Return-path: X-Andrew-Authenticated-as: 7997;andrew.cmu.edu;Ted Anderson Received: from hogtown.andrew.cmu.edu via trymail for +dist+/afs/andrew.cmu.edu/usr11/tm2b/space/space.dl@andrew.cmu.edu (->+dist+/afs/andrew.cmu.edu/usr11/tm2b/space/space.dl) (->ota+space.digests) ID ; Tue, 2 Apr 91 01:29:59 -0500 (EST) Message-ID: Precedence: junk Reply-To: space+@Andrew.CMU.EDU From: space-request+@Andrew.CMU.EDU To: space+@Andrew.CMU.EDU Date: Tue, 2 Apr 91 01:29:50 -0500 (EST) Subject: SPACE Digest V13 #342 SPACE Digest Volume 13 : Issue 342 Today's Topics: Re: Advancing Launch Technology Re: Economic vs Technical Limits ( Cheap Fares?) * SpaceNews 01-Apr-91 * Genesis Rock? How 'bout them Titans? MAJOR SOLAR FLARE ALERT - 31 MARCH - TWO EVENTS Administrivia: Submissions to the SPACE Digest/sci.space should be mailed to space+@andrew.cmu.edu. Other mail, esp. [un]subscription requests, should be sent to space-request+@andrew.cmu.edu, or, if urgent, to tm2b+@andrew.cmu.edu ---------------------------------------------------------------------- Date: 1 Apr 91 17:29:46 GMT From: eplrx7!leipold@louie.udel.edu (Walt Leipold) Subject: Re: Advancing Launch Technology In article <21439@crg5.UUCP> szabo@crg5.UUCP (Nick Szabo) writes: >Over the long term, EML or gas gun could drop costs to $10/lb. to GEO >or L-5. With warm superconductors, the cost could drop much further, my >guess being $1/lb. >-- >Nick Szabo szabo@sequent.com I don't know about you, but I can't even fly across the US for $1/lbm. I don't know how much an EML system will cost, but I'm pretty sure what it will cost more than :-). What *are* the absolute minimum costs of a a *practical* EML system? For the sake of discussion, let's assume a modest 500g acceleration in a purely horizontal launcher. Further, assume a 'muzzle velocity' of 10 mi/s to provide some extra 'oomph' to punch through the atmosphere and get us to LEO. This requires a launcher some 26 km in length. Finally, assume a launch rate of a thousand tons/month, or 2800 lbm/hr (this is more than thirty times the Shuttle's current launch rate, equivalent to launching a Pegasus every fifteen minutes). Energy: At $0.04/kW.hr, assuming no losses, the energy cost of accelerating one pound mass to 10 mi/s is: 0.08*(10 lbm.mi2/s2) = 0.08*(3.26333013 kW.hr) = $0.265/lbm. I can't remember what the losses are in an EML, but would expect that in practice this number would quadruple, to around $1/lbm. Hardware: How much does a linear foot of high-capacity, reliable, maintainable, weatherproof railgun cost? Ten thousand dollars? If so, your 26-km railgun will cost $850 million dollars. If you don't believe this cost/foot, what would you believe? How much more expensive is a railgun than an equivalent length of interstate highway? Real estate: Since you're launching horizontally, you'll need some easement around the muzzle of your gun. How much? Well, for a 1000 meter vertical clearance (not enough, of course), you'll need only a measly 113 km downrange... Of course, you can place your muzzle on the beach to avoid buying out everyone in your easement, but then you're (a) buying expensive beachfront property, (b) letting your high-powered cannon cut across some very valuable coastal highways and rail lines, and (c) threatening coastwise shipping. Nope, it's more practical to build the thing in the desert and buy a large easement. If your right-of-way is 200 meters wide, you'll only need 1300 acres for the gun, plus maybe 20,000 acres in a gently diverging fan shape for the easement. In the absence of hard data, I'll assume that this piece of land will cost about $100 million -- this is probably reasonable if we include the cost of relocating highways, rail lines, power lines, etc. Management: We'll assume a revolution in management