Shuttle to Tow Satellite Around Earth on 12-Mile-Long Tether
In 1988, a space shuttle is scheduled to tow a satellite around the Earth with a 12-mile-long “umbilical cord”--the largest structure ever flown--and Stanford University scientists designing the slender tether say that it may lead to several key discoveries.
The shuttle will travel at 17,000 m.p.h. and will haul a circular satellite resembling a tiny globe around the Earth at the end of a cord that is barely a half-inch wide, Stanford Professor Roger Williamson said.
The National Aeronautics and Space Administration selected Stanford’s Shuttle Electrodynamic Tether System (SETS) from more than 75 proposals submitted by scientist worldwide to participate in a shuttle flight studying ionized gases and their properties in the ionosphere.
“It will be the largest object ever flown anywhere, anytime. It will be more than 100 times larger than anything that has ever flown,” said Williamson, a member of a team of Stanford electrical engineers led by Professor Peter Banks.
Stanford Selected
NASA and the National Space Plan Office of the Italian National Research Council last week selected the Stanford experiment for three special flights.
Tether systems allow scientists to work in two areas of space simultaneously, Williamson said.
Instruments aboard the satellite and shuttle will study the upper regions of the Earth’s atmosphere, looking for clues to the structure and behavior of forces at work in the ionosphere, he said.
The region is filled with charged gas particles in forms that are rare on Earth but are believed to be the most abundant type of matter in the universe.
The tether system will help scientists gain firsthand knowledge about the electrical characteristics of the atmosphere, also known as space plasma physics, Williamson said.
Effects to Be Studied
An international team of scientists, including the half-dozen Stanford scientists, also will study how a large structure such as the shuttle towing a satellite 12 miles away disturbs these excited particles, which interact together to form a dense type of cold, ionized gas known as “plasma,” he said.
