Home - Search - Browse - Alphabetic Index: 0- 1- 2- 3- 4- 5- 6- 7- 8- 9
A- B- C- D- E- F- G- H- I- J- K- L- M- N- O- P- Q- R- S- T- U- V- W- X- Y- Z
STS-93
Part of STS
STS-93
STS-93
Credit: NASA
Delivered Chandra spacecraft. Hydrogen fuel leaked out during ascent, resulting in shuttle running out of propellant and ending up in an orbit 11 km lower than planned.

AKA: Columbia. Launched: 1999-07-23. Returned: 1999-07-28. Number crew: 5 . Duration: 4.95 days.

STS-93 was first rolled out to pad 39B on June 7 1999. The Chandra/IUS-27 vehicle was placed in the payload canister on June 19. The first launch attempt was on July 20, but controllers aborted the launch at T-6 seconds, just before main engine ignition, due to a data spike in hydrogen pressure data. This was determined to be due to a faulty sensor and a second attempt was on July 22. A lightning storm prevented launch during the 46 minute window, and the launch was again scrubbed. Finally the vehicle lifted off the pad on July 23, but five seconds after launch a short in an electrical bus brought down two of the three main engine controllers. Backup controllers took over, but a further failure on the backup controller bus would have resulted in engine shutdown and the first ever attempt at an RTLS (Return To Launch Site) abort. To further complicate matters engine 3 (SSME 2019) had a hydrogen leak throughout the ascent, causing the engine to run hot. Controllers sweated as temperatures neared redline. The hot engine's controller compensated as programmed by using additional liquid oxygen propellant. The final result was that the shuttle ran out of gas - main engine cut-off (MECO) was at 04:39 GMT, putting Columbia into a 78 km x 276 km x 28.5 degree transfer orbit. Columbia was 1,700 kg short of oxygen propellant and 5 meters/sec slower than planned. The OMS-2 engine burn at 05:12 GMT circularized the orbit 10 km lower than planned.

The orbiter payload bay contained only the Chandra spacecraft, the IUS, and the IUS tilt table. The following payloads were carried in the shuttle's 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. MSX and SIMPLEX experiments were also to be carried out.

Chandra/IUS-27 was deployed from Columbia at 11:47 GMT July 23. Flight duration was limited; this was the heaviest shuttle (122,534 kg) and heaviest payload (19,736 kg) to that date. Columbia landed at 03:20 GMT on July 28 on runway 33 at Kennedy Space Center. Post-flight inspection found the presence of holes in the cooling lines on the nozzle of SSME 2019 (engine 3) which caused a hydrogen leak. A loose repair pin in the engine broke free and caused the failure. The cause of the short was found to be chaffed wiring inside the shuttle. The entire fleet was grounded for inspection and replacement of wiring as necessary.

NASA Official Mission Summary:

STS-93
(Chandra X-ray Observatory)
Columbia
Pad B
95th Shuttle mission
26th flight
OV-102
48th KSC landing
Crew:
Eileen M. Collins, Commander (3rd Shuttle flight)
Jeffrey S. Ashby, Pilot (1st)
Steven A. Hawley, Mission Specialist (5th)
Catherine G. "Cady" Coleman, Mission Specialist (2nd)
Michel Tognini, Mission Specialist (2nd) (CNES, French Space Agency)
Orbiter Preps:
OPF - May 4, 1998
VAB - Feb. 10, 1999 (Temporary storage)
OPF - April 15, 1999
VAB - June 2, 1999
Pad 39 B - June 7, 1999

Launch:

July 23, 1999, at 12:31:00 a.m. EDT. The originally scheduled launch on July 20 was scrubbed at about the T-7 second mark in the countdown. Following a virtually flawless countdown, the orbiter's hazardous gas detection system indicated a 640 ppm concentration of hydrogen in Columbia's aft engine compartment, more than double the allowable amount. System engineers in KSC's Firing Room No. 1 noted the indication and initiated a manual cutoff of the ground launch sequencer less than one-half second before the Shuttle's three main engines would have started. Following preliminary system and data evaluation, launch managers determined the hydrogen concentration indication was false.

