big Dan Newsgroups: sci.space In article <985191f@ofa123.fidonet.org> Wales.Larrison@ofa123.fidonet.org writes: >>a new industry coalition is forming the national spacelifter >>consortium, formed of 5 companies... > Actually, it's Lockheed, GD, Martin, Rockwell, and _Boeing_. :-)... >... According to sources within the beltway, MDC supposedly >was invited to participate, but declined... Thank heavens there is *one* competitive company left. This consortium has a distinct smell of "let's make sure there's some easy pork for everybody on this one". -- SVR4 resembles a high-speed collision | Henry Spencer @ U of Toronto Zoology between SVR3 and SunOS. - Dick Dunn | henry@zoo.toronto.edu utzoo!henry ------------------------------ Date: Sat, 8 May 1993 21:51:09 GMT From: "Phil G. Fraering" Subject: Vandalizing the sky. Newsgroups: sci.astro,sci.space DPierce@world.std.com (Richard D Pierce) writes: >In article joe@montebello.soest.hawaii.edu writes: >> In Hawaii billboards of any kind are illegal. If a space-billboard's >>orbit carried it over Hawaii (which it almost certainly would) could they >>be prosecuted for violating Hawaii state law? >Come on, get serious. By the same logic, everytime Mir passes over the >U.S. borders, it would have to go through Customs and Immigration! >National and (especially) local territorial borders do not extend to LEO. I just realized something similar: maybe my rather flippant attitude towards people talking about their "right" to a dark sky is the fact that I live in Louisiana, which is like looking up at the sky from under about 20 feet of beef stew with mashed potatoes. -- Phil Fraering |"Where's my kaboom? Where's my Earth-shattering pgf@srl02.cacs.usl.edu|kaboom?" - anomynous "dark skies" activist ------------------------------ Date: Thu, 6 May 1993 15:53:20 GMT From: Gene Wright Subject: Will NASA's Mars Observer Image the Fa Newsgroups: sci.space mccall@mksol.dseg.ti.com (fred j mccall 575-3539) writes: > In <1993May4.135953.25192@mksol.dseg.ti.com> a193522@dseg.ti.com (Michael Mur > > >schumach@convex.com (Richard A. Schumacher) writes: > >> Settle the Face question? Hardly. 95% of people who care already realize > >> that it's a pile of dirt showing no intelligent modification. > > >Well now Richard, I didn't know you knew everything. The "face" is probably > >of dirt coupled with some nice shadowing effects, but not definitely. It is > >you obviously have a great interest in science but already succomb to turnin > >into fact without much evidence. At least Ron Baalke at JPL is not as close > > >..Your welcome, Ron. > > I thought that this was all pretty settled, actually, and that it *is* > definite that it is just a pile of dirt with some nice shadowing > effects. I think there's a picture of the same area with different > lighting and the thing looks nothing like a face. It's not even > bilaterally symmetrical. In fact, I seem to recall that one of the > things that makes it look so 'face-like' in the photo (one of the > eyes?) is actually an artifact -- a product of the imaging process > rather than anything that is really there, like a pixel dropout, for > example. > > -- > "Insisting on perfect safety is for people who don't have the balls to live > in the real world." -- Mary Shafer, NASA Ames Dryden > ----------------------------------------------------------------------------- > Fred.McCall@dseg.ti.com - I don't speak for others and they don't speak for m There is NOT a picture of the face area that shows it is a pile of dirt. NASA has only two good shots of the area from viking and both are at about the same local time with shadows. The picture doesn't exist that your reference. I just want to see the difference with the observer camera. That's all. Gene. -- gene@jackatak.raider.net (Gene Wright) ------------jackatak.raider.net (615) 377-5980 ------------ ------------------------------ Date: Wed, 5 May 1993 00:59:17 GMT From: Gene Wright Subject: Will NASA's Mars Observer Image the Face on Mars? Newsgroups: sci.space mccall@mksol.dseg.ti.com (fred j mccall 575-3539) writes: > In gene@jackatak.raider.net (Gene Wright) > > >All consipiracy theories aside, (they are watching though :-)), will NASA > >try to image the Cydonia region of Mars where the "Face > >" is? If they can image it with the High resolution camera, it would > >settle the FACE question once and for all. I mean, with a camera that > >will have a pixel resolution of about 6 feet, we'd know whether all this > >stuff is real or imagination. > > As I understand it, initially there were no plans to do this (because > it is apparently in a basically uninteresting area), but 'lunatic > fring' outcry has gotten things set up so that they will now run at > least one image of the area. > > From what I understand, the *original* picture is enough to convince > everyone whether this stuff is real or imagination, with the exception > of those folks who really want to believe in it. > > >Come on JPL and NASA folks, try to image it and settle this thing. > > Do you seriously expect to settle this kind of thing with *facts*? > That almost never works. It's not like it hasn't been tried in the > past. > > -- > "Insisting on perfect safety is for people who don't have the balls to live > in the real world." -- Mary Shafer, NASA Ames Dryden > ----------------------------------------------------------------------------- > Fred.McCall@dseg.ti.com - I don't speak for others and they don't speak for m But, you can't continue to believe that it is a face if you have resolution of about 6 feet per pixel and it looks like every other cliff on MARS. There are some "scientists" who are into this thing too. Please note, I don't believe this stuff personally, I just think its fun to look at how different people see the same thing and come to different conclusions. The big problem with the imaging is that the HIGH resolution camera cannot be aimed. It is bolted to the spacecraft and can only image what it is pointing at by the spacecrafts orientation. Enjoy. Gene -- gene@theporch.raider.net (Gene Wright) theporch.raider.net 615/297-7951 The MacInteresteds of Nashville ------------------------------ End of Space Digest Volume 16 : Issue 550 ------------------------------