Tuesday, January 30, 2007

Hubble in Safe Mode, ACS cooked?

Rumors started flying around yesterday morning (29-01-2007) that the Hubble Space Telescope had entered Safe Mode (i.e. it detected an operational anomaly and entered a mode of operation designed to prevent further harm or damage until engineers on the ground fix the problem), and worse still, that the flagship instrument on HST, the Advanced Camera for Surveys (ACS) was the instrument with the problem, possibly a big problem.

I didn't want to post anyhting about it until there was an official release of information, which occured some time last night. You can read about the problem yourself on the official ACS web pages. It sounds like ACS might be permanently broken.

The good news is that the other instrument on HST, the Wide Field and Planetary Camera 2 (WFPC2) is still working, and they expect to start normal observations with it later this week.

Unfortunately, this still means a major disruption. Ironically WFPC2 (an older instrument) does not have either the wide field of view or the sensitivity that ACS does, meaning that many scientific programs created with ACS in mind can not be performed using WFPC2.

HST entered inertial safe mode on Saturday January 27. Preliminary indications are that this event was associated with an ACS anomaly. GSFC and STScI engineers and scientists are still investigating the situation, but it appears unlikely that ACS CCD observations (both WFC and HRC) will be available in Cycle 16. Current indications are that ACS/SBC can be restored using operational workarounds, so observers should assume that the ACS/SBC configuration will be available in Cycle 16.

The formal Cycle 16 deadline was 8 pm EST on Friday Jan 26. We received a total of 747 proposals, including 498 to use ACS/WFC or ACS/HRC. The latter proposals are unlikely to be viable. In order to ensure that we accommodate the science areas covered by those programs, we are extending the HST Cycle 16 deadline.

Let's hope the engineers can fix ACS from the ground, as the proposed Shuttle-based servicing mission is toward the end of 2008.

Sunday, January 28, 2007

Sunday morning relaxation...

It is Sunday morning, and I'm sipping my first coffee of the day while trying to relax after the last two weeks of Hubble proposal deadline stress - the deadline is still only less than 36 hours in the past. Outside thick low clouds, almost white, are threatening a few flurries of snow. I'm reading blogs, pharyngula, kos, TPM, all the normal crowd, while waiting for a certain online game still in beta to successfully connect to its servers.

Thanks to Pharyngula, I now know that if I were a Science Fiction writer I'd apparently be like this this guy:

I am:
Hal Clement (Harry C. Stubbs)
A quiet and underrated master of "hard science" fiction who, among other things, foresaw integrated circuits back in the 1940s.

Which science fiction writer are you?

Which is embarrassing, as consider myself widely-read (in SciFi) yet I've never heard of him.

Wednesday, January 24, 2007

A fiery moon falls

Some say the world will end in fire,
Some say in ice.
From what I've tasted of desire
I hold with those who favor fire.
-- Fire and Ice, Robert Frost

A nice space.com article on how Earth's Moon is destined to disintergrate and rain fire onto a dead world... in about 5 billion years.

Tuesday, January 23, 2007

Overcoming Bias rips Francis Collins a new one.

Overcoming Bias rips Francis Collins a new one. That is not the title of their blog post (its actually "Outside the Laboratory") but that is the subtext. And more importantly its a good examination of the basic question: Can you be religious and still be a good scientist? Go read O.B.'s argument for why you can't.

[Hat tip to PZ for this one.]

Monday, January 22, 2007

A space arms race?

On January 11 2007 the Chinese government successfully tested an anti-satellite weapon. (Note that "ASAT" weapons are feasible as the target has a known orbit from which it can hardly deviate, and satellites are fragile things. Anti-ballistic missile weaponry is currently not physically feasible, despite both the Clinton and Bush administration's claims.)

The militarization of space is a cause for grave concern - for many reasons not the least of which being that "Star Wars"-like systems are most effective as offensive (and not defensive) weapons. They essentially encourage a first-strike mentality.

Meteor Blades argues that this action by the Chinese was partially a response to the bellicose US defense department's Space Policy that published last year. And it is hard to believe the current US administrations claims that their policy, and the Chinese governments actions, do not constitute evidence of a new weapons race.

“We do not think there is an arms race in space. The United States believes that the existing body of existing international agreements — including the Outer Space Treaty, as well as the liability and respective compensation conventions — provide the appropriate legal regime for space,” the State Department official said in a Jan. 19 telephone interview.


“Arms control is not a viable solution for space. For example, there is no agreement on how to define space weapon. Without a definition you are left with loopholes and meaningless limitations that endanger national security. No arms control is better than bad arms control,” the State Department official said.

Another issue of great importance is that even these tests constitute a danger to the existing satellites of all countries. Space debris is a problem even at the moment, even without the deliberate creation clouds of expanding debris. From the same space.com news article:

“It made a lot of debris potentially affecting other satellites in [low Earth orbit]. We have to track each piece to see where it goes to see which satellites specifically are potentially at risk,” the aide said, adding: “I hope the U.S. does now spend more and take space situational awareness more seriously.”

Western society relies on satellite technology to a surprising degree, for communications, weather forecasting, GPS, all manor of sciences, and even spying.
Let us hope that saner and less ignorant minds steer national and international space policy back to calmer waters before it is too late.

Postscript: I couldn't help but notice that wikipedia's article on the Militarisation of Space, specifically the section describing the current US National Missile Defense, has been spoiled by some ones idea of a neutral point of view being the same thing as Fox's "fair and balanced".

