History

SETS originally meant "Shuttle Electrodynamic Tether System". 
The SETS experiment was one of thirteen science experiments to fly on the first and reflight missions of the Tethered Satellite System (TSS-1, TSS-1R) onboard the space shuttles Atlantis (STS-46) and Colombia (STS-75) in 1992 and 1996, respectively. These missions were dedicated to the exploration of SPACE TETHERS as a science and technology tool.

The first mission of the Tethered Satellite System (TSS-1), launched 31 July 1992 aboard the space shuttle Atlantis on STS-46 , deployed an electrically conductive 1.6m diameter satellite that was tethered to the Orbiter by a conductive tether. The goals of the TSS-1 mission were to demonstrate the feasibility of deploying and controlling long tethers in space, and to evaluate some of the unique applications of the TSS as a tool for research by conducting exploratory experiments in space plasma physics.

A maximum separation of 267m between the Orbiter and satellite was achieved. Several unsuccessful attempts were made to extend the tether to its full planned extension of 20km. Deployed operations lasted nearly one full 24 hour period. Even though the primary mission goals were not achieved many interesting results were obtained. 

An electric potential was induced in the tether system owing to the relative velocity of the tether with respect to the earth's magnetic field. This potential has magnitude emf = VxB.L, where V was velocity, B was the geomagnetic field, and L was the vector from one end of the tether to the other. The sign of the induced potential was such that the satellite would tend to charge positively, attracting electrons, while the Orbiter would charge negatively, attracting ions. During TSS-1 the magnitude of the induced potential was seen to vary up to approximately 60V. 

The second mission of the Tethered Satellite System (TSS-1R), launched February 22, 1996, 2:18 PM CST aboard the Space Shuttle Columbia on STS-75. At 3/5:15 the tether broke during the deployment. The tether was approximately 12.2 miles long (19.7 km) when it broke, close to the maximum deploy length of 12.8 miles (20.7 km). During deployment five hours of data were collected. 

These missions have provided valuable insight for planning the current mission, ProSEDS, and they are a guide for future missions.

News & Updates

April 8, 2003
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Pardon our pixel dust, as we are currently in the process of redesigning the SETS webpage.