PAGEOS
 Test inflation of PAGEOS, 5 August 1965 | |
| Names | PAGEOS-A |
|---|---|
| Operator | NASA Office of Space Applications |
| COSPAR ID | 1966-056A |
| SATCAT no. | 02253 |
| Spacecraft properties | |
| Launch mass | 56.7 kg (125 lb) |
| Dimensions | 30.48 m (100.0 ft) diameter[1] |
| Start of mission | |
| Launch date | 00:14:00, June 24, 1966 (UTC) |
| Rocket | Thrust augmented Thor-Agena D |
| Launch site | Vandenberg AFB |
| End of mission | |
| Destroyed | partially disintegrated July 1975 |
| Orbital parameters | |
| Reference system | Geocentric[2] |
| Eccentricity | 0.00301 |
| Perigee altitude | 4,207 km (2,614 mi) |
| Apogee altitude | 4,271 km (2,654 mi) |
| Inclination | 87.14° |
| Period | 181.43 min |
| Epoch | 24 June 1966 |
PAGEOS (PAssive Geodetic Earth Orbiting Satellite) was a balloon satellite which was launched by NASA in June 1966.[1] It was the first satellite specifically for use in Geodetic surveying[3] by serving as a reflective and photographic tracking target, and at the time it improved on terrestrial triangulations by about an order of magnitude. The satellite, which carried no instrumentation, broke up between 1975 and 1976.[4] One of the largest fragments of the satellite finally deorbited in 2016.[5]
PAGEOS was part of a larger program of inflatable satellites that grew from the original concept by William J. O'Sullivan of a 30-inch diameter inflatable satellite in 1956 to measure air drag at high altitudes, called the Sub-Satellite. While the Sub-Satellite failed, the idea of a visible balloon satellite escalated during the Cold War into a program of similar, larger satellites, including Echo 1 and Echo 2 of Project Echo, which were also used for experiments in geodetic surveying,[3] the Explorer satellites, and eventually PAGEOS 1.[6]
Design
PAGEOS had a diameter of exactly 100 feet (30.48 m), consisted of a 0.5 mils (12.7 μm) thick polyethylene terephthalate plastic film coated with vapour deposited aluminium enclosing a volume of about 524,000 cubic feet (14,800 m3)[7] and formed the base of the Weltnetz der Satellitentriangulation (Worldwide Satellite Triangulation Network).[8]
Finished in 1974, the network connected around 45 stations, each around 3000–4000km from each other, of all continents, with an accuracy about an order of magnitude better than terrestrial triangulations at the time.[8]
Its predecessors in US satellite triangulation were the Echo 1 and Echo 2 from Project Echo, and the Rebound A-13.[3]
Orbit
The PAGEOS spacecraft was placed into a polar orbit (inclination 85–86°) with an initial height of 4200km,[5] which had gradually lowered during its 9 years of operation.[citation needed] The satellite partly disintegrated in July 1975, which was followed by a second break-up that occurred in January 1976 resulting in the release of a large number of fragments. Most of these re-entered during the following decade.[4] In 2016, one of the largest fragments of PAGEOS de-orbited.[5] The satellite's orbital period was approximately three hours. [2]
See also
References
- ^ a b "PAGEOS 1". National Aeronautics and Space Administration. Retrieved March 16, 2017.
- ^ a b "NSSDCA – PAGEOS 1 – Trajectory Details". nssdc.gsfc.nasa.gov. NASA. Retrieved June 22, 2016.
- ^ a b c "Modern Surveying". Encyclopaedia Britannica. Retrieved March 24, 2024.
- ^ a b "PAGEOS 1". Gunter's Space Page. Retrieved March 16, 2017.
- ^ a b c J.-C. Liou (February 1, 2017). "USA Space Debris Environment, Operations, and Research Updates" (PDF). 54th Session of the Scientific and Technical Subcommittee, Committee on the Peaceful Uses of Outer Space, United Nations, 30 January – 10 February 2017, Vienna. Retrieved February 5, 2017.
- ^ Hansen, James (March 12, 2013). Spaceflight Revolution: NASA Langley Research Center from Sputnik to Apollo. Cia Publishing.
- ^ Teichman, L. A. (June 1, 1968). "The fabrication and testing of Pageos 1". NASA Technical Reports Server
- ^ a b Kleusberg, Alfred (2003). "Satelliten im Dienst der Geodäsie und Geoinformatik" (PDF). University of Stuttgart. Archived from the original (PDF) on May 23, 2006.