National Reconnaissance Office Satellite 

Successfully Launched

3 October 1998

VANDENBERG AIR FORCE BASE, Calif. -- The National Reconnaissance Office's Space 

Technology Experiment satellite was successfully launched aboard an Orbital Science 

Corporation Taurus booster from SLC-576E here today.

The Space Technology Experiment (STEX) satellite 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 spacecraft system, and if it can be operated in space. 

STEX was built by Lockheed-Martin Astronautics Corporation and takes advantage of the 

NRO's partnerships with industry and the Air Force and Naval Research Labs.

SPACE TECHNOLOGY EXPERIMENT

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. 

SPACE TECHNOLOGY EXPERIMENT (STEX) PHOTOS