1 00:00:00,020 --> 00:00:04,030 2 00:00:04,050 --> 00:00:08,080 3 00:00:08,100 --> 00:00:12,110 Hi, I'm John Dorelli. I'm a space scientist at NASA's Goddard Space Flight Center. 4 00:00:12,130 --> 00:00:16,140 I'd like to tell you a little bit about NASA's MMS mission. 5 00:00:16,160 --> 00:00:20,230 MMS was designed to study a phenomenon known as magnetic reconnection, 6 00:00:20,250 --> 00:00:24,240 which is kind of a magnetic explosion in space. You can think of 7 00:00:24,260 --> 00:00:28,270 Earth as a giant bar magnet with magnetic lines of force emanating out into 8 00:00:28,290 --> 00:00:32,340 space in a dipole pattern. Under just the right conditions, energy 9 00:00:32,360 --> 00:00:36,350 in this magnetic field is explosively converted into plasma energy, creating 10 00:00:36,370 --> 00:00:40,380 spectacular space weather phenomenon like the aurora and magnetic storms. 11 00:00:40,400 --> 00:00:44,490 To catch these explosions in action, the MMS orbits were designed 12 00:00:44,510 --> 00:00:48,520 in two phases: a day-side phase, and a night-side phase. 13 00:00:48,540 --> 00:00:52,550 MMS is actually four identical spacecraft flying in a geometrical formation 14 00:00:52,570 --> 00:00:56,620 known as a tetrahedron. Scientists hope to capture the magnetic explosions 15 00:00:56,640 --> 00:01:00,660 somewhere inside this tetrahedron. At closest approach to Earth, the 16 00:01:00,680 --> 00:01:04,670 tetrahedron is highly stretched, and not suitable for capturing the magnetic explosions. 17 00:01:04,690 --> 00:01:08,760 But by the time we get out to 76,000 kilometers, MMS will be 18 00:01:08,780 --> 00:01:12,780 in nearly perfect formation, the four spacecraft separated by only 19 00:01:12,800 --> 00:01:16,970 ten kilometers. The Sun is constantly blowing out its atmosphere 20 00:01:16,990 --> 00:01:21,020 into space, and this solar wind meets Earth's magnetic field at the magnetopause. 21 00:01:21,040 --> 00:01:25,050 Here, at the magnetopause, scientists expect to catch magnetic reconnection in action. 22 00:01:25,070 --> 00:01:29,060 So the apogee of the orbit is designed so that the tetrahedron 23 00:01:29,080 --> 00:01:33,080 cuts across the boundary twice per orbit while in perfect formation. 24 00:01:33,100 --> 00:01:37,100 As it crosses the magnetopause, MMS will take 25 00:01:37,120 --> 00:01:41,160 high-speed snapshots of the magnetic explosions as they unfold. 26 00:01:41,180 --> 00:01:45,170 27 00:01:45,190 --> 00:01:49,210 [ whoosh ] [beep beep... beep beep... beep beep...] 28 00:01:49,230 --> 00:01:53,260 [ beep beep... beep beep... beep beep... ] 29 00:01:53,280 --> 00:01:56,263