OV3-4

Last updated
OV3-4
Ov3 satellite.jpg
OV3 satellites schematic
Mission type Earth science
Operator USAF
COSPAR ID 1966-052A OOjs UI icon edit-ltr-progressive.svg
SATCAT no. S02201
Spacecraft properties
Manufacturer Space General
Launch mass77 kg (170 lb)
Start of mission
Launch date10 June 1966 04:15:00 (1966-06-10UTC04:15) UTC
Rocket Scout B
Launch site Wallops Flight Facility Launch Area 3A [1]
Orbital parameters
Regime Medium Earth Orbit
Eccentricity 0.22423
Perigee altitude 647.00 km (402.03 mi)
Apogee altitude 4,711.00 km (2,927.28 mi)
Inclination 40.900°
Period 143 minutes [2]
Epoch 10 June 1966 04:19:00
OV3
  OV3-1
OV3-3  
 

Orbiting Vehicle 3-4 (also known as OV3-4, PHASR, [1] and OPS 1427 [3] ), launched 10 June 1966, was the second satellite to be launched in the OV3 series of the United States Air Force's Orbiting Vehicle program. The satellite measured radiation above the Earth, helping to determine the hazard posed to human spaceflight at typically traveled altitudes. OV3-4 is still in orbit as of 6 June 2021.

Contents

History

The Orbiting Vehicle satellite program arose from a US Air Force initiative, begun in the early 1960s, to reduce the expense of space research. Through this initiative, satellites would be standardized to improve reliability and cost-efficiency, and where possible, they would fly on test vehicles or be piggybacked with other satellites. In 1961, the Air Force Office of Aerospace Research (OAR) created the Aerospace Research Support Program (ARSP) to request satellite research proposals and choose mission experiments. The USAF Space and Missiles Organization created their own analog of the ARSP called the Space Experiments Support Program (SESP), which sponsored a greater proportion of technological experiments than the ARSP. [4] :417 Five distinct OV series of standardized satellites were developed under the auspices of these agencies. [4] :425

Unlike the previously initiated OV1 and OV2 series of satellites, which were designed to use empty payload space on rocket test launches, the six OV3 satellites all had dedicated Scout boosters. In this regard, the OV3 series was more akin to its civilian science program counterparts (e.g. Explorer). OV3 differed from NASA programs in its heavy use of off-the-shelf equipment, which resulted in lower unit cost. [4] :422–423

The first four satellites in the series were made the Aerojet subsidiary Space General Corporation under a $1.35m contract awarded 2 December 1964, the first satellite due October 1965. The last two satellites were built by Air Force Cambridge Research Laboratory (AFCRL), which also managed the entire series and provided four of the OV3 payloads. [4] :422–423

Charles H. Reynolds, Technical Manager of OV3 Charles H. Reynolds.jpg
Charles H. Reynolds, Technical Manager of OV3

Charles H. Reynolds, who worked at AFCRL from 1955, was the technical manager for the OV3 program. [5]

OV3-1, launched 22 April 1966, was the first satellite in the OV3 series of the United States Air Force's Orbiting Vehicle program. The satellite measured radiation around the Earth, returning data for over a year. [5]

Spacecraft design

Like the rest of the OV3 satellites, OV3-4 was an octagonal prism, .74 m (2 ft 5 in) in length and width, with experiments mounted on booms. 2560 solar cells provided 30 Watts of power. The satellite was spin-stabilized, but because it was asymmetrical once its booms were extended, [6] OV3-4 maintained its attitude in orbit with a precession damper. [4] A Sun sensor, as well as an onboard tri-axial magnetnometer, gave information on the satellite's aspect (facing), its spin rate, and rate of precession. [7] [4] :423

OV3-1 massed 77 kilograms (170 lb) [8] Its design life-span was one year. [4] :423:422–423

Experiments

OV3-4's scientific payload, provided by the Air Force Weapons Laboratory (AFWL) and called Personnel Hazards Associated with Space Radiation (PHASR) carried six ionization chambers of differing amounts of shielding ("Tissue Equivalent Ion Chambers" or TEIC) [9] designed to model biological tissue as well as two five-channel spectrometers. The purpose of PHASR was to determine radiation energy-spectrum and dosage data with application toward understanding the long-term impact of radiation on human spaceflight. OV3-4 also carried a triaxial magnetometer (to verify the direction the satellite's instruments were facing at any given time) [10] ) and two charged-particle spectrometers, all provided by AFCRL. [4] :423

