NASA is one large step closer to putting the James Webb Space Telescope into service. The agency has successfully deployed the JWST's signature gold-coated primary mirror, completing all major deployments for the instrument. The mission crew still has to align the telescope's optics by moving the primary mirror's segments (a months-long process), but it's a strong sign the $10 billion device is in good shape.

The JWST also requires a third course correction burn as it heads toward the L2 Lagrange point over 930,000 miles from Earth. Astronomers will use the point to study infrared light without interference, potentially offering insights into the early Universe that aren't possible with Hubble and other equipment.

First images from the telescope won't be available until the summer, and it could take much longer before those images translate to meaningful discoveries. Even so, the deployment is an achievement. JWST represents the first time NASA has unpacked a complex observatory in space — it shows projects like this are viable, even if they're unlikely to be commonplace in the near future.