FYI.

This story is over 5 years old.

Tech

After Nine Years in Space, NASA's Pluto Probe Is About to Wake Up

New Horizons won't actually reach the dwarf planet until July, but it has a lot of work to do before then.
​Image: NASA

​Nearly nine years ago, NASA sent its ​New Horizons spacecraft to Pluto. On Saturday, after all that time in transit, it will come out of hibernation for the last time as it finally approaches what was, at the time of the launch, the furthest planet in our solar system.

Throughout the journey, New Horizons has sent weekly pings back to Earth to let the team know it was still alive, as it was in hibernation for most of the trip. Earlier this week, New Horizons sent its last ping ahead of Saturday's wake up.

Advertisement

"Usually, we talk very matter of factly about everything. 'Did we hear the ping? Yes?' and we move on," said deputy project scientist Dr. Leslie Young, who I chatted with on the phone this week.

"But this time there was five or ten minutes of pause," she added, noting the gravity of the occasion. "It's not quite a bittersweet feeling, but already we're nostalgic for the hibernation stage."

Though New Horizons won't reach Pluto until mid-July, it has a lot of work to do in the mean time. For the next six months, the probe will take images and measurements of Pluto, its moons, and the surrounding Kuiper Belt—a collection of icy objects that formed in the early stages of our solar system. Scientist will be looking at the data for clues into how the furthest reaches of our system were formed.

By May, New Horizons will be able to capture closer images of Pluto than any we've ever collected before with the Hubble telescope.

"It will be three months of: 'hey, we've got the best photo of Pluto ever!' and then again the next day, 'hey, we've got the best photo of Pluto ever!'" Young said.

In 2007, ​New Horizons swung around Jupiter to get a little boost from its gravity. As it did, it captured stunning images of the gas giant and its moons, so the shots of Pluto will be hotly anticipated.

A composite photo of Jupiter and its moon Io, taken by New Horizons. Image: ​NASA

As it flies past Pluto this summer, New Horizons will also be able to collect detailed maps and data about the dwarf planet, from its geology to its atmosphere.

Advertisement

The spacecraft is loaded up with equipment: it will take infrared and ultraviolet images, analyze the composition and temperature of the atmosphere, take high resolution images of Pluto's geology, and measure solar wind, plasma, and space dust.

After it swings past Pluto, New Horizons will continue on to one of two large bodies in the Kuiper Belt that NASA has been eyeing up.

On Saturday, New Horizons is set to wake up at 3 PM ET but—and this really demonstrates just how far away Pluto is—the signal indicating the spacecraft has woken up won't reach Earth for four hours, even travelling at the speed of light.

When the mission was launched in 2006, Pluto was the only planet in the solar system that hadn't been explored up close by a spacecraft. Though it's no longer classified as a planet, arriving at Pluto still checks off a major space exploration bucket list item.

For the team who has been anticipating this moment for just shy of a decade, it's exciting and daunting, Young told me.

"It feels like when you're rock climbing and you're rappelling," she said.

"There's that moment when you step off the cliff and transfer your weight from your feet to the rope. You know what you're doing. You know the people who made the rope knew what they were doing. But there's still that moment where you have to hold your breath and take the step."