Autzoo.1572 net.space utzoo!henry Sun Apr 18 19:32:53 1982 External Tank again... Suppose we are using solid strapons to boost the ET higher, and are attaching them in orbit. How much extra delta-V are we getting out of the SSMEs in getting the tank up there? If the answer is "little or none", it goes like this. Main engine cutoff. Shuttle separates from tank, maneuvers to the right position. Cargo bay opened, arm picks up first solid booster, begins to attach it. ...and at about this moment, orbiter and tank both hit atmosphere, and wind up in little pieces on the bottom of the Indian Ocean. There is very little time available between ET separation and ET reentry; if the SSMEs are used more extensively, this will lengthen, but I suspect it would still be a severe constraint. There are other problems of designing the attachment system, and the general hairiness of handling big chunks of explosive (that's what solid-fuel rocket motors are, and they are handled with elaborate care). It does look like it's better to have the solids in place at launch. Any reconfiguration for aerodynamics and balance would probably be a minor variation of what is going to have to be done anyway for the USAF's extra-boost addition (Titan engines and tanks on bottom of ET). ----------------------------------------------------------------- gopher://quux.org/ conversion by John Goerzen of http://communication.ucsd.edu/A-News/ This Usenet Oldnews Archive article may be copied and distributed freely, provided: 1. There is no money collected for the text(s) of the articles. 2. The following notice remains appended to each copy: The Usenet Oldnews Archive: Compilation Copyright (C) 1981, 1996 Bruce Jones, Henry Spencer, David Wiseman.