STS-51-A (formerly STS-19) was the 14th flight of

NASA The National Aeronautics and Space Administration (NASA ) is an independent agency of the US federal government responsible for the civil space program, aeronautics research, and space research. NASA was established in 1958, succeedin ...

Space Shuttle program The Space Shuttle program was the fourth human spaceflight program carried out by the U.S. National Aeronautics and Space Administration (NASA), which accomplished routine transportation for Earth-to-orbit crew and cargo from 1981 to 2011. I ...

, and the second flight of Space Shuttle ''Discovery''. The mission launched from

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 196 ...

on November 8, 1984, and landed just under eight days later on November 16, 1984. STS-51-A marked the first time a shuttle deployed two

communications satellite A communications satellite is an artificial satellite that relays and amplifies radio telecommunication signals via a transponder; it creates a communication channel between a source transmitter and a receiver at different locations on Earth ...

s, and retrieved from orbit two other communications satellites. The Canadian Anik D2 and

Syncom Syncom (for "synchronous communication satellite") started as a 1961 NASA program for active geosynchronous communication satellites, all of which were developed and manufactured by the Space and Communications division of Hughes Aircraft Comp ...

IV-1 satellites were both successfully deployed by the crew of ''Discovery''. Palapa B2 and Westar 6, meanwhile, had been deployed during the

STS-41-B STS-41-B was the tenth NASA Space Shuttle mission and the fourth flight of the . It launched on 3 February 1984, and landed on 11 February 1984 after deploying two communications satellites. It was also notable for including the first untethere ...

mission earlier in the year, but had been placed into improper orbits due to the malfunctioning of their kick motors; they were both safely recovered and returned to

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 sur ...

during STS-51-A.

Crew

Spacewalks

* '' Allen and Gardner '' – EVA 1 * EVA 1 Start: November 12, 1984 – 13:25 UTC * EVA 1 End: November 12, 1984 - 19:25 UTC * Duration: 6 hours, 0 minute * '' Allen and Gardner '' – EVA 2 * EVA 2 Start: November 14, 1984 – 11:09 UTC * EVA 2 End: November 14, 1984 – 16:51 UTC * Duration: 5 hours, 42 minutes

Crew seating arrangements

Mission summary

STS-51-A was launched from

Florida Florida is a state located in the Southeastern region of the United States. Florida is bordered to the west by the Gulf of Mexico, to the northwest by Alabama, to the north by Georgia, to the east by the Bahamas and Atlantic Ocean, and ...

's Kennedy Space Center (KSC) at 7:15:00 a.m. EST, on November 8, 1984, less than a month after the

STS-41-G STS-41-G (formerly STS-17) was the 13th flight of NASA's Space Shuttle program and the sixth flight of Space Shuttle ''Challenger''. ''Challenger'' launched on October 5, 1984, and conducted the second shuttle landing at Kennedy Space Center o ...

flight. A launch attempt the day before was scrubbed at T-minus 20 minutes due to high

shear wind In common usage, wind gradient, more specifically wind speed gradient or wind velocity gradient, or alternatively shear wind, is the vertical component of the gradient of the mean horizontal wind speed in the lower atmosphere. It is the rate of ...

s in the

upper atmosphere Upper atmosphere is a collective term that refers to various layers of the atmosphere of the Earth above the troposphere and corresponding regions of the atmospheres of other planets, and includes: * The mesosphere, which on Earth lies between th ...

. The five-person flight crew consisted of Frederick H. Hauck, commander, on his second flight; pilot David M. Walker; and three mission specialists – Anna Lee Fisher, Dale A. Gardner and Joseph P. Allen. Both Gardner and Allen were making their second shuttle flights. STS-51-A marked the first flight of the Space Shuttle commanded by an astronaut from the 1978 class rather than the Apollo era. The two communications satellites successfully deployed were Anik D2 (on the second day of the mission) and Syncom IV-1, also known as Leasat 1 (on the third day); both were Hughes-built satellites. The orbiter then began a series of maneuvers to meet up with the first of the two satellites to be recovered, Palapa B2. The orbits of both satellites had been lowered by ground commands from about to to facilitate recovery operations. On day five of the mission, ''Discovery'' rendezvoused with Palapa. Mission specialists Allen and Gardner performed an EVA, capturing the satellite with a device known as a "Stinger" (Apogee Capture Device (ACD)), which was inserted into the satellite's apogee motor nozzle by Allen. The satellite's rotation was slowed to 1 RPM, and Gardner, operating from a position on the end of the Remote Manipulator System (RMS) (

Canadarm Canadarm or Canadarm1 (officially Shuttle Remote Manipulator System or SRMS, also SSRMS) is a series of robotic arms that were used on the Space Shuttle orbiters to deploy, manoeuvre, and capture payloads. After the Space Shuttle ''Columbia ...

