Discoverer 18

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Discoverer 18
KH-2 CORONA.jpg
Mission typeOptical reconnaissance
Operator US Air Force / NRO
Harvard designation1960 Sigma 1
COSPAR ID 1960-018A
SATCAT no. 00067 OOjs UI icon edit-ltr-progressive.svg
Spacecraft properties
Spacecraft type Corona KH-2
Bus Agena-B
Manufacturer Lockheed
Launch mass1,240 kilograms (2,730 lb)
Start of mission
Launch date7 December 1960, 20:24:00 (1960-12-07UTC20:24Z) GMT
Rocket Thor DM-21 Agena-B
(Thor 296)
Launch site Vandenberg, LC 75-3-4
End of mission
Decay date2 April 1961 (1961-04-03)
Orbital parameters
Reference system Geocentric
Regime Low Earth
Perigee altitude 243 kilometers (151 mi) [1]
Apogee altitude 661 kilometers (411 mi)
Inclination 81.5°
Period 93.66 minutes
 

Discoverer 18, also known as Corona 9013, was an American optical reconnaissance satellite launched on 7 December 1960 at 20:24:00 GMT. [1] It was the first successful, and the third of ten total Corona KH-2 satellites, based on the Agena-B. [2]

Contents

Background

Discoverer 18 was the third of the KH-2 Corona spy satellites, which was distinguished from the predecessor KH-1 series in its incorporation of the improved C' camera, which replaced the C model carried on KH-1 missions. The improved camera had variable image motion compensation so that its carrying satellites could be flown in differing orbits. Like the C camera, the C' was manufactured by Fairchild Camera and Instrument under the supervision of Itek, [3] : 63–64  a defense contractor that specialized in making cameras for spy satellites. [3] : 34  The satellite also carried a Transit on Discoverer (TOD) payload [4]

Discoverer 16, the first of the KH-2 series, had failed to reach orbit after its launch on 26 October 1960. [4]

Discoverer 17, the second of the KH-2 series launched successfully on 12 November 1960 [4] but suffered a payload malfunction. [3] : 34 

Mission

The launch of Discoverer 18. Thor Agena B with Discoverer 18 (Dec 7, 1960) 1.gif
The launch of Discoverer 18.

The launch of Discoverer 18 occurred at 20:24:00 GMT on 7 December 1960. A Thor DM-21 Agena-B rocket was used, flying from LC 75-3-4 at the Vandenberg Air Force Base. [5] Upon successfully reaching orbit, it was assigned the Harvard designation 1960 Sigma 1.

Discoverer 18 was operated in a low Earth orbit, with a perigee of 243 kilometres (151 mi), an apogee of 661 kilometres (411 mi), 81.5° of inclination, and a period of 93.66 minutes. The satellite had a mass of 1,240 kilograms (2,730 lb), [1] and was equipped with a panoramic camera with a focal length of 61 centimetres (24 in), which had a maximum resolution of 7.6 metres (25 ft). [6] Images were recorded onto 70-millimeter (2.8 in) film, and returned in a Satellite Recovery Vehicle (SRV), which was recovered three days after the launch. The Satellite Recovery Vehicle used by Discoverer 18 was SRV-508. [5]

Discoverer 18 was placed in a near-polar orbit to test spacecraft engineering techniques, to continue the evaluation of the Agena B vehicle, and to attempt separation, deceleration, reentry through the atmosphere, and recovery from the air of an instrument package. [1]

The cylindrical Agena B stage carried a telemetry system, tape recorder, receivers for command signals from the ground, a horizon scanner, and a 136 kilograms (300 lb) recovery capsule. The capsule was a bowl-shaped configuration 84 centimetres (33 in) in diameter and 69 centimetres (27 in) deep. A conical afterbody increased the total length to about 101 centimetres (40 in). The recovery capsule payload included the photographic film packs, nuclear track plates, and biological specimens. A Thiokol retrorocket was mounted at the end of the afterbody to decelerate the capsule out of orbit. An 18 kilograms (40 lb) monitoring system was included in the capsule to report on selected events, such as the firing of the retrorocket, jettisoning of the heat shield, and others. [1]

Discoverer 18 was launched during a massive solar flare which lasted for the first 13 hours of the 48-orbit, 3-day flight. [7] After the 48th orbit, the recovery capsule was ejected, reentered the atmosphere, and was retrieved in mid-air near Hawaii by a C-119 aircraft at 42,672 metres (140,000 ft) altitude. The Agena B stage remained in orbit until 2 April 1961, when it reentered the atmosphere and burned up. [1]

Scientific results

In addition to its reconnaissance payload, Discoverer 18 carried a biological research payload, intended to investigate human tissues in space. Since at the time the United States did not publicly acknowledge its reconnaissance satellite programs, this was officially the satellite's primary mission. [8] The satellite's scientific experiment package of radiation dosimeters, infrared radiometers, and microwave band detectors was identical to that of Discoverer 17, with the addition of photographic film packs sensitive to neutrons, x-rays and gamma rays, and nuclear track plates. The spacecraft carried external lights (approximately a sixth to seventh magnitude star) for optical tracking from ground camera stations. [1]

