Date: Fri, 14 May 93 05:16:55 From: Space Digest maintainer Reply-To: Space-request@isu.isunet.edu Subject: Space Digest V16 #569 To: Space Digest Readers Precedence: bulk Space Digest Fri, 14 May 93 Volume 16 : Issue 569 Today's Topics: Excess Shuttle criticism was Re: Shuttle 0-Defects & Bizarre? DC Excess Shuttle criticism was Re: Shuttle 0-Defects & Bizarre? DC-X? (2 msgs) Galileo Update - 05/13/93 Give it a rest Man-rating boosters (was Re: Why we like DC-X) (4 msgs) Mars Observer Update - 05/13/93 SDIO kaput! Solar flux + H2O Vapor Pressure U.S. Government and Science and Technolgy Investment Who is Henry Spencer anyway? Why we like DC-X (was Re: Shuttle 0-Defects & Bizarre? DC-X?) (3 msgs) Yoo hoo, White Sands? (was Re: DC-X Status?) 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: Thu, 13 May 93 14:09:48 PDT From: Charlie Prael Subject: Excess Shuttle criticism was Re: Shuttle 0-Defects & Bizarre? DC Newsgroups: sci.space stephens@geod.emr.ca (Dave Stephenson) writes: > On the other hand the Space Shuttle was to be the orbital monkey > wrench. It was to do the work of all the other specialized launchers, > small and large. There is such a thing as too much generalization. > When does a multi-use device become a 'camel'? Build for a specific > purpose, then see if the device will adapt, don't build in over > generalization. Remember that the DC program is a research program, > lots to be learned before thinking of Moon flights, but it is nice > to dream. Dave--- You're actually more right than you might like to think. There are some excellent lessons in this in, say aviation history (and within the last 30 years, too). Take, for instance, the F-4 Phantom. It was designed as a premier carrier-based interceptor. At the time, it did that job quite well. But look at the range of roles it's fulfilled since then? Or what about the venerable C-130, which was built as "the best" tactical transport. What's it used for now? Cargo hauling, fuel tankerage, maritime patrol, search and rescue, covert operations, COIN strike, electronic warfare, battle management, firefighting.... and more. Heck, look at the ubiquitous UH-1 helo. How many variations, in how many roles, has that gone through? In contrast, look at efforts to develop generalist aircraft. The F-111 is probably *the* best example of that in world. There are others, that I'm sure you can think of. The implications is that the DC/SSTO program, if it is to succeed, must have a clear task right from the start. Something like, say, "an orbital C-130, designed to carry cargo quickly, easily, simply, into orbit and back down again." Nah. That'd be too easy. ------------------------------------------------------------------ Charlie Prael - dante@shakala.com Shakala BBS (ClanZen Radio Network) Sunnyvale, CA +1-408-734-2289 ------------------------------ Date: Thu, 13 May 1993 21:37:17 GMT From: "Phil G. Fraering" Subject: Excess Shuttle criticism was Re: Shuttle 0-Defects & Bizarre? DC-X? Newsgroups: sci.space kjenks@gothamcity.jsc.nasa.gov writes: >This argument doesn't hold water. Criticism of the Space Station has >bought us little but delays. If we had just shut up and bent metal, >we'd have a Space Station right now instead of the ninth redesign. >Design by committee benefits by random pot-shots from non-experts. >Healthy debate and public airing of issues are good, but there is a >limit. The Space Shuttle hasn't burned off enough backlog to have launched a space station by now. It would be sitting in warehouses in Florida, or (probably) launched by Shuttle-C's, Titans, Deltas (could they handle the launch of resource nodes?), or CIS hardware with the occasional Shuttle mission to coordinate assembly (until the station is built enough to not rely on shuttle; of course, the assembly sequence would be slightly different if this course were taken, but that's different than the big redesigns the thing goes through. >There is such a thing as excess criticism. There is a point where it >makes more sense to stop talking and start working. That point is long >past in the Space Shuttle Program. The SSP works as well now as it >ever will, and public criticism or lack of it isn't likely to help or >hurt much. There will never be a perfect