Date: Fri, 28 May 93 11:08:05 From: Space Digest maintainer Reply-To: Space-request@isu.isunet.edu Subject: Space Digest V16 #635 To: Space Digest Readers Precedence: bulk Space Digest Fri, 28 May 93 Volume 16 : Issue 635 Today's Topics: August Meteor Shower May Threaten Earth Satellites (2 msgs) Boeing TSTO concept (sort-of long) (2 msgs) Comet 1993e Detecting planets in other system (3 msgs) Hey Sherz! (For real!) Cost of LEO Moon Base (2 msgs) NASA CD-ROM add/price Planets around other stars The crew is toast Tom Wolfe's THE RIGHT STUFF - Truth or Fiction? Voyager Discovers the First Direct Evidence of the Heliopause 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: 26 May 93 19:02:00 GMT From: Stan Ryckman Subject: August Meteor Shower May Threaten Earth Satellites Newsgroups: sci.space,sci.astro In article <26MAY199303243201@kelvin.jpl.nasa.gov> baalke@kelvin.jpl.nasa.gov (Ron Baalke) writes: [stuff deleted] >Notes >1. [deleted] > >2. The observed activity of a meteor shower is measured in terms of >'Zenithal Hourly Rate' (ZHR). The normal peak ZHR of the Perseids is >around 100. The Leonid storm in November 1966 had a ZHR of 100,000 >for a period of 2040 minutes. ^^^^^^^^^^^^ Uh, that's 34 days. How long was it _really?_ Stan. -- X-Obligatory-.sig Stan Ryckman sgr@alden.UUCP ------------------------------ Date: 26 May 93 19:30:39 GMT From: Stan Ryckman Subject: August Meteor Shower May Threaten Earth Satellites Newsgroups: sci.space In article <792@alden.UUCP> I wrote: >In article <26MAY199303243201@kelvin.jpl.nasa.gov> baalke@kelvin.jpl.nasa.gov (Ron Baalke) writes: >> The Leonid storm in November 1966 had a ZHR of 100,000 >>for a period of 2040 minutes. > ^^^^^^^^^^^^ >Uh, that's 34 days. How long was it _really?_ Sorry, I meant 34 hours. This newsreader won't let me cancel things. But I seem to remember it was much less than one day, so the question stands. Stan. -- X-Obligatory-.sig Stan Ryckman sgr@alden.UUCP ------------------------------ Date: Wed, 26 May 1993 20:26:08 GMT From: Fred Cordes Subject: Boeing TSTO concept (sort-of long) Newsgroups: sci.space >>The B-58 wasn't capable of Mach 3 even in a dash, and neither the SR-71 >>nor the X-15 was made of aluminum. (The SR-71 was mostly titanium, and >>the X-15 used titanium for its *low-temperature* structure plus various >>refractory metals for the hot stuff.) I've been reading "Edge of Space" by Milt Thompson, about the X-15 program. The book was published in 1992 by Smithsonian Press and details the program from an insider pov. Mr. Thompson was one of the research pilots and a NASA employee. He points out that Inconel, a nickel-steel alloy, was used to construct the framework and outer skin of the 3 aircraft. There are several accounts and photos that support the author's claim that the X-15 was a "tough old bird". There is also a photo of the leading edge of the ventral fin on the plane that made the Mach 6.7 speed run. There's a large hole in the skin and lots of damage around it, indicating that the X-15 was flown to its limits (beyond the target speeds) during the tests. I've been looking for some more popular press books about hypersonic aircraft development since the X-15 era, and would welcome posts to the net about the subject. There are certainly books about the shuttle, but not much about it as a hypersonic aircraft. I find the AIAA technical papers pretty intimidating and most public library books on the subject are X-15 related (a few) or shuttle books focusing giving very superficial technical info. Fred Cordes -- Fred Cordes {uunet, ucsd, sun}!megatek!cordes 619-455-5590 ext 2594 cordes@megatek.uucp Megatek Corporation 9645 Scranton Rd. San Diego, Ca. 92121 ------------------------------ Date: 26 May 1993 17:40:18 -0400 From: Pat Subject: Boeing TSTO concept (sort-of long) Newsgroups: sci.space Mary shafer, kindly sent me the papers from the 30'th? anniversary of the X-15 flight. Maybe she has a few, these were serious historical reviews, from a day long conference. ------------------------------ Date: 26 May 93 14:02:33 From: Steinn Sigurdsson Subject: Comet 1993e Newsgroups: sci.astro,sci.space In article steinly@topaz.ucsc.edu (Steinn Sigurdsson) writes: Well, if P/C-S started out at 5km, it could make 100+ 1 km fragments, Ack, that's P/S-L, I'm clearly stuck months behind the state of the art... ------------------------------ Date: Wed, 26 May 1993 20:53:58 GMT From: Robert Casey Subject: Detecting planets in other system Newsgroups: sci.space,sci.astro In article <1993May26.184001.16542@cs.ucf.edu> clarke@acme.ucf.edu (Thomas Clarke) writes: >In a recent issue of Science there is a discussion of a project >to look for MACHOs (Massive Compact Halo Objects - things like >planets, brown dwarfs, or even black holes in the galactic halo >that might