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 31.

    The very first light to fall on the Universe; that's quite the thought.

    I hope this all goes well and we get back some solid usable data. Personally I'm looking forward to the pics!

  • rate this

    Comment number 30.

    @Balloon rake - Oh, I so totally agree with you. And while we're on the subject, I just don't get all the fuss about fire, and the wheel... Those should be done away with too.

  • rate this

    Comment number 29.

    $8.8bn+ spent on this. Think of what we could have achieved with that amount of money instead of putting it into the pockets of rich people. Its a dirty world we live in.

  • rate this

    Comment number 28.

    i agree with baloon rake this is a waste of money in a time of austraterity. we shouldnt be encoraging kids to go into space anyway as it is dangrous up there. also looking at stars can blind you. the sun is a star and it is very bright. james web should pay for the telescope himself if he wants one. i think science is going too far now with all the telescopes and GM crops and ipads, etc

  • rate this

    Comment number 27.

    Aww, bless balloon rake and terry waite. If ignorance really IS bliss, we have the 2 most blissful people on the planet gracing us with their thoughts, empty as they are.

    Terry: There IS life on other planets, we just haven't found it.....yet. (I said life, not intelligent life, not that you would be able to tell the difference).

  • rate this

    Comment number 26.

    Declaration. I work at the Observatory in Edinburgh but I don't work on MIRI itself.

    As well as doing science JWST provides an opportunity to get kids into science and engineering, just as Apollo inspired many in my generation. We run a teacher course to start that process, helping teachers to inspire kids to learn and build a better tomorrow for this country. You can't put a price on that.

  • rate this

    Comment number 25.

    12.Balloon Rake
    "When you have seen one star then you have seen them all."


  • rate this

    Comment number 24.


    Wow the ignorance is mind blowing!. What is it you suppose we do when Earth become uninhabitable? If we survive to that point, space is all we'll have to turn too.

  • rate this

    Comment number 23.

    Unless we either suddenly stop breeding or figure out how to colonise and use our solar system's resources then humanity will die out. This area drives the cutting edge of technologies that eventually filter down to everyday life. Besides, if you can't see the interest in the question of what's out there beyond us then your soul must be very empty.

  • rate this

    Comment number 22.

    @12 Balloon Rake, I am singing from the same hymn sheet as you
    You cannot criticise people who like space without them coming back saying that space is the be all and end all of everything.
    It's time space exploration was ended, fans of sci-fi have this pipe dream of hoping to see life on other planets, 2 words for you - GROW UP!
    It will never happen, they think Doctor Who will save the day!!

  • rate this

    Comment number 21.

    12.Balloon Rake

    Looks like the ship of fools left someone behind when they set sail !

    Funny how all the hypocrites who post on these boards about space science being a "waste of money" forget just how many advances in modern technology are thanks to that science. If you really have a problem with it then give up technology and go and live in a cave somewhere.

  • rate this

    Comment number 20.

    #12 same kind of thinking back in the 1930's when the country wanted a National Grid of Electricity. Thankfully people like you are normally ignored.

  • rate this

    Comment number 19.

    12. Balloon Rake
    14 Minutes ago
    James Webb has far too much time on his hands, at the end of a day a telescope is a telescope."[/quote]

    You obviously don't know who James Webb is.

    You're right about having too much time on his hands
    He's quite dead apparently.
    James E. Webb October 7, 1906 – March 27, 1992.

    Balloon Rake, you need to spend some money on your education.

  • rate this

    Comment number 18.

    To all the nay-sayers to bitch and moan about space and space exploration I say Teflon and CCD's. Next time you fry your egg and bacon in your non-stick pan or take a picture with your mobile phone or DSLR you should thank space and space exploration because it's there that these things were invented. Who knows what JWST will bring to us in the next 20 years? Bring it on. Cheap at twice the price.

  • rate this

    Comment number 17.

    @Balloon Rake
    "James Webb has far too much time on his hands, at the end of a day a telescope is a telescope."
    As the second administrator of NASA until 1968 he was responsible for most of the framework that put men on the moon. Time well spent IMHO.
    He died 20 years ago, so not much time on his hands I suspect.

  • Comment number 16.

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

  • rate this

    Comment number 15.

    "When you have seen one star then you have seen them all."

    Said by somebody who obviously hasn't 'seen' any.

    If you prefer living in caves and having to hunt for your food everyday, what are you doing browsing the internet on your swish modern laptop? What are you, some kind of 'sci-fi nut job'?

  • rate this

    Comment number 14.

    Science benefits mankind because it adds to the accumulation of knowledge about our world and universe around us and spending on increasing our knowledge can only be a good thing.
    Making a big telescope has its technological challenges too, so for scientists and engineers alike, overcoming problems of assembly and manufacture will lead to further technological advances in the future of astronomy,

  • rate this

    Comment number 13.

    This is spine tingling to think that we as humans have this kind of potential within the science community. Long may this continue. Stars and space are my most fasinating subjects. if we find the first starlight i will remember this forever

  • rate this

    Comment number 12.

    More money wasted by sci-fi nut jobs, this money could be put to much better use.
    When you have seen one star then you have seen them all.
    James Webb has far too much time on his hands, at the end of a day a telescope is a telescope.


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