In this issue:
Welcome to Inaugural Issue
DS1 Flight Spare Ion Thruster Keeps on Ticking
Dawn Flyby Target Working Group to Form
Team Members List
Email List Signup Instructions
Printable version of this newsletter (PDF format)
Welcome to the Inaugural Issue of Dawn's Early Light
Dawn, NASA's ninth Discovery mission, is scheduled to launch on May 27, 2006, on a journey that will take it into orbit about the two most massive asteroids, 4 Vesta and 1 Ceres, arriving there in July 2010 and August 2014 respectively. Dawn's goal is to understand the conditions and processes present at the solar system's earliest epoch, and to determine the role of water content and size in planetary evolution. To this end Dawn carries into orbit a framing camera, a mapping spectrometer, a gamma ray/neutron spectrometer, a laser altimeter, a magnetometer and a radio science investigation. Dawn uses solar power to energize its xenon ion thrusters to obtain an order of magnitude increase in propulsion efficiency over chemical thrusters. This high efficiency allows Dawn's ambitious trajectory to begin with a modest (Delta 2) launch vehicle, while its very low relative velocity upon arrival at the targets avoids critical timing for the orbit injection. Following orbit insertion, the spacecraft descends to low altitude, spending 11 months at each body. The Dawn website http://www-ssc.igpp.ucla.edu/dawn has a link to a brief paper giving more details of the mission. While the Dawn team is confident that Dawn will make many significant contributions to the understanding of these protoplanets in particular, and the origin and evolution of the solar system in general, it also knows that much complementary data lies in the hands of planetary astronomers and meteoriticists. Thus, Dawn envisions that the mission will be undertaken in a cooperative venture with many individuals working on common objectives, both with complementary data sets, as members of mission working groups, and eventually, when funding becomes available, as participating scientists and as part of the data analysis program. Especially in view of the long duration of the Dawn program, it is important that we maintain mechanisms to inject new blood into the science effort when the data become available.
Part of the means by which we propose to keep in close contact is through occasional newsletters. Our main distribution channel will be electronic so if you wish to be a subscriber please enroll as described here. In the newsletters there will be information about the progress of Dawn, calls for collaborative research, and suggestions for observations that would improve Dawn planning and the science return. In this newsletter we solicit volunteers for a working group on candidate Dawn flyby targets.
- Carol Raymond on behalf of Dawn Science Team