NASA James Webb Telescope: NIRSpec instrument installed into the heart

In this photo, engineers install the NIRSpec instrument in the heart (or ISIM) of NASA's James Webb Space Telescope (JWT). 

Credit: NASA/Chris Gunn

The last piece of the James Webb Space Telescope's heart was installed inside the world's largest clean room at NASA's Goddard Space Flight Center in Greenbelt, Md.


What looked like a massive black frame covered with wires and aluminum foil, the heart or Integrated Science Instrument Module (ISIM) now contains all four of Webb's science instruments.

Together, these instruments will help unlock the history of our universe, from the first luminous glows after the Big Bang, to the formation of stellar systems capable of supporting life on planets like Earth, to the evolution of our own solar system.

Teams of engineers recently navigated very cramped spaces with delicate materials and finished surgically implanting the last of the four instruments that will fly on the Webb telescope – the Near-Infrared Spectrograph (NIRSpec).

Weighing about as much as an upright piano (about 430 pounds, or 196 kilograms), the NIRSpec was suspended from a moveable counterweight called the Horizontal Integration Tool (HIT).


From below, the engineering team was tasked with painstakingly moving this vital instrument to its final position inside the large black composite frame, officially called the Integrated Science Instrument Module (ISIM).

As the team maneuvered this crucial instrument through very tight, hard to reach spaces inside the Webb telescope's heart, they ensured there was no unintentional contact with the frame because the instrument's materials are very stiff but brittle.

Disturbing any of those materials could have caused major setbacks that could damage NIRSpec.

"Part of the challenge is that this instrument cannot be installed in a straight linear move. In order to avoid interference with already installed systems, the instrument will have to follow a special pattern kind of like a dance," said Maurice te Plate, the European Space Agency's (ESA) Webb system integration and test manager at Goddard.

"During the crucial phases of the installation, the room is kept very silent because whenever there is a potential issue one of the engineers must hold the process until everything is checked out so they can proceed."

Engineers needed NIRSpec's six individual feet or legs to align with six designated "saddle" points on the ISIM within the width of a little more than that of a human hair.

To hit their marks, these engineers had rehearsed these complicated movements, performing simulations and precise calculations on both sides of the ocean.

James Webb Space Telescope (JWST): NirSpec 'First starlight' instrument complete

Europe has reached another milestone in its contribution to Hubble's successor - the James Webb Space Telescope (JWST).

An industrial team led from EADS Astrium in Germany has completed the build of the Near-Infrared spectrometer, one of four instruments that will go in JWST.

NirSpec's job will be to determine the age, composition, movement and distance of the objects in its field of view.

The expectation is that some of these targets will include the very first stars to shine in the Universe.

That would mean picking up light signals that have travelled across space for perhaps 13.6 billion light-years - something Hubble cannot do.

JWST will make it possible with a suite of next-generation technologies, including 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 keen vision against the light and heat from the Sun.

NirSpec is critical to this new capability, and represents 10 years of design and manufacturing endeavour.

In a short ceremony in Ottobrunn on Friday, the instrument was handed over to the European Space Agency (ESA), which had commissioned NirSpec.

The Paris-based organisation then immediately passed the near-200m-euro instrument to the US space agency (NASA), which leads the JWST venture.

On 20 September, NirSpec will be flown to Maryland's Goddard Space Flight Center for integration into the giant orbiting observatory.

Europe's major industrial commitments to JWST are now complete.

Mid-Infrared Instrument (Miri)
Its other instrument - the Mid-Infrared Instrument (Miri), which was assembled in the UK - was safely delivered to North America last year.

The one outstanding task - and it is a very onerous one - will be to launch JWST in October 2018.

This will be performed by an Ariane 5 rocket from Esa's Kourou spaceport in French Guiana.

When I visited NirSpec in the Ottobrunn clean room last week, there was not much to see because the finished instrument was dressed for shipment in its protective thermal coat.

But if you could lift that covering, you would lay eyes on what appears to be an impossible optical maze.

NirSpec will be mounted just behind JWST's primary mirror and will sample the gathered light via a kind of periscope.

A series of mini-mirrors will then corral and condition this light, moving it towards a grating element where it can be sliced and diced into its component colours - its spectra.

Detectors are positioned at the end of the maze to read these colours and convert them into an electronic signal that can be transmitted to the ground.

All this is done in the near-infrared, in the wavelengths from 0.6 to 5 microns. This is the region of the electromagnetic spectrum where you would expect to pick up starlight that has been stretched on its 13-billion-year journey across an expanding cosmos.

An interesting aspect of NirSpec's design is that nearly half by weight of the instrument is made from ultra-stiff silicon carbide.

"The unique feature of silicon carbide is that it allows us to make structure and mirrors out of the same material," explains Astrium programme manager Ralf Maurer.

"This helps us survive the transition going from warm to cold; there is no deformation. And that gives us a very stable alignment of the optics."

ESO VLT: New technique boosts Detection of water on Exoplanets

An artist’s impression of a hot Jupiter (at bottom right), a giant planet that orbits extremely close in to its host star. 

