REM@IMSSS (Robert Elton Maas, this host known locally only) (01/17/86)
phil%dean@BERKELEY.EDU says this message was rejected by USENET because of problems with the message-id, so I'm resubmitting without any message-id. Arpanet members please ignore duplicate. Date: 1986 January 09 18:54:45 PST (=GMT-8hr) From: Robert Elton Maas <REM@imsss> (this host known locally only) To: FIRTH@tl-20b.arpa Cc: Space@s1-b.arpa, LINDSAY@tl-20b.arpa Subject: colliding two inert masses (Sorry for tardy reply but IMSSS was down most of Dec 30 thru Jan 07 and I am just now catching up on answering mail.) F: Date: Tue 31 Dec 85 15:12:04-EST F: From: FIRTH@tl-20b.arpa F: Subject: those two masses... F: To: space@mit-mc.arpa F: Mr Throop wonders how to get my two masses to join up. F: Frankly, so do I, but the situation isn't quite as bad as he F: indicates. At the intersection point the masses are moving F: with a relative velocity of ~6000 mph (~2.7 kps). A deceleration F: of 5g for 1 minute will bring them to relative rest - which doesn't F: seem too hairy. If you have a rocket for accellerating them to achive common orbit, you don't need two in the first place, firing one then using a rocket to accellerate it into orbit. I think your answer above begs the question about how to just toss them up without having any on-board accelleration devices such as rockets. F: More likely would be a thrust of 50g for 20", and an accelerator F: therefore 60 miles long (and a height difference of 3200 feet between F: the ends). That already rules out any human cargo - but the purpose is F: simply to get MASS up there, to be assembled &c later. Even bricks will F: withstand 50g, after all. Do you see the problem? Do you know any bricks able to withstand 50 gee which can after such launch receive radio commands and accellerate as you proposed earlier? Either you have bricks, which have to be just tossed up, and you have to figure a way that such dead weight can achieve orbit, or you have delicate rocket engines or mirrors or sails or whatever and you have to figure a way to gently launch them in the first place. Probably the solution is to launch just dead weight, but have something up there already (by earlier gentle launch) that tracks them and rendezvouses (sp?) with them and catches them and applies thrust to put them in orbit. What we need is an orbital transfer vehicle, a "space tug", solar powered and controlled from Earth. On the other hand... L> Date: Tue 7 Jan 86 23:35:50-EST L> From: LINDSAY@tl-20b.arpa L> Subject: pulling heavy Gs L> There were comments recently about whether a payload could contain a rocket L> and still survive a pretty rugged launch. L> ... talked the U.S. Navy out of a battleship gun that had been L> mothballed since the first world war. ... Each shot involved L> packing the gun with wood pieces, and placing the payload in a hollow L> in the middle. Then you packed explosives in back of that, closed the L> breech, pointed the gun straight up, and blammo ! There was serious L> discussion at the time about putting a rocket motor into the payload, L> and going all the way to orbit. L> ... L> There was talk a few years ago about developing an anti-aircraft L> missile that would bank to turn, and that would be a lifting body L> rather than have wings. The stated advantage was that it would L> pull 100 or 200 Gs going around corners. Maybe you can indeed build robust rockets and use mass driver or battleship gun to replace first-stage rocket.