STS-51-B was the 17th flight of

NASA The National Aeronautics and Space Administration (NASA ) is an independent agencies of the United States government, independent agency of the US federal government responsible for the civil List of government space agencies, space program ...

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 ...

program, and the seventh flight of Space Shuttle ''Challenger''. The launch of ''Challenger'' on April 29, 1985, was delayed by 2 minutes and 18 seconds, due to a launch processing failure. ''Challenger'' was initially rolled out to the pad to launch on the STS-51E mission. The shuttle was rolled back when a timing issue emerged with the

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 ...

satellite. When STS-51E was canceled, ''Challenger'' was remanifested with the STS-51-B payloads. The shuttle landed successfully on May 6, 1985, after a week-long mission.

Crew

Backup crew

Crew seating arrangements

Mission insignia

The mission insignia features the ''Challenger'' with her payload doors open, to show the onboard Spacelab 3. The orbiter rides over the American flag. The seven crewmembers are represented by the 7 stars on the patch, that indirectly refer to the

Mercury Seven The Mercury Seven were the group of seven astronauts selected to fly spacecraft for Project Mercury. They are also referred to as the Original Seven and Astronaut Group 1. Their names were publicly announced by NASA on April 9, 1959; these sev ...

as a nod to their legacy. Behind the orbiter, the contours of Pegasus can be seen, as a reference to the European Space Agency (ESA). The white board surrounding it all has the appearance of a space suit helmet, with the names of the two respective teams grouped around them on a round band encircling the insignia , and the two mission specialists on an added section below. To further create some sort of contrast, the team colors are reprised for each member's name.

Mission summary

STS-51-B astronaut Robert Overmyer on treadmill

''Challenger'' lifted off 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 1968 ...

(KSC)'s launch pad 39A at 12:02:18 p.m. EDT on April 29, 1985. The crew members included

Robert F. Overmyer Colonel Robert Franklyn "Bob" Overmyer (July 14, 1936 – March 22, 1996) was an American test pilot, naval aviator, aeronautical engineer, physicist, United States Marine Corps, United States Marine Corps officer, and United States Air Force, US ...

, commander;

Frederick D. Gregory Frederick Drew Gregory (born January 7, 1941) is a former United States Air Force pilot, military engineer, test pilot, and NASA astronaut as well as former NASA Deputy Administrator. He also served briefly as NASA Acting Administrator in early ...

, pilot; Don L. Lind, Norman E. Thagard and

William E. Thornton William Edgar Thornton (April 14, 1929 – January 11, 2021) was an American NASA astronaut. He received a Bachelor of Science degree in physics from University of North Carolina and a doctorate in medicine, also from UNC. He flew on ''Challeng ...

, mission specialists; and

Lodewijk van den Berg Lodewijk van den Berg (; March 24, 1932 – October 16, 2022) was a Dutch-born American chemical engineer. He studied crystal growth and flew on a 1985 Space Shuttle ''Challenger'' mission as a payload specialist. Van den Berg was born in t ...

, of EG&G Energy Management, Inc., and Taylor G. Wang, of the

Jet Propulsion Laboratory The Jet Propulsion Laboratory (JPL) is a federally funded research and development center and NASA field center in the City of La Cañada Flintridge, California, United States. Founded in the 1930s by Caltech researchers, JPL is owned by NASA an ...

(JPL), both payload specialists. Average age of 48.6 was the oldest for an American space mission. Similar to the previous Spacelab mission ( STS-9), the crew was divided roughly in half to cover 12-hour shifts, with Overmyer, Lind, Thornton and Wang forming the Gold team, and Gregory, Thagard and van den Berg as the Silver team. STS-51-B was the second flight of the European Space Agency (ESA)'s

Spacelab Spacelab was a reusable laboratory developed by European Space Agency (ESA) and used on certain spaceflights flown by the Space Shuttle. The laboratory comprised multiple components, including a pressurized module, an unpressurized carrier, ...

pressurized module, and the first with the Spacelab module in a fully operational configuration. Spacelab's capabilities for multi-disciplinary research in microgravity were successfully demonstrated. The gravity gradient attitude of the orbiter proved quite stable, allowing the delicate experiments in materials processing and fluid mechanics to proceed normally. The crew operated around the clock in two 12-hour shifts. Two

squirrel monkey Squirrel monkeys are New World monkeys of the genus ''Saimiri''. ''Saimiri'' is the only genus in the subfamily Saimirinae. The name of the genus is of Tupi origin (''sai-mirím'' or ''çai-mbirín'', with ''sai'' meaning 'monkey' and ''mirím'' ...

s and 24

rats Rats are various medium-sized, long-tailed rodents. Species of rats are found throughout the order Rodentia, but stereotypical rats are found in the genus ''Rattus''. Other rat genera include ''Neotoma'' ( pack rats), ''Bandicota'' (bandicoot ...

were flown in special cages, the second time American astronauts flew live non-human mammals aboard the shuttle. The crew members in orbit were supported 24 hours a day by a temporary Payload Operations Control Center, located at the Johnson Space Center. On the mission, Spacelab carried 15 primary experiments, of which 14 were successfully performed. Two

Getaway Special Getaway Special was a NASA program that offered interested individuals, or groups, opportunities to fly small experiments aboard the Space Shuttle. Over the 20-year history of the program, over 170 individual missions were flown. The program, whi ...

(GAS) experiments required that they be deployed from their canisters, a first for the program. These were NUSAT (Northern Utah Satellite) and GLOMR (Global Low Orbiting Message Relay satellite). NUSAT deployed successfully, but GLOMR did not deploy, and was 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 surfa ...

. ''Challenger'' landed safely at Edwards Air Force Base at 12:11:04 p.m. EDT on May 6, 1985, after a mission lasting 7 days, 0 hour, 8 minutes, and 46 seconds.

Connection to the ''Challenger'' disaster

While participating in the investigation into the destruction of ''Challenger'' during STS-51L in 1986, Overmyer discovered that a problem with the shuttle's

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 round cross-section, designed to be seated in a groove and compressed during assembly between two or more par ...

s, similar to that which led to the disaster, had emerged during the launch of STS-51B. Morton-Thiokol engineers told Lind after the mission that "you came within three-tenths of one second of dying". It was the problem with the O-rings on the left

solid rocket motor A solid-propellant rocket or solid rocket is a rocket with a rocket engine that uses solid propellants (fuel/oxidizer). The earliest rockets were solid-fuel rockets powered by gunpowder; they were used in warfare by the Arabs, Chinese, Persia ...

(SRM) on this launch (SRM-16A) that prompted

Roger Boisjoly Roger Mark Boisjoly ( ,; April 25, 1938 – January 6, 2012) was an American mechanical engineer, fluid dynamicist, and an aerodynamicist. He is best known for having raised strenuous objections to the launch of the Space Shuttle ''Chal ...

to write a memo to

Bob Lund Bob, BOB, or B.O.B. may refer to: Places *Mount Bob, New York, United States *Bob Island, Palmer Archipelago, Antarctica People, fictional characters, and named animals * Bob (given name), a list of people and fictional characters *Bob (surname ...

about the potential for the O-rings to cause catastrophic failure.See

References

External links

NASA mission summary

{{Orbital launches in 1985 Space Shuttle missions Edwards Air Force Base 1985 in the United States 1985 in spaceflight Spacecraft launched in 1985 Spacecraft which reentered in 1985