Hubble trouble..., Serious problems with HST |
Hubble trouble..., Serious problems with HST |
Jan 30 2007, 12:08 AM
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#1
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The Poet Dude Group: Moderator Posts: 5551 Joined: 15-March 04 From: Kendal, Cumbria, UK Member No.: 60 |
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Jan 30 2007, 12:37 AM
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#2
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Administrator Group: Admin Posts: 5172 Joined: 4-August 05 From: Pasadena, CA, USA, Earth Member No.: 454 |
They got the notice out a full 26 minutes before the media call-in time for questions so I didn't get to listen in Did anybody else manage to call in?
--Emily -------------------- My website - My Patreon - @elakdawalla on Twitter - Please support unmannedspaceflight.com by donating here.
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Jan 30 2007, 01:07 AM
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#3
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Merciless Robot Group: Admin Posts: 8783 Joined: 8-December 05 From: Los Angeles Member No.: 602 |
<clink!!!> Looks like at least a one-year loss of service for ACS...plus, the article says that they don't plan to replace the ACS due to "enhanced capabilities" of other systems. Why don't I buy that statement completely?
-------------------- A few will take this knowledge and use this power of a dream realized as a force for change, an impetus for further discovery to make less ancient dreams real.
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Jan 30 2007, 01:21 AM
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#4
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Senior Member Group: Members Posts: 1582 Joined: 14-October 05 From: Vermont Member No.: 530 |
the article says that they don't plan to replace the ACS due to "enhanced capabilities" of other systems. Well, that could be true. But I'm also not clear on whether this problem is internal to ACS or in a separate electronics package that could be replaced or fixed. |
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Jan 30 2007, 01:36 AM
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#5
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Merciless Robot Group: Admin Posts: 8783 Joined: 8-December 05 From: Los Angeles Member No.: 602 |
That's true as well, Steve, and maybe I'm jumping the gun here....don't know how modular the Hubble instruments are, but I do suspect that they all have internal power supplies designed to operate off of a bus feed. Hope I'm wrong and that there's an easy fix.
From the article, though, it sounds as if there was an internal short @ the ACS power supply, and that probably can't be corrected by anything less than replacing the instrument...bummer. -------------------- A few will take this knowledge and use this power of a dream realized as a force for change, an impetus for further discovery to make less ancient dreams real.
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Jan 30 2007, 02:28 AM
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#6
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Member Group: Members Posts: 213 Joined: 21-January 07 From: Wigan, England Member No.: 1638 |
They got the notice out a full 26 minutes before the media call-in time for questions so I didn't get to listen in :angry: Did anybody else manage to call in? Yes, I listened in and also recorded it too, but the output was so loud (peaking at +12 dB!) that it was badly distorted. However, I made some notes during the briefing: Total loss of Side B electronics (fuse blown) ACS is now running on Side A electronics in order to maintain thermal control WFC and HRC cannot be restored on Side A since the Side A CCD Electronics Box stopped working in June 2006 (and the reason why ACS was switched to Side B) SBC has separate power supply and likely will be restored in mid-Feb in order to support New Horizons (SBC was regularly monitoring Jupiter and Saturn's auroral activity in the FUV) SM4 is still targeted for Sep 2008 and will not be brought forward by this issue SM4 will not repair ACS since the electronics control box is difficult for the astronauts to access (they would have to remove the NICMOS cryocooler control system, power off other systems etc. to reach ACS electronics) - that would take two days out of the five available - not worth deleting other tasks to do that - besides the new instrument WFC3 will largely replace ACS capability SM4 team will take heed of any review board recommendations concerning power supply issues that may affect WFC3 and COS in the same way Loss of capability after SM4: ACS WFC was optimized for far-red (600-900 nm) - WFC3 is better in the UV but poorer in the far-red - WFC3 would have to double exposure times to reach same depth as ACS/WFC UDF - however interest in far-red studies is waning amongst astronomy community (interest is now in Near-IR high-z studies) HRC coronagraph most flexible and powerful ever used on HST - SM4 hope to restore STIS which has good coronagraph for protoplanetary disk studies - but not as good as HRC which opened up a whole new field of study -------------------- "I got a call from NASA Headquarters wanting a color picture of Venus. I said, “What color would you like it?” - Laurance R. Doyle, former JPL image processing guy
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Jan 30 2007, 02:40 AM
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#7
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Administrator Group: Admin Posts: 5172 Joined: 4-August 05 From: Pasadena, CA, USA, Earth Member No.: 454 |
Del Palmer, thank you so much for these notes!
Just checking on the acronyms: ACS = Advanced Camera for Surveys (the boken one) WFC = Wide Field Planetary Camera 2 (works fine) SBC = ? FUV = Far Ultraviolet SM4 = Hubble Servicing Mission 4, currently planned for September 2008 NICMOS = Near Infrared Camera Multi-Object Spectrograph (works fine) WFC3 = Wide Field Planetary Camera 3, to be added to Hubble in servicing misson COS = Cosmic Origins Spectrograph, to be added to Hubble in servicing mission WFC UDF = ? You said you recorded it? If you could provide me with the recording I could host it on the Planetary Society site for everybody to listen... --Emily -------------------- My website - My Patreon - @elakdawalla on Twitter - Please support unmannedspaceflight.com by donating here.
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Jan 30 2007, 02:55 AM
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#8
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Administrator Group: Admin Posts: 5172 Joined: 4-August 05 From: Pasadena, CA, USA, Earth Member No.: 454 |
-------------------- My website - My Patreon - @elakdawalla on Twitter - Please support unmannedspaceflight.com by donating here.
