Key Milestones After Liftoff

Both immediately after launch and over the following weeks, the James Webb Space telescope will pass through numerous milestones on its journey of approximately 1 million miles to its final orbit around the second Lagrange point, commonly known as L2.

NASA has a detailed plan to deploy the Webb Space Telescope over a roughly two-week period. For details on any particular milestone – or to get updates on how far along Webb is in the process – please read about the deployments here. You may also watch a visualization.

The process involves hundreds of individual deployments. It is not an automatic, hands-off sequence; it is human-controlled. This means that the order, location, timing, and duration of deployments may change. However, the default order and approximate timing is as follows:

First hour:
Liftoff
~9 minutes: main stage separation
~27 minutes: upper stage separation
~33 minutes: solar array deployed

First Day
~12.5 hours: Midcourse correction burn (MCC1a)
~1 day: Release and motion test of the gimbaled antenna assembly

. . . and on
2 days: Midcourse correction burn (MCC1 b)
3 days: Forward sunshield pallet deployment
3 days: Aft sunshield pallet deployment
4 days: Deployable tower assembly
5 days: Aft momentum flap
5 days: Sunshield covers release
6 days: Sunshield port mid-boom and sunshield starboard mid-boom
7 days: Sunshield layer tensioning begins
8 days: Sunshield layer tensioning complete
10 days: Secondary mirror deployment begins and is completed
11 days: Aft Deployed Instrument Radiator
12 days: Port primary mirror wing deployment begins and is completed
13 days: Starboard primary mirror wing deployment begins and is completed
13 days: Webb is fully deployed
15-24 days: Individual mirror segment movements
29 days: Midcourse correction burn (MCC2)/L2 insertion burn
29.5 days: Orbit insertion complete