The Space Technology Experiment (STEX) is a National Reconnaissance Office (NRO)
program undertaken to meet a national need to improve the performance of overhead
intelligence collection systems while reducing costs.
STEX will test lightweight, high performance spacecraft technologies that have been proven in the
laboratory aboard an experimental satellite. The experiment helps the NRO decide if the
technology under testing is right, if it can be effectively incorporated into an operational
spaceflight system, and if it can be operated in space. Its experiments could provide potential
improvements in spacecraft technology for both military and civil satellites.
The experiments are not stand-alone techology. They are components of the spacecraft on which
they are flying and actually perform the tasks they were designed to do. STEX has 20 experiments
onboard including:
High-density nickel-hydrogen batteries designed to last longer and provide more energy with
less weight
High effeciency solar cells and a solid state data recorder employing the most dense memory
in production today
Light weight precision star tracker that helps determine the satellite's position by
referencing the locations of preselected stars
Hall-Effect electric propulsion system
Low/no shock release mechanisms for studying the effects of when a payload is released from
the platform that carried it into space
Advanced Tether Experiment designed to increase knowledge about both the control and survivability
of tethered space systems
High performance computer with high density data storage
Lightweight composite structures with integrated thermal control
The STEX satellite weights 1,540 pounds and has a design life of two years and its cost
was less than $90 million which includes its booster, launch costs and ground support. STEX
takes advantage of the NRO's partnerships with industry and other Department of Defense agencies, such as
the Air Force Research Lab and the Naval Research Lab, to optimize the use of their unique
talents and resources. STEX was built by Lockheed Martin in partnership with the NRO's Advanced
Systems and Technology Directorate and Lockheed Martin Astronautics Corporation and will be launched on
board Orbital Science Corporation's Taurus booster.
