Space Digest Sun, 8 Aug 93 Volume 17 : Issue 001 Today's Topics: 6 million parts... DC-X Update 8/6/93 (4 msgs) Do astronauts use sleeping pills? (2 msgs) engine failures and safety Exploding Heads Info on the upcomming Perseid shower new nasa wind tunnels Refit/Rebuild old Rockets! Low Tech? Standardize! (3 msgs) What is ZHR? Why I hate the space shuttle (2 msgs) 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: Sat, 7 Aug 1993 15:18:54 GMT From: Quagga Subject: 6 million parts... Newsgroups: sci.space In article amon@elegabalus.cs.qub.ac.uk writes: >> Seems to me that I heard that this was actually said by one of the >> Mercury astronauts during an interview on a Florida radio station >and >> went something like, "You are sitting out there on top of one of >the >> most complex, powerful things ever put together, and you know that >all >> 6 million parts were let to the lowest bidder. How would *you* >feel?" >> > > >Not a legend. It is quoted on the To The Moon record set by >Time/Life, circa 1970. > Golly, synchronicity! I was just suggesting to the keeperof the SPACE-TRIVIA list that he perhaps start a "pithy astronaut sayings" section, and start it with this quote. It's Michael Collins, Apollo 11 CMP, and is quoted in his book "Carrying The Fire" which you might find interesting.. equus quagga. quagga@trystero.com "But you can call me Cheryl.." "I have found that a non-opening parachute will get your COMPLETE and UNDIVIDED attention very very quickly." -me. ------------------------------ Date: 7 Aug 1993 14:39:02 -0500 From: hvanderbilt@BIX.com Subject: DC-X Update 8/6/93 Newsgroups: sci.space DC-X Update, August 6th, 1993 Copyright 1993 by Henry Vanderbilt and Space Access Society. DC-X Test Program Status DC-X Background DC-X is a low-speed flight regime testbed for a proposed reusable rocket- powered Single Stage To Orbit (SSTO) transport, McDonnell-Douglas Aerospace's "Delta Clipper". DC-X is intended to prove out rocket-powered vertical takeoff, nose-first lifting-body to tail-first flight transition, and tail- first landing. It is also intended to prove out rapid turnaround of a reusable rocket by a minimal ground support crew. DC-X is being tested and flown by approximately thirty people. DC-X has already pretty much proved out rapid low-cost development of an advanced aerospace X-vehicle type engineering testbed by a small highly- motivated engineering team on a tight budget. DC-X was built by less than two hundred people, in less than two years, for about $60 million. Of course, this sort of thing has been done before -- just not recently. DC-X stands 40 feet tall, is 13 feet across the base, and is roughly cone- shaped, with a circular cross-section forward blending into a square base. The vehicle has four maneuvering flaps, one set into each side near the base, and sits on four landing legs. DC-X masses 22,300 lbs empty and 41,630 lbs fully fuelled, and is powered by four 13,500 lb thrust Pratt & Whitney RL-10- A5 liquid oxygen/liquid hydrogen rocket motors, each able to gimbal +- 8 degrees. The RL-10-A5 is a special version of the RL-10-A designed for wide throttling range (30% to 100%) and sea-level operation. The single DC-X vehicle was officially rolled out of its construction hangar at MDA's Huntington Beach CA plant at the start of April, then trucked out to White Sands, New Mexico for ground and then flight tests. Between Thursday, May 20th and Thursday, June 17th, DC-X underwent a series of nine engine firings/vehicle systems exercises, including two firings in one day with complete defueling/vehicle servicing/refueling in between. On Friday, June 18th, the DC-X crew began breaking down the ground support equipment and moving it to the White Sands Missile Range (WSMR) flight test site, a distance of about fifty miles. Meanwhile DC-X was stored in a hangar. On Friday, July 16th, the ground support equipment move was completed. DC-X was taken out of storage, trucked out to the flight test site, and hoisted upright onto its launch pad. On Monday, July 19th, the DC-X crew began running a series of ground tests to make sure everything had made it over intact and was hooked back together properly. Latest DC-X Flight Date Estimates DC-X is currently at the White Sands Missile Range (WSMR) flight test site, undergoing final ground checkout before flight test gets underway. The pre-flight checkout looks like culminating in a "burp test" this weekend. This will be a four-second "hot firing" of DC-X's engines, with DC-X locked down on the launch pad, to check that all the plumbing is OK. The plan is to do this tomorrow, Saturday. If things run late they'll come back and do it Sunday. Up till now they've generally been taking Sundays off. If this hot firing test doesn't find any problems, the "bunny hop" flight stability test series should start one week later. The first of these stability test flights is tentatively set for -- wait for it -- Friday the 13th, with Saturday and Sunday of that weekend as the backup dates. These flights will consist of takeoff, sideways transition of several hundred feet, and landing, done under varying wind conditions. A lot of people will be keeping their fingers crossed during the initial "bunny hop", as it will be the first real-world test of DC-X's stability at low speed and altitude, a critical and hard-to-simulate part of the VTOL (Vertical Takeoff and Landing) flight envelope. The official "first" DC-X flight will actually be the initial flight of the second test series, when they'll be going for higher speeds and altitude. This will be the one with speeches, hoopla, VIP's, and media coverage, but alas still no admission of the general public. Chances are good for TV coverage though, between NASA Select, local TV stations, and the national networks. Chances are too that you'll have a better view on TV, since the "VIP" viewing site will be five miles from the pad. At this point the "first" flight looks like taking place two weekends from now. McDonnell Douglas says "no later than Monday August 23rd", assuming all goes well in the meantime. Given that the invitations mention a tour of the test site the day before, with the actual flight at 8 am local time (10 am Eastern), Sunday the 22nd seems most likely, with the 23rd as backup date. This assumes that they want to let the invitees fit the trip into a weekend. This may not be the DC-X crew's highest priority, however, and rightly so. The end-for-end transition maneuver won't be tried until the third, final flight test series. DC-X Followon: Political Status Background The current DC-X program is funded through flight test and data analysis this fall, and ends after that. There is an ongoing effort to get the US Congress to fund a three-year followon program, currently called SX-2 (Space Experimental 2). This tentatively looks like being a reusable suborbital vehicle powered by 8 RL-10-A5 engines, capable of reaching Mach 6 (about 1/4 orbital velocity) and 100 miles altitude, built with orbital-weight tanks and structure, and able to test orbital grade heat-shielding. The SX-2 program goal will be to demonstrate all remaining technology needed to build a reusable single-stage-to-orbit vehicle. Once SX-2 has been tested, all that should be necessary to produce a functioning reusable SSTO is to scale up the SX-2 structures and install new larger rocket engines. Proposed FY '94 funding for SX-2 startup is $75 million. Total SX-2 program cost over the next three years would be very much dependent on the contractor chosen and the details of the design, but would be on the order of several hundred million. This is the same order of magnitude as typical recent X- aircraft programs such as the X-29 and X-31. The $75 million SX-2 startup money now looks like being added to the Advanced Research Project Agency (ARPA) budget, with at least some of the funding in following years to come from other interested arms of the government. SX-2 would still be run by the current BMDO (formerly SDIO) DC-X management team, even though funded via ARPA, at least under the current House version of the FY '94 Defense Authorization Bill. The House of Representatives now seems favorably disposed toward SX-2. The biggest hurdle ahead this year will probably be convincing the Senate to go along when the House-Senate conference committee meets to work out the differences between the two versions of next year's Defense budget. Update, Friday, August 6th ** This is the section of the House Defense Authorization Bill approved last ** week that covers DC-X (SSRT) Followon. Section 217, Single Stage Rocket Technology (a) Program Funding -- the Secretary of Defense shall establish a Single Stage Rocket Technology program and shall provide funds for that program within funds available for the Advanced Research Projects Agency. That program shall be managed within the Office of the Undersecretary of Defense for Acquisition. (b) Funding -- Of the amount appropriated pursuant to section 201 for Defense-wide activities, $79,880,000 shall be available for, and may be obligated only for, Single Stage Rocket Technology. ** This is the section of the report accompanying the House Defense ** Authorization Bill that covers DC-X Followon. The report language is ** intended to clarify the intent of the bill. From The House of Representatives Committee on Armed Services Report on the FY '94 Defense Department Authorization Bill, H.R. 2401 H. Rpt. 103-200, 103rd Congress, 3rd Session; July 30th, 1993, pp. 172-173 Single Stage Rocket Technology The budget request included $4.88 million for single stage rocket technology (SSRT), also known as single-stage-to-orbit (SSTO), within the Ballistic Missile Defense Office (BMDO) follow-on technologies program to complete the final testing in phase one of the program. The United States spends over $30 billion each year