PI Update - July 2003
We will be preparing short messages on a more-or-less monthly basis to keep people up to date on the Deep Impact project. Initially, this message consists primarily of a technical update from me, the PI. In the future we will also provide updates on other aspects - new outreach activities, new additions to the web pages, and so on.
The project completed a major milestone in June as the instruments were delivered from the instrument team to the spacecraft team. The science team and the engineers at Ball Aerospace & Technologies Corp. completed their tests and their calibrations in the vacuum tanks at Ball Aerospace & Technologies Corp.. The spacecraft team is now beginning integration of the instruments into the spacecraft. The Impactor Targeting Sensor (ITS) is already integrated into the impactor spacecraft. The ITS is in two packages - the telescope and detector package and the electronics box - both of which are now integrated into the spacecraft and checked out. Meanwhile, the High Resolution Instrument (HRI), consisting of a large telescope with both an optical imager and an infrared spectrometer, and the Medium Resolution Instrument (MRI), consisting of a smaller telescope and optical imager, have been mounted on the instrument platform. This platform, which has also been checked out electronically with the spacecraft, will be mounted onto the side of the flyby spacecraft after completion of the interior components of the spacecraft. For more information on the spacecraft instruments, see deepimpact.umd.edu/tech/instruments.html.
Meanwhile, the science team is analyzing the data taken during the testing of the instruments in the vacuum chamber in order to develop the best techniques for calibrating the data that will be taken during flight. Additional calibrations will be taken during flight to fine-tune the numerical details of the calibration, but the data taken in the lab should be sufficient to determine all the effects which must be taken into account in processing the data. Pictures of the instruments are available at deepimpact.umd.edu/gallery/.
On the spacecraft side, the team completed the flash testing of the solar panels. In this test, the panels were illuminated by a flash that puts, very briefly, as much light on the panels as does the sun. The output of the solar panels is measured during the flash to verify that the solar panels will provide the voltage and power required by the spacecraft. Pictures of the flash test are at deepimpact.umd.edu/gallery/Flash_Test.html.
The science team continues to develop tools for visualizing and analyzing the impact. Jim Richardson, a graduate student working with Prof. Jay Melosh, has developed a useful tool that will allow us to vary the orientation of a simulated impact until we can reproduce our observations. Ultimately, these simulations will be used to understand the physical processes that occur in the cometary nucleus based on theories of hypervelocity impacts into solid bodies. We have posted two of these simulations on the web page for your viewing. The animations show the field of view of the two cameras. Take a look at deepimpact.umd.edu/mission/wwws.
Don't forget to Send Your Name to the Comet, if you haven't already.
(NOTE: This campaign was closed in January 2004.)
Mike A'Hearn, University of Maryland