When a delivery truck drops off its final package of the day, it isn’t abandoned – it’s prepped for more deliveries the next day. And it’s the same thing with several spacecraft. After delivering their main cargo, they’ve been given new missions – new addresses to check out.

The list has included three craft that delivered samples to Earth – bits of two asteroids, and some dust from a comet. The craft dropped capsules containing the samples into Earth’s atmosphere as they flew by. And another craft fired a cannonball into a comet.

After finishing their main missions, the spacecraft were still working. So they were given new missions. One of them is headed for a rendezvous with the asteroid Apophis, which will skim just above Earth in 2029. Another is headed for a comet.

Along the way, some of the missions have turned their cameras toward star systems with known planets. The craft can stare at a system for days or weeks. That allows them to measure tiny dips in a star’s light as a planet passes in front of it. Astronomers piece that together with information from other sources to refine a planet’s dossier – its size, mass, distance from its star, and more. One craft even found evidence of a second planet in a system, although it hasn’t been confirmed.

So even though some of these missions have long since dropped off their packages, they’re still delivering important discoveries about the universe.

Script by Damond Benningfield