styles gives us an administration cost of only $4 million/month, or $2/lbm. (Heck, just groundskeeping and road maintenance on something 26 km long will cost a lot.) Liability insurance is a big unknown, so we'll assume the same $2/lbm. Based on current practice, both of these numbers are *way* too small -- in particular, one pound moving at 10 mi/s can do a lot more than $2 worth of damage. The bottom line: Real estate plus hardware costs are $0.95 billion. I'm not a financial analyst, so let's pretend this is a house I'm buying (I'd appreciate corrections from someone who understands finance). For a $950,000,000 principal at 10% for 30 years, my mortgage payment would be somewhere around $8 million/month. Launching a thousand tons a month, we need to charge $4/lbm to pay off the mortgage, plus $1/lbm for energy, plus $4/lbm for administration and insurance, for a total of $9/lbm. But seriously, folks... $9/lbm doesn't sound like a lot, but remember that this kind of rough estimate was used to predict $100/lbm for the Shuttle a couple of decades ago. If the Shuttle is now at $2000/lbm, then my guess for the cost of a practical EML is $9*2000/100, or $180/lbm. Not bad, but only one order of magnitude lower than current launchers. Flames welcome, but I don't promise to read 'em... -- -------------------------------------------------------------------------- "If you want to read about love and marriage, Walt Leipold you've got to buy two separate books." (leipolw%esvax@dupont.com) -------------------------------------------------------------------------- -- The UUCP Mailer ------------------------------ Date: 1 Apr 91 17:23:22 GMT From: sun-barr!olivea!samsung!noose.ecn.purdue.edu!dirac!maxwell.physics.purdue.edu!bcr@apple.com (Bill C. Riemers) Subject: Re: Economic vs Technical Limits ( Cheap Fares?) In article <8FF16B56E800006E@BITNET.CC.CMU.EDU> MSKELLEY@SAMFORD.BITNET (The Wizard) writes: >In reply to Nick Szabo's comment: > >When I can pay $.10 (ten cents) for round-trip from > >PDX to Heathrow, I'll start getting ready for space colonization via > >chemical rockets. > >Of course, this tremendous price does not take into account the other >costs of flying from PDX to Heathrow. What about the food, and paying >the people to fly the plane? Your point is taken, but I feel that $0.10 >for a round-trip ticket will never happen. (Or is this what you meant?) > I not sure what you meant; however, I don't thing the analysis holds. Better- when it is possable to design an aircraft that can fly the trip for $.10 worth of fuel. If we could develope a machine that could do it for $.01, but the machine costs $100,000,000.00, I would expect the machine to be practicle for colinization; however, I would never expect anyone to use one for flying to Heathrow. Bill Maybe I should add some more zeros. Afterall $100,000,000.00 is too close to the costs of the B1 bomber. ------------------------------ Date: 1 Apr 91 15:47:54 GMT From: ka2qhd!kd2bd@rutgers.edu (John Magliacane) Subject: * SpaceNews 01-Apr-91 * SB SPACE @ AMSAT < KD2BD $SPC0401 * SpaceNews 01-Apr-91 * Bulletin ID: $SPC0401 ========= SpaceNews ========= MONDAY APRIL 1, 1991 SpaceNews originates at KD2BD in Wall Township, New Jersey, USA. It is published every week and is made available for unlimited distribution. * STS-37 LAUNCH ADVISORY * ========================== NASA managers set April 5, 1991 as the target launch date for Space Shuttle mission STS-37. This will be the 39th flight of the Space Shuttle system and will include deployment of the Gamma Ray Observatory by the Shuttle Atlantis crew and the first "spacewalk" performed by Shuttle astronauts since returning to flight. "The launch team has done a super job in getting us ready to fly STS-37" said Shuttle Director Robert