It's the fourth of July, so it's time to watch things burn. (In a safe, controlled way, please, thank you.) We speak not of fireworks, but of Juno, the NASA spacecraft that will ignite its fuel today at 11:18 pm Eastern to slow down and settle into Jupiter's orbit after five years in space.

If Juno doesn't sync up with Jupiter's gravity on the first try, it will careen off and away. NASA scientists won't get to study Jupiter's auroras or snap photos of its red streaks or learn if the gas giant actually has a secret rocky core. Because of the 49-minute communications delay between Jupiter and Earth, Juno's computer has to plot the course on its own. A lot is riding on those lines of code.

The "orbital insertion maneuver," aka lighting hydrazine fuel on fire, will begin at 11:18 pm Eastern Earth Received Time—as in that's when NASA will have learned about it given the 49 minute communications delay. (NASA's live coverage, which you can watch up top, starts at 10:30 pm Eastern.) There is no friction in empty space, so Juno's only way to brake is to fire its engines and thrust in the opposite direction of travel. Juno has to start braking precisely 2,609 miles away from Jupiter to get into place for all its scientific work.

Thirty-five minutes later at 11:53 pm Eastern, the spacecraft will have (hopefully) slowed down enough to fall into Jupiter's orbit. The spacecraft will be transmitting tones through the process, each tone a signal for a different milestone, including the final "I am in orbit" tone.

Juno has other obstacles though. Jupiter has a powerful magnetic field that traps and accelerates tiny charged particles, basically radiation. Any of these particles could punch through Juno and take out its electronics. So its most important electronic brains are shielded behind a titanium vault. And Juno will travel in an odd-looking oblong orbit around Jupiter to get away from some of the most intense areas of radiation.

If all goes well, Juno will orbit Jupiter 37 times over 20 months. Juno's nine instruments will be snapping and sensing away, and its first closeups of Jupiter will start arriving soon. That'll call for another celebration.