Close-Flying Satellites Set Record While Investigating Solar Storms

Illustration for article titled Close-Flying Satellites Set Record While Investigating Solar Storms

The quartet of spacecraft tasked with monitoring space weather are now in a tiny pyramid of satellites flying in a tighter formation than ever attempted before.


The Magnetospheric Multiscale mission (MMS) is a NASA project to measure magnetic reconnection, which will in turn hopefully lead to better prediction of solar storms. The satellites are in a tight tetrahedral constellation, each satellite at the triangle of a four-sided pyramid. The satellites are just 9.6 kilometers (6 miles) apart, closer than any satellites have ever flow before in a stable constellation. To be even more impressive, the satellites have their booms fully extended, each taking up the same area as a baseball stadium while doing this fancy flying at a staggering 24,140 kilometers per hour (15,000 miles per hour).

The Earth’s magnetic field under bombardment on July 15 to 16, 2012 with several magnetic reconnection events. Gif extracted from video byNASA/CCMC/Bridgman

The Magnetospheric Multiscale satellites fly in a tetrahedron in order to record variations in the Earth’s magnetosphere in three dimensions as it changes over time. The ambition is to measure magnetic reconnection, how the Earth’s magnetic field connects and disconnects and the subsequent explosion of high-energy particles. While these particles can put on gorgeous lightshows as colourful aurora, the electromagnetic storms can also be dangerous to vulnerable electrical systems.

Stylized concept art of magnetic reconnection, when misaligned magnetic field lines come in contact and explosively realign. Image credit: NASA/Goddard/Duberstein


The mission launched in March 2015, moved into the tetrahedral formation in July, and completed instrument checkout and commissioning on August 31st. The satellites have been moving progressively closer together; now they’re at the tightest formation it’s time for mission scientists to decide what the optimal spacing is to record magnetic reconnection events.


Image credits: NASA

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I remember reading somewhere that there was a plan to use space probes flying in formation to test for gravity waves—essentially very, very, very, very long baseline interferometry. Is that still true?