Tempel 1 First Op-Nav
Jet Propulsion Laboratory https://www.jpl.nasa.gov/ April 27, 2005
On Monday, April 25, the Deep Impact spacecraft obtained its first optical navigation (Op-Nav) image of comet Tempel 1. At the time the picture was taken the distance between spacecraft and comet was 64 million kilometers (39.7 million miles) away. The exposure -- known as a "negative image" -- is used by the spacecraft team to assist in navigation and instrument calibration. The spacecraft will start imaging the comet on a regular basis in about 10 days.