Space Digest Wed, 28 Jul 93 Volume 16 : Issue 934 Today's Topics: 11 planets (2 msgs) 3-man Shuttle EVAs Budget figures Cats in zero gee (2 msgs) Cold Fusion and its possible uses (if it is proven to exist) DC-X (2 msgs) DC-X Prophets and associated problems (2 msgs) Found your own dark-sky nation? Low Tech Alternatives, Info Post it here! Musicians and space Needed: SS-Freedom update Odds on ACTS Passenger lotteries Why I hate the space shuttle 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: 27 Jul 1993 22:38:22 GMT From: Claudio Egalon Subject: 11 planets Newsgroups: sci.space > How come we don't send up a couple satellites to > investigate these two?? Because there are not any... Claudio Oliveira Egalon C.O.Egalon@larc.nasa.gov ------------------------------ Date: Tue, 27 Jul 1993 23:40:41 GMT From: Henry Spencer Subject: 11 planets Newsgroups: sci.space In article debbiet@tecnet1.jcte.jcs.mil writes: >I keep wondering. Seems to me I've read there is a planet >closer to the sun than Mercury. One which has an orbit which >most of the time we earthlings can't see... Time to go do some more reading. There was some suspicion of such a thing at one time, but there definitely isn't anything significant there. There is no "orbit which most of the time we Earthlings can't see"; we'd have seen it. There were a couple of reported sightings when the idea was fresh, but those are now tentatively ascribed to either human error or Sun-approaching asteroids like Icarus. >Also seems I >remember there is a planet the other side of Pluto... A couple of little iceballs have been found out beyond Pluto, but nothing worthy of being called a planet. There remains some speculation that there might be another planet out there, although various recent results have weakened that theory considerably. -- Altruism is a fine motive, but if you | Henry Spencer @ U of Toronto Zoology want results, greed works much better. | henry@zoo.toronto.edu utzoo!henry ------------------------------ Date: 27 Jul 1993 22:40:10 GMT From: Dave Akin Subject: 3-man Shuttle EVAs Newsgroups: sci.space,sci.space.shuttle In article Kennelmeister, dogbowl@dogbox.acme.gen.nz writes: >Why do the umbilicals points all have to be in the airlock? > >Is there any reason why a 3rd or 4th umbilical point couldn't be >rigged within the orbiter, with EV3 (4?) using that inside a sealed >suit, and ducking into the lock just before EV1 & 2 egress, >or following them out later. > >In some instances, would there be an advantage having EV3 >come out later and possibly doing turnabout with EV1 or 2? >(Is the airlock closed up and repressurised after EVs leave the craft? > Can it be?) Well, the simplest reason for not adding another EMU servicing port outside the airlock is that it would cost many $M. The necessary plumbing is in the airlock anyway, and the middeck space is already saturated with the demands of locker experiments, food preparation, exercise, etc. There is also a very simple flight rule used for EVAs: WHEN THERE IS A CREW MEMBER OUTSIDE, YOU NEVER, NEVER, NEVER CLOSE THE (OUTSIDE) HATCH FOR ANY REASON WHATSOEVER! While there has never been a problem, the potential for thermal distortion, failure of the depress or repressurization system, etc., presents the potential for someone stuck outside with no way in. That is not a happy picture, and not one NASA is willing to consider for any reason whatsoever. (Gotta say I agree with them on that point.) ------------------------------ Date: Tue, 27 Jul 1993 21:19:42 GMT From: "Allen W. Sherzer" Subject: Budget figures Newsgroups: sci.space In article <27JUL199314200470@judy.uh.edu> wingo%cspara.decnet@Fedex.MSfc.Nasa.Gov writes: >Allen is getting old folks and his memory is going so I will post again that >according to Business week (First week of May 93) That the only way that >the 5 billion dollar investment that GM made in Saturn would be termed a >profit is if GM were to "write off" the development costs. Sure. Of what relevance is that? NASA didn't write off the Shuttle development funds, they simply pretend they don't exist. Someday Dennis when you graduate and begin working in the real world you will learn the difference between the two. One important difference: if GM continues to do this for all it's projects, it will very soon cease to exist. NASA, simply promotes the people who screwed up and gets more money. One is working under a control system which encourages effieicnt activity, the other isn't. This is why, according to a recent NASA study, NASA spends six times on the average