on space programs. Yet, unlike many other commercial activities that have benefitted and achieved greater efficiencies from military research and development, U.S. commercial launch costs are at least twice -- and in some instances as much as ten times -- the costs of foreign competitors. Similarly, it takes the United States at least four times as long to provide launch services to any given user. The Congress must remain skeptical and avoid fully embracing the sometimes overly optimistic claims regarding SSRT/SSTO technology. Yet, if the United States is to regain its international competitiveness in this critically important military and economic area, it must pursue promising enabling space launch technologies that have the potential of dramatic reductions in launch costs. Accordingly, the committee recommends the following: (1) Transitioning SSRT/SSTO from BMDO to a "Space Launch Technology" program element within the Advanced Research Projects Agency. (2) Continuing with the current management team. (3) Adding an additional $75 million to begin phase two of the program. (4) Conducting an open competition among aerospace companies for phase two of the program. (5) Examining options for DOD, other government agencies/departments, and industry cost sharing opportunities. None of the additional funds recommended to be authorized may be obligated until the congressional defense committees have been provided with a phase two program plan outlining objectives and technical milestones and certifying that funding support has been established for fiscal years 1995 and 1996. ** End of report excerpt On the whole, this looks good. The open competition clause is no great surprise -- McDonnell-Douglas obviously would have liked a no-bid contract that would guarantee them another major step toward an operational Delta Clipper, but a no-bid on a program of this size would be extraordinary. As it is, MDA will probably have the inside track on SX-2 _if_ DC-X flight test goes well. Chances are though that Lockheed, and possibly Boeing and Rockwell too, will also bid. General Dynamics, alas, seems too busy dismantling itself to take an interest. One possible problem with this report language is in the last paragraph, the phrase about "certifying funding support for fiscal years 1995 and 1996". Our best guess as to what this means is that ARPA will have to find major funding sponsors in other government agencies and/or private industry for the hundred million-plus '95 and '96 SX-2 budgets, before ARPA can go ahead with any major SX-2 startup spending. Multi-agency/multi-company funding is likely to complicate SX-2 politically, with some danger of it bogging down the way NASP has. We will need to watch for signs of this over the next few years, assuming we do get SX-2 startup funded. Meanwhile, Congress has left on its August recess. They won't be back in session until the second week of September, barring national emergencies. Both the House and Senate left town with Defense Authorization bills out of committee but not yet approved "on the floor" (by the entire membership). The House version contains the above language, the Senate version contains much less favorable language mentioning SSTO along with NASP and Spacelifter in a single $30 million USAF line item. Neither the House nor the Senate is likely to amend the SSRT sections of their Defense Authorization bills during floor debate. We could wish for favorable amendment on the Senate floor, and it's worth asking for, but it doesn't seem likely to happen. Once the full House and Senate approve their Defense Authorizations, the next milestone is the House-Senate Conference Committee, when the two bodies will resolve differences in the two versions of next year's DOD budget. This will be critical to us; we need to get the House version SSRT wording adopted. The House-Senate Defense Authorization conference should be in mid-September. After that, the Appropriations process starts, in which the Congress "writes the check", so to speak, for the projects approved in the Authorizations bill. More on this next week. SAS Action Recommendations If you have any contacts in the Senate Armed Services Committee, go on working them low-key -- there's no telling who will be on the Conference Committee, and we'll need all the help we can get on the Senate side when that eventually gets underway. Other than that, stay tuned for updates, and enjoy the summer. Senate Armed Services Committee Members List Name office# phone fax (AC 202) ("Senator XYZ", office#, "Washington DC 20510" will get mail to them) Sam Nunn (D-GA, chairman) SD-303 224-3521 224-0072 Bob Smith (R-NH, RRM) SD-332 224-2841 224-1353 James Exon (D-NE) SH-330 224-4224 224-5213 John McCain (R-AZ) SR-111 224-2235 224-8938 Richard C. Shelby (D-AL) SH-313 224-5744 224-3416 Joseph I. Lieberman (D-CT) SH-502 224-4041 224-9750 Bob Graham (D-FL) SD-241 224-3041 224-6843 Dirk