New York: After a journey of more than five years, US space agency NASA's Juno spaceship is set to reach its final destination Jupiter and begin its orbit around the largest planet in our solar system. According to NASA's Jet Propulsion Laboratory (JPL), the probe will fire its main engine, beginning a 35-minute burn at 0318 GMT on the evening of July 4 to be captured by Jupiter' s gravity and go into the desired orbit, Xinhua reported. "We are ready," Scott Bolton, principal investigator of Juno from the Southwest Research Institute in San Antonio. "The engineers and mission controllers are performing at an Olympic level getting Juno successfully into orbit," he said in a statement on Saturday. After the main engine burn, Juno will be in orbit around Jupiter. The spacecraft will spin down from 5 to 2 RPM, turn back toward the sun and ultimately transmit telemetry via its high-gain antenna. On Sunday, the solar-powered spacecraft crossed the orbit of Callisto, the outermost Galilean moon. The orbits of Ganymede, Europa and IO will be crossed on Monday. These four largest moons of Jupiter are named the Galilean moons because they were discovered by Galileo Galilei in 1609. Assuming all goes smoothly, the 1.1 billion US dollars mission will provide a lot answers to questions about Jupiter and help reveal a lot about the other planets in our solar system, including Earth.