Orbiting Solar Observatory
{{Short description|Series of American solar space observatories}}
{{Use dmy dates|date=February 2017}}
File:Dr. Nancy Roman - GPN-2002-000212 edited.jpg with a model of OSO 1 (1962)]]
Image:OSO4.gifThe Orbiting Solar Observatory (abbreviated OSO) Program was the name of a series of American space telescopes primarily intended to study the Sun, though they also included important non-solar experiments. Eight were launched successfully into low Earth orbit by NASA between 1962 and 1975 using Delta rockets. Their primary mission was to observe an 11-year sun spot cycle in UV and X-ray spectra.
The initial seven (OSO 1–7) were built by Ball Aerospace, then known as Ball Brothers Research Corporation (BBRC), in Boulder, Colorado.Todd Neff (2010) [http://www.earthviewmedia.com/books/jars.html From Jars to the Stars: How Ball Came to Build a Comet-Hunting Machine] {{Webarchive|url=https://web.archive.org/web/20180318055139/http://www.earthviewmedia.com/books/jars.html |date=18 March 2018 }} Denver, CO.: Earthview Media. OSO 8 was built by Hughes Space and Communications Company, in Culver City, California.
History
Nancy Roman oversaw the development of the Orbiting Solar Observatory program from 1961 to 1963."Roman, Nancy Grace." in American Men & Women of Science: A Biographical Directory of Today's Leaders in Physical, Biological, and Related Sciences. Ed. Andrea Kovacs Henderson. 30th ed. Vol. 6. Detroit: Gale, 2012. 339. Gale Virtual Reference Library.
The basic design of the entire series featured a rotating section, the "Wheel", to provide gyroscopic stability. A second section, the "Sail", was driven electrically against the Wheel's rotation, and stabilized to point at the Sun. The Sail carried pointed solar instruments, and also the array of solar photovoltaic cells which powered the spacecraft.
The critical bearing between the Wheel and the Sail was a major feature of the design, as it had to operate smoothly for months in the hard vacuum of space without normal lubrication. It also carried both the power from the Sail and the data from the pointed solar instruments to the Wheel, where most of the spacecraft functions were located.
Additional science instruments could also be located in the Wheel, generally looking out on a rotating radius vector which scanned the sky, and also across the Sun, every few seconds.
OSO 1 (OSO A) was launched on March 7, 1962.{{Cite web |title=OSO 1, 2, C, 3, 4, 5, 6 |url=https://space.skyrocket.de/doc_sdat/oso-1.htm |access-date=2025-01-25 |website=Gunter's Space Page |language=en}}
OSO B suffered an incident during integration and checkout activities on April 14, 1964. The satellite was inside the Spin Test Facility at Cape Canaveral attached to the third stage of its Delta C booster when a technician accidentally ignited the booster through static electricity. The third-stage motor activated, launched itself and the satellite into the roof, and ricocheted into a corner of the facility until burning out. Three technicians were burned to death. The satellite, although damaged, was able to be repaired using a combination of prototype parts, spare flight parts and new components. It was launched ten months later on February 3, 1965 and was designated OSO 2 (OSO B2) on orbit.{{cite report |url=https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19670002039.pdf |title=History of Orbiting Solar Observatory, OSO-2 |publisher=NASA{{\}}Goddard Space Flight Center |date=April 1966 |id=N67-11368; TM X-55590}}
OSO C never made it to orbit. Liftoff took place on August 25, 1965 and all went well through the second stage burn. During the coasting phase prior to third stage separation, its rocket motor ignited prematurely. This registered on ground readouts as an attitude disturbance followed by loss of second stage telemetry, and although the third stage managed to separate itself, it suffered from an 18% drop in thrust. The OSO spacecraft could not attain orbital velocity and instead fell back into the atmosphere and burned up. The failure was suspected to have been caused by a modification to the igniter mechanism in the third stage after some minor technical difficulties experienced on the previous Delta C launch (TIROS 10 on July 2).{{cite report |url=https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19670030864.pdf |title=Delta Vehicle Flight Failure Report, Launch 33 |publisher=NASA{{\}}Goddard Space Flight Center |date=October 1966 |id=N67-40193; TM X-55988}}
List of OSO telescopes
Image:Delta launches OSO 8.jpg rocket launching OSO 8 on 21 June 1975, at Cape Canaveral, Florida]]Eight OSO telescopes were launched from 1962 to 1975.
Further developments
File:Advanced Orbiting Solar Observatory, Udvar-Hazy Center.jpgThe Advanced Orbiting Solar Observatory (AOSO) program was developed in the mid 1960s as a more advanced version of the OSO series. Conceived as a polar-orbiting satellite system, these spacecraft would continuously monitor the Sun and surrounding environment with detectors and electronic imaging ranging from x-rays to visual light. Due to budget constraints, the AOSO program was cancelled in 1965. Instead, it was replaced by the OSO-I, OSO-J and OSO-K satellites. Only OSO-I, which became OSO 8, was ever launched.{{cite web |title=Advanced OSO |url=https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=AOSO |website=NASA - NSSDC - Spacecraft - Details |publisher=NASA |access-date=5 September 2014}}
Another satellite using the Orbiting Solar Observatory platform was developed and launched: the Solwind satellite. It was launched February 24, 1979. It was operated by the DoD Space Test Program. It was destroyed September 13, 1985 on an ASAT missile test.
See also
References
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External links
- [https://web.archive.org/web/20081018170745/http://nssdc.gsfc.nasa.gov/nmc/experimentSearch.do?spacecraft=OSO%201 OSO 1 experiments record] at National Space Science Data Center
- [https://web.archive.org/web/20010417113433/http://imagine.gsfc.nasa.gov/docs/sats_n_data/missions/oso1.html OSO 1] at NASA's Imagine the Universe
{{Sun spacecraft}}