Kempthorne (D-ID) SDB40-3 224-6142 224-5893 William S. Cohen (R-ME) SH-322 224-2523 224-2693 Edward M. Kennedy (D-MA) SR-315 224-4543 224-2417 Carl Levin (D-MI) SR-459 224-6221 224-1388 Dan Coats (R-IN) SR-504 224-5623 224-1966 Trent Lott (R-MS) SR-487 224-6253 224-2262 Lauch Faircloth (R-NC) SH-716 224-3154 224-7406 Jeff Bingaman (D-NM) SH-524 224-5521 224-1810 John Glenn (D-OH) SH-503 224-3353 224-7983 Strom Thurmond (R-SC) SR-217 224-5972 224-1300 John Warner (R-VA) SR-225 224-2023 224-6295 Charles S. Robb (D-VA) SR-493 224-4024 224-8689 Robert C. Byrd (D-WV) SH-311 224-3954 224-8070 Henry Vanderbilt "Reach low orbit and you're halfway to anywhere Executive Director, in the Solar System." Space Access Society - Robert A. Heinlein hvanderbilt@bix.com "You can't get there from here." 602 431-9283 voice/fax - Anonymous -- Permission granted to redistribute the full and unaltered text of this -- -- piece, including the copyright and this notice. All other rights -- -- reserved. In other words, intact crossposting is strongly encouraged. -- ------------------------------ Date: 7 Aug 93 22:30:18 GMT From: "S.H." Subject: DC-X Update 8/6/93 Newsgroups: sci.space,sci.math Any great symphony was written by One person,and only. ( Although it may have been played by many.) S.H. | ====================================================== | " Composers and singers are not the same prefessions. " | ======================================================= Some people writes songs The `singers' receive the glory. ------------------------------ Date: 7 Aug 93 23:08:57 GMT From: "S.H." Subject: DC-X Update 8/6/93 Newsgroups: sci.space,sci.math In article <53075@sdcc12.ucsd.edu> sr600uab@imath4.ucsd.edu (S.H.) writes: > `spellcheck': >S.H. | ====================================================== > | " Composers and singers are not the same prefessions. " > | ===========================================^=========== o >Some people writes songs >The `singers' receive the glory. > ------------------------------ Date: 8 Aug 1993 00:44:45 GMT From: Eric Shafto Subject: DC-X Update 8/6/93 Newsgroups: sci.space S.H. (sr600uab@imath4.ucsd.edu) wrote: : In article <53075@sdcc12.ucsd.edu> sr600uab@imath4.ucsd.edu (S.H.) writes: : > : `spellcheck': : >S.H. | ====================================================== : > | " Composers and singers are not the same prefessions. " : > | ===========================================^=========== : o : : >Some people writes songs : >The `singers' receive the glory. : > Ah, thanks for the correction. Up until now, I had been wondering what your posts meant, and why you were posting them to sci.space. Now it is all much clearer ------------------------------ Date: 7 Aug 1993 20:30:06 GMT From: Claudio Egalon Subject: Do astronauts use sleeping pills? Newsgroups: sci.space Sometime ago, I read an interview given by Byron Lichtemberg, who flew the Shuttle twice as a Payload Specialist, and, according to the interview, he complained that it was very difficult to sleep in the Shuttle because of all the noise in the Shuttle due to the pumps that must be functioning all the time to keep the spacecraft "habitable". He claimed that he could not sleep more than 3 hours per night so, based on that, I started wondering whether astronauts take sleeping pills so they can sleep in the Shuttle. Insomnia seems to be a very natural consequence not only because of the presumed noise inside the spacecraft but also because of the excitement involved in all these missions. Claudio Oliveira Egalon C.O.Egalon@larc.nasa.gov ------------------------------ Date: Sat, 7 Aug 1993 23:20:07 GMT From: Henry Spencer Subject: Do astronauts use sleeping pills? Newsgroups: sci.space In article <2413ceINNi2o@rave.larc.nasa.gov> c.o.egalon@larc.nasa.gov (Claudio Egalon) writes: >...complained that it was very difficult to sleep in >the Shuttle because of all the noise... >... I started wondering >whether astronauts take sleeping pills ... I would expect that safety considerations preclude this. In an emergency, it's important to be able to wake up quickly and completely. -- 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: Sat, 7 Aug 1993 22:53:54 GMT From: Henry Spencer Subject: engine failures and safety Newsgroups: sci.space In article <23u9e6$cmf@access.digex.net> prb@access.digex.net (Pat) writes: >Even if you are 1,000 miles off shore, you can arrange a decent >ditch into the water and radio for Emergency assistance on the way down. Assuming you've got good weather and relatively calm seas, that is. In the best of conditions, ditching is a desperate-emergency procedure involving substantial risk of a crash. Do it at night in bad weather into high seas, and the chances of surviving it approach zero. >I don't think i'd want to float for 12 hours waiting for pick up but >it will happen sometime. At 1000 miles out, 12 hours is very optimistic, unless there is shipping nearby. 