“Come on, Sarah. We've an appointment in London and we're already 30,000 years late”. 4th Doctor

Just three days shy of one year before its planned flyby of comet Tempel 1, NASA’s Stardust spacecraft has successfully performed a maneuver to adjust the time of its encounter by eight hours and 20 minutes. The delay   maximizes the probability of the spacecraft capturing high-resolution images of the desired surface features of the 2.99-kilometer-wide (1.86 mile) potato-shaped mass of ice and dust.

With the spacecraft on the opposite side of the solar system and beyond the orbit of Mars, the trajectory correction maneuver began at 5:21 p.m. EST (2:21 p.m. PST) on Feb. 17. Stardust’s rockets fired for 22 minutes and 53 seconds, changing the spacecraft’s speed by 24 meters per second (54 miles per hour).

Stardust’s maneuver placed the spacecraft on a course to fly by the comet just before 8:42 p.m. PST (11:42 p.m. EST) on Feb. 14, 2011 – Valentine’s Day. Time of closest approach to Tempel 1 is important because the comet rotates, allowing different regions of the comet to be illuminated by the sun’s rays at different times. Mission scientists want to maximize the probability that areas of interest previously imaged by NASA’s Deep Impact mission in 2005 will also be bathed in the sun’s rays and visible to Stardust’s camera when it passes by.

The full version of this story with accompanying images is at:   http://www.jpl.nasa.gov/news/news.cfm?release=2010-055&cid=release_2010-055

JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION