Jump to content

Pioneer 6,7,8,and9

From Wikipedia, the free encyclopedia
(Redirected fromPioneer 7)

Pioneer 6,7,8,and9
Artist's conception of thePioneer 6–9spacecraft.
Mission typeInterplanetary space
OperatorNASA
COSPAR IDPioneer 6
1965-105A
Pioneer 7
1966-075A
Pioneer 8
1967-123A
Pioneer 9
1968-100A
SATCATno.Pioneer 6
1841
Pioneer 7
2398
Pioneer 8
3066
Pioneer 9
3533
Mission durationPioneer 6
34 years, 11 months and 22 days
Pioneer 7
28 years, 7 months and 14 days
Pioneer 8
28 years, 8 months and 9 days
Pioneer 9
14 years, 6 months and 11 days
Spacecraft properties
ManufacturerTRW
Launch massPioneer 6
62.14 kg
Pioneer 7
62.75 kg
Pioneer 8 and 9
65.36 kg
Power79 W
Start of mission
Launch datePioneer 6
16 December 1965, 07:31:21(1965-12-16UTC07:31:21Z)UTC[1]
Pioneer 7
17 August 1966, 15:20:17(1966-08-17UTC15:20:17Z)UTC[2]
Pioneer 8
13 December 1967, 14:08(1967-12-13UTC14:08Z)UTC[3]
Pioneer 9
8 November 1968, 09:46:29(1968-11-08UTC09:46:29Z)UTC[4]
Pioneer E
27 August 1969, 21:59:00(1969-08-27UTC21:59Z)UTC
RocketPioneer 6 to 9
Delta E
Pioneer E
Delta L
Launch sitePioneer 6, 7 and E
Cape Canaveral,LC-17A
Pioneer 8 and 9
Cape Canaveral,LC-17B
End of mission
Last contactPioneer 6
8 December 2000
Pioneer 7
31 March 1995
Pioneer 8
22 August 1996
Pioneer 9
19 May 1983
Orbital parameters
Reference systemHeliocentric
Perihelion altitudebetween 0.75 to 1AU
Aphelion altitudebetween 0.99 to 1.2 AU

Pioneer 6,7,8,and9werespace probesin thePioneer program,launched between 1965 and 1969. They were a series of solar-orbiting, spin-stabilized, solar cell- and battery-powered satellites designed to obtain measurements on a continuing basis of interplanetary phenomena from widely separated points in space.[5]They were also known asPioneer A,B,C,andD.The fifth (Pioneer E) was lost in a launch accident, and therefore did not receive a numerical designation.

Purpose[edit]

Pioneers 6,7,8,and9were created to make the first detailed, comprehensive measurements of thesolar wind,solarmagnetic fieldandcosmic rays.They were designed to measure large scale magnetic phenomena and particles and fields ininterplanetary space.Data from the vehicles have been used to better understand stellar processes and the structure and flow of the solar wind. The vehicles also acted as the world's first space-based solar weather network, providing practical data onsolar stormswhich affect communications and power on Earth.[5]

The experiments studied the positiveions(cations) andelectronsin the solar wind, the interplanetary electron density (radio propagationexperiment), solar and galactic cosmic rays, and theInterplanetary Magnetic Field.[5]

The spacecraft were important collectors ofheliophysicsandspace weatherdata. In conjunction with other spacecraft these, for the first time, enabled spaceborne observations to be combined with terrestrial observations on the ground and from sounding balloons. Pioneer 9 in early August 1972 recorded significant observations of one of the most potentsolar stormsever recorded, and the most hazardous tohuman spaceflightduring theSpace Age.[6]

Vehicle description[edit]

Each craft was identical. They werespin-stabilized0.94 m (3 ft 1 in) diameter × 0.81 m (2 ft 8 in) tall cylinders with a 1.8 m (5 ft 11 in) longmagnetometerboom and solar panels mounted around the body.

The mainantennawas ahigh-gaindirectional antenna. The spacecraft were spin-stabilized at about 60 RPM, and the spinaxiswasperpendicularto theecliptic planeand pointed toward the southeclipticpole.[5]

Instruments:

  • Solar Wind Plasma Faraday Cup (6, 7)
  • Cosmic-Ray Telescope (6, 7)
  • Electrostatic Analyzer (6, 7, 8)
  • Superior Conjunction Faraday Rotation (6, 7)
  • Spectral Broadening (6)
  • Relativity Investigation (6)
  • Uniaxial Fluxgate Magnetometer (6)
  • Cosmic-Ray Anisotropy (6, 7, 8, 9)
  • Celestial Mechanics (6, 7, 8, 9)
  • Two-Frequency Beacon Receiver (6, 7, 8, 9)
  • Single-Axis Magnetometer (7, 8)
  • Cosmic Dust Detector (8, 9)
  • Cosmic Ray Gradient Detector (8, 9)
  • Plasma Wave Detector (8)
  • Triaxial Magnetometer (9)
  • Solar Plasma Detector (9)
  • Electric Field Detector (9)

Communications[edit]

By ground command, one of fivebit rates,one of four data formats, and one of four operating modes could be selected. The five-bit rates were 512, 256, 64, 16, and 8 bit/s. Three of the four data formats contained primarily scientific data and consisted of 32 seven-bit words per frame. One scientific data format was for use at the two highest bit rates. Another was for use at the three lowest bit rates. The third contained data from only theradio propagationexperiment. The fourth data format contained mainly engineering data.[5]

The four operating modes were: real-time, telemetry store, duty cycle store, and memory readout. In the real-time mode, data were sampled and transmitted directly (without storage) as specified by the data format and bit rate selected. In the telemetry store mode, data were stored and transmitted simultaneously in the format and at the bit rate selected. In the duty-cycle store mode, a single frame of scientific data was collected and stored at a rate of 512 bit/s. The time interval between the collection and storage of successive frames could be varied by ground command between 2 and 17 min to provide partial data coverage for periods up to 19 hours, as limited by the bit storage capacity. In the memory readout mode, data was read out at whatever bit rate was appropriate to the satellite distance from Earth.[5]

Time line and current status[edit]

As stated byJPL,"The Pioneer 6–9 program has been touted as one of the least expensive of all NASA spacecraft programs in terms of scientific results per dollar spent."[7]Although the four spacecraft have not been regularly tracked for science data return in recent years, a successful telemetry contact with Pioneer 6 was made on December 8, 2000, to celebrate 35 years of continuous operation since launch. Its original design life expectancy was only 6 months.

