Skip to comments.NASA comet-busting craft on course, instrument problem studied
Posted on 03/25/2005 7:27:52 PM PST by NormsRevenge
PASADENA, Calif. (AP) - NASA's Deep Impact spacecraft is on course for a July 4 encounter with comet Tempel 1 but mission officials are trying to determine why a telescope that will function as its main science instrument has not reached proper focus, the space agency said Friday.
Officials nonetheless expressed confidence that the mission will not be affected by the problem.
Deep Impact carries an "impactor" that will be released to collide with the comet, possibly creating a stadium-size gouge while the spacecraft's instruments collect data on the material that is hurled off.
The craft was launched on Jan. 12 and then underwent a period of testing in which its subsystems, autonomous navigation system and instruments were checked before it entered the cruise phase of the mission. A trajectory correction maneuver also was performed and went so well that a follow-up maneuver was canceled, NASA said.
The problem with the telescope, known as the High Resolution Instrument, was found after a process called bake-out in which heating is used to remove normal residual moisture from its barrel.
The moisture was absorbed into the instrument as the spacecraft waited on the launch pad and as it flew through the atmosphere into space, NASA said in a statement.
Subsequent test images showed that the telescope hasn't reached perfect focus, and a team has been formed to investigate the issue and ways to bring the instrument all the way to focus, NASA said.
"This in no way will affect our ability to impact the comet on July 4," Rick Grammier, the Deep Impact project manager at NASA's Jet Propulsion Laboratory, said in the statement.
The High Resolution Instrument is designed to deliver light simultaneously to a multispectral camera and to an infrared spectrometer.
The spacecraft also carries a Medium Resolution Instrument, which is a smaller telescope, and will gather data through a camera on a device called the Impactor Targeting Sensor. Both are working properly, NASA said.
"We are very early in the process of examining the data from all the instruments," said astronomer Michael A'Hearn, the Deep Space principal investigator who leads the mission from the University of Maryland at College Park, Md.
"It appears our infrared spectrometer is performing spectacularly, and even if the spatial resolution of the High Resolution Instrument remains at present levels, we still expect to obtain the best, most detailed pictures of a comet ever taken," he said.
The impact will also be observed by NASA's Hubble, Spitzer and Chandra space telescopes, and by big telescopes on Earth.
The University of Maryland provides overall mission management while JPL manages the project for NASA's Science Mission Directorate. Ball Aerospace & Technologies Corp. of Boulder, Colo., built the spacecraft for NASA.
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They gotta drill first, then insert the nukes.
What is the "impactor"? It sounds suspiciously like the're trying to not say 'weapon', 'bomb', or 'nuke'.
They were planning to call it the tickler, but the French already have that trademarked.
The impactor is just that; an impactor. No explosives.
Momentum-wise it's to the comet about like a large bug hitting the window of a Tractor-Trailer.
If I remember right, its something like a 300 pound copper slug
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