NASA s Juno spacecraft left Earth on August 5, 2011, to begin its 1.74 billion mile journey to Jupiter, the fifth planet from the sun and the largest in our solar system.
If all goes as planned, Juno will insert itself into Jupiter s orbit late this evening to begin its 20-month study.
If successful, it ll mark the first time a spacecraft has orbited Jupiter in more than a decade.
Juno is also the fastest spacecraft to enter orbit around a planet at 130,000 miles per hour.
That speed is one of the most nail-biting moments of the mission.
In order to enter Jupiter s orbit, Juno will need to fire its main engine for at least 35 minutes to slow the craft down enough for Jupiter s gravitational pull to capture it.