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20-408: OSO 7 or Orbiting Solar Observatory 7 (NSSDC ID: 1971-083A ), before launch known as OSO H is the seventh in the series of American Orbiting Solar Observatory satellites launched by NASA between 1962 and 1975. OSO 7 was launched from Cape Kennedy (now Cape Canaveral) on 29 September 1971 by a Delta N rocket into a 33.1° inclination, low-Earth (initially 321 by 572 km) orbit, and re-entered

40-562: 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 . OSO 8

60-504: The "Wheel". The "Sail" portion of the spacecraft, which was stabilized to face the Sun in all the OSO series satellites, carried two instruments on OSO 7, which continuously viewed the Sun during orbit day. These were: The rotating "Wheel" component of the spacecraft, which provided overall gyroscopic stability to the satellite, carried four instruments, which looked radially outwards and scanned across

80-652: The Earth's atmosphere on 9 July 1974. It was built by the Ball Brothers Research Corporation (BBRC), now known as Ball Aerospace , in Boulder Colorado. While the basic design of all the OSO satellites was similar, the OSO 7 was larger [total spacecraft mass was 635 kg (1397 lb)] than the OSO 1 through OSO 6, with a larger squared-off solar array in the non-rotating "Sail", and a deeper rotating section,

100-635: 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. Another satellite using the Orbiting Solar Observatory platform was developed and launched: the Solwind satellite. It

120-405: The Sun every 2 seconds. Two of these were solar-observing instruments, and the other two were cosmic X-ray instruments: Among the notable scientific results from OSO 7 were: The OSO 7 was nearly lost at launch, due to a loss of hydraulic pressure in the second-stage guidance control system ~7 seconds prior to second-stage engine cutoff. The nominal plan was for the spacecraft to be separated from

140-581: The Wheel, generally looking out on a rotating radius vector which scanned the sky, and also across the Sun, every few seconds. OSO B suffered an incident during integration and checkout activities on 14 April 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

160-640: The aerospace industry include lubricants, optical systems, star trackers and antennas. As a wholly-owned subsidiary of the Ball Corporation, Ball Aerospace was cited in 2023 as the 54th largest defense contractor in the world. Both parent and subsidiary headquarters are co-located in Broomfield, Colorado. In August 2023, Ball Corporation agreed to divest Ball Aerospace to BAE Systems Inc. for $ 5.6 billion in cash. On February 14, 2024 The companies announced that all regulatory approvals were in place to allow

180-492: The analysis of data from the sensitive X-ray and gamma-ray instruments on board. The flight spare for OSO H was later acquired by the U.S. Air Force, modified and re-instrumented, and then launched in 1979 as P78-1 (also known as Solwind), the satellite which was shot down by the USAF in a successful anti-satellite missile test in 1985. OSO 7 and P78-1 were not identical in appearance, but more similar to each other than either were to

200-472: 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 2 Jul). The 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

220-415: The controllers, directed by NASA's John Thole, to recover before the spacecraft lost power and command ability. Several hours passed as engineers attempted to interpret the signal strength from the tumbling spacecraft in terms of its transmitting antenna pattern. Finally, an hour or two before the end, Thole decided to abandon caution and "start slewing", and by luck and skill, control was regained. Because

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240-470: The earlier OSO 1 through OSO 6 spacecraft, or to the final OSO 8. [REDACTED]  This article incorporates public domain material from websites or documents of the National Aeronautics and Space Administration . Orbiting Solar Observatory The Orbiting Solar Observatory (abbreviated OSO ) Program was the name of a series of American space telescopes primarily intended to study

260-461: The resulting orbital apogee was ~572 km instead of the planned ~350 km for the nominal circular orbit, several times each day OSO 7 passed fairly deeply into the Van Allen radiation belts , so that bombardment by high energy protons made it somewhat radioactive. The activity then decayed slowly during other times of the day. The complexly varying instrument internal radioactivity complicated

280-453: 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 3 February 1965 and was designated OSO 2 on orbit. OSO C never made it to orbit. Liftoff took place on 25 August 1965 and all went well through

300-404: 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

320-448: The second stage with the spin axis normal to the Sun direction, so that the sail could be oriented to the Sun, allowing the batteries to be fully charged on orbit. As it was, the orbit was slightly eccentric instead of circular, and the orientation of the spacecraft immediately after launch was unknown, so that the sail could not acquire Sun lock. The spacecraft was launched with its batteries fully charged, giving approximately 12 hours for

340-463: 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

360-728: Was acquired by BAE Systems Inc. in 2024, and is operated as a new division within BAE called Space & Mission systems. Ball Aerospace began building pointing controls for military rockets in 1956. The aerospace part of the Ball Corporation was then known as Ball Brothers Research Corporation , and later won a contract to build some of NASA 's first spacecraft, the Orbiting Solar Observatory satellites. The company has been responsible for numerous technological and scientific projects and continues to provide aerospace technology to NASA and related industries. Other products and services for

380-477: Was built by Hughes Space and Communications Company, in Culver City, California . 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

400-669: 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. Ball Aerospace Until 2024, the firm was a wholly owned subsidiary of Ball Corporation , with primary offices in Boulder, Colorado , and facilities in Broomfield and Westminster in Colorado , with smaller offices in New Mexico , Ohio , northern Virginia , Missouri and Maryland . It

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