New Horizons completes marathon Pluto data transfer
NASA's Deep Space Network (DSN) has received the final piece of data collected by the agency's New Horizons probe during its encounter with the dwarf planet Pluto, which took place July 14, 2015. Data from the New Horizons mission has revolutionized our understanding of Pluto, revealing the planetoid to be a surprisingly dynamic and active member of our solar system.
Unlike NASA's Dawn mission, which has now spent over a year exploring the dwarf planet Ceres, New Horizons never made orbit around its target. Instead, the probe had only a brief window in which to harvest as much information as possible, before barreling past Pluto into the outer reaches of our solar system.
During the pass, New Horizons' meager power supply of only 200 watts ran a sophisticated suite of seven scientific instruments, which worked to collect over 50 gigabits of data. This information was safely stored in two solid-state digital recorders that form part of the probe's command and data-handling system.
Sending this data back to Earth would prove to be a lesson in patience. New Horizons began transmitting the stored data in September 2015 at a rate of around seven megabits per hour. The information was received back on Earth by NASA's Deep Space Network (DSN).
The transmission was not continuous. The natural spin of the Earth necessitated New Horizons to transmit data in eight hour stints when the DSN was available, resulting in a transfer rate of around 173 megabits per day.
Furthermore, the New Horizons team had to share the capabilities of the DSN with other exploration endeavors such as the Dawn mission, further frustrating the data transmission rate.
However, slow and steady wins the race, and at 5:48 a.m. EDT on the 25th of October, over a year after beginning the process, the DSN station located in Canberra, Australia, relayed the final piece of Pluto data from New Horizons to the probe's mission operations center at the Johns Hopkins Applied Physics Laboratory in Maryland.
The last data transmission contained part of an observation sequence of Pluto and its large moon Charon, as captured by the spacecraft's Ralph/LEISA imager.
"The Pluto system data that New Horizons collected has amazed us over and over again with the beauty and complexity of Pluto and its system of moons," comments Alan Stern, New Horizons principal investigator from Southwest Research Institute in Boulder, Colorado. "There's a great deal of work ahead for us to understand the 400-plus scientific observations that have all been sent to Earth. And that's exactly what we're going to do –after all, who knows when the next data from a spacecraft visiting Pluto will be sent?"