PI Update - August 2003
The instrument platform has been fully integrated with the flyby spacecraft and the full electrical functionality has been verified. This means that we are now focused on completing the spacecraft for handover to the project's flight system test team, an event that is expected later this month. Further testing of the instruments will occur as part of the testing of the entire flight system.
A major achievement was to carry out a complete, end-to-end test of the file transfer protocol, an internet-like protocol which will be flown for the first time by Deep Impact. Previous missions have communicated with the ground using "packets" of data, typically all of a fixed size, with a "data file", such as an image, being built up from many separate packets as they are received at the ground station and sometimes involving sorting out data to several different files from a single packet. Our test involved sending a complete file from the ground support equipment at JPL, through a secure communications line to the spacecraft at BATC, processing through the spacecraft computer, and sending the file back to JPL. Although this test could not involve the Deep Space Network, since the spacecraft is still on the ground, it gives us great confidence that this new telemetry mode will work well for us. It also gives us optimism about running our test program "remotely", i.e. as we will fly the mission, with the tests being conducted from JPL in California while the spacecraft is at BATC in Colorado.
Mike A'Hearn, University of Maryland