Credit: Leiden Observatory

Using ESO's Very Large Telescope (VLT), a team of astronomers have been able to detect the tell-tale spectral fingerprint of water molecules in the atmosphere of a planet in orbit around another star.

The discovery endorses a new technique that will let astronomers efficiently search for water on hundreds of worlds without the need for space-based telescopes.

Dr Jayne Birkby of Leiden University will present the new result on Friday 5 July at the RAS National Astronomy Meeting in St Andrews, Scotland.

Jayne Birkby

Since the early 1990s scientists have found almost 1000 planets in orbit around other stars.

These so-called exoplanets are mostly much larger than the Earth and many are much closer to their stars than we are to the Sun, leading them to be described as 'hot Jupiters'.

In the new work the team studied the exoplanet HD 189733b, a world that orbits its star every 2.2 days and is heated to a temperature of over 1500 degrees Celsius.

Astronomers usually find exoplanets by measuring the gravitational influence of the planet on the star, which acts to pull the star around in a very small orbit, at velocities of a few kilometres per hour.

This movement causes a small shift in the lines of the stellar spectrum (known as the Doppler shift), which move back and forth with the wobble of the star.

The Leiden University-led team have flipped the technique on its head by measuring the gravitational influence of the star on the planet, which is much larger, hurling the planet around its orbit at some 400,000 km per hour.

They measured this by tracing the Doppler shift of the water lines in the exoplanet's spectrum as it orbited the star.

Despite the much larger velocity of the planet, it is nearly a thousand times fainter than the star, which makes detecting it very difficult.

The team were able to detect the spectral line of water in the exoplanet atmosphere by using the CRyogenic high-resolution InfraRed Echelle Spectrograph (CRIRES) instrument mounted on the VLT.

More information: The new work appears in "Detection of water absorption in the dayside atmosphere of HD 189733 b using ground-based high-resolution spectroscopy at 3.2 microns", J. L. Birkby, R. J. de Kok, M. Brogi, E. J. W. de Mooij, H. Schwarz, S. Albrecht, I. A. G. Snellen, submitted to Monthly Notices of the Royal Astronomical Society. A copy of the paper can be viewed at arxiv.org/abs/1307.1133

Water detection on Mars: Russian DAN Instrument on Curiosity

A Russian neutron detector (DAN) on board NASA's Mars rover Curiosity, designed to search for any water that might be bound into shallow underground minerals along the rover's path, was activated on Friday, the Russian manufacturer said. 

"The first scientific information has been received about the substance of Mars and its radiation background in the landing area," the Russian Academy of Sciences Space Research Institute said.

Curiosity successfully touched down on the Red Planet last Monday.

The Dynamic Albedo of Neutrons instrument, or DAN, will scout for underground clues to a depth of about 50 centimeters.

DAN will bring to the surface of Mars an enhancement of nuclear technology that has already detected Martian water from orbit.

By measuring the energies of the neutrons leaking from the ground, DAN can detect the fraction that was slowed in these collisions, and therefore the amount of hydrogen.

The neutron generator is mounted on Curiosity's right hip. A module with two neutron detectors is mounted on the left hip.

With pulses lasting about one microsecond and repeated as frequently as 10 times per second, key measurements by the detectors are the flux rate and delay time of moderated neutrons with different energy levels returning from the ground.

The generator will be able to emit a total of about 10 million pulses during the mission, with about 10 million neutrons at each pulse, NASA said.

The service camera installed on the $2.5 billion plutonium-powered rover has sent the first photos from the landing site in the Gale Crater, including one showing a wheel of the rover on the surface.

Curiosity, the biggest and the most scientifically complex Mars rover, will gradually turn on its scientific equipment to carry out geological and geo-chemical research, to study the planet's atmosphere and climate, and to search for water and organic substances.

Its findings will help to determine whether Mars was ever a habitable planet and whether it has any suitable places for habitation now.

NASA Mars Rover Curiosity: X-Duetto Instrument

Just because NASA's Curiosity rover is busy preparing to trundle over the surface of Mars doesn't mean it can't help out scientists on its home world as well.

An X-ray diffraction and fluorescence instrument the robot uses to study the composition of rock on the Red Planet's surface has found an application in an unlikely field: art conservation.

The instrument caught the eye of Giacomo Chiari, chief scientist at the Getty Conservation Institute in Los Angeles, as a potentially valuable means to examine priceless works of art without damaging them.

Determining the composition of ancient sculptures, paintings and buildings helps conservationists like Chiari to come up with ways to preserve pieces against the ravages of time.

Until recently, though, only a few instruments were available to determine the composition of ancient artefacts without cutting out physical samples.

Curiosity's instrument directs a beam of X-rays at objects and reads the radiation scattered back to determine what the object is made of in a matter of minutes.

Chiari contacted the instrument's designer, California-based company inXitu, to adapt and build a a more portable instrument for art analysis. (Watch inXitu videos on YouTube)

The new instrument, dubbed the X-Duetto (pdf), can examine objects while preserving their integrity and fits comfortably into a few briefcase-sized boxes.

It is now being used by Getty scientists to analyse a large collection of museum antiques and the Roman ruins of Herculaneum, Italy.