what a private company would for a development project. >Additionally, >the article stated that only when production reached the 300,000 unit per >year rate, which has recently happened, would GM make a profit on a per >unit rate. I think I missed something. You seem to be saying that I believe that all coprorations are always profitable. No, this isn't the case. In general, they need to be or, unlike government buracracies, they cease to exist. >According to an Earlier Space News article, using the 500 million per launch >figure is only correct when you add the infrastrucure costs incurred by >the TDRSS system and the worldwide ground support for that system. Dennis, Space News said that if you include all that, the costs goes to something like $1.5 billion per flight. But let's forget the article and look at the budget. According to the 1994 budget Shuttle costs are $4.193 billion which comes out to $524 million per flight assuming you use the optimistic rate of 8 flights per year. If we add a pro-rated share of NASA overhead, we get a cost of roughly $575M per flight. Now, if you look at the budget, you will see this figure does not include the $300M for ELV launches or the $820 million cost associated with TDRSS and ground support (the Space & Ground Networks, Communications, & Data Systems line item). Look at the numbers Dennis. A Shuttle flight DOES cost well over half a billion $$ and well over three times what the commercial launches cost. If you like, I will fax you a copy of the numbers on condition that you agree to not bring it up again. >Which by the way DC will have to pay for as well. Some, I'm sure. However, DC is designed to need minimal ground support so I don't think they will need as much as you think. >So your tired old argument about people being thrown in Jail for these >accounting methods is as false now as it ever was. This will come as a real suprise to the officers of RCA who where jailed in '85 for juggling costs like NASA does. Ditto for the officers who where fired from GD the same year. Allen -- +---------------------------------------------------------------------------+ | Lady Astor: "Sir, if you were my husband I would poison your coffee!" | | W. Churchill: "Madam, if you were my wife, I would drink it." | +----------------------89 DAYS TO FIRST FLIGHT OF DCX-----------------------+ ------------------------------ Date: Tue, 27 Jul 1993 22:38:41 GMT From: kjenks@gothamcity.jsc.nasa.gov Subject: Cats in zero gee Newsgroups: sci.space : In article <22vsl4$6v4@vixen.cso.uiuc.edu>, jbh55289@uxa.cso.uiuc.edu (Josh Hopkins) writes: : > Not a cat you like certainly. And by the way, cats do not take well to : > microgravity--it's been tried. Keith Mancus (mancus@pat.mdc.com) wrote: : Could you give me a reference to this? I wasn't aware it had ever been : tried. I heard an anecdote, second hand, from a guy who worked at the Air Force's zero-gravity training aircraft (similar to NASA's Vomit Comet KC-135, but a different aircraft). It seems that the guys on the flight line thought they'd grab the cat who hung around the hangars and see what happened when they took it up on a few dozen parabolas. It was not a pretty sight. By the end of the flight, the cat was spewing bodily fluids from every orifice it had and was fighting mad. Nobody dared to get near the poor thing -- it eventually dragged itself out of its corner and slunk unsteadilly off the airplane. It took them weeks to get the smell out of the padding. DON'T try this at home. (But if you do, please post the results.) (Or maybe write it up in a scientific journal -- they'd love it.) -- Ken Jenks, NASA/JSC/DE44, Mission Operations, Space Station Systems kjenks@gothamcity.jsc.nasa.gov (713) 483-4368 "HERE MEN FROM THE PLANET EARTH FIRST SET FOOT UPON THE MOON JULY 1969, A.D. WE CAME IN PEACE FOR ALL MANKIND." ------------------------------ Date: 27 Jul 1993 23:51:22 GMT From: "Thomas A. Baker" Subject: Cats in zero gee Newsgroups: sci.space In article <1993Jul27.223841.3491@aio.jsc.nasa.gov> kjenks@gothamcity.jsc.nasa.gov writes: >: In article <22vsl4$6v4@vixen.cso.uiuc.edu>, jbh55289@uxa.cso.uiuc.edu (Josh Hopkins) writes: >: > Not a cat you like certainly. And by the way, cats do not take well to >: > microgravity--it's been tried. What was the original question here? >Keith Mancus (mancus@pat.mdc.com) wrote: >: Could you give me a reference to this? I wasn't aware it had ever been >: tried. > >I heard an anecdote, second hand, from a guy who worked at the Air [description of folklore about a cat on the