Although NASA describedPioneer 6as "extant" as of 26 March 2007,[8]there has been no contact since December 8, 2000. At this timePioneer 6had operated for 12,758 days, making it the oldest operating space probe until it was surpassed byVoyager 2on August 13, 2012.[9]It is also believed that contact is still possible withPioneer 7and8;[citation needed]onlyPioneer 9is definitely not working.

Pioneer 6[edit]

December 16, 1965 Launched at 07:31:00 UTC from Cape Canaveral to a circular solar orbit with a mean distance of 0.8 AU.

December 1995 The prime Traveling-wave tube (TWT) failed sometime after December 1995.

July 1996 Spacecraft commanded to the backup TWT.

October 6, 1997 Tracked with the70 meter Deep Space Station 43 in Australia. The MIT and ARC Plasma Analyzers, as well as the cosmic ray detector from the University of Chicago, were turned on and working.

December 8, 2000

Successful telemetry contact for about two hours.

  • Launch of Pioneer 6 on a Delta-E rocket
    Launch ofPioneer 6on aDelta-Erocket

Pioneer 7[edit]

August 17, 1966 Launched from Cape Canaveral into solar orbit with a mean distance of 1.1 AU.

March 20, 1986 Flew within 12.3 million kilometers ofHalley's Cometand monitored the interaction between the cometary hydrogen tail and the solar wind. It discovered He+ plasma produced by charge exchange of solar wind He++ with neutral cometary material.[10]

March 31, 1995 Tracked successfully. The spacecraft and one of the science instruments were still functioning.

Pioneer 8[edit]

December 13, 1967 Launched at 14:08:00 UTC from Cape Canaveral into solar orbit with a mean distance of 1.1 AU from the Sun.[11]

August 22, 1996

The spacecraft commanded to switch to the backup TWT. Downlink signal was re-acquired, one of the science instruments again functioning.

  • Pioneer 8 being prepared for launch
    Pioneer 8being prepared for launch
  • Launch of Pioneer 8 on a Delta-E1 rocket
    Launch ofPioneer 8on aDelta-E1rocket

Pioneer 9[edit]

November 8, 1968 Launched at 09:46:00 UTC from Cape Canaveral into solar orbit with a mean distance of 0.8 AU.

1983Final contact.

1987Contact was attempted, but failed.[4]

Pioneer E[edit]

August 27, 1969 Launched at 21:59:00 UTC from Cape Canaveral. The launch vehicle was destroyed byrange safetyafter hydraulics in the first stage failed.[7]

See also[edit]

  • 17776,a speculative fiction work featuring a sentient Pioneer 9

References[edit]

  1. ^"Pioneer 6 - NASA Science".science.nasa.gov.NASA.RetrievedDecember 1,2022.
  2. ^"Pioneer 7 - NASA Science".science.nasa.gov.NASA.RetrievedDecember 1,2022.
  3. ^"Pioneer 8 - NASA Science".science.nasa.gov.NASA.RetrievedDecember 1,2022.
  4. ^ab"Pioneer 9 - NASA Science".science.nasa.gov.NASA.RetrievedMarch 6,2019.
  5. ^abcdef"Pioneer 6".nssdc.gsfc.nasa.gov.NASA.Archivedfrom the original on August 4, 2021.RetrievedSeptember 9,2018.Public DomainThis article incorporates text from this source, which is in thepublic domain.
  6. ^D. J. Knipp; B. J. Fraser; M. A. Shea; D. F. Smart (2018)."On the Little‐Known Consequences of the 4 August 1972 Ultra-Fast Coronal Mass Ejecta: Facts, Commentary and Call to Action".Space Weather.16(11): 1635–1643.Bibcode:2018SpWea..16.1635K.doi:10.1029/2018SW002024.
  7. ^ab"Pioneer 6, 7, 8, 9, E - Quicklook".Jet Propulsion Laboratory.Archived fromthe originalon July 21, 2010.
  8. ^"The Pioneer Missions".nasa.gov.NASA.Archived fromthe originalon August 15, 2011.RetrievedAugust 27,2009.
  9. ^"Voyager at 35 - Break on Through to the Other Side".nasa.gov.NASA.Archivedfrom the original on March 8, 2015.RetrievedMay 5,2015.
  10. ^J. D. Mihalov; H. R. Collard; D. S. Intriligator; A. Barnes (1987). "Observation by Pioneer 7 of He+in the distant coma of Halley's Comet ".Icarus.71(1): 192–197.Bibcode:1987Icar...71..192M.doi:10.1016/0019-1035(87)90172-2.
  11. ^"Pioneer 8".nssdc.gsfc.nasa.gov.NASA.Archivedfrom the original on June 29, 2019.RetrievedFebruary 27,2022.

External links[edit]

Retrieved from "https://en.wikipedia.org/w/index.php?title=Pioneer_6,_7,_8,_and_9&oldid=1232853029"