James Webb telescope's 'first light' instrument ready to ship


BBC correspondent Jonathan Amos gets to see the Mid-Infrared Instrument (Miri) close up before its shipment to the US

One of Europe's main contributions to the James Webb Space Telescope (JWST) is built and ready to ship to the US.

The Mid-Infrared Instrument (Miri) will gather key data as the $9bn (£5.5bn) observatory seeks to identify the first starlight in the Universe.

The results of testing conducted at the Rutherford Appleton Laboratory in the UK have just been signed off, clearing Miri to travel to America.

James Webb - regarded as the successor to Hubble - is due to launch in 2018.

It will carry a 6.5m primary mirror (more than double the width of Hubble's main mirror), and a shield the size of a tennis court to guard its sensitive vision from the heat and strong light of our Sun.

The observatory has been tasked with tracking down the very first luminous objects in the cosmos - groupings of the first generation of stars to burst into life.

Prof Gillian Wright: "We can see very red and faint light from distant galaxies"

To do so, Webb will use its infrared detectors to look deeper into space than Hubble, and further back in time - to a period more than 13 billion years ago.

"The other instruments on James Webb will do massive surveys of the sky, looking for these very rare objects; they will find the candidates," explained Miri's UK principal investigator, Prof Gillian Wright.

"But Miri has a very special role because it will be the instrument that looks at these candidates to determine which of them is a true first light object. Only Miri can give us that confirmation," she told BBC News.

JWST design
  • James Webb's main mirror has around seven times more collecting area than Hubble's 2.4m primary mirror
  • The sunshield is about 22m by 12m. There will be a 300-degree difference in temperature between the two sides
  • James Webb's instruments must be very cold to ensure their own infrared glow does not swamp the observations
  • The mission will launch in 2018 on an Ariane rocket. The observing position will be 1.5 million km from Earth

JWST is a co-operative project between the US (Nasa), European (Esa) and Canadian (CSA) space agencies.

Europe is providing two of the telescope's four instruments and the Ariane rocket to put it in orbit.

Miri is arguably the most versatile of the four instruments, with a much wider range of detectable wavelengths than its peers (5-28 microns).

Fundamentally, it is a camera system that will produce pictures of the cosmos.

JWST mirror segments All of JWST's mirror segments are now complete

But it also carries a coronagraph to block the light from bright objects so it can see more easily nearby, dimmer targets - such as planets circling their stars. In addition, there is a spectrograph that will slice light into its component colours so scientists can discern something of the chemistry of far-flung phenomena.

Miri is a complex design, and will operate at minus 266C. This frigid state is required for the instrument's detectors to sample the faintest of infrared sources. Everything must be done to ensure the telescope's own heat energy does not swamp the very signal it is pursuing.

The hardware for Miri has been developed by institutes and companies from across Europe and America.

The job of pulling every item together and assembling the finished system has had its scientific and engineering lead in the UK.

Miri has just gone through a rigorous mechanical and thermal test campaign at the Rutherford Appleton Laboratory (RAL) in Oxfordshire.

This included shaking the instrument to simulate the pounding it will receive during the ascent to orbit on the Ariane.

It was also put in a vacuum chamber and subjected to the kind of temperatures it will experience in space.

"It's been a real privilege to work on Miri and great to see it finally ship out," said Paul Eccleston, the engineer at RAL who has overseen the test campaign.

"It will be so exciting when we put it on top of the rocket and light the blue touch paper, so to speak, and watch it go up into space."

The paperwork signing off the test results has now been accepted by Nasa.

The next step is for Miri to be put in a special environment-controlled shipping box, so it can travel to the US space agency's Goddard centre. The Maryland facility is where the final integration of James Webb will take place.

Miri will be fixed inside a cage-like structure called the Integrated Science Instrument Module and positioned just behind the big mirror.

The years to 2018 promise yet more testing.

Mirror comparisons (BBC)
  • James Webb's instruments will be tuned to light beyond the detection of our eyes - at near- and mid-infrared wavelengths
  • It is in the infrared that very distant objects will show up, and also those objects that in the visible range are obscured by dust
  • Hubble is a visible light telescope with some near-infrared capability, but its sensitivity will be dwarfed by JWST's technologies
  • Europe's far-infrared Herschel space telescope has a bigger mirror than Hubble, but JWST's mirror will be larger still

Recommended 16 years ago as the logical evolution beyond Hubble, the JWST has managed to garner a fair amount of controversy.

Technical difficulties and project mismanagement mean the observatory is now running years behind schedule and is billions of dollars over-budget.

Elements of the US Congress wanted to cancel the telescope last summer. That did not happen, but Capitol Hill now has James Webb on a very short leash, with Nasa required to provide monthly updates on milestones met or missed.

Dr Eric Smith, Nasa's deputy programme director for James Webb, explains what the telescope can do

Much of the talk around James Webb tends to centre on cost. The current estimate for the US side is $8.8bn, which covers the full life cycle of the project from its inception to the end of initial operations. Extra to that bill is some $650m for the European contributions like Miri and Ariane.

Dr Eric Smith is Nasa's deputy programme director for James Webb. He believes taxpayers do appreciate the venture.

"When you're able to show people that James Webb will do things that not even Hubble can do - then they understand it," he told BBC News.

"People recognise how iconic Hubble has been, and how much it has affected their lives.

"The images and scientific results that Hubble has returned have permeated popular culture. Webb pictures will be just as sharp but because the telescope will be looking at a different part of the spectrum, it will show us things that are totally new."

Jonathan Amos Article written by Jonathan Amos Jonathan Amos Science correspondent

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  • rate this

    Comment number 71.

    We have a world to worry about with starving people, debt/deficits, etc. Why desperate need to get into space NOW, see into space NOW. Do we think the common working person is truly interested? All of this just seems so mistimed.
    Q. "Technical difficulties & project mismanagement mean the observatory is now running years behind schedule & is billions of dollars over-budget."

  • rate this

    Comment number 70.

    Re 69:
    the truth has been covered up by subversive attacks since the dawn of man. It cannot be avoided, it is the will of the reptilians.

  • rate this

    Comment number 69.

    I post a complaint against a subversive attack against the truth. Light my eye?! I said the person against my response, against my comment was only a self assured pompous propagandist employed by a militaristic government wanting to hide information and creditability of the truth.

  • rate this

    Comment number 68.

    Eras3r wrote:

    "It makes me wanna puke when I see how irresponsible America is."

    China owns a small portion of America's debt. Besides, if you are not American it isn't your business.

    Qwerty wrote:

    "The US need to get their priorities straight. The budget for NASA is half a penny on a tax dollar."

    If you are not American then it isn't your place to say what America's priorities should be.

  • rate this

    Comment number 67.

    An absolutely disgusting waste of money. You know there are people on this planet that don't have access to clean water and governments spend billions exploring space? Why? What benefit does it bring us? None. It's a disgrace. We should focus our attention on earth because that's where we are, and will always be. All this about colonising another planet is fantasy, it can't and wont happen.

  • rate this

    Comment number 66.

    If you're interested in space (and, as you are reading this article, I presume you are), I highly recommend the Stellarium program that you can download for free.
    It can show the position of stars & planets from any point in the solar system (including your garden), accurate to 1000s of years. Very useful for stargazing, and can also be used to help you view the ISS as it floats silently overhead.

  • rate this

    Comment number 65.

    57.Lee Roy Sanders Jr

    Have you been smoking something you shouldn't have ???

  • rate this

    Comment number 64.

    If I transmitted or received only a specific magnetic spectrum of data (or the opposite in your case the light spectrum) only a specific electronic response will be seen. That is only a specific information and not the whole scheme.

    Electric changes into magnetic and back into electric etc. till entropy displaces it.

  • rate this

    Comment number 63.

    A shame more money and know-how goes towards a European agency instead of an American one for an American telescope. You wouldn't see it the other way around if it were ESA's telescope. Shame on you NASA.

  • rate this

    Comment number 62.

    Yes it's a lot of money but hey I'm not good at Science, but I think it's great that we can try to understand. Our whole existence is based upon understanding everthing we do is based upon a knowledge of one thing or another, so don't mock it.

    And even if all we get is some photos like we saw from Hubble I think it will be worth it, I showed them to my kids and they were blown away

  • rate this

    Comment number 61.

    I think those such as Balloon Rake etc deserve only our pity for being so obviously free from the ravages of intelligence....

  • rate this

    Comment number 60.

    Space technology gave us electronic maps in cars, it gave us non-stick frying pans, it gave the first urine recycling unit for fresh water, it gave us sunblock lotion, it gave us accurate weather warnings, it have us ultra-efficient farming, it gave us better water management, it gave us better solar panels, it gave us the best vaccine for MMR.

    And still people say it is a waste of money. Sigh.

  • rate this

    Comment number 59.

    It's still $120billion entering the economy no matter what it's spent on.

  • rate this

    Comment number 58.

    50 Robert Lucien - Indeed so, in fact the first couple of billion was probably spent just coming up with the $120bn figure. NASA's not the most efficient of agencies.

    Private companies already seem to be overtaking them, in just 9 days SpaceX will make its first trip to the ISS in preparation for privately sending humans there. Wonder if we'll see private space telescopes next.

  • rate this

    Comment number 57.

    Stephen Hawking ask him to verify what is stated. He can catch onto what I am saying and see it. Oh the big reversal of the expansion theory (Big Bang). It will not happen in one reversal because existence of every event is happening at one time and the Big Bang is just one aspect in an infinity of happenings. .

  • rate this

    Comment number 56.

    There will always be problems on Earth. If we aim to resolve these issues first like many people on here suggest then I don't think we will be exploring anywhere!

  • rate this

    Comment number 55.

    If we stop looking we'll see nothing new and learn nothing new.

  • Comment number 54.

    This comment was removed because the moderators found it broke the house rules. Explain.

  • rate this

    Comment number 53.

    Every invention you see around you, from the wheel and paper through to the smart phone and 3D TV is created by combining observations and discoveries people have made. No exceptions.
    There are no substitutes for reasearch and education. That is what enables progress and without that we are nothing more than big chimps.
    I wish the UK would spend more on Universities and research.

  • rate this

    Comment number 52.

    The opposite of electric spectrum is (Light Spectrum) the magnetic spectrum. If you were to draw a electric wave form similar to the recording of a electric heart beat resembling larger to smaller w's the opposite would be as two hands clasped together. Magnetic fields eventually expand unto their opposites and recycle one into the other in a progression of bandwidth and frequency. Me Hillbilly?


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