Ahead of its launch next year, James Webb is currently in the midst of an exhaustive series of tests to make sure that it will work properly once it gets up there. After all, it's a bit tricky to send a mechanic 1.5 million km to take a look if something goes wrong.

The latest of these tests focused on making sure the spacecraft's mirrors unfold in the right way. At an impressive 6.5 m (21.3 ft) wide, Webb has the largest mirror ever launched into space, so to fit in the rocket fairing for launch it needs to tuck its wings in. Only once it's safely in space will it stretch out to full size.

In early March, NASA conducted a full test of this deployment system. Using the internal electronics system, the two side mirror arrays were unfolded to form the full mirror surface. Of course, here on Earth is a very different environment than in space, so for this test special equipment had to be suspended from the ceiling to support the weight of those wings as they moved. When it's actually go-time, none of that will be needed, since gravity won't be a factor.