account for some of the missing mass). The scheme for >detecting MACHOs is to look for a micro-gravitational lensing event >as the MACHO passes in front of a distant star. To make the >statistics workable they have put together a 64 million (!!!) pixel >CCD which will be mounted on an otherwise little used 50-odd inch >worn-out telescope. The CCD will then stare at the large Magellenic >Cloud (LMC) to look for microlensing events. They expect a >jupiter-sized object to enhance a stares brightness for a day or two, >a week or two for dwarfs, and possibly months for a black hole. I vaguely (yes, again, I got a vague memory!) remember seeing in Sky and Telescope 6-12 months ago a brief news note saying a suspected micro lens event was seen. Suspect a Jupiter planet in a closer galaxy lensed a star in a further galaxy. But how do you prove/verify/test this? Not really repeatable, at least not the same objects again. ------------------------------ Date: Wed, 26 May 1993 21:56:00 GMT From: Leigh Palmer Subject: Detecting planets in other system Newsgroups: sci.space,sci.astro In article <1993May26.184001.16542@cs.ucf.edu> Thomas Clarke, clarke@acme.ucf.edu writes: >In a recent issue of Science there is a discussion of a project >to look for MACHOs (Massive Compact Halo Objects - things like >planets, brown dwarfs, or even black holes in the galactic halo >that might account for some of the missing mass). The scheme for >detecting MACHOs is to look for a micro-gravitational lensing event >as the MACHO passes in front of a distant star. To make the >statistics workable they have put together a 64 million (!!!) pixel >CCD which will be mounted on an otherwise little used 50-odd inch >worn-out telescope. The CCD will then stare at the large Magellenic >Cloud (LMC) to look for microlensing events. They expect a >jupiter-sized object to enhance a stares brightness for a day or two, >a week or two for dwarfs, and possibly months for a black hole. > >The point, of this is that maybe the same detector will inadvertantly >succeed in detecting planets. It would be ironic if the first >detection of a Jupiter-sized planet were in the LMC! It is even possible they may discover a variable star. Some of these are known in our own Galaxy. Such an LMC patrol presents an interesting problem, one which may be solved for them by the time they get their experiment on the air. The data processing problem will be huge! There will have to be many output spigots for a variety of interesting data. For example, Henrietta Leavitt's Cepheids ought to be monitored and many more added to those already cataloged. (At lower amplitudes - Cepheids can be quite subtle. Polaris, for example, is thought to be a Cepheid.) If the data acquisition and analysis problems can be overcome then this project should be a goldmine, at least from the point of view of the observer who feels that weekly publication is a good thing. If I had a machine like that I'd point it into the center of the Galaxy. Leigh ------------------------------ Date: 26 May 1993 22:12:36 GMT From: Dr.-DarkMatter@CRABAPPLE.SRV.CS.CMU.EDU Subject: Detecting planets in other system Newsgroups: sci.space,sci.astro The MACHO microlensing is an amibituous undertaking to detect small statistical fluctuations in the brightnesses of background stars due to a foreground population of gravitating objects. The statistical signature strongly depends upon the mass and distribution of the foreground objects. The background field is chosen to be the Large Magellanic Cloud because that has the highest density of stars per square arcminute. The detector system works quite well and much of the data acquisition flows through a 50 Mhz PC. There are several technical problems involving intrinsically variable stars, nightly seeing variations, and optimal pixel sampling, but nonetheless, the experiment is working and results are coming in. I don't think anyone in the group is prepared to make a positive statement regarding microlensing but in another 2 or 3 years there will be enough data to show it or rule it out - so in that sense it is quite a good experiment. In another sense, however, its even better because it represents the first MOSAIC CCD system that actually works and furthermore shows that 64 million pixels per readout can still be handled effectively by existing workstations. Someday, we hope, several such cameras will be routinely monitoring the sky at a variety of wavelengths. ------------------------------ Date: 26 May 93 21:56:00 GMT From: Pat Subject: Hey Sherz! (For real!) Cost of LEO Newsgroups: sci.space In article <1993May26.193103.28480@mksol.dseg.ti.com> mccall@mksol.dseg.ti.com (fred j mccall 575-3539) writes: |In <1ttm8j$90i@access.digex.net> prb@access.digex.net (Pat) writes: | |>|prb@access.digex.net (Pat) writes: |>|>Ken seems fixated on this measure of performance. |>|>I would suggest that we not look at mass returned, but Useful |>|>Cargo Returned. |>|>In that Case we have, 1 LDEF, 4-5 SpaceLab flights, and probably |>|>appx 100 GAS Cans. |>>>Not a lot for 12 years of missions. The soviets probably have |>>>returned as much using capsula vehicles and with soyuz. | | |>Nobody gunned down my thumb sketch. | >Well then, a small caliber bullet: I don't know that I'd include the >SpaceLab as 'cargo' -- it's just another matter of having to haul >facilities up and down that would be better if we could simply leave >the same facilities on orbit. I included the SpaceLabs as returned mass because they were intended to return in whole and be re-fitted for additional flights. I could have been more detailed and merely counted as mass the Spacelab Locker units, but I thought I'd give Ken thhe benefit of the doubt. I really could have subtracted most of the weight of LDEF. given LDEF has never flown again and never will, it's frame weight is essentially ir-relevant as a performance measure. I had heard though that the LDEF frame itself was extensively studied, due to it's over long stay, hence I decided to call all of LDEF useful mass returned. If i wanted to be very narrow in my estimate i could have said 128? LDEF trays, 50 Some SPaceLab Racks, and appx 100 GAS Cans. No matter what, it's ascathing condemnation of the SHuttles mass return capacity. pat Actually, here is a real condemnation of SHuttle. If shuttle is so great, why did the soviets Abandon BURAN? Buran is 99% like shuttle in capacity, except BIG PLUS, it has Liquid Boosters, and a jet engine assist on landing. Massive safety plus over STS. Yet the Soviets abandoned BURAN totally, once they saw how operationally inefficient it would be, and with the observation of how STS is strangling our space program. ------------------------------ Date: Wed, 26 May 1993 21:09:09 GMT From: James Davis Nicoll Subject: Moon Base Newsgroups: sci.space I think Mr. Coffman may have forgotten one cost of long transit times. *Someone* will have money tied up for the duration of delivery. That money had better pay back at better than bank interest rates would or the investors are potentially losing money. That is going to effect pricing. A naive calculation indicates that if the bank rate is 5%, and the cargo takes 14 months to arrive (from the asteroid belt), then the banks would have paid about $1.06 for every dollar tied up in the cargo for that time. If someone else can deliver the same product in less time, that aspect of costs will be less. Also, turning *off* the pipeline (In the event that the market for the product crashes, for example) takes time. If product x is arriving every week in the 14 month example, that means there are 56 cargos of product x that *will* arrive, after production stops. There's a certain inflexibility to 'Leinster-style' pipe-lines, which may worry investors. James Nicoll ------------------------------ Date: 26 May 1993 17:44:30 -0400 From: Pat Subject: Moon Base Newsgroups: sci.space Comments on long duration materials delivery from space. Interest rates are routinely calculated for long lead time capital equipment such as New aircraft. those have up to a 10 year lead from design to delivery, and people are making orders based upon palns 5 years out. I think it's do-able. AS for price fluctuation, then you will see a futures market in asteroid volatiles. Look at wheat. you have a 4-8 month pipeline from the time crops are planned to delivery. All parties involved sell/buy futures contracts to reduce risk. Crop failure, excess rain, Hail, storms, Bumper soviet harvests, being a farmer can sometimes be like riding a roller coaster. pat ------------------------------ Date: 26 May 1993 20:36:08 GMT From: Andy Carol Subject: NASA CD-ROM add/price Newsgroups: sci.space Does anyone have the price list and where to write for the NASA CD-ROMs which are available? I'm looking for the Voyager and Viking CD-ROMs which I've heard about. I also understand the Voyager CD-ROMs are compressed, does anyone know what method was used? Is it lossy or lossless? I've already looked in the FAQ without luck. --- Thanks! Andrew Carol carol@edfua0.ctis.af.mil ------------------------------ Date: Wed, 26 May 93 21:22:54 BSC From: chico@ccsun.unicamp.br (Francisco da Fonseca Rodrigues) Subject: Planets around other stars I read an article about the discovery of dust around Vega. Other stars show dust around them: Beta Pictoris, Fomalhaut and Epsilon Eridani are examples. In reference to Epsilon Eridani, a few years ago I read an article in a local newspaper, saying that a canadian team of astronomers had used interferometry to seek planets around near stars, and that 16 candidate stars showed some signs. Epsilon