Talk:Spitzer Space Telescope

From Wikipedia, the free encyclopedia

WikiProject Astronomy This article is within the scope of WikiProject Astronomy, which collaborates on articles related to astronomy.
B This article has been rated as B-Class on the assessment scale.

This article has been rated but has no comments. If appropriate, please review the article and leave comments here to identify the strengths and weaknesses of the article and what work it will need.

Contents

[edit] Layout Question

I can't seem to get the image size right on the artist's concept in the box. Can anyone help out with this? It's filling my whole screen on the article page, but the image I uploaded, [[Image:Sirtf 09 2002.jpg]] is only 250x180 pix. --zandperl 03:35, 24 Feb 2004 (UTC)

[edit] Instrumentation

Does anyone know more about the instruments on Spitzer, much like the Hubble Space Telescope page has? --zandperl 00:58, 18 Mar 2004 (UTC)

MIPS 160 micron array is actually a 2x20 array. See http://mips.as.arizona.edu/mipspage/instrument_f.html for full description of MIPS instrumentation. --AmberRobot 09:47, 14 Aug 2004 (CST)

[edit] Orbit

From what I can infer, the Spitzer orbit is not truly at L5, but is attracted toward L5. I believe L5 itself is rather dirty, and may not be well suited for an observatory. The only authoritative orbit detail says it is moving away from the earth at 0.1AU per year:

http://www.spitzer.caltech.edu/about/orbit.shtml

I added a bit more text to describe this, but did not delete the reference to L5 in the table.


As Spitzer's orbit is heliocentric, changed "Satellite of:" in infobox from Earth to Sun. Harperska 21:32, 23 December 2006 (UTC)

[edit] Comments by Don Barry

To the commentator above -- Spitzer's orbit is not taking it towards an Earth resonance point; it truly is a heliocentric orbit which lags Earth's by about 1/60 orbit per year, i.e. in 60 years (the synodic period of the two) it will catch up to Earth again.

There is no propulsion capability on the spacecraft other than a quite limited dry-nitrogen system intended for occasional angular momentum dumps off the reaction wheels, so there was no intent to "aim" it anywhere except in a low-precision trajectory. The spacecraft radio antenna is not steerable, so pointing in the daily data dumps is done by slewing the entire telescope -- eventually the orbit will move so far from Earth so that this maneuver would require spilling sunlight over the shielding solar panels onto the telescope itself -- this will not take place until several years after cryogen exhaustion and effective end of mission, however.

To the commentator far above -- Spitzer contains three "instrument packages", designated IRAC (infrared array camera) built by Harvard, consisting of four 256x256 detectors sampling 3.6, 4.5, 5.8, and 8.0 microns (http://cfa-www.harvard.edu/cfa/oir/Research/irac/firstpage.html), the MIPS (multiband imaging photometer) package built by the University of Arizona, consisting of a 128x128 24 micron camera, a 32x32 70 micron camera, and a 2x20 160 micron camera (http://mips.as.arizona.edu/MIPS/Home.html) and the IRS (InfraRed Spectrograph) package built by Cornell, consisting of four spectrometers, two low resolution (resolution of roughly R=100, 5-15, 15-38 microns), and two high resolution (R=600, 10-20, 19-37 microns) modules. The low resolution modules are long slit instruments providing spatial as well as spectral resolution. Currently, as of February 2006, about 50% of the requested observing time is for spectroscopic observations.

Don Barry, Spitzer Space Telescope IRS Instrument Team, Cornell University

[edit] Challenger Disaster

Challenger disaster? Isn't it supposed to be Columbia? I mean, the SST was launched after 2000, no?

The planning for the Spitzer Space Telescope took decades. At one point, it was called the Shuttle Infrared Telescope Facility, and it was supposed to operate in the cargo bay of the Space Shuttle. If my memory serves me right, a decision was made prior to the 1986 Challenger disaster to make the telescope free-flying, although I recall seeing nothing about whether it would be launched from the Space Shuttle or on its own rocket. By the time the 2003 Columbia disaster occurred, Spitzer was being prepared to launch on a Delta II rocket. I don't recall that the Columbia disaster had any impact on the launch or the program. George J. Bendo 08:44, 22 June 2006 (UTC)

[edit] f/12

"The primary mirror is 85 cm in diameter, f/12 and made of beryllium and cooled to 5.5 K." In this case, what does f/12 mean? I think that should be clarified/linked. --Eyrian 12:44, 20 March 2006 (UTC)

I added a short explanation. 193.171.121.30 18:48, 20 March 2006 (UTC)
My guess is that it is the "effective focal ratio" since it is a RC design. mcsew2k 71.189.241.42 12:26, 13 November 2007 (UTC)

[edit] Collecting Area

A circle of 85 cm diameter has got an area of no more than 0.57 m2, and part of it is occluded by the secondary mirror. Therefore the 2.3 m2 collecting area was wrong. I changed it to 0.5 m2, but this is only a guess because I don't know the exact size of the secondary mirror. 193.171.121.30 18:48, 20 March 2006 (UTC)

[edit] Requested move

Spitzer space telescope → Spitzer Space Telescope – {It's the propor name} copied from the entry on the WP:RM page

Done. —Nightstallion (?) Seen this already? 22:28, 26 March 2006 (UTC)

[edit] HD 209458 b

"As one of its most noteworthy observations, in 2005, SST became the first to directly capture the light from extrasolar planets; the "hot Jupiter" planets HD 209458b and TrES-1 respectively."

Would it be possible to find one of these images and include in the article? I looked, and couldn't find them at NASA's site, or the Spitzer site hosted at Caltech. --Eyrian 10:05, 18 June 2006 (UTC)

The wording in the article may be somewhat misleading and I am planning to change it. The Spitzer did indeed directly capture the light from the planets, but it did not (and could not) resolve that light into an actual image.Kevin Nelson 13:06, 30 August 2006 (UTC)

[edit] Pixelage=

Is the camera resolution not far too low? --maxrspct in the mud 00:34, 25 June 2006 (UTC)

[edit] I made an edit/deleted text

While reading this article I found this text was added: "Spitzer is a kid in my school who likes penis penis penis penis penis and more penis. And takes it up the butt :[" and I made the deletion. —Preceding unsigned comment added by 162.119.64.119 (talk) 18:38, 5 October 2007 (UTC)

[edit] Total cost of Spitzer at launch

I read the statement that the cost of Spitzer was $800M but the SpaceflightNow article cited claims only $670M. It is also not clear if it is the cost of just the payload or including the cost of launching it. Is that the $130M difference?

mcsew2k 71.189.241.42 12:20, 13 November 2007 (UTC)