The NASA spacecraft Juno successfully entered Jupiter’s orbit Monday, marking the a huge achievement in a five-year and $1.8 billion journey to investigate the largest planet in our solar system. Juno had to pull off a do-or-die engine burn to successfully loop into the planet’s orbit, prompting applause among NASA ground controllers when mission control announced that the maneuver was a success. “Success! Engine burn complete. #Juno is now orbiting #Jupiter, poised to unlock the planet’s secrets,” NASA announced on Twitter shortly after midnight. Juno will now spend 20 months exploring the planet as part of the mission, which seeks to map the interior of the giant planet and discover how it developed.