NASA’s Stardust-NExT (New Exploration of Tempel) spacecraft fired its engines for 22 minutes 53 seconds on February 17 to purposely delay its arrival at comet Tempel 1 by 8 hours 21 minutes. In one year, the Lockheed Martin- [NYSE: LMT] built spacecraft will still fly by the comet on February 14, 2011, Valentines’ Day, but the encounter time will now be 8:42 p.m. PT.

The low-cost Discovery Program Mission of Opportunity will expand the investigation of comet Tempel 1 initiated by NASA’s Deep Impact spacecraft. The mission uses the still-healthy Stardust spacecraft to perform a flyby of comet Tempel 1 and obtain high-resolution images of the comet and hopefully the crater made by Deep Impact in July 2005. The delayed arrival will provide project scientists the best chance of seeing both previously imaged areas and news areas of Tempel 1. By taking photos of previously imaged areas of the comet, scientists can analyze terrain changes caused by the comet’s close approach to the Sun on a successive orbit five and one-half years later.

The engine burn was performed autonomously at 2:00 p.m. PST while the spacecraft was out of contact from Earth. Spacecraft engineers at Lockheed Martin sent the trajectory correction maneuver commands to the spacecraft on Monday, Feb. 15. The maneuver reduced the spacecraft’s velocity, relative to the sun, by 54 mph (24 meters per second). The spacecraft’s velocity relative to the sun is 47,500 mph (21 km per second). The robust spacecraft recently completed it 4,000th day of flight and had traveled approximately 3.4 billion miles (5.4 billion kilometers) since its launch 11 years ago.