An artist's concept of a space based vehicle using the Propulsive Small Expendable Deployer System (ProSEDS) to generate its thrust to maintain orbit without using a propellant. ProSEDS will obtain thrust as the current flowing through the tether experiences a drag force due to interaction with the Earth's magnetic field. Drag force is coupled mechanically to the stage via the tether, thus lowering the stage's orbital altitude.

This photograph shows two Marshall Space Flight Center (MSFC) engineers, Mark Vaccaro (left) and Ken Welzyn, testing electrodynamic tethers in the MSFC Tether Winding and Spark Testing Facility. For 4 years, MSFC and industry partners have been developing the Propulsive Small Expendable Deployer System experiment, called ProSEDS. ProSEDS will test electrodynamic tether propulsion technology. Electrodynamic tethers are long, thin wires that collect electrical current when passing through a magnetic field. The tether works as a thruster as a magnetic field exerts a force on a current-carrying wire. Since electrodynamic tethers require no propellant, they could substantially reduce the weight of the spacecraft and provide a cost-effective method of reboosting spacecraft. The initial flight of ProSEDS is scheduled to fly aboard an Air Force Delta II rocket in the summer of 2002. In orbit, ProSEDS will deploy from a Delta II second stage. It will be a 3.1-mile (5 kilometer) long, ultrathin base-wire tether cornected with a 6.2-mile (10 kilometer) long non-conducting tether. This photograph shows Less Johnson, a scientist at MSFC, inspecting the nonconducting part of a tether as it exits a deployer similar to the one to be used in the ProSEDS experiment. The ProSEDS experiment is managed by the Space Transportation Directorate at MSFC.

NASA's Propulsive Small Expendable Deployer System experiment (ProSEDS) will demonstrate the use of an electrodynamic tether, basically a long, thin wire, for propulsion. An electrodynamic tether uses the same principles as electric motors in toys, appliances and computer disk drives, and generators in automobiles and power plants. When electrical current is flowing through the tether, a magnetic field is produced that pushes against the magnetic field of the Earth. For ProSEDS, the current in the tether results by virtue of the voltage generated when the tether moves through the Earth's magnetic field at more than 17,000 mph. This approach can produce drag thrust generating useable power. Since electrodynamic tethers require no propellant, they could substantially reduce the weight of the spacecraft and provide a cost-effective method of reboosting spacecraft. The initial flight of ProSEDS is scheduled to fly aboard an Air Force Delta II rocket in the summer of 2002. In orbit, ProSEDS will deploy from a Delta II second stage. It will be a 3.1-mile (5 kilometer) long, ultrathin base-wire cornected with a 6.2-mile (10 kilometer) long nonconducting tether. This photograph shows Less Johnson, a scientist at MSFC inspecting the nonconducting part of a tether as it exits a deployer similar to the one to be used in the ProSEDS experiment. The ProSEDS experiment is managed by the Space Transportation Directorate at MSFC.

Pictured is an artist's concept of NASA's Propulsive Small Expendable Deployer System experiment (ProSEDS). ProSEDS will demonstrate the use of an electrodynamic tether, basically a long, thin wire, for propulsion. An electrodynamic tether uses the same principles as electric motors in toys, appliances and computer disk drives, and generators in automobiles and power plants. When electrical current is flowing through the tether, a magnetic field is produced that pushes against the magnetic field of the Earth. For ProSEDS, the current in the tether results by virtue of the voltage generated when the tether moves through the Earth's magnetic field at more than 17,000 mph. This approach can produce drag thrust generating useable power. Since electrodynamic tethers require no propellant, they could substantially reduce the weight of the spacecraft and provide a cost-effective method of reboosting spacecraft. The initial flight of ProSEDS is scheduled to fly aboard an Air Force Delta II rocket in summer of 2002. In orbit, ProSEDS will deploy from a Delta II second stage. It will be a 3.1-mile (5 kilometer) long, ultrathin base-wire tether cornected with a 6.2-mile (10 kilometer) long nonconducting tether. The ProSEDS experiment is managed by the Space Transportation Directorate at the Marshall Space Flight Center.