Vomit Comet] I'll confirm at least the part about cats on a plane. There was a picture in a book, decades ago, taken on one. A guy in the plane had a kitten hanging in the air next to his head. The cat's kind legs were up past its ears, and it had a very confused look on its face. But, I want to add, I think "not liking the Vomit Comet" is not the same thing as not liking zero gee. That plane supplies a two hour roller coaster type of thing, alternating between double gravity and zero gravity. I think a constant, gentle zero-gee would be much more enjoyable. Tom ------------------------------ Date: Tue, 27 Jul 1993 18:25:36 CDT From: U16072@uicvm.uic.edu Subject: Cold Fusion and its possible uses (if it is proven to exist) Newsgroups: sci.physics,sci.space In article <27JUL199310403557@csa5.lbl.gov>, sichase@csa5.lbl.gov (SCOTT I CHASE) says: >This problem, and it's hypothetical solution, is supposed to have been >a motivating factor in P&F's early experiments. But P&F claimed to >have stumbled upon an effect far larger than anyone expected. That's >where the reasonable science starts to end and the pathology seems to >start. Actually Steven Jones was motivated by this problem. He had measured a much ' smaller rate and no heat. I had never heard that P&F were motivated by it. -------------------------------------------------- Thaddeus Olczyk, University of Illinois at Chicago ------------------------------ Date: Tue, 27 Jul 1993 22:34:25 GMT From: fred j mccall 575-3539 Subject: DC-X Newsgroups: sci.space In <233j4p$ld1@voyager.gem.valpo.edu> mjensen@gem.valpo.edu (Michael C. Jensen) writes: >Pat (prb@access.digex.net) wrote: >: Who needs Doors? just idle the thrusters, and they should put out >: a gas stream that will keep the re-entry barrier off the nozzles. >: pat >Intersting theory.. anybody know if this would actually be possible? >(and it brings up a concern, if one jet fails, how bad a heat-leak >would it cause?) Allen? This stuff all seems right up your alley.. This was one of the reentry options looked at (rather than the 'pitch-up' manuever). Instead of entering nose first, enter base first with the engines idled. They may still try it that way, if the pitch-up from nose first entry proves too dicey. -- "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 me. ------------------------------ Date: Tue, 27 Jul 93 22:39:08 GMT From: sextonm@univrs.decnet.lockheed.com Subject: DC-X Newsgroups: sci.space In article <1993Jul27.163944.11903@iti.org>, aws@iti.org (Allen W. Sherzer) writes: > +---------------------------------------------------------------------------+ > | Lady Astor: "Sir, if you were my husband I would poison your coffee!" | > | W. Churchill: "Madam, if you were my wife, I would drink it." | > +----------------------90 DAYS TO FIRST FLIGHT OF DCX-----------------------+ ^^ Hey Allen, Whats the deal? Has the schedual changed radicaly? Matt Sexton ------------------------------ Date: Tue, 27 Jul 1993 23:05:16 GMT From: Tommy Nordgren Subject: DC-X Prophets and associated problems Newsgroups: sci.space In article <1993Jul26.011323.1099@cs.rochester.edu>, dietz@cs.rochester.edu (Paul Dietz) writes: |> In article <1993Jul26.001949.1882@kth.se> f85-tno@nada.kth.se (Tommy Nordgren) writes: |> |> >|> In article <1993Jul21.232359.26378@cs.rochester.edu> dietz@cs.rochester.edu (Paul Dietz) writes: |> |> >|> >What is most galling about all this is that cheaper, simpler |> >|> >alternatives that could have reduced launch costs considerably were |> >|> >under development in the 1960s. |> |> > Not only that, but except that the designs suggested in the sixties |> > almost always used disposable tanks for hydrogene, they were basically very |> > similar to the DC-X design. |> |> No, you are very confused. The designs I am talking about were about |> as different from DC as they could be. Different design philosophy, |> different fuels, different materials, different engine type. These |> would *not* have been SSTOs; some were to be completely expendable. |> |> The DC-series is based on the idea of making an expensive vehicle and |> reusing it to amortize the cost over many launches. The Big Dumb |> Booster idea was to make a very cheap expendable rocket from low tech |> materials, like steel, sacrificing some Isp for lower complexity and |> cost (for example, using ablatively cooled engines rather than complex |> regeneratively cooled engines, and using pressure-feed instead of |> turbopump-feed). |> |> Paul F. Dietz |> dietz@cs.rochester.edu |> |> "Absolute stupidity of the