- Dawn Mission Patch. Credit: McREL
NASA’s Dawn spacecraft is healthy and on course as it approaches asteroid Vesta.
Dawn has traveled 2.7 billion kilometers (1.7 billion miles) since leaving Earth. The craft was launched on September 27, 2007.
Now, as of May 27, Dawn is only 580 thousand kilometers (360 thousand miles) from Vesta.
“The probe is close to the end of the first leg of its interplanetary trek,” explains Marc Rayman, Dawn’s Chief Engineer /Mission Manager at the Jet Propulsion Laboratory (JPL). Thrusting with its ion propulsion system, as it has for most of its interplanetary journey so far, the spacecraft is gradually matching its solar orbit to that of Vesta – a protoplanet.
On July 16 Vesta’s gravity will capture Dawn, with engineers and scientists aiming for a survey orbit around the body to start in early August. Based on the current approach trajectory, survey orbit will begin within a time period of August 8 to 11. The date and time will be established firmly in July.
“Because the mass is not well known, there is some uncertainty in the precise time that Dawn will become gravitationally bound to the colossal asteroid,” Rayman adds in a recent communiqué about the mission.
Second destination
One revolution around Vesta will take Dawn almost three days.
Dawn will remain in orbit around Vesta for one year. After another long cruise phase, Dawn will arrive in 2015 at its second destination, Ceres, an even more massive body.
Dawn’s goal is to characterize the conditions and processes of the solar system’s earliest epoch by investigating in detail two of the largest protoplanets remaining intact since their formations.
Ceres and Vesta reside in the extensive zone between Mars and Jupiter together with many other smaller bodies, called the asteroid belt.
The University of California in Los Angeles is responsible for overall Dawn mission science.
Orbital Sciences Corp. of Dulles, Va., designed and built the spacecraft. The framing cameras were developed and built under the leadership of the Max Planck Institute for Solar System Research in Katlenburg-Lindau in Germany, with significant contributions by the German Aerospace Center (DLR) Institute of Planetary Research in Berlin and in coordination with the Institute of Computer and Communication Network Engineering in Braunschweig. The framing camera project is funded by NASA, the Max Planck Society and DLR.
For more information about Dawn, visit: http://www.nasa.gov/dawn
By Leonard David