1000 miles is 2-3 days' steaming for all but the fastest ships. -- 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: Sat, 7 Aug 93 21:30:23 GMT From: Daniel Briggs Subject: Exploding Heads Newsgroups: sci.space In article <1993Aug6.210635.7195@mksol.dseg.ti.com> pyron@skndiv.dseg.ti.com writes: > >Several tests have shown that monkeys not only didn't boil or explode, but >that they survived. At thirty thousand feet, an airliner is a long way >towards that vaccum level, so, if say a baggage door failed and caused >explosive decompression, most of the passengers would experience short >term distress (but nothing like the distress of thinking the plane would >crash). A French skydiver by the name of Patrick de Gayardon recently did a high altitiude jump of 38,352 feet without oxygen, so an explosive decompression at 30,000 feet would definitely not be fatal in and of itself. I presume that PdG was prebreathing oxygen in the plane, but I don't know this. Ordinary skydivers routinely do jumps of 25,000 feet MSL without oxygen, prebreathing in the plane. -- | Daniel Briggs (dbriggs@nrao.edu) | USPA B-14993 | New Mexico Tech / National Radio Astronomy Observatory | DoD #387 | P.O. Box O / Socorro, NM 87801 (505) 835-7391 | Support the League for Programming Freedom (info from lpf@uunet.uu.net) ------------------------------ Date: Sat, 7 Aug 1993 11:34:00 +0200 From: Andre Knoefel Subject: Info on the upcomming Perseid shower Newsgroups: sci.space > The last info I have on this meteor shower is that it > will start around 0100 GMT on 12 August. > > Any new info out there? Maybe the storm will start around 0100 UT, but the shower is visible in the whole night (that means your are able to see 40-80 meteors per hour under good conditions). Andre ------------------------------------------------------------------------------ Andre Knoefel e-mail: starex@tron.gun.de International Meteor Organization Fireball Data Center Duesseldorf * Germany ------------------------------------------------------------------------------ ## CrossPoint v2.1 R ## ------------------------------ Date: 7 Aug 93 21:43:00 GMT From: "S.H." Subject: new nasa wind tunnels Newsgroups: sci.space In article <1469100041@igc.apc.org> tom@igc.apc.org writes: >anyone know anything about the new wind tunnels nasa is planning to build? ^^^^^^^ >they may be for commercial transport design. size? mach no? reynolds no? >tom Amazing. NASA_via_JPL_via_QMW builds everything He wrote. Private Tunnels, there are so many, already built, for transporting ___ .. ------------------------------ Date: 7 Aug 93 06:38:23 GMT From: jack hagerty Subject: Refit/Rebuild old Rockets! Low Tech? Standardize! Newsgroups: sci.space In article henry@zoo.toronto.edu (Henry Spencer) writes: > >And the USAF has been drawing on its Atlas inventory for decades now >as a source of launch vehicles; I seem to recall that there are *still* >a handful of ex-missiles yet to be used up. About a year ago I asked the question on Atlases (namely, where are they coming from since I read about 5 years ago that the last "original" one was used up) and it was you, Henry, that said that GD (I believe) had actually started up the Atlas production line again! The reasons were that all of the ground support equipment was in place, the crews were familiar (*very* familiar) with it and it was relatively reliable. - Jack ============================================================================= ||Jack Hagerty, Robotic Midwives, Ltd. jack@rml.com || ||Livermore, CA NOTE! New, improved address! ^^^ || ||(510) 455-1143 (old ones will still work) || ||-------------------------------------------------------------------------|| || "If the computer is turning the world into a global village, || || and I don't know how to use one, does that make me the global || || village idiot?" - Perfesser Cosmo Fishhawk in "Shoe" || ============================================================================= ------------------------------ Date: Sat, 7 Aug 1993 23:32:23 GMT From: Henry Spencer Subject: Refit/Rebuild old Rockets! Low Tech? Standardize! Newsgroups: sci.space In article John_Fleming@sat.mot.com (John Fleming) writes: >> One big reason why refurbishing missiles has never gone anywhere as a >> source of cheap launchers is the devastation it could cause in the US >> commercial launch industry. You really don't want to get a bunch of >> cheap launches in the near-term if it means bankrupting your long-term >> launch suppliers with subsidized competition... > >... they should sell these ICBM's at >auction as scrap (with the usual ITAR applying). Let >the LV manufacturers bid for these rockets, and resell them... Trouble is, the set of skills you need to refurbish and use those moldy old missiles is very different from the set of skills you need to design and operate a modern launch system. Selling them at scrap prices amounts to a massive subsidy -- those things are *valuable* -- to people who will not be able to continue offering launch services after the supply of surplus missiles dries up. There's a lot to be said for making cheap launches available. Growth in the payload market is good for the launch suppliers in the long run. The trick is doing it in a way that ensures that there will *be* launch suppliers in the long run. There are ways to do that. The simplest is to price the missiles at something approximating replacement cost, instead of surplus-asset prices. This has the bonus of contributing a fair bit of revenue to the government. That money can then be used to fund a launch-voucher scheme for the potential users, so they can buy whatever launch service is best for them at whatever time is best for them. >For anything less than a Titan IV, the government should only RFP for >and buy a lbs to orbit with specified reliability commercial contract. Apart from the shuttle and Titan IV, this is already the law of the land, although NASA and the USAF don't like it and have done their damndest to avoid complying with the spirit of the rules. >... And how is it that the American taxpayer has > absolutely no voice in this system of establishing national > priorities, and only the faceless unelected national security > civil _servants_ do? ... Surely you jest. Your elected representatives, who of course listen to and comply with your wishes :-) :-), have plenty of voice in this. Who do you think forced NASA out of the commercial launch business? -- 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: Sat, 7 Aug 1993 23:37:12 GMT From: Henry Spencer Subject: Refit/Rebuild old Rockets! Low Tech? Standardize! Newsgroups: sci.space In article <849@rml.UUCP> jack@rml.UUCP (jack hagerty) writes: >>And the USAF has been drawing on its Atlas inventory for decades now >>as a source of launch vehicles; I seem to recall that there are *still* >>a handful of ex-missiles yet to be used up. > >About a year ago I asked the question on Atlases (namely, where are >they coming from since I read about 5 years ago that the last "original" >one was used up) and it was you, Henry, that said that GD (I believe) >had actually started up the Atlas production line again! Indeed they have, because *they* don't own those ex-missiles -- the USAF does -- and they have other customers for Atlas launches. There are also some differences in the hardware. There have been over a dozen different Atlas versions, and the latest commercial-launcher versions -- built new by GD -- have significantly better performance than the old missiles. (For one thing, the tank shape of the old missiles is wrong for putting a Centaur on top; they are restricted to smaller upper stages with lower performance.) Even the USAF has been buying new ones for payloads that need them. -- 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: Sat, 7 Aug 1993 11:35:00 +0200 From: Andre Knoefel Subject: What is ZHR? Newsgroups: sci.space The Zenithal Hourly Rate is the number of meteors for one observer, good observing conditions (limiting magnitude 6.5) and a (theoretical) position of the radiant in the zenith. Andre ------------------------------------------------------------------------------ Andre Knoefel e-mail: starex@tron.gun.de International Meteor Organization Fireball Data Center Duesseldorf * Germany ------------------------------------------------------------------------------ ## CrossPoint v2.1 R ## ------------------------------ Date: Sat, 7 Aug 1993 22:54:29 GMT From: Henry Spencer Subject: Why I hate the space shuttle Newsgroups: sci.space In article <1993Aug6.171627.25055@ke4zv.uucp> gary@ke4zv.UUCP (Gary Coffman) writes: >>There are airliners that don't have big wings. (Hint: Chinook.) > >I thought those big things on top that go round and round were called >rotary wings. They aren't big by wing standards. -- 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: Sun, 8 Aug 1993 01:34:30 GMT From: Dan Newman Subject: Why I hate the space shuttle Newsgroups: sci.space In sci.space, gary@ke4zv.uucp (Gary Coffman) writes: >In article henry@zoo.toronto.edu (Henry Spencer) w >rites: >>There are airliners that don't have big wings. (Hint: Chinook.) > >I thought those big things on top that go round and round were called >rotary wings. > Bad choice of flight vehicle. The RAAF found its Chinooks (C models) to be the most expensive aircraft it ever operated, had to keep about half its fleet in storage because it couldn't keep up the supply of spares and highly trained technicians, and in general had life cycle costs orders of magnitude greater than the initial purchase price indicated. If this is meant to exemplify DC-X's future, MD should stop work now. Dan Newman dan@aero.ae.su.OZ.AU Department of Aeronautical Engineering Ph : 61 2 692 2347 University of Sydney Fax: 61 2 692 4841 Sydney NSW 2006 AUSTRALIA ------------------------------ End of Space Digest Volume 17 : Issue 001