It wasn’t two weeks ago when NASA publicly announced an agreement with a civilian group known as the ISEE-3 Reboot Project that would allow them to take control of the small space probe, abandoned since 1997. Well, according to the group, they’ve done it despite the long odds of success. Now comes the hard part: Acting within an extremely limited window of time to guide the craft back into a near-Earth orbit.

The team will have to act fast. The Atlantic reports that they must figure out how to properly fire ISEE-3’s rockets by June 17, lest they miss their chance to positively influence its path. As ISEE-3 nears both the Earth and moon, their gravitational forces mean that the probe’s finite amount of rocket energy will count for less and less over time, so the timing is crucial. June 17 is the inflection point – the point at which ISEE-3’s rockets won’t have enough energy to affect its trajectory at all.

They’re trying to avoid two (admittedly unlikely) scenarios: Because ISEE-3 isn’t quite on its originally programmed trajectory, there’s a small chance it might crash into the moon as it makes a pass on August 10. The other possibility is that it comes too close to Earth, likely getting destroyed upon re-entry. It will take very precise action to escape either.

The last hurdle for ISEE-3 is passing behind the moon, where it will not receive the solar rays it needs for power (its batter has long since expired). Though its lost power before, Reboot Project members fear that its decaying electrical system might prevent it from turning on again. Once it clears that obstacle, though, it’s smoother sailing. The only thing left will be to determine where they want to send it – an orbit point near Earth could yield interesting data, as could “throwing it” at another comet in 2018.

Stay tuned to the ISEE-3 Reboot Project’s webpage for updates.