Early yesterday morning this was the predawn sight in northern Alaska: a NASA rocket launching straight into an aurora. And the feeling on the ground was one of relief. With luck, the mission will tell researchers more about the particles and electric fields that combine to produce one of nature's most spectacular sights. The rocket is part of the Ground-to-Rocket Electrodynamics–Electron Correlative Experiment, or GREECE, mission. The mission seeks to understand what combination of events set up "auroral curls" – swirling structures within aurorae. The rocket – launched on March 3, 2014 at 6:09 a.m. EST from Poker Flat, Alaska – is a so-called sounding rocket. Sounding rockets are useful for low-cost missions, NASA explains
Sounding rockets carry scientific instruments into space along a parabolic trajectory. Their overall time in space is brief, typically 5-20 minutes, and at lower vehicle speeds for a well-placed scientific experiment. The short time and low vehicle speeds are more than adequate (in some cases they are ideal) to carry out a successful scientific experiments. Furthermore, there are some important regions of space that are too low for satellites and thus sounding rockets provide the only platforms that can carry out measurements in these regions.
Second Time's a Charm
Researchers had set up shop at Poker Flat once before to try to capture the aurora, between January 24 and February 6, but the right kind of auroras didn't come along. Luckily yesterday's auroral activity came just in time – the study's second window was February 24 to March 8, 2014. The researchers were looking for curls in the aurora that look like cream swirling in a cup of coffee. When they spotted those conditions, they launched the rocket on a 10-minute flight right into the heart of the aurora. “The conditions were optimal,” said Marilia Samara
Image credit: NASA/Christopher Perry