Dawn's Ion Engine Accelerates to Impressive Speed

The American space agency currently has numerous missions spread out across the solar system, but one of them stands out through its ambitions and complexity. The Dawn spacecraft is currently en route to the dwarf planet Ceres, and then onwards to the large asteroid Vesta. Its trajectory called for impressively-complex calculations, as well as for the very latest in technology to be installed on it. The ion propulsion system is one of these technologies, and its thrusters recently managed to exceed a long-standing record, held by the NASA Deep Space 1 probe. Dawn managed to accelerate to a whooping speed of 9,600 miles per hour, or about 4.3 kilometers per second, in its trek through the Inner Asteroid Belt, mission managers at the NASA Jet Propulsion Laboratory (JPL) announce.

“We are using this amazing ion-engine technology as a stepping-stone to orbit and explore two of the asteroid belt's most mysterious objects, Vesta and Ceres,” explains JPL Dawn project manager Robert Mase. The JPL, based in Pasadena, California, manages the mission for NASA's Science Mission Directorate, in Washington DC, and it is in turn managed by the California Institute of Technology (Caltech). Dawn managed to exceed Deep Space 1's record on Saturday, June 5, the team announces. “I am delighted that it will be Dawn that surpasses DS1's record. It is a tribute to all those involved in the design and operations of this remarkable spacecraft,” says former Deep Space 1 project manager, and current Dawn mission chief engineer, Marc Rayman.

Dawn's target is located at a distance of more than 249 million kilometers, or about 155 million miles, away from the Sun. The inner asteroid belt begins roughly around the point where Mars' orbit is most distant from the star. The spacecraft visited its general targeted area in June 2008, but only for a short period of time, before heading for the Sun again, to catch more speed and prepare for its Mars gravity-assist stage. The maneuver allowed it to change its trajectory and speed yet again, setting it on a general course for the asteroid Vesta.

The flight that Dawn began in 2007 will last for a total of eight years and 4.9 billion kilometers, and will represent the first time ever when a man-made object takes permanent residence in the inner asteroid belt. The 1,098-kilogram (2,421-pound) probe is powered by three DS1 heritage xenon ion thrusters, one of the few spacecraft ever to have received this propulsion system. The main objective of the mission is to provide astronomers and planetary scientists with some basic answers to how our solar system came to be. Some also hope to gain a better view of the earliest days after the Sun was formed, some 4.5 billion years ago.

“This is a special moment for the spacecraft team. In only 407 days, our minds will be on another set of records, the data records that Dawn will transmit when we enter Vesta orbit,” says University of California Los Angeles (UCLA) expert Chris Russell, the principal investigator of the Dawn mission.