Explorer S-55, a NASA Langley micrometeoroid research satellite, launched on Scout X-1 (ST-5) from Wallops Island LA-3 on 30 June 1961. Third stage failed to ignite, so the payload never reached orbit; later reflown as Explorer 13.
- Outcome
- Failure
- Payload to orbit
- Did not reach orbit
- Flight
- 3rd
- of 4 Scout X-1 flights
- Date and time
- 30 June 1961, 17:09 UTC
- Rocket
- Scout X-1
- Builder
- Vought
- Launch site
- Launch Area 3, Wallops Flight Facility, Virginia, USA
- Payload
- Unknown
- Launches in 1961
- 21st of 50