In this update on the Dawn mission, project system engineer Marc Rayman reports that the probe is headed for its low altitude mapping orbit (LAMO), where it will focus on making a census of the atomic constituents and on mapping the gravity field in order to determine Vesta's interior structure.
Dawn's fourth anniversary of being in space is very different from its previous ones. Indeed, those days all were devoted to reaching the distant destination the ship is now exploring. Celebrating its anniversary of leaving Earth, Dawn is in orbit around a kindred terrestrial-type world, the ancient protoplanet Vesta.
Dawn has completed the first phase of its exploration of Vesta with tremendous success, and the peripatetic adventurer is now in powered flight again, on its way to a new location from which to scrutinize its subject.
After covering 2.8 billion kilometers (1.7 billion miles) on its own, after traveling for nearly four years through the lonely emptiness of interplanetary space, after being bound by the gravity only of the sun, Dawn is finally in orbit around Vesta.
Dawn remains healthy and on course as it continues to approach Vesta. 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 the protoplanet just ahead.
Dawn is on the threshold of a new world. After more than three and a half years of interplanetary travel covering in excess of 2.6 billion kilometers (1.6 billion miles), we are closing in on our first destination. Dawn is starting its approach to Vesta.
Three and a half years after launch, Dawn continues its travels around the Sun, maneuvering to take the same orbital path as Vesta. The spacecraft has spent most of the past month gently thrusting with its ion propulsion system. Some of the thrusting this month, however, was not designed to propel Dawn to Vesta.