It took more than a year for New Horizons to send back the 50-plus gigabits of data collected around the time the spacecraft zipped by Pluto and its five moons on July 14, 2015.
The data downlinks came down at an average of about 2,000 bits per second a fraction of the speed of a dial-up Internet connection and were interrupted as the spacecraft conducted maneuvers and as ground antennas were needed by other deep space missions.
The long wait for scientists was part of the plan, as officials knew the data stored aboard the probe’s recorders could only come back to Earth a little at a time.
The final data fragment from the LEISA spectral camera within New Horizons’ Ralph instrument arrived at mission control at the Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland, at 5:48 a.m. EDT (0948 GMT) Tuesday. The downlink came via an antenna at NASA’s Deep Space Network station in Canberra, Australia, NASA said in a statement Thursday.
It took five hours and eight minutes for the data stream to travel the 3.4-billion-mile (5.5-billion-kilometer) gulf from New Horizons to Earth.
Mission controllers will conduct a final data verification review before erasing the two data recorders aboard New Horizons, clearing room for future science observations from the spacecraft’s extended mission, which includes a close encounter with the Kuiper Belt object 2014 MU69.
The next target for New Horizons measures just 13 to 25 miles (21 to 40 kilometers) across, and experts believe 2014 MU69 is a relic building block from left over from the ancient solar system.
New Horizons will fly by the tiny world on Jan. 1, 2019, at a distance of about 1,900 miles (3,000 kilometers) during an extended mission phase approved by NASA earlier this year.