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The Later Days of AXAF-Chandra. 1991 - 1999. 40 Years of X-ray Astronomy Workshop in honor of Gordon Garmire's 70th birthday. June 14-15, 2007 Harvey Tananbaum. AXAF RESTRUCTURING: Jan 1992 - Aug 1992. Driven by tight budgets, projected costs of Station and other science missions
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The Later Days of AXAF-Chandra 1991 - 1999 40 Years of X-ray Astronomy Workshop in honor of Gordon Garmire's 70th birthday June 14-15, 2007 Harvey Tananbaum
AXAF RESTRUCTURING: Jan 1992 - Aug 1992 • Driven by tight budgets, projected costs of Station and other science missions • Driven by Charlie Pellerin - Director of Astrophysics Division at NASA HQ • Players included HQ, MSFC, AXAF SWG, TRW, ... • Costs of servicing HST becoming apparent - exceed costs to build and launch • Meetings, conference calls, trades - cost, schedule, and science capability • Considered at least 18 options over the Jan-June time-frame • Baseline + 11 M' options in LEO with 4 or 6 mirror pairs and 2 or 3 SIs - rejected on basis of cost (all but 1 included servicing) or schedule, or loss of science • 4 options in HEO with 1-3 mirror pairs and 1-2 SIs (no servicing) - issues with costs, schedule, and esp science • Agreed on option with 2 missions: AXAF-I in HEO (3 or 4 mirror pairs) & 2 SIs (plus gratings) and AXAF-S in LEO with foil optics & micro-calorimeter
AXAF Becomes Chandra Mrs. Chandrasekhar with contest winners Jatila van der Veen (center) and Tyrel Johnson
STS-93 Crew • July 20 - launch aborted due to possible fuel leak • July 22 - launch canceled due to nearby thunderstorms • L+5s - short circuit disabled computers controlling 2 of 3 engines • L+? - plug patch blows out, punches small holes and creates small fuel leak • Columbia returns - Shuttles grounded for several months
Time-line for Key Activation Events 07/23/99 Launch Chandra/IUS Deploy Inertial Upper Stage Burns 1 & 2 Solar Array Deploy IUS/Chandra Separation 07/24/99 Integral Propulsion (IPS) Burn 1 07/25/99 IPS Burn 2 07/26/99 HRC Door Open 07/31/99 IPS Burn 3 08/04/99 IPS Burn 4 08/07/99 IPS Burn 5 08/08/99 ACIS Door Opening Sequence 08/11/99 Aft Contamination Cover Open 08/12/99 Sunshade Door Open First X-ray Image (Leon X-1) Aspect Camera First Star Solution 08/17/99 Safe Mode #1 08/19/99 Recover from Safe Mode #1 08/19/99 ACIS First Light (Cas A) 08/30/99 HETG First Light 09/05/99 LETG First Light
Gordon Garmire & Martin Weisskopf Celebrate First ACIS Image