RM-86 Exos
# RM-86 Exos

The Exos, originally designated RM-86 and later PWN-4, was a sounding rocket developed by the University of Michigan and NACA for use by the United States Air Force.

## History

Developed by the University of Michigan for use by the Air Force Cambridge Research Center, Exos used a three-stage configuration, consisting of a first-stage rocket from an Honest John rocket, a second stage from a Nike-Ajax surface-to-air missile, and a Thiokol XM19 upper stage. It was designated XRM-86 in April 1959, and redesignated PWN-4A in June 1963.

Utilising a rail launcher, the first launch of a full Exos vehicle took place in June 1958, launched from the Wallops Flight Facility. Eight operational launches took place between 1960 and 1965, launched from Eglin Air Force Base.

## Launch history

| Date (UTC) | Rocket | Launch site | Apogee | Outcome | Mission |
| - | - | - | - | - | - |
| 26 June 1958 | Exos | Wallops Island | 370 kilometres (230 mi) | Success | Test launch |
| 25 September 1958 | Exos | Wallops Island | 460 kilometres (290 mi) | Success | Test launch |
| 19 February 1960 | Exos | Eglin AFB | 37 kilometres (23 mi) | Failure | Chemical release research |
| 11 August 1961 | Exos | Eglin AFB | 114 kilometres (71 mi) | Success | Ionospheric research |
| 3 August 1962 | Exos | Eglin AFB | 365 kilometres (227 mi) | Success | Bipolar Probe ionospheric research |
| 25 October 1962 | Exos | Eglin AFB | 669 kilometres (416 mi) | Success | Ionospheric research |
| 25 July 1963 | Exos | Eglin AFB | 623 kilometres (387 mi) | Success | Ionospheric research |
| 25 May 1965 | Exos | Eglin AFB | 488 kilometres (303 mi) | Success | Ionospheric research |
| 2 November 1965 | Exos | Eglin AFB | 686 kilometres (426 mi) | Success | International Quiet Sun Year aeronomy mission |