The onboard film pack "Nuclear Emulsion" experiment comprised two groups of films coated with nuclear emulsions, arranged horizontally and vertically, were used to measure the intensity and direction of cosmic radiation and to distinguish among electrons, protons, and heavier charged particles. These emulsions were sensitive to neutrons, x-rays, and gamma rays. Nuclear track plates were also included in the experiment package. Neutron density was measured by changes induced in a metallic bismuth detector. The experiment was contained in the recovery capsule, which was retrieved in mid-air after 48 orbits. [9]

Discoverer 18 also carried a biological package including Neurospora conidia, nerve tissue, algae, human bone marrow, eyelid tissue, gamma globulin, and cancer cells. Results from the flight suggested that biological specimens might withstand radiation from solar flares with a minimum of shielding and that aluminum shielding seemed to offer more protection than lead. [7]

Related Research Articles

Corona (satellite) Series of American strategic reconnaissance satellites (1959-72)

The CORONA program was a series of American strategic reconnaissance satellites produced and operated by the Central Intelligence Agency (CIA) Directorate of Science & Technology with substantial assistance from the U.S. Air Force. The CORONA satellites were used for photographic surveillance of the Soviet Union (USSR), China, and other areas beginning in June 1959 and ending in May 1972.

Samos (satellite)

The SAMOS or SAMOS-E program was a relatively short-lived series of reconnaissance satellites for the United States in the early 1960s, also used as a cover for the initial development of the KH-7 GAMBIT system. Reconnaissance was performed with film cameras and television surveillance from polar low Earth orbits with film canister returns and transmittals over the United States. SAMOS was first launched in 1960 from Vandenberg Air Force Base.

Discoverer 14 Reconnaissance satellite

Discoverer 14, also known as Corona 9009, was a spy satellite used in the Corona program managed by Advanced Research Projects Agency (ARPA) of the Department of Defense and the United States Air Force. On 19 August 1960, usable photographic film images of the Soviet Union taken by the satellite were recovered by a C-119 recovery aircraft. This was the first successful recovery of film from an orbiting satellite and the first mid-air recovery of an object returning from Earth orbit.

Discoverer 13 Reconnaissance satellite

Discoverer 13 was an American optical reconnaissance satellite launched on 10 Aug 1960 at 20:37:54 GMT. The last of five test flights of the Corona KH-1 spy satellite series, it was the first fully successful flight in the Discoverer series. On 11 Aug, after 17 orbits, the satellite's reentry capsule was recovered in the Pacific Ocean by the Haiti Victory. Its payload, an American flag, was presented to President Eisenhower four days later.

Discoverer 11 Reconnaissance satellite

Discoverer 11, also known as Corona 9008, was an American optical reconnaissance satellite launched on 15 Apr 1960 at 20:30:37 GMT. The eighth of ten operational flights of the Corona KH-1 spy satellite series, it successfully employed the first space-worthy camera film; however, Discoverer's film return capsule was lost during reentry on 16 Apr when the satellite's spin motors exploded.

Discoverer 20, also known as KH-5 9014A, was a USAF photographic reconnaissance satellite under the supervision of the National Reconnaissance Office (NRO) which was launched in 1961. Discoverer 20 was the first KH-5 ARGON satellite to be launched.

Discoverer 23, also known as KH-5 9016A, was a USAF photographic reconnaissance satellite under the supervision of the National Reconnaissance Office (NRO) which was launched in 1961. It was a KH-5 ARGON satellite, based on an Agena-B. It was the second KH-5 mission to be launched, and the second to end in failure.

Discoverer 17 Reconnaissance satellite

Discoverer 17, also known as Corona 9012, was an American optical reconnaissance satellite launched on 12 November 1960 at 20:38:00 GMT. It was the second of ten Corona KH-2 satellites, based on the Agena-B.

Discoverer 35 Reconnaissance satellite

Discoverer 35, also known as Corona 9028, was an American optical reconnaissance satellite which was launched in 1961. It was the last of ten Corona KH-2 satellites, based on the Agena-B.

Discoverer 4 Reconnaissance satellite

Discoverer 4, also known as Corona 9001, was an American optical reconnaissance satellite launched on 25 Jun 1959 at 22:47:45 GMT, the first of ten operational flights of the Corona KH-1 spy satellite series, and the first satellite to be equipped for photo surveillance. The satellite was not successfully orbited. Its loss spurred improvements of its rocket booster to ensure the success of subsequent missions.

Discoverer 9 Reconnaissance satellite

Discoverer 9, also known as Corona 9006, was an American optical reconnaissance satellite launched on 4 Feb 1960 at 18:51:45 GMT, the sixth of ten operational flights of the Corona KH-1 spy satellite series, and the first of them to be equipped with a new, vacuum-proof, polyester-based film. The satellite was not successfully orbited.

