Nicholas Johnson, NASA chief scientist for orbital debris, has received the Department of Defense Joint Meritorious Civilian Service Award for his critical contributions to the successful interception of a non-functional DoD satellite.

The award was presented July 30 at NASA’s Johnson Space Center in Houston by Gen. Kevin Chilton, commander of the U.S. Strategic Command and former NASA astronaut.

"It took a lot of people to make it happen," said Chilton. "The guy who helped facilitate coming to a decision was Nick Johnson, a true unsung hero."

Johnson’s analysis was critical in identifying the risks associated with the uncontrollable re-entry of the National Reconnaissance Office satellite, known as USA-193, that was predicted to enter Earth’s atmosphere late February to early March 2008. His expertise proved vital to U.S. Strategic Command’s success in planning Operation BURNT FROST, a plan to mitigate possible dangers posed by the satellite’s re-entry.

"All of us in our NASA family are proud of Nick Johnson and the contributions he made to the successful satellite interception," said JSC Director Mike Coats. "Nick is considered our foremost orbital debris expert, and his expertise was instrumental in the decision and successful execution of this difficult mission."

USA-193 was launched in December 2006 into a low Earth orbit. The spacecraft soon suffered a catastrophic failure and could not respond to ground commands. The spacecraft contained a titanium tank with about 1,000 pounds (450 kg) of hydrazine for planned orbital maneuvers. The orbit of the spacecraft gradually decayed throughout 2007.

A U.S. government interagency effort began in January 2008 to address issues associated with the situation. Issues included evaluating the risk the spacecraft would pose to a populated area if it re-entered in an uncontrolled manner, determining the ability of the United States to mitigate any potential re-entry risk, and assessing the potential risk to in-orbit spacecraft including the International Space Station and the space shuttle. The NASA administrator designated Johnson as NASA’s technical liaison to the interagency working group.

NASA provided technical analyses of the situation including an assessment of the survivability of the hydrazine tank and its contents during a natural re-entry, calculation of the statistical risk posed to people from hydrazine released after tank impact, characterization of the amount of debris following a successful elimination of USA-193 and how long that debris would remain in orbit, and an assessment of collision risks between the generated debris and the space station or space shuttle. Johnson’s contributions to a U.S. Strategic Command decision brief led to presidential authorization to conduct an intercept of USA-193.

On Feb. 14, 2008, the U.S. government announced its intention to attempt to mitigate the threat posed by USA-193 and its hazardous hydrazine by destroying the spacecraft with a missile launched from a U.S. naval vessel. On Feb. 19, Johnson made a presentation on behalf of the United States at the United Nations in Vienna, Austria, to describe the anticipated results of the engagement and to confirm that such action was consistent with all U.S. national and international orbital debris mitigation guidelines.

Space shuttle Atlantis landed the morning of Feb. 20. That evening the threat from USA-193 was eliminated by a missile fired from the USS Lake Erie from a position north of Hawaii. As designed, the engagement ensured that the vast majority of the debris which remained in orbit would be short-lived. As of June only two small pieces were known to be in orbit and they will re-enter within the next few months.

Johnson previously received the NASA Distinguished Service Medal for his efforts in this national undertaking. He is a scientist in the Astromaterials Research and Exploration Science Directorate at JSC.

Images of the award presentation can be found at:

http://www.nasa.gov/centers/johnson/multimedia/njohnson.html