CONTOUR - Mission

Mission

CONTOUR launched on a Delta 7425 (a Delta II Lite launch vehicle with four strap-on solid-rocket boosters and a Star 27 third stage) on July 3, 2002, at 6:47:41 UT (2:47:41 a.m. EDT) from Cape Canaveral Air Force Station. It was launched into a high-apogee Earth orbit with a period of 5.5 days. Following a series of phasing orbits, the Star 30 solid rocket motor was used to perform an injection maneuver on August 15, 2002, to put CONTOUR in the proper trajectory for an Earth flyby in August 2003 followed by an encounter with comet Encke on November 12, 2003, at a distance of 100 to 160 km and a flyby speed of 28.2 km/s, 1.07 AU from the Sun and 0.27 AU from Earth. During the August 2002 injection maneuver, the probe was lost.

Three more Earth flybys would have followed, in August 2004, February 2005, and February 2006. On June 18, 2006, CONTOUR would have encountered comet Schwassmann-Wachmann-3 at 14 km/s, 0.95 AU from the Sun and 0.33 AU from Earth. Two more Earth flybys were scheduled in February 2007 and 2008, and a flyby of comet d'Arrest might have occurred on 16 August 2008 at a relative velocity of 11.8 km/s, 1.35 AU from the Sun and 0.36 AU from Earth. All flybys would have had a closest encounter distance of about 100 km and would have occurred near the period of maximum activity for each comet. After the comet Encke encounter, CONTOUR might have been retargeted towards a new comet if one was discovered with the desired characteristics (e.g. active, brighter than absolute magnitude 10, perihelion within 1.5 AU).