Scientist leads Dawn mission to unexplored space

By Stuart Wolpert

At Astrotech, workers secure the attachments of the Dawn spacecraft onto the upper stage booster.

This story updated July 9, 2007.

Christopher T. Russell, professor of geophysics and space physics, has spent 15 years working on NASA's Dawn mission that will send a spacecraft to the doughnut-shaped asteroid belt between Mars and Jupiter.

As the three-stage Delta II launch vehicle is prepared for liftoff from Cape Canaveral Air Force Station (originally scheduled for July but postponed, due to weather conditions, to September), Russell, who is principal investigator on the mission, is more than ready to begin this long-awaited journey to an unexplored region of space. He is a bit anxious.

Mission control

To see a video on the mission, visit dawn.jpl.nasa.gov.

"I want to get this spacecraft up in space, where it belongs," he said. "I'm really confident about the spacecraft. We've been testing and re-testing."

Dawn will conduct a detailed study of the structure and composition of two of the first bodies formed in our solar system: the "dwarf planet" Ceres and the massive asteroid Vesta. Dawn, which will be the first spacecraft to orbit two planetary bodies on the same mission, is expected to reveal the conditions under which these objects formed.

Once the spacecraft is launched, it is scheduled to fly past Mars by April 2009; after more than four years of travel, the spacecraft will rendezvous with Vesta in 2011. Dawn will then orbit the asteroid for approximately nine months before it leaves in 2012 on a three-year journey to Ceres, to begin orbiting that planet in 2015.

"I think of Dawn as two journeys," said Russell, who proposed the mission to NASA. "One is a journey into space. This is analogous to what ancient explorers did — [they] knew there was unexplored territory and wanted to discover what was there. We're going to explore a region for the first time to find out what the conditions are today."

Dawn's other journey will transport scientists back in time, so to speak, to the early solar system.

"Ceres and Vesta have been altered much less than other bodies," Russell said. "The Earth is changing all the time. The Earth hides its history, but we believe that Ceres and Vesta, formed more than 4.6 billion years ago, have preserved their early record [which is] frozen into their ancient surfaces. By looking at the surface and how it was modified by the bombardment of meteoroids, we will get an idea of what the early conditions of Ceres and Vesta were and how they changed."

Scientists are also eager to discover whether Ceres harbors life. "Evidence indicates it has substantial water or ice beneath its rocky crust," Russell said. "Our instruments on board will be able to determine whether there is water."

Dawn is expected to send back high-resolution images of previously unseen worlds, including perhaps mountains, canyons, craters and ancient lava flows. Dawn will also generate spectra that will help scientists identify geologic minerals. UCLA graduate students and postdoctoral scholars will work on the mission, including helping to analyze data.

Russell is hard at work, bringing together the mission's partners, managing the budget and participating in all major decisions.

"I'm putting my entire being into doing this mission. It's all-consuming, but fun," said Russell of the 80-hour weeks he has been working.

To see a video on the mission, visit http://dawn.jpl.nasa.gov.