Dawn’s Early Light Volume 4, Issue 1 March 2005

Dawn Mission Status

Christopher T. Russell
Dawn Principal Investigator, UCLA

The Dawn Assembly, Test, and Launch Operations [ATLO] Readiness Review [ARR] was held on December 14-15, 2004. Dawn passed the ARR and officially entered ATLO on January 19, 2005. ATLO activities are led by Orbital Sciences Corporation, the spacecraft contractor, except for elements of the ion propulsion system. The graphite composite flight core structure was delivered to JPL in October for integration of the feed system for the xenon fuel used in the ion propulsion system, and the xenon tank was mounted inside the structure. That integration was completed and the flight core structure was shipped to Orbital on March 4. All spacecraft subsystems are going through, or have completed, environmental testing, and the flight solar panels completed thermal vacuum chamber testing and were delivered from Emcore to Dutch Space for array integration and test. The first Flight System Testbed is fully functional and the second Flight System Testbed is nearly complete.

Instrument deliveries occur between April and July, 2005. The LANL Gamma Ray and Neutron Detector (GRaND) will be delivered in April. The Framing Cameras (FC) from Germany and Vis/IR Mapping Spectrometer (VIR) from Italy will be delivered by early July. The FC and VIR deliveries are behind schedule due to the project’s decision to swap out the FPGAs and late delivery of the VIR beryllium mirrors from the vendor. The instrument schedules are being worked to reduce the impact of these delays on ground testing and calibration activities.

Overall, the project is making smooth progress, absorbing the inevitable bumps in the road. The schedule remains tight, and is being aggressively managed with judicious application of reserves.