space vehicle; there will >always be something to criticize. But before you complain, think >about what effects -- if any -- your complaints will have. >If you don't like the manned space program or the way it's being run, >don't just sit there and complain. Get down here to Houston and put >your career where your mouth is. >-- Ken Jenks, NASA/JSC/GM2, Space Shuttle Program Office > kjenks@gothamcity.jsc.nasa.gov (713) 483-4368 > "Posting to Usenet is like blabbering in the town square." > -- Steve Yelvington, steve@thelake.mn.org, in alt.culture.usenet noz ni ki ri blu rad raz... -- Phil Fraering |"Number one good faith! You convert, pgf@srl02.cacs.usl.edu|you not tortured by demons!" - anon. Mahen missionary ------------------------------ Date: Thu, 13 May 1993 21:41:13 GMT From: "Phil G. Fraering" Subject: Excess Shuttle criticism was Re: Shuttle 0-Defects & Bizarre? DC-X? Newsgroups: sci.space davem@ee.ubc.ca (Dave Michelson) writes: >In article henry@zoo.toronto.edu (Henry Spencer) writes: >>>Allen, could you please drop this goofy fantasy? The engineering >>>needs of a space tug and a lunar transit vehicle are very different >>>from those of an SSTO rocket... >> >>Indeed they are, but the question is, are they *too* different for one >>design to meet both? The one thing that seems to me like a potential >>problem is adequate view for the landing (which is what ultimately >>killed the Earth Orbit Rendezvous mission mode in Apollo -- being able >>to custom-build the lander for a good view looked better and better >>the more it was studied). >That brings up the obvious question... What sort of view will a DC-? pilot >have during the landing phase? (They aren't going to use some sort of >mirror-based scheme, are they?) By now you could do some sort of closed circuit TV system that would be better than either some sort of mirror system or the setup used on the Lunar Module. >-- >Dave Michelson -- davem@ee.ubc.ca -- University of British Columbia -- Phil Fraering |"Number one good faith! You convert, pgf@srl02.cacs.usl.edu|you not tortured by demons!" - anon. Mahen missionary ------------------------------ Date: 13 May 1993 22:52 UT From: Ron Baalke Subject: Galileo Update - 05/13/93 Newsgroups: sci.space,sci.astro,alt.sci.planetary Forwarded from Neal Ausman, Galileo Mission Director GALILEO MISSION DIRECTOR STATUS REPORT POST-LAUNCH May 7 - 13, 1993 SPACECRAFT 1. On May 7, a cruise science Memory Readout (MRO) was performed for the Magnetometer (MAG) instrument. Analysis indicates the data was received properly. 2. On May 7, the second of two suppressed carrier/DSN (Deep Space Network) advanced receiver characterization tests was performed over DSS-14 and DSS-15 (Goldstone 70 and 34 meter antennas). The spacecraft modulation index was varied from 43 degrees to 90 degrees for a range of ground receiver bandwidth settings. The test ran nominally and data analysis is in progress. 3. On May 10, a NO-OP command was sent to reset the command loss timer to 264 hours, its planned value for this mission phase. 4. On May 10, cruise science Memory Readouts (MROs) were performed for the Extreme Ultraviolet Spectrometer (EUV), Dust Detector (DDS), and Magnetometer (MAG) instruments. Preliminary analysis indicates the data was received properly. 5. On May 10, an Ultra-Stable Oscillator (USO) test was performed to verify the health status of the USO and to collect gravitational red shift experiment data; long term trend analysis is continuing. 6. On May 13, a cruise science Memory Readout (MRO) was performed for the Magnetometer (MAG) instrument. Preliminary analysis indicates the data was received properly. 