Are we there yet?
One of the fastest spacecraft ever built — NASA’s New Horizons — is hurtling through the void at nearly one million miles per day. Launched in 2006, it has been in flight longer than some missions last, and it is nearing its destination: Pluto.
“The encounter begins next January,” says Alan Stern, of the Southwest Research Institute and the mission’s principal investigator. “We’re less than a year away.”
Closest approach is scheduled for July 2015 when New Horizons flies only 10,000 km from Pluto, but the spacecraft will be busy long before that date. The first step, in January 2015, is an intensive campaign of photography by the Long Range Reconnaissance Imager or “LORRI.” This will help mission controllers pinpoint Pluto’s location, which is uncertain by a few thousand kilometers.
“LORRI will photograph the planet against known background star fields,” explains Stern. “We’ll use the images to refine Pluto’s distance from the spacecraft, and then fire the engines to make any necessary corrections.”
At first, Pluto and its large moon Charon will be little more than distant pinpricks-“a couple of fat pixels,” says Stern–but soon they will swell into full-fledged worlds.
By late April 2015, the approaching spacecraft will be taking pictures of Pluto that surpass the best images from Hubble. By closest approach in July 2015, a whole new world will open up to the spacecraft’s cameras. If New Horizons flew over Earth at the same altitude, it could see individual buildings and their shapes.