Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!linus!philabs!seismo!hao!hplabs!sri-unix!postman@UCLA-CS From: postman%UCLA-CS@sri-unix.UUCP Newsgroups: net.space Subject: Undeliverable mail Message-ID: <15322@sri-arpa.UUCP> Date: Thu, 12-Jan-84 06:20:04 EST Article-I.D.: sri-arpa.15322 Posted: Thu Jan 12 06:20:04 1984 Date-Received: Sat, 14-Jan-84 04:08:14 EST Lines: 146 From: Mail Handler ===== POSTMAN output follows ===== AERROR - (n < SLOCKTRIES) CAN NOT GET LCK.SEQL "v.Burris": not delivered ===== unsent message follows ===== Received: from S1-A by SU-AI with TCP/SMTP; 12 Jan 84 03:03:35 PST Date: 12 Jan 84 0303 PST From: Ted Anderson Subject: SPACE Digest V4 #88 To: SPACE@MIT-MC Reply-To: Space-Enthusiasts at MIT-MC SPACE Digest Volume 4 : Issue 88 Today's Topics: height requirements Lunar landings, cold mining, launchings Why nuke planets? Re: Deuterium on Venus ---------------------------------------------------------------------- Date: Wednesday, 11 January 1984 09:34 est From: Chris Jones Subject: height requirements To: Space-Enthusiasts@MIT-MC.ARPA Message-ID: <840111143423.136768@MIT-MULTICS.ARPA> re the comment "All space suits are custom made": not true anymore! The era of off the rack space suits has arrived. According to the Space Shuttle Operator's Hnadbook, suits come in "several" standard sizes, with straps inside to adjust them for fit. They don't say how many "several" is, but do mention that there are fifteen glove sizes available. Still, I don't see this as preventing people who are too small for any of the standard sizes from riding the shuttle, since only two crew members are equipped with suits, while the rest have to climb into those rescue balls in the event of cabin decompression. ------------------------------ Date: 11 Jan 1984 11:03-PST From: dietz%usc-cse%USC-ECL@SRI-NIC To: space@mit-mc Subject: Lunar landings, cold mining, launchings Last month I sent a message describing an idea by Krafft Ehricke to land payloads on the lunar surface. It involved skidding the payloads on a long strip of lunar soil at orbital velocity (about 1650 m/sec). A difficulty is sifting the lunar soil to remove rocks from the top 1/2 to 1 meter. But this may not be necessary. The rocks could be removed by a special vehicle. The vehicle would have pipes that would be extended several meters into the lunar soil. Around the outside of the vehicle is a gas-tight skirt that would be anchored in the soil. Gas would be injected into the lunar soil through the pipes. Sufficient gas flow would liquify the soil, causing large objects such as rocks to sink. Smaller soil particles would be buoyed by the gas flow. Gas would be collected under the skirt for recirculation. Care must be taken not to let the vehicle sink. Subsurface lunar soil is quite cold, so the gas will have to reheated, probably with sunlight. Or, the cold gas could be used as a heat sink to increase the efficiency of solar powered heat engines. Another way to sift the soil would be to give the soil particles electrical charges. The particles repel one another, allowing large rocks to sink. This suggest a novel form of earth moving possible only in a vacuum: spray the soil to be removed with an electron beam while giving a soil collector a positive charge. Lack of moving parts should help reliability. I previously proposed using an aluminum strip to levitate rockets for lunar launches. Samarium-cobalt magnets should be sufficiently light to make the scheme practical. For extra efficiency, high launch accelerations could be used (10 gee's, say), and the strip could be covered by a gas-tight tunnel ~14 km long. The rocket would use lunar oxygen and imported hydrogen as fuel; the water produced by combustion would be trapped in the tunnel, recovered and the hydrogen recycled. The tunnel would have gas tight doors on the east end which would close after launch to trap the water. This scheme will help keep a lunar atmosphere from developing. ------------------------------ Date: Wed 11 Jan 84 21:13:58-EST From: Anthony J. Courtemanche Subject: Why nuke planets? To: space-enthusiasts@MIT-MC I hope I do not sound like I'm flaming but I am a bit concerned with this talk of significantly altering our solar system. What gives us the right to nuke Venus or any other planet or moon in the hopes that it will make it habitable? We have done much to destroy Terra's ecology, so now we must work on other places??!! It seems to me that until Mankind learns to be responsible enough to take care of his own planet, he should lay off trying to change other planets to suit his needs. Anthony ac@mit-oz ------- ------------------------------ Date: 10 Jan 84 16:29:28-PST (Tue) To: space @ Mit-Mc From: decvax!duke!ucf-cs!giles @ Ucb-Vax Subject: Re: Deuterium on Venus In-Reply-To: Article <14945@sri-arpa.UUCP> 3 January 1984, <730@ssc-vax.UUCP> Let us say you wanted to raise the temperature by a factor of 4. This requires 64 times as much incident intensity. Assume that this is gotten from solar sails in Venus vicinity. They need a total surface area of 7.24 billion km**2. If their thickness is .15 microns, then the volume of material required is only 1.1 km**3, not an unreasonable quantity. And we wave a fond farewell to the lightsails as they accelerate into the darkness of interstellar space. (may not make too much sense towards the end, but it sounds good) (hint: divide 7.24 billion km**2 light pressure at Venus by the mass of 1.1 km**3 of material, and use F = ma). Bruce Giles --------------------------------------------- UUCP: decvax!ucf-cs!giles cs-net: giles@ucf ARPA: giles.ucf-cs@Rand-Relay Snail: University of Central Florida Dept of Math, POB 26000 Orlando Fl 32816 --------------------------------------------- ------------------------------ End of SPACE Digest *******************