7. The AC/DC bus imbalance measurements have not exhibited significant change (greater than 25 DN) throughout this period. The AC measurement reads 19 DN (4.3 volts). The DC measurement reads 148 DN (17.4 volts). These measurements \ are consistent with the model developed by the AC/DC special anomaly team. 8. The Spacecraft status as of May 13, 1993, is as follows: a) System Power Margin - 70 watts b) Spin Configuration - Dual-Spin c) Spin Rate/Sensor - 3.15rpm/Star Scanner d) Spacecraft Attitude is approximately 22 degrees off-sun (lagging) and 5 degrees off-earth (leading) e) Downlink telemetry rate/antenna- 40bps(coded)/LGA-1 f) General Thermal Control - all temperatures within acceptable range g) RPM Tank Pressures - all within acceptable range h) Orbiter Science- Instruments powered on are the PWS, EUV, UVS, EPD, MAG, HIC, and DDS i) Probe/RRH - powered off, temperatures within acceptable range j) CMD Loss Timer Setting - 264 hours Time To Initiation - 184 hours GDS (Ground Data Systems) : 1. Two Galileo Ground Data System (GDS) tests of MGDS V18.0 CMD took place May 7, 1993 with DSS-42 (Canberra 34 meter antenna) and CTA-21 (Compatibility Test Area at JPL). The test with V18.0 CMD over DSS-42 was successful. The second test with CTA-21 was unsuccessful due to GCF (Ground Communications Facility) routing problems causing command files to have checksum errors upon transmission to the CPA (Command Processor Assembly). This routing problem caused two blocks to be transmitted to CTA-21 from the CCP. This was strictly a GCF configuration problem with CTA-21 only. This problem was not seen on tests with actual DSS stations. 2. A test review of GDS testing for V18.0 was conducted on May 11, 1993. A formal GDS test report for GDS/UAT testing will be released by May 21, 1993. TRAJECTORY As of noon Thursday, May 13, 1993, the Galileo Spacecraft trajectory status was as follows: Distance from Earth 225,906,200 km (1.51 AU) Distance from Sun 314,793,300 km (2.11 AU) Heliocentric Speed 85,200 km per hour Distance from Jupiter 502,010,500 km Round Trip Light Time 25 minutes, 14 seconds SPECIAL TOPIC 1. As of May 13, 1993, a total of 70261 real-time commands have been transmitted to Galileo since Launch. Of these, 65152 were initiated in the sequence design process and 5109 initiated in the real-time command process. In the past week, one real time command was transmitted and was initiated in the sequence design process. Major command activities included a command to reset the command loss timer. ___ _____ ___ /_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov | | | | __ \ /| | | | Jet Propulsion Lab | ___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Once a year, go someplace /___| | | | ___/ | |/__ /| Pasadena, CA 91109 | you've never been before. |_____|/ |_|/ |_____|/ | ------------------------------ Date: Thu, 13 May 93 18:52:25 EDT From: Tom <18084TM@msu.edu> Subject: Give it a rest Ken sez; >>I was a test subject in that thing. They're calling it the Pre-flight >>Adaptation Trainer (PAT). Dr. Harm here at MSC (oops, I mean JSC) >>seems to be in charge. Fred responds: >Hey, a gadget designed to make you barf and it's named PAT. Now, >that's so nigh-on to a perfect straight line that I can't pass up >comment. ;-) This from the same guy that interprets anyone's jokes as 'flame-bait'. Control your emotions, Fred. -Tommy Mac ------------------------------------------------------------------------- Tom McWilliams 517-355-2178 wk \ They communicated with the communists, 18084tm@ibm.cl.msu.edu 336-9591 hm \ and pacified the pacifists. -TimBuk3 ------------------------------------------------------------------------- ------------------------------ Date: Thu, 13 May 1993 21:17:50 GMT From: Dave Michelson Subject: Man-rating boosters (was Re: Why we like DC-X) Newsgroups: sci.space In article henry@zoo.toronto.edu (Henry Spencer) writes: >>Allen, you seem to feel that "man-rating" is somehow different from what >>I've just outlined. More to the point, you seem to feel that the current >>process for man-rating is a waste of time and money. What have I missed? > >The absence of any evidence that the man-rating process actually improves >launcher reliability and crew safety. > >My position on this isn't quite as extreme as Allen's, but it does appear >that much of the money spent on man-rating is basically wasted. Sure, >you can add a few more 9s to the thing's reliability if you spend enough, >but is it worth the trouble? Well, I sure wouldn't want to ride a launcher which demonstrated excessive Pogo and would happily see funds spent to correct the problem. -- Dave Michelson -- davem@ee.ubc.ca -- University of British Columbia ------------------------------ Date: 13 May 93 14:57:05 From: Jim Larson Subject: Man-rating boosters (was Re: Why we like DC-X) Newsgroups: sci.space In article henry@zoo.toronto.edu (Henry Spencer) writes: My position on this isn't quite as extreme as Allen's, but it does appear that much of the money spent on man-rating is basically wasted. Sure, you can add a few more 9s to the thing's reliability if you spend enough, but is it worth the trouble? It depends on where you add your 9's: Reliability Reliability for one mission for 300 missions 0.99 0.04 0.999 0.740 0.9999 0.9704 If you want to design an operational transportation system you need a *few* 9's before they become superfluous. Of course, whether man-rating gives you those 9's is another discussion... -- Jim Larson Navigation Software Development jsl@zeus.jpl.nasa.gov Jet Propulsion Laboratory ------------------------------ Date: Thu, 13 May 1993 21:46:00 GMT From: "Phil G. Fraering" Subject: Man-rating boosters (was Re: Why we like DC-X) Newsgroups: sci.space higgins@fnalf.fnal.gov (Bill Higgins-- Beam Jockey) writes: >Did the Soviets have a process equivalent to "man-rating?" Of course >they never sent people up (we think) on any rocket except various >models of the R7/"A"/Soyuz/Vostok launcher. But it was indeed a >converted ICBM. And they must have considered the Proton, for >example, as a possible personnel launcher from time to time. They were way back before they gave up on the Zond program. >Anybody know any facts? Even now, I'm not sure we know all the facts about Zond. >-- > O~~* /_) ' / / /_/ ' , , ' ,_ _ \|/ > - ~ -~~~~~~~~~~~/_) / / / / / / (_) (_) / / / _\~~~~~~~~~~~zap! > / \ (_) (_) / | \ > | | Bill Higgins Fermi National Accelerator Laboratory > \ / Bitnet: HIGGINS@FNAL.BITNET > - - Internet: HIGGINS@FNAL.FNAL.GOV > ~ SPAN/Hepnet: 43011::HIGGINS -- Phil Fraering |"Number one good faith! You convert, pgf@srl02.cacs.usl.edu|you not tortured by demons!" - anon. Mahen missionary ------------------------------ Date: Fri, 14 May 1993 00:34:45 GMT From: Josh Hopkins Subject: Man-rating boosters (was Re: Why we like DC-X) Newsgroups: sci.space higgins@fnalf.fnal.gov (Bill Higgins-- Beam Jockey) writes: >Did the Soviets have a process equivalent to "man-rating?" Of course >they never sent people up (we think) on any rocket except various >models of the R7/"A"/Soyuz/Vostok launcher. But it was indeed a >converted ICBM. And they must have considered the Proton, for >example, as a possible personnel launcher from time to time. I believe the Proton was the launcher for the Zond series of lunar orbiting spacecraft. When Georgy Grechko came to speak here he stated that the Zond program was ready to make its first manned launch when the Apollo landings made Zond politically pointless. Since he was in the Lunar training group he seemed very dissapointed. On the other hand, looking at the Proton's launch record in 1969 I wouldn't have touched the thing with a ten foot cattle prod. The data I have shows 9 launches in 1969, of which two were successful. Am I wrong about something or were they really going to try to put people on this thing? -- Josh Hopkins jbh55289@uxa.cso.uiuc.edu "Find a way or make one." -attributed to Hannibal ------------------------------ Date: 13 May 1993 21:47 UT From: Ron Baalke Subject: Mars Observer Update - 05/13/93 Newsgroups: sci.space,sci.astro,alt.sci.planetary Forwarded from the Mars Observer Project MARS OBSERVER STATUS REPORT May 13, 1993 2:00 PM PDT Flight Team members are finalizing plans for recovering the spacecraft which remains in Contingency mode since early Sunday, May 9. While the capability to recover sooner has been available to the team, the opportunity has been taken to better analyze memory readouts to determine specific causes, and develop a permanent solution. The Verification Test Laboratory (VTL) has been successful in replicating the events leading up to the Good Friday (4/9/93) occurrence of C Mode Entry. Flight Software and Attitude Control subsystem engineers have proposed a solution which will prevent future occurrence of entry into C- Mode as a result of the same set of events. That solution, which involves a relatively minor parameter change in celestial body sensing software, is being tested on the VTL, modified Realtime Application Interactive Debugger, and Flight Software VAX. Depending on the results of