), attempted unsuccessfully to grapple the satellite. Allen was able to manually maneuver the satellite into its cradle with Gardner's help, further aided by the Canadarm, which was operated by Fisher. The successful, improvised rescue effort took two hours. The recovery of Westar 6 was not as difficult, and took place a day later. This time, Gardner, using the same muscle-power technique Allen had used for Palapa B2's rescue, easily captured the satellite. With Allen's help, he placed it in a cradle in the cargo bay. Following Westar 6's recovery, Gardner humorously held up a "For Sale" sign, as if trying to find someone to sell the malfunctioning satellites to, as a means to indicate the successful recovery and as a means to provide some comical relief for the troubled owners. The Westar satellite was, ironically enough, indeed later sold to Hong Kong-based

AsiaSat Asia Satellite Telecommunications Holdings Limited, known by its brand name AsiaSat, is a commercial operator of communication spacecraft. AsiaSat, based in Hong Kong, is incorporated in Bermuda. AsiaSat is jointly owned by Chinese state-owned ...

. The STS-51-A mission also carried the Diffused Mixing of Organic Solutions (DMOS) experiment. It was the first of a series of comprehensive organic and

polymer A polymer (; Greek '' poly-'', "many" + '' -mer'', "part") is a substance or material consisting of very large molecules called macromolecules, composed of many repeating subunits. Due to their broad spectrum of properties, both synthetic a ...

science experiments sponsored by 3M. This mid-deck experiment was successful, and the proprietary results of the chemical mixes were turned over to 3M. One other experiment, a

radiation monitoring Radiation monitoring involves the measurement of radiation dose or radionuclide contamination for reasons related to the assessment or control of exposure to radiation or radioactive substances, and the interpretation of the results. Environment ...

experiment, was also performed. The satellite recoveries on STS-51-A were the last untethered spacewalks until 1994, and marked the last use of the

Manned Maneuvering Unit The Manned Maneuvering Unit (MMU) is an astronaut propulsion unit that was used by NASA on three Space Shuttle missions in 1984. The MMU allowed the astronauts to perform untethered extravehicular spacewalks at a distance from the shuttle. ...

(MMU). In 1994, the

Simplified Aid For EVA Rescue Simplified Aid For EVA Rescue (SAFER) is a small, self-contained, propulsive backpack system (jet pack) worn during spacewalks, to be used in case of emergency only. If an untethered astronaut were to lose physical contact with the vessel, it wou ...

(SAFER) was tested on STS-64. On all subsequent spacewalks conducted by both NASA and the

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n space agencies, the astronauts were tethered to the craft by some means. The second mission of ''Discovery'' ended at 6:59:56 a.m. EST on November 16, 1984, with a successful landing on Runway 15 at KSC. Footage of the landing was used in opening scene of the 1985

IMAX IMAX is a proprietary system of high-resolution cameras, film formats, film projectors, and theaters known for having very large screens with a tall aspect ratio (approximately either 1.43:1 or 1.90:1) and steep stadium seating. Graeme ...

movie '' The Dream is Alive''. The flight completed 127 orbits, and lasted 7 days, 23 hours, 44 minutes, and 56 seconds. It was the third shuttle landing at KSC, and the fifth and last shuttle mission of 1984.

Mission insignia

STS-51-A Mission insignia depicts the Space Shuttle ''Discovery'' en route to Earth orbit for NASA's STS-51-A mission and is reminiscent of a soaring eagle, shown in the insignia. The red and white trailing stripes, the blue background, and the presence of the Eagle, generate memories of America's 208 year-old history and traditions. The two satellites orbiting the Earth backgrounded amidst a celestial scene are a universal representation of the versatility of the Space Shuttle. The two satellites it is meant to retrieve are also included as a more specific reference to the mission's main objective and a highlight of what part of the Shuttle's versatile mission capabilities she would be covering this time. White lettering against the blue border lists the surnames of the five-member crew.

Wake-up calls

NASA began a tradition of playing music to astronauts during the

Project Gemini Project Gemini () was NASA's second human spaceflight program. Conducted between projects Mercury and Apollo, Gemini started in 1961 and concluded in 1966. The Gemini spacecraft carried a two-astronaut crew. Ten Gemini crews and 16 individual ...

, and first used music to wake up a flight crew during

Apollo 15 Apollo 15 (July 26August 7, 1971) was the ninth crewed mission in the United States' Apollo program and the fourth to land on the Moon. It was the first J mission, with a longer stay on the Moon and a greater focus on science than ear ...

. 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.

Gallery

Image:STS-51-A Syncom IV-1 deployment.jpg, Syncom IV-1 after deployment Image:STS-51-A Westar 6 retrieval.jpg, Dale Gardner retrieves Westar 6. Image:STS-51-A Palapa B-2 retrieval.jpg, Palapa B2 is loaded into the payload bay.

References

External links

NASA mission summary

Video from post mission press conference with extensive footage available for download at www.archive.org The Internet Archive

{{Orbital launches in 1984 Space Shuttle missions 1984 in spaceflight 1984 in science 1984 in the United States Spacecraft launched in 1984 Spacecraft which reentered in 1984