There’s little time left until the New Horizons spacecraft will end its hibernation and come online one last time in order to prepare for its approach to Pluto.This will happen on December 6, this Saturday, but the contact with the planet will only happen next year in July.
New Horizons has left Earth nine years ago and has had 18 hibernations during the 3 billion mile trek towards the dwarf planet. The reason behind these offline periods was to reduce deterioration to the electronics onboard and to lower NASA’s operational costs. In this way, the agency is able to distribute funding to other missions. Only the flight computer remains up in order to monitor the system’s health and also to broadcast weekly status reports back to Earth. Other than that, the New Horizons spacecraft remains unpowered. Since New Horizons’s departure, the space probe has “slept” 1,873 days. According to John Hopkins University Applied Physics Laboratory, this would mean about two- thirds of its flight time. When it did wake up (about 2 times per year) it was to calibrate instruments, gather data and to correct the course if it came to that.
The wake-up call was preprogrammed in New Horizons in August and on Saturday at 3 p.m EST the spacecraft will be back online. Word of its activity will come through 90 minutes later. After that it would take another 4 hours and 25 minutes before the signal reaches Earth. So, basically we won’t know for sure if New Horizons woke up until 9:30 p.m EST. From that point, New Horizons will have another 162 million miles before it reaches Pluto. When New Horizons arrives, it will begin collecting data that deals with the planet’s topography and geology. Not only Pluto but also its large moon, Charon. Besides these duties, it will also search for new moons and rings. After this is all over, we’ll have the most detailed mapping of Pluto to date.