Flying To New Heights With The Magnetospheric Multiscale Mission

Flying to New Heights With the Magnetospheric Multiscale Mission

A mission studying Earth’s magnetic field by flying four identical spacecraft is headed into new territory. 

The Magnetospheric Multiscale mission, or MMS, has been studying the magnetic field on the side of Earth facing the sun, the day side – but now we’re focusing on something else. On February 9, MMS started the three-month-long process of shifting to a new orbit. 

One key thing MMS studies is magnetic reconnection – a process that occurs when magnetic fields collide and re-align explosively into new positions. The new orbit will allow MMS to study reconnection on the night side of the Earth, farther from the sun.

Magnetic reconnection on the night side of Earth is thought to be responsible for causing the northern and southern lights.  

To study the interesting regions of Earth’s magnetic field on the night side, the four MMS spacecraft are being boosted into an orbit that takes them farther from Earth than ever before. Once it reaches its final orbit, MMS will shatter its previous Guinness World Record for highest altitude fix of a GPS.

To save on fuel, the orbit is slowly adjusted over many weeks. The boost to take each spacecraft to its final orbit will happen during the first week of April.

On April 19, each spacecraft will be boosted again to raise its closest approach to Earth, called perigee. Without this step, the spacecraft would be way too close for comfort – and would actually reenter Earth’s atmosphere next winter! 

The four MMS spacecraft usually fly really close together – only four miles between them – in a special pyramid formation called a tetrahedral, which allows us to examine the magnetic environment in three dimensions.

But during orbit adjustments, the pyramid shape is broken up to make sure the spacecraft have plenty of room to maneuver. Once MMS reaches its new orbit in May, the spacecraft will be realigned into their tetrahedral formation and ready to do more 3D magnetic science.

Learn more about MMS and find out what it’s like to fly a spacecraft.