worst sort" |> -- Freeman Dyson commenting on the space shuttle. I was referring specifically to the following suggestions: Pegasus,ROMBUS,Hyperion, which were all suggestions very similar to the DC-X design -- ------------------------------------------------------------------------- Tommy Nordgren "What is a woman that you forsake her Royal Institute of Technology and the hearth fire, Stockholm and the home acre, f85-tno@nada.kth.se to go with the old grey widow maker." -------------------------------------------------------------------------- ------------------------------ Date: Tue, 27 Jul 1993 23:51:05 GMT From: Keith Mancus Subject: DC-X Prophets and associated problems Newsgroups: sci.space mjensen@gem.valpo.edu (Michael C. Jensen) writes: > and personally I believe that people get more excitement and pride out of > our manned missions than our unmanned missions, justified or not.. That's the fundamental difference, you see. I am not interested in "excitement and pride"; I am interested in living and working in space myself someday. If I can't, then my children. I am NOT NOT *NOT* interested in anything which does not move us toward that goal. I suspect this is the real reason that many people are pushing for more commercial spaceflight today. It's not that they are fanatical libertarians; they are just tired of seeing space as a big PR/glory campaign, and figure that some hard-headed businessmen are more likely to move spaceflight towards maturity. I approve of Henry Spencer's criteria. He said something like "my support is reserved for vehicles I have a hope of riding someday". Amen. -- Keith Mancus | N5WVR | "Black powder and alcohol, when your states and cities fall, | when your back's against the wall...." -Leslie Fish | ------------------------------ Date: Tue, 27 Jul 1993 23:08:08 GMT From: Leigh Palmer Subject: Found your own dark-sky nation? Newsgroups: sci.astro,sci.geo.geology,sci.space In article <233ni7$roi@access.digex.net> Robert Bunge, rbunge@access.digex.net writes: >So was using a 6-inch f/5 reflector from a ship on the equator >in the middle of the Indian Ocean (during the winter). OK, Bob, let us in on how one defines winter on the equator. Leigh ------------------------------ Date: Tue, 27 Jul 1993 23:23:23 GMT From: Keith Mancus Subject: Low Tech Alternatives, Info Post it here! Newsgroups: sci.space In article <231kn3$cv0@agate.berkeley.edu>, gwh@soda.berkeley.edu (George William Herbert) writes: > The only problem with this is that Space isn't inherently a small-business > environment. The business plan for Retro for example, at the _lowest_ > expected flight rate, is making ten million dollars a year in 1995 or 96, > and the high end of the possible growth curve has us in the half-billion > range by 1998. So do I become a bad guy once I start making serious > money? Personally, I define a small business in terms of number of people employed rather than $$$ earned. The reason for this is that bureaucracy, the enemy of creativity, correlates well with the number of employees. So no, earn as much as you can, just don't turn into an empire. -- | Keith Mancus | | N5WVR | | "Black powder and alcohol, when your states and cities fall, | | when your back's against the wall...." -Leslie Fish | ------------------------------ Date: Tue, 27 Jul 1993 22:47:52 GMT From: kjenks@gothamcity.jsc.nasa.gov Subject: Musicians and space Newsgroups: sci.space amon@elegabalus.cs.qub.ac.uk wrote: : Lots of people straddle : music and science. Weir of the Grateful Dead was one of the original : L5 members. Astronaut McNair was a jazz musician, and one of his : friends did a video that was on MTV as a remembrance. : Look at all the rock bands that used space themes in their music and : in their videos. ZZ Top "Rough Boy" comes to mind, as do many others. : I won't put myself in anywhere near the same category, but I did get : my (albiet small) PRS check this month :-) (That's the UK/Ireland : equivalent of ASCAP and BMI, only better ;-) You probably won't find them on any major labels, but the NASA Astronaut Office sports its own band, Max Q. These are astronauts (mostly) who play at selected official and (mostly) unofficial functions. They're not bad at all, but I don't think they've ever gotten a video produced a la MTV. -- Ken Jenks, NASA/JSC/DE44, Mission Operations, Space Station Systems kjenks@gothamcity.jsc.nasa.gov (713) 483-4368 ASCAN (Astronaut Candidate) 10 COMMANDMENTS 1. Keep smiling, but not grinning 2. Keep your humor harmless, pure and perfect. People don't understand irony. 