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Jan 30 2007, 03:25 AM
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#9
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Senior Member Group: Moderator Posts: 2262 Joined: 9-February 04 From: Melbourne - Oz Member No.: 16 |
Just checking on the acronyms: WFC = Wide Field Planetary Camera 2 (works fine) SBC = ? WFC UDF = ? WFC = Wide Field Channel (of ACS - busted) SBC = Solar Blind Channel ((possibly) the only channel of ACS still working) UDF = Ultra Deep Field? James EDIT: and you didn't mention: HRC = High-Resolution Channel (also gone) -------------------- |
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Jan 30 2007, 03:27 AM
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#10
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Senior Member Group: Members Posts: 2511 Joined: 13-September 05 Member No.: 497 |
Just checking on the acronyms: ACS = Advanced Camera for Surveys (the boken one) WFC = Wide Field Planetary Camera 2 (works fine) SBC = ? WFC3 = Wide Field Planetary Camera 3, to be added to Hubble in servicing misson COS = Cosmic Origins Spectrograph, to be added to Hubble in servicing mission WFC UDF = ? WFC is the Wide Field Camera subsystem of ACS; WFPC2 is the Wide Field Planetary Camera 2 (pronounced "wif-pic".) WFC3 is the new instrument to be installed on the next servicing mission. SBC is the ACS Solar Blind Channel. WFC UDF is the Ultra-Deep Field taken with WFC. -------------------- Disclaimer: This post is based on public information only. Any opinions are my own.
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Jan 30 2007, 12:12 PM
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#11
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Interplanetary Dumpster Diver Group: Admin Posts: 4404 Joined: 17-February 04 From: Powell, TN Member No.: 33 |
The press release left out the STIS, which is still functioning...So here is a rundown of the working instruments -
NICMOS - Near Infrared Camera/Multi-Object Spectrometer STIS - Space Telescope Imaging Spectrograph FGS - Fine Guidance Sensors (for engineering, but also used for astrometry and photometry0 WF/PC-2 - Wide Field/Planetary Camera 2 - this is getting confused with the ACS's WFC Ted P.S. For planet-heads, such as us, this is a really big deal. The WF/PC-2's wide field camera is the best for closeup planetary shots - most famous Hubble planetary shots are from its PC camera (PC= Planetary Camera). Because the ACS HRC can take higher resolution shots (although it has down side of not getting Jupiter/Saturn's ring all in one field and, in the case of Mars, can't take a shot when it is at its closest without the coronograph finger blocking a bit - although I don't think that this will be a problem again until the close apparitions in about a decade), WF/PC-2's replacement lacks a high-resolution planetary camera, and is instead focused on wide field coverage. Given the nature of Hubble's focal plane set-up, all of the wide field cameras have slightly offset from the other instruments, and have been designed accordingly. Hence, on could not simply remove a broken ACS to install the new camera. WF/PC-2 has to go, or its replacement can't be installed (which isn't going to happen). All the more reason to bite our nails! -------------------- |
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Jan 30 2007, 12:32 PM
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#12
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Special Cookie Group: Members Posts: 2168 Joined: 6-April 05 From: Sintra | Portugal Member No.: 228 |
Just got a quicky one from Lars Christensen:
"There are are good chances that the Solar Blind Channel of ACS can be recovered. The WFC (Wide Field Channel, the most used one) and HRC (High-Resolution Channel) will most likely not be recovered." -------------------- "Ride, boldly ride," The shade replied, "If you seek for Eldorado!"
Edgar Alan Poe |
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Jan 30 2007, 12:48 PM
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#13
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Interplanetary Dumpster Diver Group: Admin Posts: 4404 Joined: 17-February 04 From: Powell, TN Member No.: 33 |
Just got a quicky one from Lars Christensen: "There are are good chances that the Solar Blind Channel of ACS can be recovered. The WFC (Wide Field Channel, the most used one) and HRC (High-Resolution Channel) will most likely not be recovered." Still, I wonder what he means by not recovered...not recovered by what they are doing now, or can't be recovered by a servicing mission. By the way, I have come to realize something....While the WFC3, to be installed next servicing mission, has no planetary camera, its wide field array - wider than WFPC/2 - has a resolution of .040 arc seconds/pixel in UV/VIS/Very near IR, compared with WFPC/2's planetary camera, which as a resolution of .046 arc seconds/ pixel! WFC3 also has .13 arc/second per pixel resolution in infrared, extending nearly through about two thirds of the wavelengths that NICMOS covers. For a comparison, the WFC on the ACS has a much narrower field of view and .05 arc seconds/pixel resolution. The HRC has .027 arc/second per pixel resolution, which is sometimes improved upon using super-resolution techniques (lots of short exposures taken at slightly different pointings added up to make the full exposure, rather than one long exposure). The SBC has .032 pixels/arc second resolution, but can only be used for faint objects without overexposure. So, it is very important to recover ACS if at all possible. But, fortunately, for planet folks, it doesn't look like we will be without the coverage we have gotten used to over the past 12 years or so (an exciting side, at least to me, about using WFC3 for planetary coverage, is the increased chance that moons will not escape the high resolution zone). -------------------- |
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Jan 30 2007, 01:59 PM
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#14
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Special Cookie Group: Members Posts: 2168 Joined: 6-April 05 From: Sintra | Portugal Member No.: 228 |
Still, I wonder what he means by not recovered...not recovered by what they are doing now, or can't be recovered by a servicing mission. I believe it is a permanent loss... -------------------- "Ride, boldly ride," The shade replied, "If you seek for Eldorado!"
Edgar Alan Poe |
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Guest_AlexBlackwell_* |
Feb 7 2007, 08:56 PM
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#15
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Guests |
John Spencer has another excellent glog entry, this one relating to Hubble.
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