STS-51-C
Encyclopedia
STS-51-C was the 15th flight of NASA
's Space Shuttle program
, and the third flight of Space Shuttle Discovery
. It was also the first shuttle mission to deploy a dedicated United States Department of Defense
(DoD) payload, and as such many mission details remain classified. STS-51-C launched on 24 January 1985, and made the fourth shuttle landing at Kennedy Space Center
, Florida
, on 27 January.
(KSC) on 24 January 1985 at 14:50 EST, and was the first of nine shuttle missions that year. It was originally scheduled for 23 January 1985, but was delayed because of freezing weather conditions. Challenger
had been scheduled for this flight, but Discovery was substituted when problems were encountered with Challenger' s thermal protection tiles. STS-51-C marked the 100th human spaceflight to achieve orbit.
The mission was the first shuttle flight dedicated to the Department of Defense
(DoD), and as such STS-51-C's accomplishments are classified
for national security reasons. According to Aviation Week & Space Technology
, STS-51-C launched a Magnum
ELINT satellite into geosynchronous orbit
. Identical satellites were also launched by STS-33
and STS-38
.
Also according to Aviation Week, the shuttle initially entered a 204 kilometres (126.8 mi) x 519 kilometres (322.5 mi) orbit, at an inclination of 28.45 degrees to the equator
. It then executed three Orbital Maneuvering System (OMS) burns, the last being executed on the fourth orbit. The first burn was conducted to circularize the shuttle's orbit at 519 kilometres (322.5 mi).
The DoD satellite was deployed on the mission's seventh orbit, and successfully boosted into its operating orbit by a U.S. Air Force Inertial Upper Stage
(IUS) booster.
The mission's duration was 3 days, 1 hour, and 33 minutes. Discovery touched down on Runway 15 at KSC on 27 January 1985, at 16:23 EST.
Video footage of the STS-51-C launch was used in the 1986 movie SpaceCamp
.
during the STS-51-L
mission including Ellison Onizuka
, a crew member on both flights. During the investigation into the disaster, it was reported to the Rogers Commission
that during the launch of STS-51-C, the worst solid rocket booster
(SRB) blow-by effects of any mission prior to STS-51-L occurred, indicating conclusively that the Viton
O-ring
s were not sufficiently sealing the hot gases inside the combustion chamber
s of the SRBs while firing. After they were recovered post-flight, the O-rings in both the right and left SRBs showed some degree of charring, but analysis of the center field joint of the right SRB showed an unprecedented penetration of the primary O-ring and heavy charring on the secondary O-ring.
This information was significant to the established consensus that low air temperature was a major factor in Challengers
destruction because the temperature at STS-51-C's launch was also, up to its time, the coldest recorded during a shuttle launch, at only 53 degrees Fahrenheit
.
NASA
The National Aeronautics and Space Administration is the agency of the United States government that is responsible for the nation's civilian space program and for aeronautics and aerospace research...
's Space Shuttle program
Space Shuttle program
NASA's Space Shuttle program, officially called Space Transportation System , was the United States government's manned launch vehicle program from 1981 to 2011...
, and the third flight of Space Shuttle Discovery
Space Shuttle Discovery
Space Shuttle Discovery is one of the retired orbiters of the Space Shuttle program of NASA, the space agency of the United States, and was operational from its maiden flight, STS-41-D on August 30, 1984, until its final landing during STS-133 on March 9, 2011...
. It was also the first shuttle mission to deploy a dedicated United States Department of Defense
United States Department of Defense
The United States Department of Defense is the U.S...
(DoD) payload, and as such many mission details remain classified. STS-51-C launched on 24 January 1985, and made the fourth shuttle landing at Kennedy Space Center
Kennedy Space Center
The John F. Kennedy Space Center is the NASA installation that has been the launch site for every United States human space flight since 1968. Although such flights are currently on hiatus, KSC continues to manage and operate unmanned rocket launch facilities for America's civilian space program...
, Florida
Florida
Florida is a state in the southeastern United States, located on the nation's Atlantic and Gulf coasts. It is bordered to the west by the Gulf of Mexico, to the north by Alabama and Georgia and to the east by the Atlantic Ocean. With a population of 18,801,310 as measured by the 2010 census, it...
, on 27 January.
Crew
Backup crew
Mission parameters
- MassMassMass can be defined as a quantitive measure of the resistance an object has to change in its velocity.In physics, mass commonly refers to any of the following three properties of matter, which have been shown experimentally to be equivalent:...
