The encounter with Pluto itself will be broken into phases that begin on Jan. 6, 2015, says Young.
“Approach Phase 1, where we're just beginning our science, mostly doing optical navigation,” she says. “Approach Phase 2 [April 4-June 23, 2015] we begin to pass Hubble resolution and our science picks up. Approach Phase 3 is when we start to do our more exciting science in our last few rotations before closest approach. All of our [priority] required science objectives are taking in the near-encounter phase, just a day before and a day after encounter, and then as we leave on the departure phase, things slow down.”
Stern says the team is “really looking forward to knocking people's socks off” with “several hundred scientific activities” in the final week before closest encounter and “several hundred more” in the closest two days. Surface imagery with resolution comparable to the Voyager images of Triton are likely, and maps of frost on Pluto's far side are possible.
“The data sets that are going to come down from New Horizons are absolutely mouth-watering,” says Stern, who helped overcome opposition from then-NASA Administrator Sean O'Keefe to send the mission on its way. “Because of the diversity and sophistication of the instruments in this payload, there really hasn't been anything like this in the entire history of planetary exploration for a first encounter. . . . We will exceed Hubble resolution not for a week or two, but from April to October. We will image every one of Pluto's satellites and Pluto itself. We will make compositional maps of Pluto and Charon and Nix, and unresolved compositional information on the other three known satellites. We will map certain temperature fields. We'll measure Pluto's [atmospheric] escape rate. We'll determine its temperature and pressure structure as a function of altitude; we'll address interior models and do many, many other things relating to the satellites, the system and the environment.”