From: utzoo!decvax!harpo!eagle!karn Newsgroups: net.space Title: Re: Saving the Shuttle External Tank Article-I.D.: eagle.830 Posted: Mon Mar 14 15:49:15 1983 Received: Thu Mar 17 19:11:05 1983 References: alice.1568 uofm-cv.158 floyd.1297 Getting the external tank into a long-lived orbit might not be as easy as many think. Remember, even the orbit into which the orbiter puts itself after ET separation is a very low one, typically 300 km or so. An object as large and light as an empty external tank would last hardly any time at all in such an orbit. Even moving it up to 500 km, which would take considerable added fuel on the orbiter (perhaps an OMS kit or two) would keep it up there for only several years at best. It is probably feasible to take a tank up to a stable altitude, but it would not be "almost free" as has been suggested; it would involve the sacrifice of considerable payload mass. Phil