The administration has continued to push the program, despite publicized failures and the objections of some scientists who oppose it. The projected cost of the program for the years 2004 to 2009 will be 53 billion US dollars, making it the largest single line in The Pentagon's budget.

Note the lack of any link or further discussion of the tests and failures, and the the use of some as to imply not many.

An honest and still non-partisan assessment would describe the many failures; how the many special conditions used in the successful tests largely invalidate them as honest tests of an operational defense; that many scientists oppose it and for reasons of both sound political science (i.e. they have sound reasons to believe that the NMD actually increases the chances of war, and/or that they have good reason to expect that unilaterally breaking international treaties might ultimately be a bad thing for the USA) and that fundamentally the science presents such challenges as to make it impossible to build a system that actually defends the average citizen within the foreseeable future).

Monday, January 15, 2007

Why are plants mainly green?

Why are plants green, and does the biophysics of photosynthesis force any extra-terrestrial photosynthetic organisms to be green too?

A preprint by Kiang, Siefert, Govindjee, & Blankenship (astro-ph/0701382) of a paper to appear in the March 2007 edition of Astrobiology discusses these and other issues.

Saturday, January 13, 2007

Replacing IDL

I try to avoid using and proprietary and/or commercial software for scientific research, for a variety of reasons, but given the number of different self-administered computers I use the financial issue is not insignificant. If there is a free alternative then it seems bad to needlessly waste grant (and ultimately tax-payer) money on commercial software.

Unfortunately I've just been forced to start using IDL in preparing for one of the Cycle 16 HST proposals I'm in the middle of working on - there isn't time for me to rewrite the IDL procedures I'm using in some other language before the proposal deadline (in the course of this I discovered i2py, an IDL to Python converter, but I haven't tried it yet).

And IDL is one of the commercial packages I dislike the most that is also most often used by other astronomers... in my humble opinion its too expensive, too slow compared to compiled languages like C++, too much of a memory hog and worse still, too inelegant an language compared to modern interpreted languages like Python and Ruby. Yeah, they've tried to update it by adding OO features to old-fashioned procedural IDL, but still this is only cool to people who have a large existing investment in using (and access to) IDL. Do you really want to pay (lots of) money to get it?

Some people (most of them die-hard long-time IDL users) would argue with this characterization of IDL, but for me its remaining Fortran-based heritage is too 1970's to bear (I like Fortran... for some things it is great, but why would I want to use an interpreted language with Fortran-like syntax and structuring?).

Still, I've spent the last few days messing about with IDL on a departmental Sun workstation that is so old and out of date it still uses Netscape as a browser, processing files on a modern Linux PC at least ten times faster than the ancient Sun Ultra 20 workstation and then scp'iong files over and waiting the hours it takes for the slow Sun machine to run IDL before it runs into some memory limitation or whatever it decides to inflict on me... painful. Very painful. And the sodding bog-standard-and-absolutely-vital readfits routine doesn't work on v6.1 of IDL so I have to use 5.6 instead. Great.

However this evening I remembered that there was a GNU project to re-implement IDL from scratch, which is unsurprisingly called GDL. But does it work? Well, the good news is all I needed to do was run "yum -y install gdl" on FC6 to install GDL, install a few IDL libraries the GDL page provided links to, and the IDL code I have to use rather magically works.

Its not enough to get me to like IDL, nor will it stop rewriting this stuff later in a modern language if the proposal is accepted, but at least I can now edit the IDL code, modify the input fits data files, and run the damn procedures all on the same modern machine, maybe in time to get this proposal written. Thanks GDL programmers!

Friday, January 12, 2007

Sudden Futue Singularities: Not what we need with a HST proposal deadline coming up...

Currently I have little time for blogging, having (a) just finished off (and had accepted) my NGC 6810 paper and (b) just started on HST Cycle 16 observing proposal creation, so I've only just noticed that this blog seems to have disappeared from the web (blogspot server problems?).

The shown are NGC 6810, taken from the paper. The image on the left is NGC 6810 as seen in the near-ultraviolet (NUV) and optical (specifically blue is the XMM-Newton Optical monitor UVW1 band, green is a U band filter and red is R band), while the image on the right contrasts the stellar light (optical R band shown in blue) with ionized gas at T~ 10000 K (continuum-subtracted H-alpha + [N II], shown in red) and soft X-ray emission (green, also mainly ionized gas, except now at T ~ 4000000 K).

As a test that its still working here are some interesting things I read about on coffee break this morning:

  1. A conference proceedings on arXiv (in General Relativity and Quantum Cosmology, cross-posted to Astronomy) discusses the possibility of Sudden Future Singularities (see gr-qc/0701056), which would be bad news for those of us with up-coming proposal deadlines. Time runs faster than I like at the moment. The paper is way over my head, but I get the impression that a SFS is NOT actually a sudden discontinuous jump into the future, despite the cool name (get writing you SciFi authors).
  2. Software coding errors, specifically over-writing the wrong memory addresses, may be responsible for the long-serving Mars Global Surveyor's sudden demise last year. Space.com has the story.
  3. Rosa Williams makes the news with N19, a superbubble in the Small Magellanic Cloud. And if you name is Sally or You-Hua, I haven't given up on writing up that LMC superbubble data... I'll do it soon. Just after the proposal deadlines and grant reports due in January are done. Honest.

Tuesday, January 02, 2007

RealClimate reviews 2006

RealClimate summarizes the highlights of 2006, climate-wise.