MMS Satellites to study fundamental phenomenon of magnetic reconnection

Diagram of MMS spacecraft with communication components identified. 

Credit: NASA

First thing every morning, the engineering team for NASA's Magnetospheric Multiscale mission (MMS) gathers for a 10-minute meeting.

A white board sits at the front of the room with the day's assignments, who will wrap tape around the wires, which instruments need to be installed where, which observatory needs to undergo its next test.

This is the nerve center for the MMS engineers and technicians at NASA's Goddard Space Flight Center in Greenbelt, Md.

Goddard is tasked with an unprecedented feat for the center: building four identical observatories simultaneously.

The four spacecraft will launch together on a single rocket and then maneuver out into a pyramid configuration to orbit Earth.

Mechanical Engineers completed installation of the Solar Array panels for Observatory #4. 

There are eight panels per spacecraft, one enclosing each of the eight bays of the octagonal structure. 

When in orbit, the solar arrays will provide power to the Spacecraft during sunlight phases, while the battery (mounted inside the spacecraft deck) provides power during the 4 hour eclipses.

On its journey, MMS will observe a little-understood, but universal phenomenon called magnetic reconnection, responsible for dramatic re-shaping of the magnetic environment near Earth, often sending intense amounts of energy and fast-moving particles off in a new direction.

Not only is this a fundamental physical process that occurs throughout the universe, it is also one of the drivers of space weather events at Earth.

To truly understand the process, requires four identical spacecraft to track how such reconnection events move across and through any given space.

Building four spacecraft at once has many advantages. It saves on time and mission cost. However, such a massive undertaking requires meticulous logistical planning.

"This is the first time NASA has ever built four satellites simultaneously like this," said Craig Tooley, project manager for MMS at Goddard.

"It feels like we're planning a giant game of musical chairs to produce multiple copies of a spacecraft.

One instrument deck might be 2/3 finished, while another one is 1/3 finished, and the same people will have to test a nearly complete deck one day, and install large components on another one another day."

One of the earliest important feats for this group of engineers and technicians came during the design phase. Each spacecraft must carry, in addition to the navigational and power instruments, 25 scientific instruments.

These had to be carefully laid out so that each instrument had a full range of view and so that the eight booms sticking out from the spacecraft would not interfere with any other instrument's line of sight or electromagnetic systems.