STS-43, the ninth mission for

Space Shuttle The Space Shuttle is a retired, partially reusable low Earth orbital spacecraft system operated from 1981 to 2011 by the U.S. National Aeronautics and Space Administration (NASA) as part of the Space Shuttle program. Its official program ...

''Atlantis'', was a nine-day mission whose primary goal was launching the TDRS-E satellite (TDRS-5). The flight also tested an advanced heatpipe radiator for potential use on the then-future space station and conducted a variety of medical and materials science investigations.

Crew

Crew seating arrangements

Preparations and launch

The launch took place on August 2, 1991, 11:01:59 a.m. EDT. Launch was originally set for July 23, 1991, but was moved to July 24 to allow time to replace a faulty integrated electronics assembly that controls orbiter/external tank separation. The mission was postponed again about five hours before liftoff on July 24, 1991, due to a faulty main engine controller on the number three main engine. The controller was replaced and retested; launch was reset for August 1, 1991. Liftoff set for 11:01 a.m. delayed due to cabin pressure vent valve reading and postponed at 12:28 p.m. due to unacceptable return-to-launch site weather conditions. Launch finally occurred on August 2, 1991, without further delays.

Mission highlights

The primary payload, TDRS-E, attached to an

Inertial Upper Stage The Inertial Upper Stage (IUS), originally designated the Interim Upper Stage, was a two-stage, solid-fueled space launch system developed by Boeing for the United States Air Force beginning in 1976 for raising payloads from low Earth orbit to ...

(IUS), was deployed about six hours into flight, and the IUS propelled the satellite into geosynchronous orbit. TDRS-5 became the fourth member of the orbiting TDRS cluster. Secondary payloads were Space Station Heat Pipe Advanced Radiator Element (SHARE II); Shuttle Solar Backscatter Ultra-Violet (SSBUV) instrument; Tank Pressure Control Equipment (TPCE) and Optical Communications Through Windows (OCTW). Other experiments included Auroral Photography Experiment (APE-B) Protein Crystal Growth Ill (PCG Ill); Bioserve / Instrumentation Technology Associates Materials Dispersion Apparatus (BIMDA); Investigations into Polymer Membrane Processing (IPMP); Space Acceleration Measurement System (SAMS); Solid Surface Combustion Experiment (SSCE); Ultraviolet Plume imager (UVPI); and the Air Force Maui Optical Site (AMOS) experiment. TDRS-E, which became TDRS-5 on orbit, was successfully boosted to geosynchronous orbit at more than 22,000 miles () above

Earth Earth is the third planet from the Sun and the only astronomical object known to harbor life. While large volumes of water can be found throughout the Solar System, only Earth sustains liquid surface water. About 71% of Earth's surfa ...

by two firings of the Inertial Upper Stage (IUS) booster, the last of which occurred approximately 12½ hours into the mission. TDRS then deployed its antennas and solar panels, and separation from the IUS took place less than 45 minutes later. The TDRS network of satellites provides the vital communication link between Earth and low-orbiting spacecraft such as the Space Shuttle. Until the STS-43 deployment, there were three TDRS spacecraft on orbit above the equator: two were in the west position over the

Pacific Ocean The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south, and is bounded by the contin ...

, southwest of

Hawaii Hawaii ( ; haw, Hawaii or ) is a state in the Western United States, located in the Pacific Ocean about from the U.S. mainland. It is the only U.S. state outside North America, the only state that is an archipelago, and the only state ...

TDRS-4 TDRS-4, known before launch as TDRS-D, is an American communications satellite, of first generation, which was operated by NASA as part of the Tracking and Data Relay Satellite System from 1989 until 2011. It was constructed by TRW, based on a ...

was in the east position over the northeast corner of

Brazil Brazil ( pt, Brasil; ), officially the Federative Republic of Brazil (Portuguese: ), is the largest country in both South America and Latin America. At and with over 217 million people, Brazil is the world's fifth-largest country by area ...

TDRS-B TDRS-B was an American communications satellite, of first generation, which was to have formed part of the Tracking and Data Relay Satellite System. It was destroyed in 1986 when the disintegrated 73 seconds after launch. Launch TDRS-B was la ...

was lost in the ''Challenger'' accident in 1986. After STS-43, the two satellites in the west became on-orbit spares; TDRS-5, after activation, checkout and calibration, officially became the primary provider of services in the west location on October 7, 1991. It was stationed at 175° west

longitude Longitude (, ) is a geographic coordinate that specifies the east– west position of a point on the surface of the Earth, or another celestial body. It is an angular measurement, usually expressed in degrees and denoted by the Greek lette ...

