NASA's James Webb Space Telescope: Here's what you need to know about the largest telescope ever placed in space
NASA's James Webb Space Telescope (also called JWST or Webb) is an orbiting infrared observatory that will complement and extend the discoveries of the Hubble Space Telescope, with longer wavelength coverage and improved sensitivity.
The longer wavelengths enable it to look much closer to the beginning of time and hunt for the unobserved formation of the first galaxies and to look inside dust clouds where stars and planetary systems are being born.
It is expected to go into space later this October aboard the Ariane V rocket from French Guiana. There are about 50 deployments that will take place after launch to set up the vast system of Webb Telescope and around 350 'single point failures' that need to be addressed for the mission to be successful.
1- Webb will be the premier space observatory for astronomers worldwide to extend the discoveries of the Hubble Space Telescope.
2- It will be the largest telescope ever placed in space and 100 times more powerful than Hubble.
3- The telescope will peer back in time over 13.5 billion years to see the first galaxies born after the Big Bang.
4- It will help astronomers to draw a comparison between the faintest, earliest galaxies to the present day's grand spirals and ellipticals. It will also help us to understand how galaxies assemble over billions of years.
5- It is designed to see right through and into massive clouds of dust to visible-light observatories like Hubble, where stars and planetary systems are forming today.
6- Webb will orbit the sun, a million miles away from Earth at the second Lagrange point. It is to be noted that L2 is four times farther than the moon.
7- Its 18-segment primary mirror is over 6 times bigger in area than Hubble's and will be 100 times more powerful. It is approximately 6.5 metres in diameter. The secondary mirror is as big as Spitzer's primary mirror. It is 0.74 m in diameter while Spitzer's primary mirror is 0.85 m in diameter.
8- Webb will fold in an origami style to fit in the Ariane 5 rocket and will unfold like a transformer in space. It can fold up to about a quarter of its longest dimension so it fits in the 5m wide rocket.
9- Its operating temperature is -370F, just a few degrees above absolute zero!
10- Webb will see the universe in light invisible to human eyes. Though it sees primarily infrared light, it can also see red and gold visible light.
11- It will be the biggest telescope ever launched into space with a total mass of 6200 kg.
12- It could detect the heat signature of a bumblebee at the distance of the moon, and can see details of the size of a US penny at the distance of about 24 miles (40 km).
13- Webb can see water vapour in extrasolar planet atmospheres.
Webb vs Hubble
Unlike the Hubble telescope that orbits the Earth at an altitude of around 570 km, the Webb will instead sit 1.5 million kilometres away from the Earth to stay in a stable, predictable orbit around the Sun.
Furthermore, Webb is capable of viewing the Universe in longer-wavelength infrared light while Hubble studies it primarily at optical and ultraviolet wavelengths.
With a much bigger mirror than Hubble, Webb can peer farther back into time than Hubble as it has a larger light-collecting area.
Webb has over 1200 skilled scientists, engineers and technicians from 14 countries and more than 29 US states with the District of Columbia building it. It is a joint NASA/ESA/CSA mission. The assembly and testing of the mirror and instruments occurred at NASA Goddard.