Twin satellites rocketed into orbit Thursday on a quest to explore Earth's treacherous radiation belts and protect the planet from solar outbursts.
NASA launched the science probes before dawn, sending them skyward aboard an unmanned rocket.
"They're now at home in the Van Allen belts where they belong," said Nicola Fox, the deputy project scientist for the Johns Hopkins University Applied Physics Laboratory.
It's the first time two spacecraft are flying in tandem amid the punishing radiation belts of Earth, brimming with highly charged particles capable of wrecking satellites.
These new satellites - shielded with thick aluminum - are designed to withstand an onslaught of cosmic rays for the next two years.
"We're going to a place that other missions try to avoid and we need to live there for two years. That's one of our biggest challenges," said Richard Fitzgerald, project manager for Johns Hopkins.