Eridani and Gama Cephei were the more promising stars. But after this, I heard no more about this research. I remember that an article was submitted to Astronomy Magazine, and published. I think the year was 1987 or 1988. Does someone have any information about other results or even confirmation of those observations? Other star I read that could have planets (or a brown dwarf) is 70 Ophiuchi, a binary star 17 light-years from Sol. But I also read that this possibility was rulled out after new researches. If someone have other information about this, please send them. Thank you very much, Francisco. -----------------------=====================================----the stars,---- | ._, | Francisco da Fonseca Rodrigues | o o | | ,_| |._/\ | | o o | | | |o/^^~-._ | COTUCA-Colegio Tecnico da UNICAMP | o | |/-' BRASIL | ~| | o o o | |\__/|_ /' | Depto de Processamento de Dados | o o o o | | \__ Cps | . | | o o o o | | | * __/' | InterNet : chico@ccsun.unicamp.br | o o o | | > /' | BitNet : cotucamp@brcfetmg | o | | /' /' | Fone/Fax : 55-0192-32-9519 | o o | | ~~^\/' | Campinas - SP - Brasil | o o | -----------------------=====================================----like dust.---- ------------------------------ Date: 26 May 1993 18:07:51 -0400 From: Pat Subject: The crew is toast Newsgroups: sci.space THe F-111, and the B-1A? had a crew ejection capsule that was designed for such a similiar escape. THe problem is, at least on STS, a probable ejection occurs over water, thus the crew compartment must have a bouyant capcity. A tough problem for a supersonic break up. No good, surviving the water impact to drown as the compartment floods, as it may have done during 51-L. What they really needed were ejection seats. According to henry, Martin baker had a design for seats for all STS occupants. Of course, that would require Nasa spending money on safety improvements as opposed to shuttle ops. My opinion, here. ------------------------------ Date: Wed, 26 May 1993 21:42:50 GMT From: Robert Tilden Subject: Tom Wolfe's THE RIGHT STUFF - Truth or Fiction? Newsgroups: sci.space,sci.space.shuttle,rec.arts.books I think Tom Wolfe painted a fairly accurate picture of the early part of the US space program. His book certainly captures the emotions of the times better than any other book I've run across. I grew up on the east coast of Florida, quite near the Cape, and remember many of the details Wolfe mentions in his book. I could watch the launches from my back yard, bright balls of fire rising up and out over the Atlantic, the rocket itself not visible without binoculars. If a manned launch occured during school hours the school would often hold a fire drill so we could watch. It took a minute or so for the low rumble of sound to get to us- usually (as I remember) just as the rocket's first stage was jettisoned and it disappeared from sight. I remember riding my bike to Patrick AFB to watch the homecoming 'parades' for the Mercury astronauts. They were usually hot, dusty, glaring affairs with people lined up on either side of A1A and a small motorcade of convertibles moving by at a leisurely pace. Didn't seem very heroic at the time. _The Right Stuff_ brought back a lot of memories of the times, and Wolfe was pretty accurate about the events I'm familiar with... -Bob Tilden tilden@nuhepl.phys.nwu.edu ------------------------------ Date: Wed, 26 May 1993 22:10:36 GMT From: Roger Noe Subject: Voyager Discovers the First Direct Evidence of the Heliopause Newsgroups: sci.space,sci.astro,alt.sci.planetary In article <26MAY199316020920@kelvin.jpl.nasa.gov> baalke@kelvin.jpl.nasa.gov (Ron Baalke) writes: >... my best guess for the upper limit >of the heliopause currently is about 90 to 120 astronomical units >(AU) from the sun," said Dr. Ralph McNutt, ... > Voyager 1 currently is at 52 AU (4.9 billion miles or 7.8 >billion kilometers from the sun), and Voyager 2 is at 40 AU (3.7 >billion miles or 6 billion kilometers) from the sun. In what range of time are Voyager 1 and 2 expected to actually reach the heliopause? Will there be a pronounced discontinuity, where it can be said objectively that the satellites have "reached the heliopause", or is this more of a continuum and a subjective determination of where the heliopause begins? Didn't something similar happen when each of our interplanetary satellites reached Earth's magnetopause? Isn't there at least a qualitative similarity between these two "boundaries"? OK, I'm done asking questions for today. :-) Thanks in advance to anyone who endeavors to produce serious answers. -- Roger Noe noe@cs.uiuc.edu Department of Computer Science 40:06:39 N. 88:13:41 W. University of Illinois (217) 244-6173 Urbana, IL 61801 USA ------------------------------ End of Space Digest Volume 16 : Issue 635 ------------------------------