A second launch attempt 48 hours later was scrubbed due to weather at KSC. A 24-hour turnaround was initiated and the third launch attempt succeeded with Columbia lifting off the pad on July 23.

During the countdown for launch on the third attempt, a communications problem occurred that resulted in the loss of the forward link to Columbia. The problem was corrected at the Merritt Island Launch Area (MILA) ground facility and communications was restored. As a result of this problem, the time of the planned launch was slipped seven minutes to 12:31 a.m. EDT on July 23.

About 5 seconds after liftoff, flight controllers noted a voltage drop on one of the shuttle's electrical buses. Because of this voltage drop, one of two redundant main engine controllers on two of the three engines shut down. The redundant controllers on those two engines - center and right main engines - functioned normally, allowing them to fully support Columbia's climb to orbit. The orbit attained, however, was 7 miles short of that originally projected due to premature main engine cutoff an instant before the scheduled cutoff. This problem was eventually traced to a hydrogen leak in the No. 3 main engine nozzle. The leak was caused when a liquid oxygen post pin came out of the main injector during main engine ignition, striking the hotwall of the nozzle and rupturing three liquid hydrogen coolant tubes.

The orbiter eventually attained its proper altitude and successfully deployed the Chandra X-ray Observatory into its desired orbit.

Landing:

July 27, 1999 at 11:20:37 p.m. EDT. Runway 33, Kennedy Space Center, Fla. Rollout distance 6,851 feet. Rollout time: 43.3 seconds. Mission duration: 4 days, 22 hours, 49 minutes, 37 seconds. Landed on orbit 80, logging 1.8 million miles. It marked the 12th nighttime landing in the shuttle program and the 7th at Kennedy Space Center.

Mission Highlights:

STS-93 was the first mission in Space Shuttle history to be commanded by a woman, Commander Eileen Collins. Also, this was the shortest scheduled mission since 1990.

On the first day of the scheduled five-day mission, the Chandra X-ray Observatory was deployed from Columbia's payload bay. Chandra's two-stage Inertial Upper Stage (IUS) propelled the observatory into a transfer orbit of 205 miles by 44,759 miles in altitude.

Following the second IUS burn, Chandra's solar arrays were deployed and the IUS separated from the observatory as planned. During the rest of the mission secondary payloads and experiments were activated. The Southwest Ultraviolet Imaging System (SWUIS) was used aboard Columbia to capture ultraviolet imagery of Earth, the Moon, Mercury, Venus and Jupiter.

Astronauts monitored several plant growth experiments and collected data from a biological cell culture experiment. They used the exercise treadmill and the Treadmill Vibration Information System to measure vibrations and changes in microgravity levels caused by on-orbit workouts.

High Definition Television equipment was tested for future use on both the shuttle and the International Space Station to conform to evolving broadcasting industry standards for television products.

More at: STS-93.
Family: Manned spaceflight. People: Ashby, Coleman, Catherine, Collins, Eileen, Hawley, Tognini. Country: USA. Spacecraft: Columbia. Projects: STS. Launch Sites: Cape Canaveral. Agency: NASA, NASA Houston. Bibliography: 4457.
1999 July 23 - .
1999 July 23 - .
1999 July 23 - .
1999 July 23 - .
1999 July 23 - . 04:31 GMT - . Launch Site: Cape Canaveral. Launch Complex: Cape Canaveral LC39B. Launch Platform: MLP1. LV Family: Shuttle. Launch Vehicle: Space Shuttle.
1999 July 24 - .
1999 July 24 - .
1999 July 24 - .
1999 July 25 - .
1999 July 25 - .
1999 July 25 - .
1999 July 26 - .
1999 July 26 - .
1999 July 26 - .
1999 July 27 - .
1999 July 27 - .
1999 July 27 - .
1999 July 27 - .
1999 July 28 - .
1999 July 29 - .
Back to top of page
Home - Search - Browse - Alphabetic Index: 0- 1- 2- 3- 4- 5- 6- 7- 8- 9
A- B- C- D- E- F- G- H- I- J- K- L- M- N- O- P- Q- R- S- T- U- V- W- X- Y- Z
© 1997-2019 Mark Wade - Contact
© / Conditions for Use