Discoverer 21 (MIDAS RM-2), a U.S. Air Force/ARPA technology mission on Thor Agena-B from Vandenberg. The Agena-B spacecraft demonstrated an orbital engine restart and tested infrared sensors for the MIDAS missile early-warning program, remaining in orbit until April 1962.
- Outcome
- Success
- Payload to orbit
- 146 kg
- Flight
- 6th
- of 40 Thor DM-21 Agena-B flights
- Date and time
- 18 February 1961, 22:57 UTC
- Rocket
- Thor DM-21 Agena-B
- Builder
- McDonnell Douglas
- Launch site
- Space Launch Complex 1E, Vandenberg SFB, CA, USA
- Payload
- Unknown
- International designator
- 1961-006
- Launches in 1961
- 6th of 50
See it in orbit
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