Mission

OV3-4 and Scout Scout B with ov3-04 (10 june 1966).jpg
OV3-4 and Scout

Launched from Wallops Flight Facility Launch Area 3A on 10 June 1966 at 4:15:00 UTC via Scout B rocket, [1] OV3-4 was the second to be launched in the OV3 satellite series. The instruments returned good data [4] :423 throughout June and July. [11] By April 1967, the experiments were normally only activated once a week since sufficient results had been obtained, although activation was made as frequently as possible (range-scheduling capability permitting) during periods of high solar activity. [5] Data returned by OV3-4 helped prove and refine the 1966 Vette theoretical model of radiation dosage an astronaut would receive at orbital altitudes. Specifically, it was found that the Vette model was accurate to a factor of two at lower radiation energies, but at higher energies (the radiation that could penetrate the shielding of the thickest TEIC) the Vette model was found to be low by as much as a factor of six. [9]

Legacy and status

As of 7 June 2021, OV3-4 is still in orbit, and its position can be tracked on-line. [3]

The OV3 program ultimately comprised 6 missions, five of them successful. The last (OV3-6) flew on 4 December 1967. [1] The OV3 program was terminated following OV3-6 in favor of the cheaper OV1 program. [4] :423

Related Research Articles

<span class="mw-page-title-main">Orbiting Vehicle</span> American satellite family

Orbiting Vehicle or OV, originally designated SATAR, comprised five disparate series of standardized American satellites operated by the US Air Force, launched between 1965 and 1971. Forty seven satellites were built, of which forty three were launched and thirty seven reached orbit. With the exception of the OV3 series and OV4-3, they were launched as secondary payloads, using excess space on other missions. This resulted in extremely low launch costs and short proposal-to-orbit times. Typically, OV satellites carried scientific and/or technological experiments, 184 being successfully orbited through the lifespan of the program.

<span class="mw-page-title-main">OV1-1</span> US Air Force satellite

Orbiting Vehicle 1-1, was the first satellite in the OV1 series of the United States Air Force's Orbiting Vehicle program. OV1-1 was an American Earth science research satellite designed to measure radiation, micrometeoroid density, and magnetic fields in orbit. Launched 21 January 1965, the mission resulted in failure when, after a successful launch of its Atlas booster, OV1-1's onboard Altair motor failed to fire.

<span class="mw-page-title-main">OV1-3</span> US Air Force satellite

Orbiting Vehicle 1-3, was the second satellite in the OV1 series of the United States Air Force's Orbiting Vehicle program. OV1-3 was an American life science research satellite designed to measure the effects of orbital radiation on the human body. Launched 28 May 1965, the mission resulted in failure when its Atlas booster exploded two minutes after launch.

<span class="mw-page-title-main">OV1-2</span> US Air Force satellite

Orbiting Vehicle 1-2, launched 5 October 1965, was the third, and first successful, satellite in the OV1 series of the United States Air Force's Orbiting Vehicle program. A radiation measuring satellite designed to conduct research for the planned Manned Orbital Laboratory project, OV1-2 was the first American spacecraft to be placed into orbit on a western trajectory. The satellite stopped functioning in April 1967 after a series of technical problems starting two months after launch.

<span class="mw-page-title-main">OV1-4</span> US Air Force satellite

Orbiting Vehicle 1-4, launched 30 Mar 1966, was the fourth, and second successful, satellite in the OV1 series of the United States Air Force's Orbiting Vehicle program. OV1-4 was a long-term bioscience and materials science satellite, designed to return data relevant to long-term human presence in space. Its launch marked the first time two satellites were placed into orbit side by side with each other.

<span class="mw-page-title-main">OV1-5</span> US Air Force satellite

Orbiting Vehicle 1-5 was launched 30 Mar 1966, and was the fifth satellite in the OV1 series of the United States Air Force's Orbiting Vehicle program. OV1-5 conducted optical experiments, surveying the Earth in the infrared spectrum to see if water, land, mountains and deserts could be distinguished by their thermal gradients. It was launched concurrently with OV1-4 in the first ever side-by-side satellite orbital deployment.

