Injun (satellite)

The Injun program was a series of six satellites designed and built by researchers at the University of Iowa to observe various radiation and magnetic phenomena in the ionosphere and beyond.

Injun 2 satellite

The design specifics of the satellites had little in common, though all were solar-powered and the first five used magnetic stabilization to control spacecraft attitude. (The last in the series was spin-stabilized.) Instruments included particle detectors of varying types, magnetometers, and photometers for observing auroras.^[1] The last three satellites were launched as part of the Explorer program of the NASA.

In spite of various hardware difficulties and the loss of Injun 2 due to an upper stage failure, the program was generally successful. In particular, they produced data on the Van Allen radiation belts including electrical convection in the magnetosphere,^[2] and the radiation after effects of the Starfish Prime high-altitude nuclear test.^[3]

Launch

Name	Also known as	Launched	Vehicle	Ceased operation		Notes
Injun 1		29 June 1961	Thor-Able	6 March 1963		Failed to separate from Solrad 3; still in orbit.[4]
Injun 2		24 January 1962	Thor-Able	Failed to orbit		Upper stage produced insufficient thrust.
Injun 3		12 December 1962	Thor-Agena	25 August 1968		Deorbited on 25 August 1968.
Injun 4	IE-B, Explorer 25	21 November 1964	Scout X-4	December 1966		Still in orbit.[5]
Injun 5	IE-C, Explorer 40	8 August 1968	Scout X-4	June 1971		Still in orbit.[6]
Injun 6	IE-D, Hawkeye, Neutral Point Explorer, Explorer 52	3 June 1974	Scout X-4	28 April 1978		Main article: Explorer 52

See also

• Spaceflight portal

• Donald Gurnett

References

1. Swift, Daniel W.; Gurnett, Donald A. (1973). "Direct comparison between satellite electric field measurements and the visual aurora". Journal of Geophysical Research. 78 (31): 7306–7313. Bibcode:1973JGR....78.7306S. doi:10.1029/JA078i031p07306. hdl:2060/19730016689.
2. Gurnett, Donald. Dyer, E.R. (ed.). Electrical Fields and Plasma Observations in the Magnetosphere, in Critical Problems in Magnetospheric Physics (PDF). American Geophyscial Union. pp. 123–138. Retrieved 8 February 2015.
3. Hess, Wilmot N. (September 1964). "The Effects of High Altitude Explosions" (PDF). NASA. NASA TN D-2402. Archived from the original (PDF) on 11 October 2011. Retrieved 7 October 2007. This article incorporates text from this source, which is in the public domain.
4. "Injun 1". NASA. 28 October 2020. Retrieved 8 November 2021. This article incorporates text from this source, which is in the public domain.
5. "Explorer 25 (Injun 4)". NASA. 28 October 2021. Retrieved 8 November 2021. This article incorporates text from this source, which is in the public domain.
6. "IE C (Injun 5, Explorer 40)". Gunter's Space Page. Retrieved 6 February 2022.

External links

• "Injun 1". Gunter's Space Page. 11 December 2017. Retrieved 8 November 2021.
• "Injun 2". Gunter's Space Page. 11 December 2017. Retrieved 8 November 2021.
• "Injun 3". Gunter's Space Page. 11 December 2017. Retrieved 8 November 2021.
• "IE B (Injun 4, Explorer 25)". Gunter's Space Page. 8 April 2020. Retrieved 8 November 2021.
• "IE C (Injun 5, Explorer 40)". Gunter's Space Page. 8 April 2020. Retrieved 8 November 2021.
• "IE D (Injun 6, Hawkeye, Neutral Point Explorer, Explorer 52)". Gunter's Space Page. 8 April 2020. Retrieved 8 November 2021.