Crippen. "With the delay in STS-39 Discovery, the team had a real challenge to meet, and they came through right on schedule." The launch window on April 5 opens at 9:18 a.m. EST with the mission projected to last just over 5 days. A launch on April 5 at the opening of the window would put landing at Edwards Air Force Base, California on April 10. STS-37 Launch Windows: 05-Apr-91 1418 - 1648 UTC 06-Apr-91 1417 - 1647 UTC 07-Apr-91 1416 - 1646 UTC 08-Apr-91 1414 - 1644 UTC 09-Apr-91 1413 - 1643 UTC [Info via NASA] * SAREX INFO * ============== SAREX will communicate with amateur stations in line-of-sight of Atlantis in one of four transmission modes: FM voice, slow scan television (SSTV), packet radio or (uplink only) fast scan television (FSTV). The voice mode is operated in the crew-attended mode while SSTV, packet or FSTV can be operated in either an attended or automatic mode. During STS-37, Pilot Ken Cameron, a licensed amateur radio operator (KB5AWP), will operate SAREX when he is not scheduled for orbiter or other payload activities. Cameron will make at least four transmissions to test each transmission mode. The remaining members of the STS-37 crew -- Commander Steve Nagel (N5RAW) and mission specialists Linda Godwin (N5RAX), Jay Apt (N5QWL) and Jerry Ross (KB5OHL) -- also are licensed ham operators. SAREX is a joint effort of NASA, the American Radio Relay League (ARRL)/Amateur Radio Satellite Corporation (AMSAT) and the JSC Amateur Radio Club. The 10 U.S. educational groups scheduled to contact Atlantis are: Clear Creek Independent School District of Houston; The University School in Shaker Heights, Ohio; Discovery Center Museum in Rockford, Ill.; Potter Junior High School in Fallbrook, Calif.; Hanover Elementary School in Bethlehem, Pa.; several schools in Southwest Oklahoma with operations based in Lawton; Lyman High School in Longwood, Fla.; Monroe Central School in Parker City, Ind.; Beaver Creek Elementary School in Downington, Pa.; and Reizenstein Middle School in Pittsburgh, Pa. [Info via NASA] * SAREX FREQUENCIES * ===================== Get out your HT's and HT programming manuals. You will want to program your 2 meter FM transceivers with the following information. Note that only stations with prior arrangements can uplink FSTV signals (special authorization is required from the FCC). It is expected that uplinking FSTV will require about 15kw ERP. FSTV ops and 2m can occur simultaneously. Mode Downlink Freq Uplink Freq -------------- ------------- ----------- Voice/SSTV 145.55 144.95 (primary), 144.91, 144.97 Packet 145.51 144.91 (primary), 144.93, 144.99 FSTV none 70cm band Please note that the frequencies they will be listening for stations ARE DIFFERENT than the one they will transmit on. This is a very important fact to understand. They will transmit to earth (downlink) on a single frequency 145.55 MHz for voice and SSTV. They will listen for stations transmitting to the shuttle (uplink) on the other frequencies listed. This "split" operation is used quite successfully by DXers when operating in an environment where large pile ups are expected. There will be no simplex operation with SAREX on either voice or packet. Although packeteers are not accustomed to operation with a TX/RX offset, in this case, it is the only way to connect to SAREX. If you transmit on 145.55 or 145.51 MHz the only people who will hear you are those other Hams in your area trying to hear the shuttle. [Info via Gary Morris, N5QWC/W5RRR] * TNX QSL! * ============ A special thanks to all those who sent QSLs to SpaceNews: OH8UV : Markku Korhonen, Rimmetie, Finland WH6I : Buzz Gorsky, Honolulu, Hawaii, USA ...and e-mail messages: DG9MAQ, DL5KR, KB6LQV, N6TTR, UW3AX, VE7DFR, WD4MKQ 73 de John, KD2BD /EX -- John A. Magliacane FAX : (908) 747-7107 