The James Webb Space Telescope (JWST) successfully unfurled its sunshield on Friday, in another milestone for the groundbreaking project.
The $10 billion observatory now resembles its full, kite-shaped form in space, following the extension of Webb's second sunshield mid-boom arm.
The intricate process was completed in less than four hours, with each of the 107 membrane release devices associated with the sunshield deployment released.
The telescope has 178 of the "non-explosive actuators" in total and 107 were used to keep the sunshield safe and folded before deployment.
The motor-driven mid-booms pulled the folded membranes of the sunshield, extending it to its full 47-foot width.
The deployments took longer than anticipated, NASA said, due to the operations team moving forward with caution.
"Today is an example of why we continue to say that we don’t think our deployment schedule might change, but that we expect it to change," Keith Parrish, Webb observatory manager at NASA’s Goddard Space Flight Center, said in a statement. "The team did what we had rehearsed for this kind of situation – stop, assess, and move forward methodically with a plan. We still have a long way to go with this whole deployment process."
Now, the two mid-booms are locked and will hold the sunshield membranes as the Webb team turns to the final stage of deployment.
Work on the deployment of the sunshield mid-booms stretched late into the evening and Webb mission management decided to pause deployment activities for Saturday.
Webb's sunshield tensioning will begin on Sunday and take place over at least two days.
The team will separate and individually tension each of the five sunshield layers, stretching them into their final shape.
This act will create space between the membranes to allow heat to radiate out.
"Webb’s engineers will begin with the bottom layer – the largest and flattest layer, which is closest to the sun and will reach the highest temperatures. They will proceed sequentially to the fifth and smallest layer, closest to the primary mirror. Tensioning the layers involves sending commands to activate several motors to reel in a total of 90 cables through numerous pulleys and cable management devices," the agency explained. "Sunshield tensioning will take at least two days but may take longer, due to the complexity of the process and the flexibility built into the timeline."
After tensioning, the secondary mirror will be deployed and locking Webb's mirrors into their proper positions will bring its deployment phase to a close.
The JWST launched on Christmas and will "explore every phase of cosmic history," according to NASA.