The $10bn James Webb Space telescope, the biggest space telescope ever conceived went into orbit on Christmas day. The observatory was lifted skyward by an Ariane rocket from the Kourou spaceport in French Guiana, South America at 7:20 a.m. EST. The telescope will try to image the very first stars and galaxies to shine in the Universe. It will also have the power to probe the atmospheres of distant planets to look for gases that might hint at the presence of life.
The project has taken 30 years to design and build. It is regarded as one of the grand scientific endeavours of the 21st Century.
To get to space, Webb survived a 27-minute ascent on what is, in effect, a controlled explosion. The telescope then has to unfold itself in a series of complex deployments. The world’s largest and most complex space science observatory will begin six months of commissioning in space. At the end of commissioning, Webb will deliver its first images. Webb carries four state-of-the-art science instruments with highly sensitive infrared detectors of unprecedented resolution. Webb will study infrared light from celestial objects with much greater clarity than ever before. The premier mission is the scientific successor to NASA’s iconic Hubble and Spitzer space telescopes, built to complement and further the scientific discoveries of these and other missions.
The James Webb telescope is named after one of the architects of the Apollo Moon programme, and the space agencies of the US, Europe and Canada, who are all partners on the project, regard it as a science flagship of no less importance. Webb's mission is to build on the discoveries of the Hubble Space Telescope, which, after 31 years in orbit, is nearing the end of operations.
At the core of the new facility's capabilities is its 6.5m-wide golden mirror. This remarkable reflecting surface, allied to four super-sensitive instruments, should enable Webb to detect the light from the pioneer stars. These objects are theorised to have ignited more than 13.5 billion years ago. Webb will look deeper into the cosmos and, as a consequence, much further back in time.
The pioneer stars are more than a mere curiosity. They began the process of seeding the cosmos with the first heavy chemical elements. The calcium in our bones, the phosphorus in our DNA and the iron in our blood - all these atoms had to be "manufactured" in the nuclear reactions that make stars shine, and in the mighty explosions that end their existence. In this sense, Webb will be charting our origins.
The telescope is being put on a path to an observing station some 1.5 million km beyond the Earth. In the course of travelling to this location, Webb will have to unpack itself from the folded configuration it adopted at launch - like a butterfly emerging from its chrysalis.
"This telescope actually will be at minus 233 degrees Celsius. Only then will it stop glowing at the infrared wavelengths beyond the visible where we want this telescope to work. And only then will it be able to take the sensitive pictures of the distant Universe where the first galaxies were born, and of planets going around other stars. So there's a long way to go. And then the critical thing is that it all has to get very cold," explained Mark Mark McCaughrean, senior science adviser with the European Space Agency.
The unfurling process will take about two weeks. Webb's big mirror then has to be focused. The 18 segments that form this reflector have little motors on the back that will adjust the curvature.
Source BBC, NASA