that testing, commands to recover to Array Normal Spin could be sent as soon as tomorrow, Friday, May 14, or on Monday, May 16. The MO Navigation Team Chief advises that the spacecraft trajectory has not yet been negatively affected by the effects of solar wind producing a "sailing" effect on the solar array while the spacecraft is sun-coning, so as to require an additional trajectory correction maneuver (TCM). No TCM-4, provided for in mission schedules but predicted to not be necessary based on the accuracy of previous TCMs, appears to be required at this time. ___ _____ ___ /_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov | | | | __ \ /| | | | Jet Propulsion Lab | ___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Once a year, go someplace /___| | | | ___/ | |/__ /| Pasadena, CA 91109 | you've never been before. |_____|/ |_|/ |_____|/ | ------------------------------ Date: Thu, 13 May 1993 18:52:32 GMT From: Ben Burch Subject: SDIO kaput! Newsgroups: sci.space I just heard on the radio (CNN Radio News) that the SDI has been renamed the "Ballistic Missile Defense Initiative". It is to concentrate on ground-based interceptors. Does anybody have a clue if this means the end of DC-X and Clementine? -Ben Burch Burch_Ben@msmail.wes.mot.com ------------------------------ Date: 13 May 93 23:41:14 GMT From: Mike Hicks Subject: Solar flux + H2O Vapor Pressure Newsgroups: alt.sci.space,sci.space,sci.astro Hi folks! I need to do some calculations and I was hoping if someone could help me out: I have a formulae for the vapor pressure of h2o ice given in the International Critical Tables: log(P) = -2445.5646/T + 8.2312 log(T) - 0.01677006 T 2 +0.0000120514 T - 6.757169 (mm Hg) The reference tablulates this equation down to about 180 K. I was hoping to be able to find out the vapor pressure all the way down to 50 K or below. I am wondering if anyone has a better reference for these lower temperatures. Does anyone know what sort of error am introducing by extrapolating from this above equation? I also have in front of me a table of solar irradiance from 0.2 microns to ~100 microns (Labs and Neckel 1968) I was hoping if someone has this information already in ascii format they could mail me a copy and save me a bit of trouble. ------------------------------ Date: Thu, 13 May 1993 21:48:27 GMT From: "Phil G. Fraering" Subject: U.S. Government and Science and Technolgy Investment Newsgroups: sci.space,talk.politics.space,sci.research,talk.politics.misc,talk.politics.libertarian,misc.education mccolm@darwin.math.usf.edu. (Gregory McColm) writes: >In article conor@owlnet.rice.edu (Conor Frederick Prischmann) writes: >>In article <1srfii$79k@suntan.eng.usf.edu> mccolm@darwin.math.usf.edu. (Gregory McColm) writes: >>> >>>[...] >> >>Huh? Please state your criteria for selecting the "greatest philosopher" >>title. P.S. Ever read any Nietzsche? >> >Greatest = most likely to be remembered five hundred years hence. >I must admit that that makes many of my personal favorites not >that great. I make no comment on Nietzche except to remark that >he was no Immanuel Kant. Interpret that cryptic remark as you >please. Some people have appended that remark, that Nietzche was no Kant, with "thankfully." I haven't read enough of either to comment, although everyone tells me I should read Nietzche. -- Phil Fraering |"Number one good faith! You convert, pgf@srl02.cacs.usl.edu|you not tortured by demons!" - anon. Mahen missionary ------------------------------ Date: Thu, 13 May 1993 21:43:34 GMT From: "Phil G. Fraering" Subject: Who is Henry Spencer anyway? Newsgroups: sci.space Ben Burch writes: >In article <1993May13.121950.22816@cs.rochester.edu> Paul Dietz, >dietz@cs.rochester.edu writes: >> No, "Henry Spencer" is a pseudonym for Sandor at the Zoo, a military >> corporation of the High Beyond. I don't understand how they get >> their feed into the Slow Zone, though. >Paul! I hope your will is in order! Now *they* will be coming for you! >-Ben Burch >Burch_Ben@msmail.wes.mot.com Ben, from what I hear, *they* can't do much to Paul. I've included him in my coverage policy from Uncle Enzo's Nova Cicilia. -- Phil Fraering |"Number one good faith! You convert, pgf@srl02.cacs.usl.edu|you not tortured by