:- Orbiter Liftoff: 250891 lbs
- Orbiter Landing weight is classified
- PerigeePerigeePerigee is the point at which an object makes its closest approach to the Earth.. Often the term is used in a broader sense to define the point in an orbit where the orbiting body is closest to the body it orbits. The opposite is the apogee, the farthest or highest point.The Greek prefix "peri"...
: 206 miles (331.5 km) - Apogee: 212 miles (341.2 km)
- InclinationInclinationInclination in general is the angle between a reference plane and another plane or axis of direction.-Orbits:The inclination is one of the six orbital parameters describing the shape and orientation of a celestial orbit...
: 28.4° - PeriodOrbital periodThe orbital period is the time taken for a given object to make one complete orbit about another object.When mentioned without further qualification in astronomy this refers to the sidereal period of an astronomical object, which is calculated with respect to the stars.There are several kinds of...
: 91.3 min
Mission summary
STS-51-C launched from Kennedy Space CenterKennedy Space Center
The John F. Kennedy Space Center is the NASA installation that has been the launch site for every United States human space flight since 1968. Although such flights are currently on hiatus, KSC continues to manage and operate unmanned rocket launch facilities for America's civilian space program...
(KSC) on 24 January 1985 at 14:50 EST, and was the first of nine shuttle missions that year. It was originally scheduled for 23 January 1985, but was delayed because of freezing weather conditions. Challenger
Space Shuttle Challenger
Space Shuttle Challenger was NASA's second Space Shuttle orbiter to be put into service, Columbia having been the first. The shuttle was built by Rockwell International's Space Transportation Systems Division in Downey, California...
had been scheduled for this flight, but Discovery was substituted when problems were encountered with Challenger
The mission was the first shuttle flight dedicated to the Department of Defense
United States Department of Defense
The United States Department of Defense is the U.S...
(DoD), and as such STS-51-C's accomplishments are classified
Classified information
Classified information is sensitive information to which access is restricted by law or regulation to particular groups of persons. A formal security clearance is required to handle classified documents or access classified data. The clearance process requires a satisfactory background investigation...
for national security reasons. According to Aviation Week & Space Technology
Aviation Week & Space Technology
Aviation Week & Space Technology, often abbreviated Aviation Week or AW&ST, is a weekly magazine owned and published by McGraw-Hill...
, STS-51-C launched a Magnum
Magnum (satellite)
Magnum is the code name for a class of SIGINT spy satellites reportedly operated by the National Reconnaissance Office for the United States Central Intelligence Agency...
ELINT satellite into geosynchronous orbit
Geosynchronous orbit
A geosynchronous orbit is an orbit around the Earth with an orbital period that matches the Earth's sidereal rotation period...
. Identical satellites were also launched by STS-33
STS-33
-Crew notes:S. David Griggs, the originally scheduled pilot for STS-33, died in a plane crash in June 1989, five months prior to the scheduled launch, and was replaced by John E...
and STS-38
STS-38
-Mission parameters:*Mass:**Payload: Magnum ELINT satellite ~ **Booster: IUS upper stage ~ **Total: ~ *Perigee: *Apogee: *Inclination: 28.5°*Period: 87.5 min-Preparations and Launch:...
.
Also according to Aviation Week, the shuttle initially entered a 204 kilometres (126.8 mi) x 519 kilometres (322.5 mi) orbit, at an inclination of 28.45 degrees to the equator
Equator
An equator is the intersection of a sphere's surface with the plane perpendicular to the sphere's axis of rotation and containing the sphere's center of mass....
. It then executed three Orbital Maneuvering System (OMS) burns, the last being executed on the fourth orbit. The first burn was conducted to circularize the shuttle's orbit at 519 kilometres (322.5 mi).
The DoD satellite was deployed on the mission's seventh orbit, and successfully boosted into its operating orbit by a U.S. Air Force Inertial Upper Stage
Inertial Upper Stage
The Inertial Upper Stage , originally known as the Interim Upper Stage, is a two-stage solid-fueled booster rocket developed by the U.S...
(IUS) booster.
The mission's duration was 3 days, 1 hour, and 33 minutes. Discovery touched down on Runway 15 at KSC on 27 January 1985, at 16:23 EST.
