Re: AXAF Burn Visibility?
Philip Chien (kc4yer@amsat.org)
Mon, 12 Jul 1999 22:58:25 -0400
>>> Has anyone here started to look into the potential of viewing some of
>>> the insertion burns for the upcoming Chandra (formerly AXAF) X-Ray
>>> observatory deployment on STS-93?
>>>
>>> Bill Moore
Ron Lee <ronlee@pcisys.net> said:
>Here is where I am at a loss. I have ZERO data on the orbit and ZERO
>info on the burn times. That adds up to almost no chance to tell
>people when and where to look. Perhaps Mr Chien can correct the
>lack of info.
Well, I would if people would still call it AXAF instead of Chandra ...
(Who me bitter that they didn't select the name I proposed - nah!)
>The IUS was under investigation due to failure placing a DSP into orbit.
>I have not seen anything that clears the IUS for flight. If it is not
>cleared, I suspect the Chandra flight will be delayed.
While the Air Force investigation on DSP-19/IUS-21 is ongoing the IUS-27
for AXAF has been cleared for flight with launch planned for July 20th at
12:36 am EDT. (4:36 UT).
Here's the predicted shuttle orbit for the AXAF/IUS deploy -
STS-93 OMS-2
1 99993P 99201.22870020 .00018250 13934-8 44256-4 0 14
2 99993 28.4662 199.3456 0003191 302.7331 301.7244 15.95038814 15
Here's the key events -
07 h 17 m AXAF deploy from the shuttle
08 h 17 m IUS stage 1 ignition
08 h 19 m IUS stage 1 burnout
320 x ??? km. orbit - I can probably figure this out based on the amount of
propellant in the first IUS stage
08 h 22 m IUS stage separation
08 h 23 m IUS stage 2 ignition
08 h 24 m IUS stage 2 shutdown
320 x 64000 km. orbit, 28.5 degree inclination
Surprisingly the online shuttle press kit at http://www.shuttlepresskit.com
actually has a decent amount of information.
With a bit of effort I could probably precess the orbits and determine
where the burns take place.
Philip Chien, KC4YER
Earth News
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