NASA’s barrier-breaking Deep Space 1 probe will be set adrift today 232 million miles from the sun, shutting down its futuristic ion propulsion engine less than three months after the craft captured the best views yet of a comet’s core.
Launched in October 1998, the $150 million probe’s original mission was to test a dozen forward-looking technologies, including an autonomous navigation system and an engine that relies on electrically charging its fuel, rather than burning it.
That mission ended in July 1999. The probe went on to take pictures of the asteroid Braille. Then it survived a November 1999 breakdown of its guidance system to move on to a September 2001 encounter with comet Borrelly, where Deep Space 1 would photograph the inside of a comet for only the second time ever.
The craft was not expected to survive the comet’s choking dust and speeding debris. But it did, and it produced the most detailed look yet of what scientists believe may be the darkest object in the solar system.
It will be a bittersweet moment for the Jet Propulsion Lab scientists and engineers who worked with Deep Space 1 when, shortly after noon Pacific time, the command is given to shut down the probe’s ion propulsion engine. While the craft defied expectations and far outlasted its original purpose, the end still feels, to some, like a death in the family.
“I remember when my grandfather died at an old age, a friend of mine from China said, ‘Oh, you should be happy.’ I immediately understood: Rather than being sad he died I was happy he had lived so long. So I suppose I have the same feeling with Deep Space 1,” wrote Marc Rayman, Deep Space 1’s project manager on the JPL website.
Some JPL scientists had wanted Deep Space 1’s journey to continue a little longer, by meeting up with asteroid 1999 KK1 next year. The idea was quashed, however, before it was proposed to NASA higher-ups.
“It’s really not that interesting to go to a little asteroid and get some pictures,” Rayman said. “Plus, we’re putting other missions at risk because they’re expecting all of the expertise of the Deep Space 1 people to be applied to them.”
Only five members remain from a Deep Space 1 team that was once as large as 100. Rayman himself will be moving on to the StarLight project.
Originally named Deep Space 3, the mission’s plan is to send into space twin craft that will test telescopes used for detecting planets orbiting distant stars. The launch is scheduled for June 2006.