Which begets another question...or actually five - 1. The tank fill schedule (as I understand it) was low flow to 2% then high flow (5,000 gal/min) til 98% then low flow again to 100% a. What was the low flow rate? b. How do it know? No 2% sensor...Dave
2. The feed lines openings were offset (as I measure it, 10 degrees for LOX and 6 degrees for LH2). a. I ASSUME that this was to make up for gravity effect, si or no? b. Why are these not the same? (density delta twix LO2 & LH2?) c. Was the offset towards or away from the orbiter?Dave
Thanks again! Excellent response/info.I'm trying to get my (very) limited grey matter wrapped around the offset CG thing - I realize why the CG was offset, but did the offset cause/require a pitch that in turn caused the feed ports to be "canted"?
Why didn't the shuttle external tank have LOX/LH2 common bulkhead - unlike Saturn S-II ? they were of similar sizes and volumes. I thought it could have made the E.T lighter, helping the shuttle performance a little ? by 1979 the Air Force was considering strapping Titan engines or solid rocket motors to improve performance. Could a common bulkhead external tank have been fitted to shuttles as an upgrade ?
Recently was looking at old mission pictures and the images of Challenger post landing and actually in the preflare on 61a gave me a start! The browned burn from nose cap up to the cabin window was striking. I've never seen the shuttle look like that in that area. Was is a different reentry plan? High inclined orbit?
My other question was regarding I believe sts 8 or maybe 9. I read that there was tile slumping. I don't know what that is and what would cause it?
Quote from: penguin44 on 10/01/2017 07:45 amRecently was looking at old mission pictures and the images of Challenger post landing and actually in the preflare on 61a gave me a start! The browned burn from nose cap up to the cabin window was striking. I've never seen the shuttle look like that in that area. Was is a different reentry plan? High inclined orbit?No, just waterproofing material burning off. no different entry
Yes. What they used pre-Challenger was stock 3M ScotchGuard that was sprayed directly onto the orbiter. It was later found that the ScotchGuard wasn’t working too well with the adhesive used to bond the tiles to the orbiter. This caused alot tiles to debond and was what was really behind the “TPS issues” with Challenger that forced her substitution with Discovery for STS-51C. In fact the problems were so severe that they removed Challenger’s original body flap and used the one intended for Atlantis. The body flaps were never changed back prior to the loss of Challenger so even to this day, Atlantis still have the refurbished body flap from Challenger.