Archive for JWST

Posted in Science Politics with tags , , , on October 26, 2011 by telescoper

No time for a post of my own today – it’s our “Staff Away Day” (which owing to budget cuts is only half a day and is being held in Cardiff, at the Millennium Stadium). Anyway, I was going to pass on the same rumours that Andy Lawrence is writing about, and he knows more about this than I do, so over to him for the ongoing ramifications of JWST…

JWST: Over and Out?

Posted in Science Politics, The Universe and Stuff with tags , , , , on August 23, 2011 by telescoper

News filtered through recently that the cost of the James Webb Space Telescope, which is already  threatened with cancellation owing to cuts in NASA’s budget, is now estimated to be around $8.7 billion dollars, about $2.2 billion higher than previous figures. In fact about a decade ago, when I was a lad, and chair of the old PPARC Astronomy Advisory Panel, the price tag of  the NGST (Next Generation Space Telescope), as it was then called, was put at significantly less than one billion dollars.

The implications of cancelling JWST are profound on both sides of the Atlantic. As Mark McCaughrean explains in detail over on the e-astronomer, the European Space Agency has already made a substantial investment in JWST and planned future contributions include the launch and substantial operating costs. The instrument development is nearly finished, but whether there will actually be a telescope to put instruments on remains to be seen. It’s clear that this, together with previous unilateral decisions by NASA, is putting some strain on the relationship with ESA.

There were many who reacted to the initial suggestion that JWST should be cancelled by arguing that it was mere political posturing by Republicans in the House of Representatives and that it could and would be reversed if appropriate campaigning took place. To this end there has been, e.g.,  a letter to the White House Science Advisor (here for non-US astronomers and there for US ones). There’s also been a letter of support from the President of the Royal Astronomical Society. NASA’s administrators have also apparently come up with a plan to divert funds from other projects to support it. These efforts notwithstanding I get the distinct feeling that cancellation of JWST is a very real prospect and it goes without saying that the chances of avoiding it are not helped by  the increased estimated expense.

I’ve talked about this to a number of astronomers and cosmologists over the summer and found very mixed views not only about  (a) whether JWST will be cancelled or not but also about (b) whether it should be cancelled or not. Even astronomers have expressed exasperation with the spiralling cost of JWST and pointed out that if we had known a decade ago that it would take so long and involve such an outlay then it would never have gone ahead in the first place.

So let me try a straw poll:

JWST: Too Big to Fail?

Posted in Finance, Science Politics, The Universe and Stuff with tags , , , , , on July 7, 2011 by telescoper

News emerged last night that the US Government may be about to cancel the  James Webb Space Telescope, which is intended to be the successor to the Hubble Space Telescope. I’m slow out of the blocks on this one, as I had an early night last night, but there’s already extensive reaction to the JWST crisis around the blogosphere: see, for example, Andy Lawrence, Sarah Kendrew, and Amanda Bauer; I’m sure there are many more articles elsewhere.

The US House Appropriations Committee has released its Science Appropriations Bill for the Fiscal Year 2012, which will be voted on tomorrow. Among other announcements (of big cuts to NASA’s budget) listed in the accompanying press release we find

The bill also terminates funding for the James Webb Space Telescope, which is billions of dollars over budget and plagued by poor management.

It is undoubtedly the case that JWST is way over budget and very late. Initial estimates put the cost of the at $1.6 billion and that it would be launched this year (2011). Now it can’t launch until at least 2018,  and probably won’t fly until as late as 2020, with an estimated final price tag of $6.8 billion. I couldn’t possibly comment on whether that is due to poor management or just that it’s an incredibly challenging project.

There’s a very informative piece on the Nature News Blog that explains that this is an early stage of the passage of the bill and that there’s a long way to go before JWST is definitely axed, but it is a worrying time for all those involved in it. There are serious implications for the European Space Agency, which is also involved in JWST, to STFC, which supports UK activity in related projects, and indeed for many groups of astronomers around the world who are currently engaged in building and testing instruments.

One of the arguments against cancelling JWST now is that all the money that has been spent on it so far would have been wasted, in other words that it’s “too big to fail”, which is an argument that obviously can’t be sustained indefinitely. It may be now it’s so far over budget that it’s become a political liability to NASA, i.e. it’s too big to succeed. It’s too early to say that JWST is doomed – this draft budget is partly a political shot across the bows of the President by the Republicans in the House – but it does that the politicians are prepared to think what has previously been unthinkable.

UPDATE: A statement has been issued by the American Astronomical Association.

 

Back Early…

Posted in The Universe and Stuff with tags , , , , , on September 11, 2009 by telescoper

As a very quick postscript to my previous post about the amazing performance of Hubble’s spanking new camera, let me just draw attention to a fresh paper on the ArXiv by Rychard Bouwens and collaborators, which discusses the detection of galaxies with redshifts around 8 in the Hubble Ultra Deep Field (shown below in an earlier image) using WFC3/IR observations that reveal galaxies fainter than the previous detection limits.

Amazing. I remember the days when a redshift z=0.5 was a big deal!

To put this in context and to give some idea of its importance, remember that the redshift z is defined in such a way that 1+z is the factor by which the wavelength of light is stretched out by the expansion of the Universe. Thus, a photon from a galaxy at redshift 8 started out on its journey towards us (or, rather, the Hubble Space Telescope) when the Universe was compressed in all directions relative to its present size by a factor of 9. The average density of stuff then was a factor 93=729 larger, so the Universe was a much more crowded place then compared to what it’s like now.

Translating the redshift into a time is trickier because it requires us to know how the expansion rate of the Universe varies with cosmic epoch. The requires solving the equations of a cosmological model or, more realistically for a Friday afternoon, plugging the numbers into Ned Wright’s famous cosmology calculator.

Using the best-estimate parameters for the current concordance cosmology reveals that at redshift 8, the Universe was only about 0.65 billion years old (i.e. light from the distant galaxies seen by HST set out only 650 million years after the Big Bang). Since the current age of the Universe is about 13.7 billion years (according to the same model), this means that the light Hubble detected set out on its journey towards us an astonishing 13 billion years ago.

More importantly for theories of galaxy formation and evolution, this means that at least some galaxies must have formed very early on, relatively speaking, in the first 5% of the time the Universe has been around for until now.

These observations are by no means certain as the redshifts have been determined only approximately using photometric techniques rather than the more accurate spectroscopic methods, but if they’re correct they could be extremely important.

At the very least they provide even stronger motivation for getting on with the next-generation space telescope, JWST.

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