STS-93

Infobox Space mission
mission_name = STS-93
insignia = STS-93 patch.svg
shuttle = Columbia
launch_pad = 39B
launch = July 23, 1999 12:31 a.m. EDT
landing = July 27, 1999 11:20 p.m. EDT
duration = 4 days, 22 hours, 50 minutes, 18 seconds
altitude = 153 nautical miles (283 km)
inclination = 28.4 degrees
orbits = 80
distance = 1,796,000 miles (2,890,000 km)
crew_photo = STS-93_crew.jpg
crew_caption =
previous = STS-96
next = STS-103

STS-93 marked the 95th launch of the Space Shuttle, the 26th launch of "Columbia", and the 21st night launch of a Space Shuttle. Eileen Collins became the first female shuttle Commander on this flight. Its primary payload was the Chandra X-ray Observatory. It would also be the last mission of "Columbia" until March 2002. During the interim, "Columbia" would be out of service for upgrading, and would not fly again until STS-109. The launch was originally scheduled for July 20 but the launch was aborted at T-7 seconds. The successful launch of the flight occurred three days later.

Five seconds after liftoff, an electrical short disabled one primary and one secondary controller on two of the three main engines. In this event, the engines automatically switched to their backup controllers. The short was later discovered to have been caused by poorly routed wiring which had rubbed on an exposed screw head. This wiring issue led to a program-wide inspection of the wiring in all orbiters. Concurrently, an oxidizer post, which had been intentionally plugged, came loose inside one of the main engine's main injector and impacted the engine nozzle inner surface rupturing a hydrogen cooling line allowing a small leak. To maintain a proper mixture ratio in the event of this leak, the engine's controller increased oxidizer flow resulting in a premature engine shutdown near the end of the projected burn due to low liquid oxygen level. Despite the premature shutdown, the vehicle safely achieved a slightly lower orbit and was able to complete the mission as planned. This incident brought on a maintenance practice change which required damaged oxidizer posts to be removed and replaced as opposed to being intentionally plugged, as was the practice beforehand.

Crew

*Eileen M. Collins (3), Commander
*Jeffrey S. Ashby (1), Pilot
*Steven A. Hawley (5), Mission Specialist
*Catherine G. Coleman (2), Mission Specialist
*Michel Tognini (2), Mission Specialist - flag|France CNES

Number in parentheses indicates number of spaceflights by each individual prior to and including this mission.

Mission parameters

*Mass:
**"Orbiter Liftoff:" 122,536 kg
**"Orbiter Landing:" 99,783kg
**"Payload:" 22,781 kg
*Perigee: 260 km
*Apogee: 280 km
*Inclination: 28.5°
*Period: 90 min

Mission objectives

The primary objective of the STS-93 mission was to deploy the Chandra X-ray Observatory (formerly the Advanced X-ray Astrophysics Facility) with its Inertial Upper Stage booster. At its launch, Chandra was the most sophisticated X-ray observatory ever built. It is designed to observe X-rays from high energy regions of the universe, such as hot gas in the remnants of exploded stars.

Other payloads on STS-93 included the Midcourse Space Experiment (MSX), the Shuttle Ionospheric Modification with Pulsed Local Exhaust (SIMPLEX), the Southwest Ultraviolet Imaging System (SWUIS), the Gelation of Sols: Applied Microgravity Research (GOSAMR) experiment, the Space Tissue Loss - B (STL-B) experiment, a Light Weight Flexible Solar Array Hinge (LFSAH), the Cell Culture Module (CCM), the Shuttle Amateur Radio Experiment - II (SAREX - II), EarthKAM, Plant Growth Investigations in Microgravity (PGIM), the Commercial Generic Bioprocessing Apparatus (CGBA), the Micro-Electrical Mechanical System (MEMS), and the Biological Research in Canisters (BRIC).

The Shuttle Ionespheric Modification with Pulsed Local Exhaust (SIMPLEX) payload activity researched the source of Very High Frequency (VHF) radar echoes caused by the orbiter and its OMS engine firings. The Principal Investigator (PI) used the collected data to examine the effects of orbital kinetic energy on ionospheric irregularities and to understand the processes that take place with the venting of exhaust materials.

The Southwest Ultraviolet Imaging system (SWUIS) was based around a Maksutov-design ultraviolet (UV) telescope and a UV-sensitive, image-intensified Charge-Coupled Device (CCD) camera that frames at video frame rates. Scientists can obtain sensitive photometric measurements of astronomical targets.

The objective Gelation of Sols: Applied Microgravity Research (GOSAMR) experiment was to investigate the influence of microgravity on the processing of gelled sols. In particular, the purpose was to demonstrate that composite ceramic precursors composed of large particulates and small colloidal sols can be produced in space with more structural uniformity.

The focus of the Space Tissue Loss - B (STL-B) experiment was direct video observation of cells in culture through the use of a video microscope imaging system with the objective of demonstrating near real-time interactive operations to detect and induce cellular responses.

The Light Weight Flexible Solar Array Hinge (LFSAH) payload consists of several hinges fabricated from shape memory alloys. Shape memory deployment hinges offered controlled shockless deployment of solar arrays and other spacecraft appendages. LFSAH demonstrated this deployment capability for a number of hinge configurations.

The objectives of the Cell Culture Module (CCM) were to validate models for muscle, bone, and endothelial cell biochemical and functional loss induced by microgravity stress; to evaluate cytoskeleton, metabolism, membrane integrity and protease activity in target cells; and to test tissue loss medications.

The Shuttle Amateur Radio Experiment (SAREX-II) demonstrated the feasibility of amateur short-wave radio contacts between the shuttle and ground-based amateur radio operators. SAREX also served as an educational opportunity for schools around the world to learn about space by speaking directly to astronauts aboard the shuttle via amateur radio.

The EarthKAM payload conducted Earth observations using the Electronic Still Camera (ESC) installed in the overhead starboard window of the Aft Flight Deck.

The Plant Growth Investigations in Microgravity (PGIM) payload experiment used plants to monitor the space flight environment for stressful conditions that affect plant growth. Because plants cannot move away from stressful conditions, they have developed mechanisms that monitor their environment and direct effective physiological responses to harmful conditions.

The Commercial Generic Bioprocessing Apparatus (CGBA) payload hardware allows for sample processing and stowage functions. The Generic Bioprocessing Apparatus - Isothermal Containment Module (GBA-ICM) is temperature controlled to maintain a preset temperature environment, controls the activation and termination of the experiment samples, and provides an interface for crew interaction, control and data transfer.

The Micro-Electrical Mechanical System (MEMS) payload examines the performance, under launch, microgravity, and reentry conditions of a suite of MEMS devices. These devices include accelerometers, gyroscopes, and environmental and chemical sensors. The MEMS payload is self-contained and requires activation and deactivation only.

The Biological Research in Canisters (BRIC) payload was designed to investigate the effects of space flight on small arthropod animals and plant specimens. The flight crew was available at regular intervals to monitor and control payload/experiment operations.

"Columbia"'s landing at Kennedy Space Center marked the twelfth night landing in the Shuttle program's history. Five had been at Edwards Air Force Base in California and the rest KSC. To date, there had been 19 consecutive landings at KSC and 25 of the last 26 had been there.

External links

* [http://science.ksc.nasa.gov/shuttle/missions/sts-93/mission-sts-93.html NASA PAO page about STS-93]
* [http://spaceflight.nasa.gov/shuttle/archives/sts-93/ STS-93 Archives]
* [http://www.nss.org/resources/library/shuttlevideos/shuttle95.htm STS-93 Video Highlights]