3. Keep your weaknesses to yourself. If you don't point them out to others, they will never see them. 4. Never complain; make survival look easy. 5. You are expected to say something nice after each flight, class, of simulation. 6. If you can't say something nice, lie -- nicely. 7. In particular, practice saying, "Thanks for pointing that out, sir. I'll really work on that." 8. Be aggressively humble and dynamically inconspicuous. Save your brilliance for your friends and family. 9. Remember -- whatever's encouraged is mandatory. Whatever's discouraged is prohibited. 10. Nothing is sometimes a good thing to do and always a clever thing to say. REVIEW THIS LIST DAILY ------------------------------ Date: 27 Jul 1993 22:01:39 GMT From: Tony Hamilton Subject: Needed: SS-Freedom update Newsgroups: sci.space Where can I find a comprehensive update of the status of SSF today? Something which explains what the current design is, what work has been done so far, schedules, and so forth. Is there a document on the Internet somewhere? A good article in a recent magazine? Ya hear things now and then on the news, but not much (like the recent decision to lay off a thousand or so people working on the project). Any help would be appreciated. Thanks. Tony Hamilton thamilto@pcocd2.intel.com ------------------------------ Date: Tue, 27 Jul 93 02:23:00 BST From: h.hillbrath@genie.geis.com Subject: Odds on ACTS > Date: Fri, 16 Jul 93 06:32:00 -0500 > Charles Radley Writes: Pa> Message-ID: <224jka$g8j@access.digex.net> Pa> Newsgroup: sci.space Pa> Organization: Express Access Online Communications, Greenbelt, MD USA Pa> In article henry@zoo.toronto.edu (Henry Pa> Spencer) writes: Pa> |In article <223vf2$58d@access.digex.net> prb@access.digex.net (Pat) Pa> writes: |>But real question. ANyone know why it's going up on the TOS? |>I guess the IUS is too small and the Centaur is banned from shuttle ops. Pa> | Pa> |No, IUS is too big. TOS is a mid-sized upper stage, for loads too Pa> heavy |for PAMs and too light for effective use of IUS. Unfortunately Pa> for OSC, |there aren't many such shuttle payloads any more. Pa> |-- Excuse me for interjecting here, I am sure that all the experts, like Henry and Pat understand all this, but I am afraid that there may be those who do not understand the relationship between the TOS and the IUS. The IUS is a two stage vehicle which consists of two solid rocket motors, called, very unimaginatively, SRM-1 and SRM-2. Unlike most of the current upperstages, it takes a payload from a low orbit and delivers it to geostationary orbit (if that is where the customer wants to go) with out any action by the payload, and with no spinning, jostling, or other disturbances which some of your more discriminating payloads do not like. In addition to the two solid stages there is also a full set of avionics, including dual inertial navigation systems, a reaction control system, and other payload services. (The IUS has also been used for several planetary missions, firing the two SRM sequentially to attain earth escape velocity, which, as it turns out, is somewhat easier than GSO.) As far as "size" goes, the IUS is roughly the same weight as the Shuttle Centaur was going to be, both push the Shuttle to its max weight limits, both are variable in propellant capacity. Obviously, the Centaur, with LO2/LH2 has somewhat more payload capacity, on paper. At some point, NASA decided that for some missions, they didn't want anything except the first stage, and for reasons that I won't go into (for one reason, I am not unbiased, having been associated with the IUS program for quite a while, and another, I don't know all the details, and couldn't talk about them, if I did.) it was decided to buy a "new" vehicle from a different source. However, the "loaded motor case" was identical to, and produced by the same supplier as the IUS motor. Therefore, the TOS is exactly the same size as the IUS SRM-1, which is a maximum of about 21,000 pounds of propellant. The nozzle is different, in that it does not have thrust vector control capability, and, of course, it does not have the actuators, either. Pa> I sincerely hope the Manufacturing costs of a TOS are significantly Pa> less then both a centaur and a IUS then. The parts of the TOS that are the same as the IUS cost exactly the same, presumably, to produce. (There is, of course, a difference in "cost" and "price.") As it turns out, there has only been, I think, one TOS launch to date. The Mars Observer. Due to some bad luck, the TOS motor was damaged in