<span class="mw-page-title-main">OV3-1</span> US Air Force satellite

Orbiting Vehicle 3-1, launched 22 April 1966, was the first satellite in the OV3 series of the United States Air Force's Orbiting Vehicle program. The satellite measured radiation above the Earth, returning useful data for over a year. It is still in orbit as of 1 April 2021.

<span class="mw-page-title-main">OV1-7</span> US Air Force satellite

Orbiting Vehicle 1-7, launched 14 July 1966, was the sixth satellite launched in the OV1 series of the United States Air Force's Orbiting Vehicle program. OV1-7 was a sky science satellite, designed to return data on charged particles in orbit as well as measurements of solar X-rays and nightglow. Co-launched with OV1-8, the satellite was lost when it failed to detach from its launch rocket.

<span class="mw-page-title-main">OV1-8</span> US Air Force satellite

Orbiting Vehicle 1-8, launched 14 July 1966, was the seventh satellite launched in the OV1 series of the United States Air Force's Orbiting Vehicle program. OV1-8 was designed to test the passive communications utility of an aluminum grid sphere versus a balloon satellite.

<span class="mw-page-title-main">OV3-3</span> US Air Force satellite

Orbiting Vehicle 3-3, launched 4 August 1966, was the third satellite to be launched in the OV3 series of the United States Air Force's Orbiting Vehicle program. The satellite measured charged particles in orbit so that their danger to space-based payloads could be assessed. OV3-3 is still in orbit as of 29 July 2021.

<span class="mw-page-title-main">OV3-2</span> US Air Force satellite

Orbiting Vehicle 3-2, launched 28 October 1966, was the fourth satellite to be launched in the OV3 series of the United States Air Force's Orbiting Vehicle program. The satellite measured charged particles in orbit, mapping irregularities in the ionosphere, particularly the auroral zone. OV3-2 reentered the Earth's atmosphere on 29 September 1971.

<span class="mw-page-title-main">OV1-6</span> US Air Force satellite

Orbiting Vehicle 1-6 was launched via Titan IIIC rocket into orbit 2 November 1966 along with two other satellites in the United States Air Force's Orbiting Vehicle series on the first and only Manned Orbiting Laboratory test flight. The eighth satellite in the OV1 series to be launched, OV1-6 was designed to release a number of inflatable spheres, which would then be used in classified tracking experiments conducted on the ground. It is uncertain whether or not the satellite successfully released any of its spheres. OV1-6 reentered the Earth's atmosphere on 31 December 1966.

<span class="mw-page-title-main">OV1-9</span> US Air Force satellite

Orbiting Vehicle 1-9, launched 11 December 1966 along with OV1-10, was the ninth satellite in the OV1 series of the United States Air Force's Orbiting Vehicle program. OV1-9 recorded low frequency radio emissions and particle radiation in Earth's exosphere; the satellite also collected data on the impact of long-term radiation on biological samples and tissue equivalents. OV1-9 returned the first proof that Earth has an electric field.

<span class="mw-page-title-main">OV1-10</span> US Air Force satellite

Orbiting Vehicle 1-10, launched 11 December 1966 along with OV1-9, was the tenth satellite in the OV1 series of the United States Air Force's Orbiting Vehicle program. Designed to observe atmospheric airglow, X-ray and cosmic radiation, OV1-10 returned significant data on the Sun as well as on geophysical phenomena in Earth's magnetic field. OV1-10 reentered Earth's atmosphere on 30 November 2002.

<span class="mw-page-title-main">OV3-5</span> US Air Force satellite

Orbiting Vehicle 3-5, launched 31 January 1967, was the fifth satellite to be launched in the OV3 series of the United States Air Force's Orbiting Vehicle program.

<span class="mw-page-title-main">OV1-86</span> US Air Force satellite

Orbiting Vehicle 1-86 was a satellite launched 27 July 1967 to measure the temperature radiation properties of different types of terrain. Part of the OV1 series of USAF satellites, using standardized designs and sent to orbit on decommissioned Atlas ICBMs to reduce development and launching costs, OV1-86 was launched with two other satellites in the series, OV1-11 and OV1-12, in the first triple launch of the program. It was the only OV1 satellite to be cobbled together from two of its sister satellites, utilizing the unused body on OV1-8 and the unused propulsion module on OV1-6. OV1-86's was only partially successful due to the failure of its Vertistat gravity-gradient_stabilization system. The satellite reentered the Earth's atmosphere on 22 February 1972.

