Pluto bound - NASA's New Horizons spacecraft. Credit: NASA/APL
Launched in January 2006, the NASA New Horizons mission to distant Pluto is on target to whisk by that faraway world in July 2015.
New news from the New Horizons team: Unless significant new hazards are found, the spacecraft is set to stay on its original course past Pluto and its moons.
That’s the call of mission managers after they concluded that the danger posed by dust and debris in the Pluto system is less than they once feared.
The New Horizons team recently completed an 18-month study of potential impact hazards – mostly dust created by objects hitting Pluto’s small satellites – the spacecraft would face as it speeds some 30,000 miles per hour (more than 48,000 kilometers per hour) past Pluto in July 2015.
Alternate plans
The project team expects to keep New Horizons on this baseline course, which includes a close approach of about 12,500 kilometers (nearly 7,800 miles) from the surface of Pluto.
Still, two alternative timelines, in the event that the impact risk turns out to be greater than the team expects, have been blueprinted.
Those alternate plans (called SHBOTs, short for Safe Haven by Other Trajectories) are being developed should new information – gathered from New Horizons camera observations during the approach to Pluto, for example, or new dust-dynamics analyses – indicate less-than-smooth sailing for New Horizons.
Encounter rehearsal
New Horizons Principal Investigator Alan Stern, of the Southwest Research Institute, says the mission team is now finalizing plans for the Pluto encounter.
In early July, the team will rehearse the most critical nine-day segment of the baseline encounter plan, putting itself and the spacecraft through the paces of the flight toward and just past Pluto and its moons.
New Horizons is the first mission to Pluto and the Kuiper Belt of rocky, icy objects beyond.
The nuclear-powered spacecraft crossed the orbits of Saturn (June 8, 2008) and Uranus (March 18, 2011), with Neptune coming up in August 2014.
Johns Hopkins University Applied Physics Laboratory (APL), builder of the New Horizons spacecraft, also provides mission management, development and spacecraft operations.
By Leonard David