| Gravity Gradient Test Satellite (GGTS) | |
| Mission Type: | Gravity-gradient stabilization |
| Operator: | United States Air Force |
| Cospar Id: | 1966-053A |
| Satcat: | 2207[1] |
| Launch Mass: | 470NaN0 |
| Launch Date: | 14:00:01 UTC |
| Launch Rocket: | Titan IIIC |
| Launch Site: | Cape Canaveral LC41 |
| Orbit Reference: | Geocentric |
| Orbit Regime: | Geosynchronous |
| Orbit Periapsis: | 336630NaN0 |
| Orbit Apoapsis: | 338580NaN0 |
| Orbit Inclination: | 4.2° |
| Orbit Period: | 1,334.00 minutes[2] |
| Apsis: | gee |
The Gravity Gradient Test Satellite was launched by the US Air Force from Cape Canaveral LC41 aboard a Titan IIIC rocket on June 16, 1966, at 14:00:01 UTC.[3] The satellite was launched along with seven IDCSP satellites, with which it shared a bus. In contrast to the solar-powered IDCSP satellites, GGTS was battery powered.
GGTS utilized the 26.4lb Magnetically Anchored Gravity Systems (MACS), which consisted of two identical subsystem packages, each containing an extensible rod unit and a magnetically anchored spherical viscous damper.[4] The rod units had an extended length of 15.8m (51.8feet), and their 5kg (11lb) damper tip weights gave the satellite a symmetric dumbbell configuration. The dampers were produced by General Electric and consisted of two concentric spheres separated by a viscous damping fluid. The internal sphere contained a hollow cylindrical magnet which served to "anchor' the inner sphere to the Earth's magnetic field, stabilizing the satellite over time.
It had been hoped that within 60 days of launch, the satellite would reach a stabilization of ±8° on the x- and y-axis. The results were compromised, as one of the dampers was magnetically contaminated.
A follow-up GGTS mission was lost due to a launch vehicle failure on August 28, 1966.[5]