The CONTOUR (COmet Nucleus TOUR) was a NASA probe launched in 2002. It was intended to fly by two and possibly three comets to study their properties and analyze dust. The launch was successful, but the probe was destroyed during a subsequent solid rocket burn intended to transfer it from Earth to solar orbit.


I was lucky enough to be present at Cape Canaveral Launch Complex 17 to witness the spectacular nighttime launch of CONTOUR atop a Delta II rocket on 3 July 2002. The launch went exactly as planned, with no problems.


The CONTOUR spacecraft made its final potentially visible pass over North America on the evening of August 9, 2002. It was planned to enter its escape trajectory on 15 August and be on course for its rendezvous with Comet Encke on November 12, 2003. I was able to capture this pass through my telescope, but was unable to see it visually. My estimate from the image is that the spacecraft was at about magnitude 7, which is pretty much at the edge of sensitivity for the human eye.

The CONTOUR spacecraft was commanded to fire its solid rocket motor as scheduled on 15 August, and radio contact was never regained. Several telescopic observations have now identified two objects traveling nearly together close to CONTOUR's planned path. The objects are moving apart from each other at about 20 km/h. The evidence strongly suggests that the SRM firing did occur, but something caused the spacecraft to break up very near the end of the burn. Since the actual forces experienced by CONTOUR during this burn were less than those experienced during its launch (and far less than it was designed to handle), it is reasonable to conclude that the failure was caused by some type of explosion.

Technical Details

  • Location: Central Colorado, N38° 47.166' W105° 29.017' (Altitude 2767m)
  • Telescope: Meade LX200, aperture 305mm, focal length 2122mm (f/7)
  • Camera: SBIG ST8i
  • Filter: Johnson V
  • Exposure time: 120 seconds
  • Start time: UT 2002-08-10 04:46:02 (9 Aug 2002 10:46:02 PM MDT)
  • Image size: 765 x 510 pixels (22 x 15 arcmin)
  • Image scale: 1.75 arcsec/pixel
  • Orientation: north up, spacecraft traveling west to east (right to left in the image)
  • Image center: 15h 49m 57s +16° 09' 48"
  • Image depth (V band): magnitude 17.5
  • Duration of spacecraft pass: 7 seconds
  • Estimate of spacecraft brightness: magnitude 7