The Vampan satellite was part of a series of so called Program 11 or P-11 "Subsatellite Ferrets", low orbit ELINT/SIGINT satellites to pinpoint and characterize different Radar emitters in the Soviet Union and Warsaw pact states.
Vampan was a general search SIGINT payload in the 100–1000 MHz range targeted at ABM radars. It was equipped with two pairs of planar spiral circularly polarized antennas called “window shade antennas” because they were rolled up during launch and would spread out once the satellite was spinning in orbit. One pair was for low-band (100 to 400 MHz) reception and the other pair for high-band (400 to 1000 MHz) reception. The spiral elements were formed using a gold deposition process on dacron mesh sheets and made to be as nearly omnidirectional as possible. One sheet with both the high-band and one of the low-band spirals was on a 1.2 by 2.4 meter dacron sheet and the other low-band spiral was on a separate 1.2 by 1.2 meter sheet.
The satellites were based on Lockheed's P-11 bus, which was designed to fit on the aft rack of the Agena-D upper stage. The bus contained each one or two focused payload black boxes and different antenna configurations according to payload, as well as deployable solar arrays. The satellite featured two solid rocket motors, which allowed them to rise and circularize their orbit after deployment from the host satellite. Both spin or gravity gradient stabilization was possible.
This subsatellite was deployed from the propulsion rack of the Agena-D stage of KH-4A Corona reconnaissance satellites. It used two solid-fuel kick-motors to maneuver itself into its operational orbit after deployment.
A second satellite Vampan 2, was planned, but this mission was cancelled and the P-11 satellite bus was reasigned to the Savant 2 payload.
|Type / Application:||ELINT, SIGINT|
|Operator:||US Air Force (USAF)|
|Contractors:||Lockheed (bus); Sylvania Electromagnetic Development Lab (payload)|
|Power:||Solar cells, batteries|
|Orbit:||491 km × 503 km, 83.21°|
|Vampan 1 (P-11 4413, Mission 7325, OPS 8595)||1968-078B||18.09.1968||Va SLC-1E||Thorad-SLV2G Agena-D||with KH-4A 48|
|Vampan 2 (P-11 4419, Mission 7331)||-||cancelled||Va||with ? / → Savant 2|