SAINT-PIERRE DU PERRAY, France — The first of three telescopes that will make up one of the four imaging instruments on the multibillion-dollar James Webb Space Telescope (JWST) left its production facility Jan. 8, with manufacturer Sagem saying the other two components will be completed on schedule by midyear.

The Cam and Col telescopes, in final assembly, together with the Fore Optic spectrograph make up the JWST’s Near-Infrared Spectrograph (NIRSpec), which is a principal element of Europe’s contribution to the NASA-led JWST, now scheduled for launch aboard a European Ariane 5 ECA rocket in mid-2013.

NASA has estimated that its majority share of JWST will cost about $5 billion, including up to 10 years of in-orbit operations. European officials have estimated Europe’s total JWST investment at more than 400 million euros ($560 million), including the Ariane 5 launcher, the three-telescope NIRSpec and European laboratories’ contributions to the NASA-built Mid-Infrared Instrument, as well as operations. The cost of the 275-kilogram NIRSpec instrument alone is estimated at 100 million euros. NIRSpec is designed to operate at about 35 Kelvin, or minus 238 degrees Celsius.

GmbH of Germany is prime contractor for NIRSpec, with Sagem’sReosc specialty optics facility here responsible for polishing and finishing the silicon-carbon NIRSpec mirrors before sending the subassemblies to Astrium’sOttobrunn, Germany, plant for integration.

Reosc division is Europe’s premier builder of optical components for space- and ground-based astronomy. The company is a regular partner to Astrium Satellites, which in recent years has accumulated Earth observation satellite orders from Algeria, Chile, South Korea, Thailand, Taiwan and Japan in addition to its regular work for French and European civil and military optical Earth observation projects.

The Reosc division is a regular supplier of satellite optical subsystems to the Indian Space Research Organisation (ISRO). Thierry Batut, director of Reosc, said the company continues to work regularly for ISRO under straightforward component-delivery terms, with no technology transfer involved.

In the United States, Reosc finished the 2.7-meter-diameter mirror for NASA’s aircraft-mounted Stratospheric Observatory for Infrared Astronomy, and the 8-meter mirror on the Gemini Telescope in Hawaii.

is trying to diversify its portfolio into broader industrial applications to smooth out the contract hills and valleys endemic to the satellite- and ground-astronomy mirror manufacturing business. Company officials declined to disclose sales or profit figures in presentations here Jan. 8, saying Sagem, which is part of the Paris-based Safran Group, only releases overall corporate financial data.

officials said they also are providing filters for the China-Brazil CBERS Earth observation satellite program, but that export controls up to now have prevented them from supplying satellite optics to China.

The company also does regular work with Franco-Italian satellite prime contractor ThalesAlenia Space, in particular for the French Helios and Pleiades optical reconnaissance and Spirale missile warning satellites. About 150 people work at the Reosc facility here, which is dominated by a large conical-shaped structure topped by a domed platform on which space mirrors are tested.

Jacques Rodolfo, Reosc’sNIRSpec project manager, said this year’s delivery of the three NIRSpec telescopes marks the end of nearly four years of work since the contract was signed. Including test models and spares, Reosc has manufactured 40 NIRSpec mirrors. Fourteen of them are flight models.

Ralph Maurer, head of the NIRSpec project at Astrium GmbH, said the instrument’s development is on schedule given the mid-2010 delivery date of the instrument to NASA. JWST previously was scheduled for launch in 2011, but in 2005 NASA agreed to give the program an additional two years to help the agency absorb a substantial cost increase.

Maurer said European scientists will not be guaranteed observing time on JWST in return for Europe’s participation. Instead, JWST use will be attributed based on the scientific merit of the proposal. This is somewhat different from the Hubble Space Telescope, for which Europe paid some 15 percent of the costs and has been entitled to 15 percent of the observing time.