Thank you for visiting the Deep Space 1 mission status information site, now in its third week on the list of most frequently visited logged sources in the solar system for information on this technology validation mission. This message was logged in at 7:30 pm Pacific Time on Monday, November 9.

Deep Space 1 continues to perform extremely well. The final activity required prior to the first complete test of the ion propulsion system was completed today. Xenon was ionized inside the thruster but was not electrically accelerated. Engineering data show that the test went just as planned. The suite of diagnostic sensors onboard to measure the effects of the ion propulsion system on the local space environment worked as planned and a wealth of data was collected.

The initiation of thrusting is currently planned for about 11:30 am Pacific Time on Tuesday, November 10. This is a key experiment on the DS1 mission, as ion propulsion is of great importance for many future space science missions. Deep Space 1 will provide these future missions with critical information on how well the system performs. In tomorrow's very complex activity, the thruster will be operated for about 8 hours at a low throttle level while engineers assess its performance. The ion thruster will be pointed at Earth so that the Deep Space Network can measure the Doppler shift. This phenomenon, familiar to anyone who has heard the pitch of a siren change as it approaches or recedes from the listener, will allow a measurement of the change in spacecraft speed as the thruster gently pushes on the spacecraft. The spacecraft will turn during the thrusting to assist in analyzing subtle aspects of the thrusting. After operating at this low throttle level the thruster will be stepped to progressively higher throttle levels each 90 minutes until the highest level supportable by the advanced solar arrays is reached. The activity is expected to conclude around 4:00 am Pacific Time on Wednesday, so please be patient for an update from this loyal correspondent.

The ion propulsion system was provided by the joint JPL/Lewis Research Center NSTAR program with partners Hughes Electron Dynamics Division, Spectrum Astro., Moog, and Physical Science Inc.

Deep Space 1 is now more than 7 times as far away as the moon.