The latest spacecraft in Europe’s long-running Meteosat series has just gone into orbit on an Ariane rocket.
It is now being manoeuvred into a position some 36,000 km above the Earth from where it can keep a constant watch on developing weather systems.
The spacecraft is the 10th Meteosat platform to go into service since 1977.
Its pictures will soon be feeding into the daily forecasts provided to the public by national meteorological agencies right across Europe.
“Verification and testing of the satellite’s systems will take two months. We expect to publish the first image on 6 August,” said Alain Ratier, the director-general of Eumetsat, the intergovernmental organization based in Darmstadt, Germany, that is charged with operating Europe’s weather platforms.
Thursday’s ascent to orbit from the Kourou spaceport in French Guiana lasted some 34 minutes.
When it came off the Ariane’s upper-stage, the satellite was moving in a stretched ellipse around the planet, running from an altitude of 250 km out to 35,950 km.
The latest spacecraft in Europe's long-running Meteosat series has just gone into orbit on an Ariane rocket
Controllers at the European Space Operations Centre (ESOC), also in Darmstadt, will need to circularise that path in the coming 10 days.
They are targeting a geostationary observing position at zero degrees longitude, over the Gulf of Guinea on the Equator.
The satellite’s orbital speed will be matched to that of the Earth’s rotation, giving the platform’s sensors a constant view of Europe and Africa.
The Meteosats are now into the “second generation” (MSG) of design. This was introduced in 2002 to substantially increase the flow and quality of information to Europe’s forecasters. And Meteosat-10 is the third in that particular series (MSG-3).
As on the two antecedents, the primary instrument on Meteosat-10 is the Spinning Enhanced Visible and Infrared Imager, or Seviri.
It builds its pictures of evolving meteorological systems, line by line, by spinning across the field of view.
Data is acquired at 12 different wavelengths, tracing information such as cloud movement and changing temperature.
The two currently operational MSGs are used in distinct ways.
Meteosat-9 builds images of the entire field of view – a full Earth disc – in 15 minutes, while Meteosat-8 rapidly scans a smaller area covering Europe, to provide imagery in just five minutes.
This allows the weather agencies to better follow the development of powerful and potentially dangerous thunderstorms in Eumetsat member states.
“Assuming it comes through its commissioning, Metosat-10 is destined to image the full Earth disc, and that means Meteosat-9 will then take on the rapid scan role,” said Michael Williams, who heads Eumetsat’s control centre division.
“It’s possible Meteosat-8 may eventually be moved to the Indian Ocean to assume observing duties there, if that’s what our member states decide.”
This is a big year for Europe’s weather agencies. Not only are they getting a new geostationary Meteosat, they will also see the launch a new polar orbiting meteorological platform in September called Metop-B.
This spacecraft is arguably even more important than Meteosat-10. Metop will circle the Earth a few hundred kilometres above the ground, sampling the different layers in the atmosphere. Its data will feed into the numerical models that forecast likely weather conditions 24 hours to a few days ahead.
Its antecedent, Metop-A has made a major contribution to the improvement of these predictions, and Metop-B will maintain the data stream.
Eumetsat and its R&D partner, the European Space Agency, are also putting in place the 3bn-euro programme to succeed Metop at the end of the decade.
The Eumetsat Council has been meeting in Darmstadt to finalise details of the scientific instrumentation that will fly on the next-generation spacecraft.
Thursday’s gathering decided to include an Ice Cloud Imager (ICI) among the 10-instrument payload.
This will have been most keenly in the UK and in Spain where industrial consortia are very interested in building the instrument.
Britain’s Met Office has already been engaged in the design of prototype technology that can be tested on a plane.
ICI will see ice crystals forming in the high atmosphere, a phenomenon that influences the amount of solar radiation reflected back into space.
“This microwave imager will see ice crystals in cirrus clouds, which have a critical impact on the greenhouse effect,” said Alain Ratier.
“These crystals are semi-transparent and are therefore very difficult to see with Meteosat and infrared techniques. This instrument will be important for climate studies,” he said.
• Meteosats are spin stabilised spacecraft, and their visible and infrared imagers build up pictures line by line, south to north
• One platform – currently Meteosat-8, which was launched in 2002 – makes an image of Europe (A) every five minutes
• Meteosat-9 (B), launched in 2005, scans the full Earth disc. One image every 15 minutes comes down to controllers
• The satellites report the current status of the weather. Forecasters use this information as a check against modeled predictions
Mid-Infrared Instrument (MIRI), one of Europe’s main contributions to the James Webb Space Telescope (JWST) is built and ready to ship to the US.
MIRI will gather key data as the $9 billion 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.
To do so, James 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 said.
• 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
Mid-Infrared Instrument (MIRI), one of Europe's main contributions to the James Webb Space Telescope (JWST) is built and ready to ship to the US
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.
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 colors 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.
• 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.
Much of the talk around James Webb tends to centre on cost. The current estimate for the US side is $8.8 billion, which covers the full life cycle of the project from its inception to the end of initial operations. Extra to that bill is some $650 million 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 said.
“People recognize 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.”