. Previously, orbiting spacecraft could communicate with Earth only when in sight of a ground tracking station – about 15 percent of each orbit. The TDRS network allows communication from 85% to 100% of an orbit, depending on the spacecraft's altitude. The crew was kept busy with the operation of varied experiments during the nine-day flight. The Space Station Heat Pipe Advanced Radiator Element (SHARE-II) experiment tested a natural cooling process for transferring thermal energy that could serve as a cooling system for

Space Station Freedom Space Station ''Freedom'' was a NASA project to construct a permanently crewed Earth-orbiting space station in the 1980s. Although approved by then-president Ronald Reagan and announced in the 1984 State of the Union address, ''Freedom'' ...

. The Solid Surface Combustion Experiment (SSCE) provided some answers about how fire behaves in microgravity. The crew also activated other previously flown materials science experiments and participated in medical experiments in support of long-duration flights. One test showed that optical fibers could provide video and audio links between the flight deck and the payload bay. Crew members in space and flight controllers on the ground demonstrated their ingenuity when they adapted a camera part to replace one that had not been packed for the mission. The mission was also notable for being the first one to send an

email Electronic mail (email or e-mail) is a method of exchanging messages ("mail") between people using electronic devices. Email was thus conceived as the electronic ( digital) version of, or counterpart to, mail, at a time when "mail" mean ...

from space. On August 9, 1991, astronauts Lucid and Adamson used

AppleLink AppleLink was the name of both Apple Computer's online service for its dealers, third-party developers, and users, and the client software used to access it. Prior to the commercialization of the Internet, AppleLink was a popular service for Mac ...

to write an email from a

Macintosh Portable Macintosh Portable is a laptop designed, manufactured, and sold by Apple Computer, Inc. from September 1989 to October 1991. It is the first battery-powered Macintosh, which garnered significant excitement from critics, but sales to customers w ...

addressed to Marsha S. Ivins at Johnson Space Center. The message read: The crew experienced some minor problems, none of them critical to the safety or success of the mission. A cooling system for

Auxiliary Power Unit An auxiliary power unit (APU) is a device on a vehicle that provides energy for functions other than propulsion. They are commonly found on large aircraft and naval ships as well as some large land vehicles. Aircraft APUs generally produce 115& ...

(APU 2) failed to activate during an on-orbit test. APU 2 is one of three redundant systems which provide hydraulic pressurization to orbiter steering systems during entry and landing. APU 2 was still available for use in landing. ''Atlantis'' landed on August 11, 1991, at 8:23:25 a.m. EDT, on Runway 15, at

Kennedy Space Center The John F. Kennedy Space Center (KSC, originally known as the NASA Launch Operations Center), located on Merritt Island, Florida, is one of the National Aeronautics and Space Administration's (NASA) ten field centers. Since December 1968 ...

Mission insignia

According to the mission's official

Press Kit A press kit, often referred to as a media kit in business environments, is a pre-packaged set of promotional materials that provide information about a person, company, organization or cause and which is distributed to members of the media for pr ...

, the STS-43 insignia portrays the evolution and continuity of the U.S. space program by highlighting thirty years of American crewed spaceflight experience, from

Project Mercury Project Mercury was the first human spaceflight program of the United States, running from 1958 through 1963. An early highlight of the Space Race, its goal was to put a man into Earth orbit and return him safely, ideally before the Soviet Un ...

to the Space Shuttle. The emergence of the shuttle ''Atlantis'' from the outlined configuration of the Mercury space capsule commemorates this special relationship. The energy and momentum of launch are conveyed by the gradations of blue which mark the shuttle's ascent from Earth to space. Once in Earth orbit, ''Atlantis cargo bay opens to reveal the Tracking and Data Relay Satellite (TDRS) which appears in gold emphasis against the white wings of ''Atlantis'' and the stark blackness of space. As primary mission objective, the

Tracking and Data Relay Satellite System The U.S. Tracking and Data Relay Satellite System (TDRSS) is a network of American communications satellites (each called a tracking and data relay satellite, TDRS) and ground stations used by NASA for space communications. The system was desig ...

(TDRSS) will enable almost continuous communication from Earth to space for future space shuttle missions. The stars on the insignia are arranged to suggest this mission's numerical designation, with four stars left of ''Atlantis'' and three to the right.

Wake-up calls

NASA began a tradition of playing music to astronauts during the Project Gemini, and first used music to wake up a flight crew during Apollo 15. Each track is specially chosen, often by the astronauts' families, and usually has a special meaning to an individual member of the crew, or is applicable to their daily activities.

References

External links

NASA mission summary

{{Orbital launches in 1991 Space Shuttle missions Spacecraft launched in 1991