STS-48

Int. Designation	1991-063A
Launched	12 September 1991
Launch Site	Pad 39A, Kennedy Space Center, Florida
Landed	18 September 1991
Landing Site	Runway 22, Edwards AFB, California
Launch Vehicle	OV-103 Discovery/ET-42/SRB BI-046/SSME #1 2019; #2 2031; #3 2107
Duration	5 days 8 hours 27 min 38 sec
Call sign	Discovery
Objective	Deployment of the Upper Atmosphere Research Satellite (UARS)

Flight Crew

CREIGHTON, John Oliver, 48, USN, commander, 3rd mission Previous missions: STS 51-G (1985); STS-36 (1990)

REIGHTLER Jr., Kenneth Stanley, 40, USN, pilot

GEMAR, Charles Donald “Sam”, 36, US Army, mission specialist 1,

2nd mission

Previous mission: STS-38 (1990)

BUCHLI, James Frederick, 46, USMC, mission specialist, 4th mission Previous missions: STS 51-C (1985); STS 61-A (1985); STS-29 (1989) BROWN, Mark Neil, 40, USAF, mission specialist, 2nd mission Previous mission: STS-28 (1989)

Flight Log

There was only a fourteen-minute delay to the launch of STS-48, caused by a faulty communications link between KSC and MCC in Houston. The landing, however, was scheduled for KSC but was diverted to Edwards due to bad weather around the Cape.

The 6,577 kg UARS was deployed by the RMS on the third day of the flight for a planned 18-month primary mission that would make the most extensive study yet conducted of the upper level of Earth’s atmosphere (called the troposphere). Astro­nauts Gemar and Buchli had trained to open the satellite’s solar panels and release its antennas during a contingency EVA, should the automatic systems fail. In the event, this training was not put into practice as the deployment went according to plan. The initial lock-on to TDRS proved difficult, but a back-up system resolved the communication problems with the satellite. Full operations were planned from mid – October 1991, although some instruments began sending data as soon as they were deployed while the rest of the satellite’s payload was being checked out.

While the primary objective of the STS-48 mission was the deployment of UARS to study the upper atmosphere, the crew was also busy with investigations aimed at supporting future programmes. Here, Mark Brown (left) and James Buchli work with the Structural Test Article, a scale model of the space station truss designed to test vibration characteristics on the joints of the truss structure in microgravity

In addition to deploying UARS, the crew worked on proton crystal growth experiments; a zero-gravity dynamic experiment studying how fluids and structures react in weightlessness; research into creating polymer membranes to be used as filters for use in industrial refining processes; an experiment that researched the effects of space flight on rodents; and studies of various radiation levels inside the orbiter from gamma rays, cosmic rays and other radiation sources. They also assisted in calibrating USAF optical instruments in Hawaii, and a particle monitor in the payload bay that measured contaminants during launch that might affect the payload being carried, as well as continuing the programme of Earth observations and photography carried on almost all Shuttle missions. On FD 4, Discovery took evasive action to avoid a piece of Soviet space debris that was predicted to pass only 350 metres below the orbiter.

The UARS satellite had a design life of just three years but some ten years after its deployment, six of its ten instruments were still operating. From June 1992 through to 1999, the satellite experienced power and equipment failures but continued to gather data from the surviving instruments. On 20 May 2005, UARS surpassed 5,000 days in orbit with five instruments still working, but by 21 August, the spacecraft had suffered

a short circuit in Battery #2, signifying the end of useful operations. One of its three batteries had already been lost in June 1997. UARS was planned for decommissioning during 2006.

Milestones

144th manned space flight 73rd US manned space flight 43rd Shuttle mission 13th mission for Columbia

1st major flight element for NASA’s Mission to Planet Earth programme 1st time a Shuttle required evasive action to avoid space debris