<span class="mw-page-title-main">OV1-12</span> US Air Force satellite

Orbiting Vehicle 1–12 was a satellite launched 27 July 1967 to measure the radiation hazard posed by solar flares. Part of the OV1 series of USAF satellites, using standardized designs and sent to orbit on decommissioned Atlas ICBMs to reduce development and launching costs, OV1-12 was launched with two other satellites in the series, OV1-11 and OV1-86, in the first triple launch of the program. Only partially successful due to an inability to remain stable in orbit, the satellite reentered the Earth's atmosphere on 22 July 1980.

<span class="mw-page-title-main">OV3-6</span> US Air Force satellite

Orbiting Vehicle 3-6, launched 5 December 1967, was the sixth and last satellite to be launched in the OV3 series of the United States Air Force's Orbiting Vehicle program. The satellite measured electron density and neutral density ion composition, as functions of latitude and time. The satellite reentered the Earth's atmosphere on 9 March 1969.

<span class="mw-page-title-main">OV5-1</span> US Air Force satellite

Orbiting Vehicle 5-1, was an X-ray measuring microsatellite launched in support of the United States Air Force's space weather prediction program. Launched on 28 April 1967, it was the first satellite in the OV5 series of the United States Air Force's Orbiting Vehicle program. Data was collected until November 1967, and the satellite turned itself off in June 1967. OV5-1 is still in orbit as of 11 February 2023.

<span class="mw-page-title-main">OV1-13</span> US Air Force satellite

Orbiting Vehicle 1–13 was a satellite launched on 6 April 1968 to measure the level of radiation in orbit at altitudes as high as 8,000 km (5,000 mi). Part of the OV1 series of USAF satellites, using standardized designs and sent to orbit on decommissioned Atlas ICBMs to reduce development and launching costs, OV1-13 was launched side-by-side with OV1-14. The launch marked the first usage of the Atlas F in the OV program. Operating for more than a year and a half, OV1-13 mapped the grosser characteristics of the Van Allen radiation belts and contributed to the understanding of how particles flow and cause increased intensities during solar storms. As of 12 May 2023, OV1-13 is still in orbit.

References

  1. 1 2 3 4 McDowell, Jonathan. "Launch Log". Jonathan's Space Report. Retrieved 7 June 2021.
  2. "OV3-4". NASA. Retrieved 7 June 2021.
  3. 1 2 "OPS 1427 (OV3-4)" . Retrieved 7 June 2021.
  4. 1 2 3 4 5 6 7 8 9 10 Powell, Joel W.; Richards, G.R. (1987). "The Orbiting Vehicle Series of Satellites". Journal of the British Interplanetary Society. Vol. 40. London: British Interplanetary Society.
  5. 1 2 3 Charles H. Reynolds (July 1967). "Anniversary of OV3-1". research review. Vol. 6, no. 7. Office of Aerospace Research. pp. 10–11. Retrieved 1 April 2021.
  6. George A. Kuck (August 1968). Low-Energy Auroral Electrons Measured by Satellite OV3-1 . Retrieved 8 June 2021.
  7. "AFCRL covers November 1966 Eclipse". Research Review. Vol. 6, no. 2. Office of Aerospace Research. February 1967. p. 4-5.
  8. William R. Corliss (1967). Scientific Satellites. Washington D.C.: Science and Technical Information Division, Office of Technology Utilization, NASA. pp. 770–1. Retrieved 1 April 2021.
  9. 1 2 Cornelius A. Tobias and Paul Todd, ed. (1974). Space Radiation Biology and Related Topics Prepared Under the Direction of the American Institute of Biological Sciences for the Office of Information Services, United States Atomic Energy Commission. Academic Press Inc. p. 68.
  10. "OV3 Program". Missiles and Rockets. American Aviation Publications. 18: 30. 1966. Retrieved 8 June 2021.
  11. Allen L. Thede (1 January 1969). "OV3-4 Dose Rate and Proton Spectral Measurements". Technical Rept. Oct 63-Oct 68. AIR FORCE WEAPONS LAB KIRTLAND AFB NM: 74. Archived from the original on June 8, 2021. Retrieved 8 June 2021.