demons!" - anon. Mahen missionary ------------------------------ Date: Thu, 13 May 1993 21:52:46 GMT From: "Richard A. Schumacher" Subject: Why we like DC-X (was Re: Shuttle 0-Defects & Bizarre? DC-X?) Newsgroups: sci.space In <1sstkc$h58@hsc.usc.edu> khayash@hsc.usc.edu (Ken Hayashida) writes: >If DC-Y carries people into orbit, then it's gonna need that toilet >too! Unless you wanta pull out your local ziplock baggie and tape it >to your fellow passenger's rectum (i.e. apollo style). Are you sure? Not too many trucks, busses or cars have toilets. Given the expense and crankiness of existing zero-gee toilets, it may just be simpler, easier and perfectly acceptable to put a few baggies in a vehicle that, in initial configurations at least, is not meant to spend more than a few hours off the ground. (And as I recall the baggy users did their own taping.) ------------------------------ Date: Thu, 13 May 1993 21:50:09 GMT From: "Phil G. Fraering" Subject: Why we like DC-X (was Re: Shuttle 0-Defects & Bizarre? DC-X?) Newsgroups: sci.space mccall@mksol.dseg.ti.com (fred j mccall 575-3539) writes: ... >Hmmm. Not sure what's required for ships. Probably not much, since >if a ship goes down it doesn't hurt too many people other than those >on the ship and those who invested in it. Which is why there are tough standards for shipbuilding, even if the government had _nothing_ to do with it. >If a plane or spacecraft >goes down, it can make quite a nasty mess on the ground, should it >land in an inappropriate place. Ever heard of the Exxon Valdez? -- Phil Fraering |"Number one good faith! You convert, pgf@srl02.cacs.usl.edu|you not tortured by demons!" - anon. Mahen missionary ------------------------------ Date: Fri, 14 May 1993 00:48:55 GMT From: Josh Hopkins Subject: Why we like DC-X (was Re: Shuttle 0-Defects & Bizarre? DC-X?) Newsgroups: sci.space schumach@convex.com (Richard A. Schumacher) writes: >In <1sstkc$h58@hsc.usc.edu> khayash@hsc.usc.edu (Ken Hayashida) writes: >>If DC-Y carries people into orbit, then it's gonna need that toilet >>too! Unless you wanta pull out your local ziplock baggie and tape it >>to your fellow passenger's rectum (i.e. apollo style). >Are you sure? Not too many trucks, busses or cars have toilets. Given >the expense and crankiness of existing zero-gee toilets, it may just >be simpler, easier and perfectly acceptable to put a few baggies in a >vehicle that, in initial configurations at least, is not meant to spend >more than a few hours off the ground. This strategy was used in the first Mercury missions. The problem arose when a vehicle which would only spend 15 minutes off the ground spent hours on the ground before launch. Hopefully this will not be a problem with Delta Clipper. I suspect that the two most important pieces of hardware for passenger travel in space are going to be the toilet and a space rated airsickess bag. On the other hand, if flights are reasonably short, maybe people can get by with just not eating the evening before. -- Josh Hopkins jbh55289@uxa.cso.uiuc.edu "Find a way or make one." -attributed to Hannibal ------------------------------ Date: 13 May 1993 15:51:48 GMT From: Jim Jones Subject: Yoo hoo, White Sands? (was Re: DC-X Status?) Newsgroups: sci.space In article <1993May12.093712.1@fnalf.fnal.gov> higgins@fnalf.fnal.gov (Bill Higgins-- Beam Jockey) writes: > >I think McDAC would cheerfully emphasize a local spaceport anywhere >they were talking, though. They'd like nothing better than to have a >bunch of space launch facilities, all flying McDAC hardware into orbit >continually. But that's a *long* way off. Still, it's in the >tradition of Delos D. Harriman... If McDAC ever got to build DC-Y and they _didn't_ name the first prototype the "Robert A. Heinlein," they'd be missing one of the great space PR coups of the century. I say this because the DC-style SSTO craft would look and perform much more like a traditional Heinlein-era "rocket ship" than anything else around. The name would invoke the feeling of the space stories people read and loved as kids. Not that I think RAH is much of a writer. But I sure tnought so when I was 12. ------------------------------ End of Space Digest Volume 16 : Issue 569 ------------------------------