MSL "Heat shield woes" |
MSL "Heat shield woes" |
Feb 17 2008, 04:20 PM
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#1
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The Poet Dude Group: Moderator Posts: 5551 Joined: 15-March 04 From: Kendal, Cumbria, UK Member No.: 60 |
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Feb 19 2008, 08:38 AM
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#2
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Senior Member Group: Members Posts: 1870 Joined: 20-February 05 Member No.: 174 |
Mariners 6 and 7 <1969> had unusually short trip times to Mars, something like 5 months. They were launched as second generation Mariners on Atlas Centaur rockets instead of the Atlas Agena that launched the early Mariners and Rangers. Launch vehicle had more or less the same capability as the one that launched Mariner 9 to orbit Mars on the next opportunity, BIG fuel tanks and all. Mariner 69 were flybys and a little ?more? than half the weight of Mariner 9, so the launches had energy to spare. They were kicked into fast flybys, that also had a mission irrelevant gravity assist that kicked the aphelion out to the edge of the inner belt. Had the record as the furthest solar powered spacecraft from the sun till NEAR, Stardust, or perhaps Rosetta got further out at aphelion.
You would NOT have wanted to retro into Mars orbit from those encounters. The "Hyperbolic excess velocity" -- very useful term in these discussions, the speed the spacecraft approaches and receeds from the planet at effectively infinity (ignoring the sun) -- was much larger than for an orbit insertion bound mission. |
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