Iris 2 (satellite)

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Iris 2
Iris 2
Type: Research satellite
Country: EuropeEurope Europe
Operator: ESRO
COSPAR-ID : 1968-041A
Mission dates
Dimensions: 89 kg
Begin: May 17, 1968, 02:06 UTC
Starting place: Vandenberg , SLC-5
Launcher: Scout 2B
Flight duration: 3 years
Status: burned up on May 8, 1971
Orbit data
Rotation time : 98.9 min
Orbit inclination : 97.2 °
Apogee height 1085 km
Perigee height 334 km

Iris 2 (International Radiation Investigation Satellite), or ESRO-2B , was an 89 kg spin-stabilized European research satellite . Its mission was the first successful satellite mission of the European research organization ESRO after the launch of its predecessor Iris 1 failed.

The main goal of Iris 2 was to conduct a study on solar astronomy and cosmic rays . The Iris-2 experiments had their counterparts in the NASA OSO series. The purpose of the spacecraft was to conduct the solar ray observation carried out by OSO 4 , which was launched on October 18, 1967. The particle experiments were developed to carry out similar measurements with the Ariel 1 satellite .

construction

research

IRIS 2 had seven detectors for cosmic rays on board:

telecommunications

The data from the detectors were permanently recorded on magnetic tape. The storage capacity corresponded to a little more than the duration of one cycle. The satellite was in radio communication with a ground station for only about five minutes during one orbit. During this time, the recorded data was sent to earth at 32 times the speed on 136.05 MHz with 2 W. Another 0.2 W transmitter served as a radio beacon at 136.00 MHz. The satellite was remote-controlled at 148.25 MHz with pulse length coding.

power supply

Iris 2 was powered by solar cells and batteries. The satellite rotated at about 40 revolutions per minute.

Takeoff and orbit

Iris 2 was launched into polar orbit on May 17, 1968 (May 16 local time) by a Scout-B missile from Vandenberg Air Force Station SLC-5.

End of mission

After a failure of the magnetic tape recorder on board, no more stored data could be received from December 10, 1968. This reduced the amount of data by 80%, even though a combination of ESRO's ESTRACK ground stations and NASA's STADAN stations were used. Iris entered the earth's atmosphere on May 8, 1971 and burned up.

Web links

Individual evidence

  1. ^ Gunter Krebs: ESRO 2A, 2B (Iris 1, 2). In: Gunter's Space Page. March 27, 2017, accessed April 21, 2017 .
  2. a b c ESRO 2 in the NSSDCA Master Catalog , accessed on April 21, 2017 (English).
  3. Yves Amram et al: Experiences embarquées. (PDF) In: Spectrometre pour protons cosmiques et solaires experience s 72 embarquee a bord du satellite ESRO December II , 1968, p. 10 , accessed on April 21, 2017 (French).
  4. Yves Amram et al: Télécommunications. (PDF) In: Spectrometre pour protons cosmiques et solaires experience s 72 embarquee a bord du satellite ESRO , December 2nd , 1968, pp. 11–12 , accessed on April 21, 2017 (French).
  5. ^ ESRO 2. In: NASA Space Science Data Coordinated Archive. NASA, accessed April 21, 2017 .