Discoverer 10 Reconnaissance satellite

Discoverer 10, also known as Corona 9007, was an American optical reconnaissance satellite launched on 19 Feb 1960 at 20:15:14 GMT, the seventh of ten operational flights of the Corona KH-1 spy satellite series,

Discoverer 2 Reconnaissance satellite

Discoverer 2 was an American optical reconnaissance satellite launched on 13 April 1959 at 21:18:39 GMT, the second of three test flights of the Corona KH-1 spy satellite series. Discoverer 2 was the first satellite to be stabilized in orbit in all three axes and to be maneuvered on command from the earth. Though it carried no film and thus conducted no surveillance, Discoverer 2 was both the first satellite equipped with a reentry capsule and the first to return a payload from orbit. A timing error caused the reentry capsule to land near the island of Spitsbergen, Norway, rather than Hawaii. A joint US-Norway recovery operation was mounted, but was unsuccessful, and there was fear that the capsule ended in the possession of the Soviet Union. Such claims have never been verified. The flight and loss of Discoverer 2 was the inspiration for the book and film Ice Station Zebra.

Discoverer 3 Reconnaissance satellite

Discoverer 3 was an American optical reconnaissance satellite launched on 3 June 1959 at 20:09:20 GMT, the third of three test flights of the Corona KH-1 spy satellite series. The first Discoverer mission to carry live animal passengers, Discoverer 3 was lost when its carrying Agena-A booster crashed into the Pacific Ocean.

Discoverer 5 Reconnaissance satellite

Discoverer 5, also known as Corona 9002, was an American optical reconnaissance satellite launched on 13 August 1959 at 19:00:08 GMT, the second of ten operational flights of the Corona KH-1 spy satellite series. Though the satellite was successfully orbited, the onboard camera failed within the first orbit, and the film-return capsule failed to deorbit.

Discoverer 6 Reconnaissance satellite

Discoverer 6, also known as Corona 9003, was an American optical reconnaissance satellite launched on 19 August 1959 at 19:24:44 GMT, the third of ten operational flights of the Corona KH-1 spy satellite series. Though the spacecraft was orbited successfully, the onboard camera ceased operating by the second orbit, and the film-return capsule could not be recovered.

Discoverer 7 Reconnaissance satellite

Discoverer 7, also known as Corona 9004, was an American optical reconnaissance satellite launched on 7 November 1959 at 20:28:41 GMT, the fourth of ten operational flights of the Corona KH-1 spy satellite series. Though the satellite was orbited successfully, its film capsule failed to separate from the main satellite.

Discoverer 8 Reconnaissance satellite

Discoverer 8, also known as Corona 9005, was an American optical reconnaissance satellite launched on 20 November 1959 at 19:25:24 GMT, the fifth of ten operational flights of the Corona KH-1 spy satellite series. Overburn by the carrier rocket placed the satellite in a higher apogee, more eccentric orbit than planned, the camera failed to operate, and the film return capsule was lost on reentry after separation from the main satellite on 21 November.

Discoverer 12 Reconnaissance satellite

Discoverer 12 was an American optical reconnaissance satellite launched on 29 Jun 1960 at 22:00:44 GMT. The fourth of five test flights of the Corona KH-1 spy satellite series, it was lost when the second stage failed during launch.

Discoverer 15 Reconnaissance satellite

Discoverer 15, also known as Corona 9010, was a spy satellite used in the Corona program managed by Advanced Research Projects Agency (ARPA) of the Department of Defense and the United States Air Force. Launched on 13 September 1960, the satellite took reconnaissance photos of the Soviet Union. However, its recoverable film capsule was lost in the Pacific Ocean after reentry outside the recovery zone on 15 September.

References

  1. 1 2 3 4 5 6 7 https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=1960-018A - 5 September 2019
  2. ↑ Krebs, Gunter. "KH-2 Corona". Gunter's Space Page. Retrieved 23 October 2020.
  3. 1 2 3 Day, Dwayne A.; Logsdon, John M.; Latell, Brian (1998). Eye in the Sky: The Story of the Corona Spy Satellites. Washington and London: Smithsonian Institution Press. p. 176. ISBN   1-56098-830-4.
  4. 1 2 3 McDowell, Jonathan. "Launch Log". Jonathon's Space Report. Retrieved 7 November 2020.
  5. 1 2 https://nssdc.gsfc.nasa.gov/nmc/spacecraft/displayTrajectory.action?id=1960-018A - 5 September 2019
  6. ↑ "Corona". Mission and Spacecraft Library. NASA. Archived from the original on 3 October 2007. Retrieved 26 June 2010.
  7. 1 2 Significant Achievements in Space Bioscience 1958-1964. Washington D.C.: NASA. 1966. p. 70. OCLC   914183237.
  8. ↑ Wade, Mark. "KH-2". Encyclopedia Astronautica. Archived from the original on 23 January 2013. Retrieved 26 June 2010.
  9. ↑ https://nssdc.gsfc.nasa.gov/nmc/experiment/display.action?id=1960-018A-01 - 5 September 2019
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