handling (could have happened to anyone) and it was replaced with a "loaner" IUS motor, so in that case, I think that the cost was probably exactly the same. > IUS puts the payload into circular GEO. ACTS and all commercial > comm-sats need to go into GTO, it is cheaper to use an on-board > apogee kick than use the IUS. Based on the idea that it is cheaper to have a custom designed apogee motor, avionics, and software in each payload than to have one common set for all. A lot of people believe this, and it probably is true that almost anything costs less than an IUS second stage and avionics package, but that does not make it true, in general. > IUS was designed to Air Force requirements, not commercial requirements. Not only was the IUS designed to Air Force requirements, it is an Air Force program, which means that if NASA wants one, they have to get it from the Air Force. Having two agencies involved always seems to cause problems, it has been alleged that there was some friction between those two organizations over the AF having to procure launch services from NASA, and it is possible that there could be something like that in return, who knows? That could have had something to do with the reasons for NASA preferring the TOS in the first place. A way to get an already developed motor directly, without having to deal with the AF. Although it may well be that the TOS is cheaper in the abstract, I think that it is very questionable if it did in fact save money if there are only the two launches that are now programmed (to my knowledge) as there were considerable "non recurring" costs associated with it, and there are "hidden" costs, too. Someone has to do the second burn for GSO, which the TOS does not do.And, someone has to provide the avionics, software, integration, etc. although it may be charged against something other than the launch vehicle. Spacecraft managers do have a tendency to see money spent "in their own shop" as being quite different from that which goes "out of house." . Henry S. Hillbrath ---------------------------------------------------------- NO ONE believes an analysis... | EVERYONE believes a.test... - except the guy who did it. | - except the guy who did it. T. M. ("Scotty") Davidson ------------------------------ Date: 28 Jul 1993 00:02:56 GMT From: Josh Hopkins Subject: Passenger lotteries Newsgroups: sci.space nsmca@aurora.alaska.edu writes: >Now to old business, what about a lottery to ride onthe shuttle or DC-X?? The shuttle is flat out not available for tourists and the DC-X is not a passenger vehicle. It might be possible for a modified DC-X to carry a passenger (Conrad volunteered and managment has threatened, but both jokingly). However, DC-X is not a space vehicle. It's not even supersonic if I recall correctly. >=== >Ghost Wheel - nsmca@acad3.alaska.edu -- Josh Hopkins jbh55289@uxa.cso.uiuc.edu "Physics is like sex: sure, it may give some practical results, but that's not why we do it." -R. Feynman ------------------------------ Date: 27 Jul 1993 21:16:07 GMT From: henshaw@hops.larc.nasa.gov Subject: Why I hate the space shuttle Newsgroups: sci.space In article <2835@heimdall.sdrc.com>, spfind@sgidq7.sdrc.com (jeff findley) writes: |> In article <230m4i$enm@voyager.gem.valpo.edu>, mjensen@gem.valpo.edu (Michael C. Jensen) writes: |> |> |> : 7) I have a better more reliable computer system in my 2 mb amiga 500 |> |> |> |> Perhaps a cheaper more powerful system (in SOME respects) but more |> |> reliable?.. no.. |> |> How about triple redundant Amiga 500's with a backup Amiga 500? This is |> how the shuttle's computers are reliable, aside from being radiation |> hardened, etc. Well, not exactly. Triple redundancy is _one_ way they are made reliable. Another has to do with spaceflight certification. The three main shuttle computers are IBM processors, whose main design was around in the 1960s. (Read: VERY SIMPLE). The Amiga 500 is based on the Motorola 680x0 family, around since the 1980s. In this case, newer is not necessarily better: instead, it is more complex, and the more complex a computer system is, in general, the more statistically possible it is for that system to fail. In fact, I have heard from some NASA people that the Intel 80486 family will probably never be spaceflight certified: it is just too complex to be relied upon. -- Glen Henshaw HALOE Data Processing henshaw@hops.larc.nasa.gov "Stop being stupid." This advice is offered in leiu of . ------------------------------ End of Space Digest Volume 16 : Issue 934 ------------------------------