[X] My Assistant

[cIclops]

An overlooked mission yet one that will be the focus of media attention in 155 days from now on July 4 2005, so there's time left to post a message before impact

cIc

[OWW]

(2) DI did indeed take some calibration photos of the Moon shortly after leaving Earth, and one has been released. It looks -- unlike the fuzzy misted-up Stardust photos -- nice and clear.

Here it is:



119 days until impact.

[Bob Shaw]

It appears that Deep Impact is suffering from a re-run of the old Hubble optical problem. Ball Aerospace used an optical surface during the camera manufacturing process which changed shape slightly with different temperatures, and the flyby images will need to be deconvoluted to recover detail. The impact vehicle appears to be OK, however.

I think the only response possible is 'D'oh!'.

[dilo]

Tempel-1 pictured with Medium Resolution Imager (MRI) camera:
http://deepimpact.umd.edu/gallery/DI_T1_doy164.html
(quite strange linear artifacts near the comet... ).

A sad question/consideration. The impactor uses a high-precision star tracker, which imply some kind of optical instrument... why they didn't planned to use it (or add a dedicated small camera) to take a "movie" of nucleus approach?
Even using a low resolution and limiting bit rate (let's say, one picture/min) last images should easily reach sub-meter resolution of pre-impact area, a result impossible even with perfectly focused HRI...

[jamescanvin]

A sad question/consideration. The impactor uses a high-precision star tracker, which imply some kind of optical instrument... why they didn't planned to use it (or add a dedicated small camera) to take a "movie" of nucleus approach?
Even using a low resolution and limiting bit rate (let's say, one picture/min) last images should easily reach sub-meter resolution of pre-impact area, a result impossible even with perfectly focused HRI...

It will.

From the Press Kit:

The impactor begins science imaging 22 hours before impact with a pair of full-frame
images -- one exposed for the nucleus, and one exposed for the coma, the dimmer
cloud that surrounds the nucleus. Similar image pairs will then be obtained every two
hours until 12 hours before impact. At that time, the impactor will spend two minutes
taking the same pictures and other data that it will collect during the final two minutes
before impact. This demonstration is designed to verify that it will execute this critical
data-taking correctly during the final and most critical segment of its mission.
Beginning 10 hours before impact, images will be taken every two hours until 8 hours
before impact; every hour from 7 to 4 hours before impact; and every 30 minutes from
3 to 1 hour before impact. At that time, the pace of imaging will increase until it reaches
a maximum of one picture every 0.7 second at about 12 seconds before impact.
Engineers say that odds are at least 50-50 that dust hitting the impactor will end transmission
of its images during the final 10 seconds before impact. The final potential
image that could be transmitted in its entirety is one scheduled at about 2 seconds
before impact, with a scale of about 20 centimeters (approximately 8 inches) per pixel.