On Friday, NASA’s Dawn rocket entered orbit around Ceres to solve some of its mysteries. It’s the first mission to visit a dwarf planet, also the first time a spacecraft has circled two distinctive alien bodies amid its goal. Dawn recently spent 14 months at Vesta, the biggest asteroid in the belt between Mars and Jupiter, and is currently settled in for a long haul stay with Ceres, its last stop.
By contrasting the asteroid and the dwarf planet, NASA researchers want to find out about the formation of every object in the asteroid belt, the advancement of Ceres and the history of the whole solar system.
Joe Makowski, Dawn’s project supervisor at Orbital ATK, clarified that Ceres’ water is the thing that makes it so critical to study. “The first body that we visited, Vesta, was what we expected — very dry, basically rocky and heavily cratered, and probably pretty much intact in that fashion for billions of years,” he said.
“Ceres is in the same asteroid belt, but it’s very different. It’s very large — almost twice the diameter of Vesta — and it contains a lot of water,” Mr. Makowski said. “Visiting both will enable us to understand why one ended up so dry and one has so much water, and in turn how they developed and why they’re so different.”
Dawn will be on the dark side of the planet for around a month. It will take its next set of photographs April 10 and will begin its first intensive science observations on April 23.
Friday morning’s orbital entry was really tame, as space missions go. It was not like the landing of the Rosetta orbiter’s Philae probe on a comet the previous fall, when engineers and researchers were truly on the edge of their seats, waiting to discover whether the mission was a win.
Marc Rayman, Dawn’s chief engineer, said the spacecraft wouldn’t elicit much nail-biting from its creators. “This is going to be a typical day on Dawn for people. When a conventional spacecraft enters an orbit, it has to execute this big whiplash-inducing, bone-rattling maneuver to drop in,” he explained. In any case the ion propulsion system and exact mobility that made Dawn’s two-visit mission conceivable implies that it has more than one shot.
“If for some reason there’s a glitch” Friday, Mr. Rayman said, “a cosmic ray or just bad luck, and it doesn’t go into orbit, that’s okay. We’ll just restore it to normal operations and go into orbit some other day.”
NASA said the spacecraft was captured by Ceres’ gravity around 7:39 a.m. EST, when Dawn was more or less 38,000 miles out.
Dawn, which was designed and constructed by Orbital ATK of Dulles, Va., in organization with NASA’s Jet Propulsion Laboratory, has an extraordinary propulsion system. Its mission is the first to depend on ion propulsion, an innovation that was effectively tried on the Deep Space 1 mission in 1998. Propelled in 2007, Dawn has utilized only 10 percent of the fuel that a shuttle with a customary ignition motor would utilize. “It’s like having a car that gets 300 miles per gallon,” Mr. Rayman said.
Researchers are amped up for the confirmation of liquid water also about those brilliant recognize bright spots, the two reflective patches that have appeared amidst one of Ceres’ craters. “ I don’t think it’s possible to look at those without thinking of shining beacons, calling out to us as travelers on the cosmic seas,” he said.