In a little over 173 days, on July 4, NASA’s Juno spacecraft will arrive at its destination: Jupiter. There, the spacecraft will orbit the world 33 times, getting within 3,100 miles of the planet’s storming clouds. What may be learned is left to be seen, but Juno reached a different milestone on Wednesday, Jan. 13.
At 11 a.m.—Pacific Standard Time—Juno nabbed the title of farthest distance traveled by a solar-powered spacecraft, travelling a whopping 493 million miles from the sun.
The new record outdistances the 492 million miles traveled by the European Space Agency’s Rosetta spacecraft, which was achieved in October 2012.
According to NASA, Juno and Rosetta are the only solar-powered spacecraft to operate beyond the asteroid belt.
Each of Juno’s solar arrays are 261 square feet, and there are around 19,000 solar cells spanning the three arrays. When at Earth distance from the sun, Juno’s solar arrays can generate around 14 kW of electricity. During its orbit around Jupiter, they’ll generate around 500 W. Operating at full-potential, the solar arrays can convert 28% of sunlight into power.
NASA’s history with solar-powered spacecraft dates back to the late 1950s. On March 17, 1958—St. Patrick’s Day—the agency launched the Vanguard 1 from Cape Canaveral. It was the world’s first solar-powered satellite, and the second U.S. satellite flung into orbit. Though its battery-powered transmitter gave out in June 1958, its solar-powered transmitter remained operational until May 1964. The spherical satellite was only 16.5 cm in diameter, whereas the Juno is 66 ft.
At its maximum distance, Juno will be around 517 million miles from the sun.
“It is cool we got the record and that our dedicated team of engineers and scientists can chalk up another first in space exploration,” said Juno’s principal investigator Scott Bolton. “But the best is yet to come. We are achieving these records and venturing so far out for a reason—to better understand the biggest world in our solar system and thereby better understand where we came from.”
Specifically, Juno aims to discover how much water is in Jupiter’s atmosphere; what Jupiter’s atmospheric composition is like; and map the planet’s magnetic and gravity fields, among other tasks.