Video footage of the STS-51-C launch was used in the 1986 movie SpaceCamp
SpaceCamp
SpaceCamp is a 1986 American film based on a book by Patrick Bailey and Larry B. Williams and inspired by the U.S. Space Camp in Huntsville, Alabama. Directed by Harry Winer from a screenplay by Clifford Green and Casey T. Mitchell, the film stars Kate Capshaw, Kelly Preston, Larry B...
.
Connection to the Challenger disaster
Almost exactly a year after STS-51-C, Space Shuttle Challenger was destroyed with all hands on boardSpace Shuttle Challenger disaster
The Space Shuttle Challenger disaster occurred on January 28, 1986, when Space Shuttle Challenger broke apart 73 seconds into its flight, leading to the deaths of its seven crew members. The spacecraft disintegrated over the Atlantic Ocean, off the coast of central Florida at 11:38 am EST...
during the STS-51-L
STS-51-L
STS-51-L was the twenty-fifth flight of the American Space Shuttle program, which marked the first time an ordinary civilian, schoolteacher Christa McAuliffe, had flown aboard the Space Shuttle. The mission used Space Shuttle Challenger, which lifted off from the Launch Complex 39-B on 28 January...
mission including Ellison Onizuka
Ellison Onizuka
was a Japanese American astronaut from Kealakekua, Kona, Hawaii, who successfully flew into space with the Space Shuttle Discovery on STS-51-C, before losing his life to the destruction of the Space Shuttle Challenger, where he was serving as Mission Specialist for mission STS-51-L...
, a crew member on both flights. During the investigation into the disaster, it was reported to the Rogers Commission
Rogers Commission Report
The Rogers Commission Report was created by a Presidential Commission charged with investigating the Space Shuttle Challenger disaster during its 10th mission, STS-51-L...
that during the launch of STS-51-C, the worst solid rocket booster
Space Shuttle Solid Rocket Booster
The Space Shuttle Solid Rocket Boosters were the pair of large solid rockets used by the United States' NASA Space Shuttle during the first two minutes of powered flight. Together they provided about 83% of liftoff thrust for the Space Shuttle. They were located on either side of the rusty or...
(SRB) blow-by effects of any mission prior to STS-51-L occurred, indicating conclusively that the Viton
Viton
Viton is a brand of synthetic rubber and fluoropolymer elastomer commonly used in O-rings and other molded or extruded goods. The name is a registered trademark of DuPont Performance Elastomers L.L.C.....
O-ring
O-ring
An O-ring, also known as a packing, or a toric joint, is a mechanical gasket in the shape of a torus; it is a loop of elastomer with a disc-shaped cross-section, designed to be seated in a groove and compressed during assembly between two or more parts, creating a seal at the interface.The O-ring...
s were not sufficiently sealing the hot gases inside the combustion chamber
Combustion chamber
A combustion chamber is the part of an engine in which fuel is burned.-Internal combustion engine:The hot gases produced by the combustion occupy a far greater volume than the original fuel, thus creating an increase in pressure within the limited volume of the chamber...
s of the SRBs while firing. After they were recovered post-flight, the O-rings in both the right and left SRBs showed some degree of charring, but analysis of the center field joint of the right SRB showed an unprecedented penetration of the primary O-ring and heavy charring on the secondary O-ring.
This information was significant to the established consensus that low air temperature was a major factor in Challengers
Space Shuttle Challenger
Space Shuttle Challenger was NASA's second Space Shuttle orbiter to be put into service, Columbia having been the first. The shuttle was built by Rockwell International's Space Transportation Systems Division in Downey, California...
destruction because the temperature at STS-51-C's launch was also, up to its time, the coldest recorded during a shuttle launch, at only 53 degrees Fahrenheit
Fahrenheit
Fahrenheit is the temperature scale proposed in 1724 by, and named after, the German physicist Daniel Gabriel Fahrenheit . Within this scale, the freezing of water into ice is defined at 32 degrees, while the boiling point of water is defined to be 212 degrees...
.
See also
- SpaceflightSpaceflightSpaceflight is the act of travelling into or through outer space. Spaceflight can occur with spacecraft which may, or may not, have humans on board. Examples of human spaceflight include the Russian Soyuz program, the U.S. Space shuttle program, as well as the ongoing International Space Station...
- Space ShuttleSpace ShuttleThe Space Shuttle was a manned orbital rocket and spacecraft system operated by NASA on 135 missions from 1981 to 2011. The system combined rocket launch, orbital spacecraft, and re-entry spaceplane with modular add-ons...
- List of space shuttle missions
- List of human spaceflights chronologically