The telescope will be the successor to Hubble, and it includes a five-layer sunshield which blocks infrared light from the sun to keep the delicate components cool. The sunshield was already integrated with the spacecraft that will launch the project, and the telescope itself had to be lifted onto to this combination using a crane. Engineers aligned and secured the two halves together to complete the mechanical connection.

Next, the engineers must electrically connect the two halves and test the electrical connections before unfurling the sunshield and performing environmental and deployment testing.

"This is an exciting time to now see all Webb's parts finally joined together into a single observatory for the very first time," said Gregory Robinson, the Webb program director at NASA Headquarters. "The engineering team has accomplished a huge step forward and soon we will be able to see incredible new views of our amazing universe."

Launch is scheduled for 2021, when the telescope will investigate celestial bodies from our solar system but also those in distant galaxies.