Strawman 1, 2, 3, 4, 5

Strawman 3 [NRO]

Strawman 4 [NRO]

The Strawman series of ELINT/SIGINT satellites, known for decades only as "Heavy Ferrets", are the fourth variation of Agena-based ELINT satellites. These satellites were designed to detect, map and investigate SAM and ABM radars.

Using improved versions of the Multigroup and Setter payloads sharing a new solid·state core memory for the digital data and an improved tape recorder, called a data storage unit, for the wideband analog data, the proposed Strawman payload ofTered increased flexibility combined with improved payload performance, Moreover, room would be available for one additional payload that could share the recorders and other new support systems.

The Strawman satellites carried a number of payloads:

• The Thresher digital EOB collection and processing system produced radar locations with a 24 km accuracy. This payload featured two deployable mesh antennas.
• Reaper produced locations with a 8 km accuracy. It was a follow-on system to the earlier Bird Dog and Setter payloads. It featured an array of helical antennas.
• The first two Strawman missions carried an auxiliary payload called CONVOY designed to determine detailed characteristics of the Hen House and Dog House ABM radars or of the SA-5 (A-35) anti-ballistic-missile sytem at Tallinn.
• The fourth Strawman flew another auxiliary payload called Harvester to determine characteristics of the SA-5 system. It featured two fold-out dish antennas.

All ELINT payloads that were a part of the Strawman collection system - Thresher, Reaper, Convoy and Harvester - were connected to the predetection analog recorder in the prime payload.

The satellites of this series used a larger hammerhead payload fairing than the preceding Multigroup version of the Heavy Ferret series.

This series was discontinued 1971 and the fifth satellite was cancelled due to the design capabilities of the upcoming geosynchronous ELINT satellites (Canyon or Rhyolite), and the capabilities of other low-orbiting ELINT satellites.

The launches were conducted using the Thorad-SLV2G Agena-D and Thorad-SLV2H Agena-D versions. The Agena-D performed two burns for orbit insertion and circulation.

The Strawman 1 or Mission 7164 launch, another in the Project 770 series, was Agena vehicle 2734 on 5 October 1968. All of the payloads and support systems operated as designed. The satellite worked for a little over a year, twice the planned lifetime of six months. It featured the Thresher 1, Reaper 1 and Convoy 1 payloads.

Strawman 2 or Mission 7165, Agena 2735, launched on 31 July 1969, and operated for over 13 months, resulting in a projection of at least a nine month lifetime for the following launches. It featured the Thresher 2, Reaper 2, and Convoy 2 payloads.

Strawman 3 or Mission 7166, Agena 2736 continued the record by lasting for almost 18 months after a launch on 26 August 1970. It featured the Thresher 3 and Reaper 3 payloads.

Strawman 4 or Mission 7167, the final flown vehicle, Agena 2737, was launched on 16 July 1971 and lasted over 20 months. It featured the Thresher 5, Reaper 4 and Harvester payloads and likely one more still classified payload. On this mission the antenna connector to the lower band antenna of Harvester failed, thereby eliminating any chance to intercept the SA-5 signals at 5 GHz. This was the only major failure of any of the four vehicles. Strawman 4 also carried the RM 19 radiometer payload.

Strawman 5 or Mission 7168 was cancelled in 1971. It would have carried the Thresher 5 and Reaper 5 payloads. It is not clear, how far the hardware for this satellite progressed before cancellation.