The Pegasus Project was a NASA initiative to study the frequency of

micrometeoroid A micrometeoroid is a tiny meteoroid: a small particle of rock in space, usually weighing less than a gram. A micrometeorite is such a particle that survives passage through Earth's atmosphere and reaches Earth's surface. The term "micrometeoro ...

impacts on spacecraft by means of a

constellation A constellation is an area on the celestial sphere in which a group of visible stars forms Asterism (astronomy), a perceived pattern or outline, typically representing an animal, mythological subject, or inanimate object. The first constellati ...

of three

satellite A satellite or an artificial satellite is an object, typically a spacecraft, placed into orbit around a celestial body. They have a variety of uses, including communication relay, weather forecasting, navigation ( GPS), broadcasting, scient ...

s launched in 1965. All three Pegasus satellites were launched by

Saturn I The Saturn I was a rocket designed as the United States' first medium lift launch vehicle for up to low Earth orbit Payload (air and space craft), payloads.Terminology has changed since the 1960s; back then, 20,000 pounds was considered "heavy l ...

rocket A rocket (from , and so named for its shape) is a vehicle that uses jet propulsion to accelerate without using any surrounding air. A rocket engine produces thrust by reaction to exhaust expelled at high speed. Rocket engines work entirely ...

s, and remained connected with their upper stages. The Pegasus satellites were named for the winged horse of Greek mythology and was first lofted into space by a NASA

rocket on February 16, 1965. Like its namesake, the Pegasus satellite was notable for its "wings", a pair of , arrays of 104 panels fitted with sensors to detect punctures by micrometeoroids at high altitudes, in support of the

Apollo Program The Apollo program, also known as Project Apollo, was the United States human spaceflight program led by NASA, which Moon landing, landed the first humans on the Moon in 1969. Apollo followed Project Mercury that put the first Americans in sp ...

to send crewed lunar landing missions starting by 1970. Micrometeoroids were believed to be potentially hazardous to the Apollo crew if they could puncture the spacecraft skin. The sensors successfully measured the frequency, size, direction and penetration of scores of micrometeoroid impacts. The satellite also carried sample protective shields mounted on the arrays. The

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

Marshall Space Flight Center Marshall Space Flight Center (officially the George C. Marshall Space Flight Center; MSFC), located in Redstone Arsenal, Alabama (Huntsville, Alabama, Huntsville postal address), is the Federal government of the United States, U.S. government's ...

was responsible for the design, production and operation of the three Pegasus satellites which were launched by Saturn I rocket test flights in 1965. At launch, a boilerplate

Apollo Command/Service Module The Apollo command and service module (CSM) was one of two principal components of the United States Apollo (spacecraft), Apollo spacecraft, used for the Apollo program, which landed astronauts on the Moon between 1969 and 1972. The CSM functi ...

and

launch escape system A launch escape system (LES) or launch abort system (LAS) is a crew-safety system connected to a space capsule. It is used in the event of a critical emergency to quickly separate the capsule from its launch vehicle in case of an emergency requiri ...

tower were atop the Saturn I, with the Pegasus experiment folded inside the Service Module. After first stage separation and second-stage ignition, the launch escape system was jettisoned. When the second stage attained orbit, the 10,000-pound Apollo boilerplate Command and Service modules were jettisoned into a separate orbit. Then a motor driven device extended the winglike panels on the Pegasus to a span of . The Pegasus wings remained attached to the Saturn I's second stage as planned. Detector arrays of a Pegasus satellite

A television camera, mounted on the interior of the Service Module adapter, provided pictures of the satellite deploying in space and as historian Roger E. Bilstein has written, "captured a vision of the eerie silent wings of Pegasus I as they haltingly deployed." The satellite exposed more than of instrumented surface, with thickness varying up to . Ernst Stuhlinger, then director of the MSFC Research Projects Laboratory, noted that all three Pegasus missions provided more than data on micrometeoroid penetration. Scientists also were able to gather data regarding gyroscopic motion and orbital characteristics of rigid bodies in space, lifetimes of electronic components in the space environment, and thermal control systems and the degrading effects of space on thermal control coatings. Space historian Roger Bilstein reported that for physicists the Pegasus missions provided additional knowledge about the radiation environments of space, the

Van Allen radiation belt The Van Allen radiation belt is a zone of energetic charged particles, most of which originate from the solar wind, that are captured by and held around a planet by that planet's magnetosphere. Earth has two such belts, and sometimes others ma ...

s and other phenomena.

Orbits

* Pegasus 1 **Launched: February 16, 1965 **Launch vehicle: A-103 **Orbital inclination: 31.7 degrees. **

Perigee An apsis (; ) is the farthest or nearest point in the orbit of a planetary body about its primary body. The line of apsides (also called apse line, or major axis of the orbit) is the line connecting the two extreme values. Apsides perta ...

: 510 km **Apogee: 726 km **Launch weight: 10.5 tons. **Dry weight: 1451.5 kg **Decayed: September 17, 1978 ** International Designator
1965-009A
*

Pegasus 2 Pegasus 2 or Pegasus II, known before launch as Pegasus B was an American satellite which was launched in 1965 to study micrometeoroid impacts in Low Earth orbit. It was the second of three Pegasus satellites to be launched, following the launch ...

**Launched: May 25, 1965 **Launch vehicle: A-104 **Orbital inclination: 31.7 degrees. **

: 502 km **Apogee: 740 km **Launch weight: 10.46 tons. **Dry weight: 1451.5 kg **Decayed: November 3, 1979 **International Designator
1965-039A
* Pegasus 3 **Launched: July 30, 1965 **Launch vehicle: A-105 **Orbital inclination: 28.9 degrees. **

: 441 km **Apogee: 449 km **Launch weight: 10.5 tons. **Dry weight: 1451.5 kg **Decayed: August 4, 1969 **International Designator
1965-060A

References

External links

* {{Include-NASA 1965 in spaceflight Satellites formerly orbiting Earth Spacecraft launched by Saturn rockets Satellite constellations NASA programs