Jonathan's STS-93/Chandra (AXAF) Page

Jonathan McDowell's Unofficial STS-93 Launch Page

STS-93 - Chandra X-Ray Observatory Deployment Mission

Crew - Vehicle - Images - Press Releases - Links - Deployment - Milestones

Eileen Collins (CDR), Jeff Ashby (PLT), Cady Coleman (MS1), Steve Hawley (MS2), Michel Tognini (MS3)

The Advanced X-ray Astrophysics Facility (AXAF) will be launched on Space Shuttle mission STS-93. In Dec 1998 AXAF was named the Chandra X-ray Observatory after physicist Subrahmanyan Chandrasekhar Chandra is a mission in NASA's SEU (Structure and Evolution of the Universe) program. As a user of the Chandra Observatory, I'm providing this page to keep my fellow guest observers and other interested folks up to date with the progress of the mission.

STS-93 LAUNCHED 1999 JUL 23 AT 0431 UTC

The STS-93 crew:

Commander: Lt-Col. Eileen Collins, USAF, NASA
Pilot: Cmdr. Jeff Ashby, USN, NASA
Mission Specialist: Dr. Steven Hawley, NASA
Mission Specialist: Dr. Cady Coleman, Maj. USAF, NASA
Mission Specialist: Col. Michel Tognini, AAF, CNES

The STS-93 launch vehicle:

Chandra has been launched by the NASA Space Transportation System (STS) from NASA John F. Kennedy Space Center in Florida. The STS vehicle consists of the Space Shuttle Orbiter - in this case, the original flight vehicle, OV-102 Columbia - a disposable External Tank containing liquid hydrogen and liquid oxygen, and two Redesigned Solid Rocket Motors in recoverable Solid Rocket Boosters. Chandra, attached to a Boeing IUS rocket, is mounted in the Orbiter's payload bay for launch. The Orbiter reaches a low circular orbit and deploys the Chandra/IUS combination. The two IUS solid motors fired in succession to place Chandra in a highly elliptical orbit. Chandra's own IPS integral propulsion system, derived from TRW's DM-LAE comsat apogee engine, will fire several times to raise the orbit to its final height of 10000 x 140000 km. As of Jul 30, two IPS burns have been made successfully, and the ACIS and HRC cameras were switched on for initial checks.
Component Name/Serial Status
Launch Complex LC39B Refurb
Solid Rocket Motors RSRM-69 Being towed to port
External Tank ET-99 (Super Light Weight Tank) Reentered over Pacific?
Orbiter OV-102 Columbia In orbit
Payload Bay Cargo IUS Tilt Table Aboard Columbia
Upper Stage Inertial Upper Stage IUS-27 In orbit
Spacecraft Chandra X-Ray Observatory (AXAF)In transfer orbit
..ETE-1 test completed 2/98
..Final assembly completed 3/98
..Thermal vac testing complete 7/98
..ACIS/SIM retest 8/98
..Undergoing tests at TRW 10/98
..Arrived KSC 2/99
..Fuelled 4/99
..Mate to IUS-27 6/99
..Transfer to pad 39B 6/99
..In Columbia, Jun 27
..Launch Jul 23
..Deploy and IUS burns, Jul 23

STS-93 payloads:

The orbiter payload bay contains only the Chandra spacecraft, the IUS, and the IUS tilt table. STS-93 also carries the following payloads in its cabin: STL-B (Space Tissue Loss), CCM (Cell culture module), SAREX-II (Shuttle Amateur Radio Experiment), EarthKam, PGIM (Plant Growth Investigations in Microgravity), CGBA (Commercial Generic Bioprocessing Apparatus), MEMS (Micro-electric Mechanical System), and BRIC (Biological Research in Canisters) and SWUIS (the Southwest Ultraviolet Imaging System, an 0.18-m UV telescope to be used for airglow and planetary observations); GOSAMR (the Gelation of Sols: Applied Microgravity Research experiment) and LFSAH, the Lightweight Flexible Solar Array Hinge. The MSX and SIMPLEX experiments will also be carried out.

STS-93 images:

Chandra was uncrated at KSC
Chandra was bagged for transport to KSC
CXO in final assembly
A Boeing IUS in its tilt table being lifted into the Vertical Processing Facility test stand
Orbiter Columbia (OV-102) in the Vehicle Assembly Building
Orbiter Columbia (OV-102) launched on mission STS-87
An IUS being deployed from the tilt table in the payload bay

STS-93 NASA press releases:

STS-93 links:

AXAF/Chandra launch and deployment:

Time (UTC) Event Description Orbit (perigee x apogee, km)
Jul 23 0431 Launch RSRM ignition, liftoff .
Jul 23 0433 SRB Sep RSRM burnout, separation .
Jul 23 0439 MECO Main engine cutoff .
Jul 23 0439 ET Sep External Tank separation 78 x 276
Jul 23 0512 OMS-2 OMS orbit circ burn 320 x 320
Jul 23 0610 PLBD Payload bay doors open .
Tilt Raise tilt table to 4 deg .
Jul 23 1000? Tilt Raise tilt table to 29 deg .
. Chandra to internal power .
Jul 23 1142 Tilt Raise tilt table to 58 deg .
Jul 23 1147 Deploy Chandra/IUS-27 deploy 320 x 320
Jul 23 1248 SRM-1 IUS-27 SRM-1 burn .
Jul 23 1250 SRM-1 cutoffIUS-27 SRM-1 sep from SRM-2 320 x ?
Jul 23 1251 SRM-2 IUS-27 SRM-2 burn .
Jul 23 1253 SRM-2 cutoffIUS-27 SRM-2 cutoff 320 x 72000
Jul 23 1322 SA Deploy Chandra solar panels deploy.
Jul 23 1350 SRM-2 sep IUS-27 SRM-2 sep from AXAF.
Jul 25 0111 IPS-1 IPS burn 1, apogee 1200 x 72000
Jul 26 0145 IPS-2 IPS burn 2, perigee
Jul 31 2227 IPS-3 IPS burn 3, apogee
Aug 2 0446 IPS-4 IPS burn 4, apogee?
Aug 4 2027 IPS-5 Trim burn, apogee

Chandra project milestones

(Thanks to Wallace Tucker for this information)

HEAO-LOXT proposal 1970
HEAO descoped 1973
AXAF phase A study 1978
AXAF phase B study 1985
Technology mirror (TMA) tested1985
Approved as new start 1988
TRW chosen as contractor1988
SAO/MIT chosen as AXAF science center1991
AXAF rescoped into AXAF-I and AXAF-S 1992
AXAF-S cancelled 1993 Oct
HRMA complete1996
Mirror calibration1996 Dec - 1997 Feb
Instrument calibration1997 Feb-May
Spacecraft assembly 1998 Mar
Thermal vac tests1998 Jun
End-to-end tests1998 Jul
AXAF named Chandra X-ray Observatory1998 Dec
AXAF arrive at KSC1999 Feb
IUS mate to AXAF1999 Jun
AXAF/IUS transfer to Columbia1999 Jun
Launch 1999 Jul

Chandra launch and deployment sequence. The IPS burn times on this picture are out of date.

Chandra in Shuttle payload bay

Chandra in Shuttle payload bay

Chandra exploded view

Questions and corrections: email Jonathan McDowell at