One of HST's Cameras Is Back In Action

StupendousMan writes "One of the two big cameras aboard the Hubble Space Telescope is the Wide Field and Planetary Camera 2, or WFPC2 for short. As the most recent HST status report indicates, the camera was recently powered up again and sent commands to take some test images. Today (Sunday, Oct 26), I received E-mail from a colleague at STScI indicating that the calibration images were 'nominal.' That's NASA-speak for 'fine and dandy.' The E-mail goes on to say 'The data look nominal, indicating that Hubble optical imaging capabilities are in fine shape. (We can expect more glorious Hubble images in the near future.) ... Science with WFPC2 has resumed, and plans are underway to restore ACS/SBC to service this coming week.' Let's hope that the other big instrument, the Advanced Camera for Surveys (ACS), also comes back to life successfully. We should find out in just a week or so."

Just to clarify the status of ACS...

[Einer2]

The Solar Blind Channel (the least useful component of ACS, unless you happen to use it) is the only component coming back. The Wide Field Channel and High Resolution Channel, the real workhorses, aren't coming back until after the Servicing Mission. Even then, the ACS repair is on the bottom of their priority list since most of its functionality is duplicated (albeit not as well) by the optical channel of WFC3. This means that the ACS repair, perhaps along with the STIS repair, most likely will be crowded out of the schedule by replacement of the instrument control computer.

Re:Just to clarify the status of ACS...

[ChrisCampbell47]

This means that the ACS repair, perhaps along with the STIS repair, most likely will be crowded out of the schedule by replacement of the instrument control computer.

Sh*t, I knew this would get modded up to +5. NOT "most likely" at all. Everyone at all of the briefings has been saying over and over that they can "most likely" fit this into the existing plan, without pushing out any of the other repairs. They've said it would take about 1.5-2.0 hours of EVA timeline.

Assuming the ACS and STIS repairs go well (and that is indeed a big assumption) they'll have plenty of time.

Now, it is true that the ACS repair is not the highest priority, and they already weren't planning on getting around to it until EVA 3. And the SI/CDH repair is looking to be an EVA 1 task, since it IS indeed a high priority. But don't say it's likely to push ACS out, because it's not.

Re:Just to clarify the status of ACS...

[Einer2]

Well, there's a lot of gloomy talk circulating among people whose Cycle 17 programs are directly affected by this. This means that either the PR people at STScI are being excessively optimistic or the liaisons to the community aren't quashing rumors very effectively.

Re:Just to clarify the status of ACS...

[ChrisCampbell47]

Hmmm, could be. I guess we'll see in a few weeks when they make the STS-125 decision, and when they come out with the reworked timeline.

Re:Moon for a calibration image

[Kligat]

How much something can be magnified with a telescope is attainable through simple trigonometry. At 589km above Earth, a kilometer is about 180 arcseconds. The Wide Field and Planetary Camera 2's field of vision is about 164 arcseconds. Anything the Hubble would spot would be as interesting as a random Google Earth image, and besides, the Hubble Telescope orbits Earth at 5,700 m/s and probably wasn't designed to cope with that velocity just to target Earth.

As far as the Moon, I'd guess it would probably make a poor calibration target, because it is just so big. The WFPC2's field of vision is 8% of the Moon's diameter. It's also a few hundred thousand times brighter than the brightest star. At 78x magnification, with my simple telescope, the Moon takes up the entire field of vision. From this I can deduct that the Hubble Telescope's magnification with that camera is around 975x.