Electronics Technology Department AMPR : KD2BD @ NN2Z.NJ.USA.NA Brookdale Community College UUCP : ...!rutgers!ka2qhd!kd2bd Lincroft, NJ 07738 USA VOICE: (908) 842-1900 ext 607 ------------------------------ Date: 29 Mar 91 20:52:10 GMT From: mips!swrinde!elroy.jpl.nasa.gov!zardoz.cpd.com!dhw68k!ofa123!Mark.Perew@apple.com (Mark Perew) Subject: Genesis Rock? I was watching "The Other Side of the Moon" on Cinemax a few nights ago and James Irwin made reference to an object called the "Genesis Rock". It appears that this is a white rock brought back from the moon by Irwin. Would someone please elaborate on this object and its name? aTdHvAaNnKcSe -- Mark Perew Internet: Mark.Perew@ofa123.fidonet.org Compuserve: >internet:Mark.Perew@ofa123.fidonet.org -------------------------------------------------------------------------- ------------------------------ Date: 2 Apr 91 03:32:54 GMT From: skipper!shafer@ames.arc.nasa.gov (Mary Shafer) Subject: How 'bout them Titans? Looked to me like a lot of creosote bushes died for the Titan IV. Before everyone gets excited and blames the wound casing, remember that the Pegasus had a wound casing and lived to reach orbit and that metal casings have died ugly, ignominious deaths, too. I'm a little embarrassed to admit this, but I thought the explosion was kind of pretty, in a pyromaniacal way. Of course, knowing that the folks in the control room were OK helped. -- Mary Shafer shafer@skipper.dfrf.nasa.gov ames!skipper.dfrf.nasa.gov!shafer NASA Ames Dryden Flight Research Facility, Edwards, CA Of course I don't speak for NASA "A MiG at your six is better than no MiG at all"--Unknown US fighter pilot ------------------------------ Date: Mon, 1 Apr 91 01:17:17 MST From: oler%HG.ULeth.CA@BITNET.CC.CMU.EDU (CARY OLER) Subject: MAJOR SOLAR FLARE ALERT - 31 MARCH - TWO EVENTS X-St-Vmsmail-To: st%"space+@andrew.cmu.edu" -- MAJOR SOLAR FLARE ALERT -- MARCH 31, 1991 Flare Event Summary Potential Impact Assessment -------- MAJOR ENERGETIC EVENT SUMMARY Region 6555 is still apparently complex enough to generate some explosive activity. This region spawned two major flares today, both right on the west limb. The first, a class X1.0/SF began at 19:07 UT, peaked at 19:12 UT and ended at 19:19 UT on 31 March. This event was associated with a 440 s.f.u. tenflare. No sweeps were observed with this flare. The location of the flare was estimated at S21W98. The second major event was of long-duration. This flare was rated at a class M6.3 level that was optically uncorrelated, although a bright limb surge was observed which coincided with this event, so the spawning region the event occurred from is known (6555). The preliminary duration of the flare is 272 minutes. A moderate intensity Type II sweep was observed with this event. A moderate intensity, long-duration short-wave fade was also produced by this event over sunlit areas. The SID/SWF began around 19:07 UT on 31 March and ended sometime around 01:00 UT on 01 April. POTENTIAL TERRESTRIAL IMPACT ASSESSMENT These last two major flares will have no impact with the Earth. Region 6555 is too far west to produce any significant terrestrial impacts (aside from potential proton activity) caused by potentially powerful flaring. Region 6555 (which is now over the west limb), was continuing to decay as it departed from view and is expected to continue to decay as it traverses the far side of the sun. The following warnings are still IN PROGRESS: - POTENTIAL MAJOR SOLAR FLARE WARNING - POTENTIAL PROTON FLARE WARNING (will end shortly) - POTENTIAL POLAR CAP ABSORPTION EVENT WARNING (will end shortly) - POTENTIAL POLAR LATITUDE RADIO SIGNAL BLACKOUT WARNING (will end shortly) ** End of Alert ** ------------------------------ End of SPACE Digest V13 #342 *******************