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 51.

    48. Lee Roy Sanders Jr
    "There are still too limited parameters. REC/TX in your information. That prior and after your wave lengths. Think about the magnetic spectrum as a medium of reception it will cover what you can not yet begin to touch that exist."

    This guy needs to let some light into his head!

  • rate this

    Comment number 50.

    #42 Drunken Hobo

    'Estimated total cost to USA of Iraq War: $1,900 B
    Estimated cost of returning to the moon: $120 B'

    Is that a NASA figure, I suppose that's 100 billion for the bureaucracy and 20 billion for the mission.

    As an interesting aside $120 billion plus 20 years is probably about what we need to solve the problems of fusion rockets. Commercial flights to Mars anyone?

  • rate this

    Comment number 49.

    I laugh at how pitiful the people are who make negative comments about this story. They can be compared with ants. An ant does not care that the room it is in is massive, never mind the building the room sits in, or the city where the building sits or the country the city sits. People with little desire for the bigger picture cause those with real dreams to drag them along, complete wasters.

  • rate this

    Comment number 48.

    There are still too limited parameters. REC/TX in your information. That prior and after your wave lengths. Think about the magnetic spectrum as a medium of reception it will cover what you can not yet begin to touch that exist.

  • rate this

    Comment number 47.

    #37 badger_fruit

    'Also, on a slightly related topic; who thought that the LHC failure a few years ago was sabbotage?'

    Definitely not sabotage, just a new machine suffering a few teething troubles. When we build anything really complex and new it almost never works perfectly the first time.
    The LHC basically failed because of a bad solder joint, which overheated and failed causing a ..[400 char]

  • rate this

    Comment number 46.

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

    =>Wonderful! This is just what we need to give us hope for a better future.

  • rate this

    Comment number 45.

    "$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."

    Oh i don't know that's about the cost of a few more days in Iraq isn't it. Don't get me wrong this isn't an anti war rant, but when looking at the price of large scientific projects please have some perspective.

  • rate this

    Comment number 44.

    All that money is owed to someone or some country (china?). I think we found a black hole even before it lifts off. It makes me wanna puke when I see how irresponsible America is.

  • rate this

    Comment number 43.

    badger-fruit. You are right. There are matters we need to address on earth. But, a lot of these may be solved by us constantly questioning, probling, and gaining insight into matters of the universe. No-one knows where this research will lead, but no harm can come in attempting to find out.

    It's about more, much more, than just getting "pretty pictures", although I can't wait to see them myself

  • rate this

    Comment number 42.

    Estimated total cost to USA of Iraq War: $1,900,000,000,000
    Estimated cost of returning to the moon: $120,000,000,000

    They definitely made the right choice there...

  • rate this

    Comment number 41.

    Love the quote from Faraday. Thanks for that, Ron. I cringe when I read that the challenge in finding the money for this $8bn project. That money spent here opens a magnificent window into our universe adding knowledge that will be built upon for generations to come. Or it can fund about 4 days of the US defense budget. Which do you think will be remembered and valued in a 100 years. Priorities.

  • rate this

    Comment number 40.

    Just to remind all those who doubt the "value" of this kind of work the when Michael Faraday (whose efforts became the foundation of all electrical technology) was questioned in similar terms, his response was: What is the value of a new-born baby?

  • rate this

    Comment number 39.

    As the venerable John Wheeler once remarked, "This is OUR universe, our museum of wonder and beauty. Our Cathedral".

    Fingers crossed that the JWST gets the go ahead, in light of the recent funding problems. I can't wait for the treasure trove of knowledge it will reveal about the early universe.

  • rate this

    Comment number 38.

    Amazing technology, and a real example of the best of human endeavour.

    Can't wait for the stunning images we're going to see from the JWST, and hope it gets another generation of young people interested in science and technology.

  • rate this

    Comment number 37.

    Please don't get me wrong, space explorationa and the technological advancements that can come of it are utterly wonderful; I just think that there are still a number of problems that need to be addressed on Earth. Also, on a slightly related topic; who thought that the LHC failure a few years ago was sabbotage?

  • rate this

    Comment number 36.

    Could we have a loony toons filter to get rid of the illiterate and banal comments desecrating your comments? They may pay taxes, have a vote and drive a car but we should be able to ignore them whilst letting them air their ignorance.

  • rate this

    Comment number 35.

    I highly recommend to anyone interested in the universe that they watch Cosmos, a series by Carl Sagan based on his book of the same name. You can easily find it on the net. A great insight into the wonders of space and truly humbling once you realise just how massive the universe is. I feel privileged to live in an age where humans have truly started to explore our cosmic surroundings...

  • rate this

    Comment number 34.

    Why does every science or arts story involving financial investment always get sabotaged by commentators bitching about the cost, and how stupid they think it all is? Projects like this push humanity forward, and if you don’t get why, it might be best to stay quiet.

  • rate this

    Comment number 33.

    The universe is an unimaginably massive place; to ever hope to explore even a tiny fraction is amazing but I do think that we need to stop blowing each other up first before we humans reach for the stars. I mean, what's the use of knowing about the super-massive and super-small, when there are still children who have no food or clean water on this planet?

  • rate this

    Comment number 32.

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

    Comments like this just go to what show complete and utter ignorance govern some people. This has nothing to do with sci-fi whatsoever, but more to increase our knowledge and understanding. But you wouldn't know anything about that would you? Naive and pathetic remarks like this will get you nowhere.


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