The successor to the Hubble Observatory has reached an important milestone in its construction.
All elements of the James Webb Space Telescope (JWST) were merged for the first time.
This will create the conditions for some critical tests that will hopefully launch into orbit in 2021.
JWST will use a huge mirror and state-of-the-art instruments to see the glow of the very first stars in the universe.
It will also have the power to dissolve the atmospheres of many new planets discovered beyond our solar system, and to analyze their atmospheres for their living potential.
The telescope is a joint project of the American (NASA), European (ESA) and Canadian (CSA) Space Agency.
One can imagine three main parts – a telescope (mirrors and instruments); a large sunshade shading the delicate view of the sky; and a spaceship unit that controls the daily operation of the observatory in orbit.
These three segments were finally screwed together in a Los Angeles factory owned by prime contractor Northrop Grumman.
All components JWST products have been tested repeatedly, both on an individual and integrated level.
This test cycle will now continue because the three main segments are interconnected.
An important test is the demonstration that Webb can fully extend the sunscreen.
This tennis court size parasol consists of five extremely thin layers of kapton insulating film. His task is to completely overshadow the mirrors and four instruments in the observation of the cosmos. Stray light from our sun would otherwise heat surfaces and flood the weak infrared radiation from distant galaxies.
However, to be effective, the shield must be properly extended without kinks or cracks.
"This is an exciting time to see how all the Webb parts were put together for the first time in a single observatory." Gregory Robinson, the Webb program director at NASA headquarters in Washington, DC.
"The engineering team has taken a big step forward and soon we will be able to see incredible new views of our amazing universe."
Anyone who has followed the story of JWST knows it's late – very late, more than a decade.
The project also went well beyond the budget. The cost of construction, deployment and five years of operation is estimated at approximately $ 10 billion. But this is an endeavor that astronomers fully expect to be a revelation.
For example, the current Hubble telescope is limited to how deep it can see into space – and therefore how far back in time. Its 2.4-meter-wide mirror can not collect enough photons, and its instruments are not sensitive to the right part of the electromagnetic spectrum to study the era of first star formation-more than 13.5 billion years ago.
JWST In contrast, it has a 6.5-meter-wide mirror that is seven times the size of Hubble's light collection area, and its infrared-tuned instruments are perfectly tuned to capture the light from these founding stars.