By Dr. Tony Phillips
Congratulations! Youâre an oceanographer and youâve just received a big grant to investigate the Pacific Ocean. Your task: Map the mighty Pacificâs wind and waves, monitor its deep currents, and keep track of continent-sized temperature oscillations that shape weather around the world. Funds are available and you may start immediately.
Oh, thereâs just one problem:Â Youâve got to do this work using no more than one ocean buoy.
âThat would be impossible,â? says Dr. Guan Le of the Goddard Space Flight Center. âThe Pacificâs too big to understand by studying just one location.â?
Yet, for Le and her space scientist colleagues, this was exactly what they have been expected to accomplish in their own studies of Earthâs magnetosphere. The                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                magnetosphere is an âoceanâ? of magnetism and plasma surrounding our planet. Its shores are defined by the outer bounds of Earthâs magnetic field and it contains a bewildering mix of matter-energy waves, electrical currents and plasma oscillations spread across a volume billions of times greater than the Pacific Ocean itself.
âFor many years weâve struggled to understand the magnetosphere using mostly single spacecraft,â? says Le. âTo really make progress, we need many spacecraft spread through the magnetosphere, working together to understand the whole.â?
Enter Space Technology 5.
In March 2006 NASA launched a trio of experimental satellites to see what three âbuoysâ? could accomplish. Because they weighed only 55 lbs. apiece and measured not much larger than a birthday cake, the three ST5 âmicro-satellitesâ? fit onboard a single Pegasus rocket. Above Earthâs atmosphere, the three were flung like Frisbees from the rocketâs body into the magnetosphere by a revolutionary micro-satellite launcher.
Space Technology 5 is a mission of NASAâs New Millennium Program, which tests innovative technologies for use on future space missions. The 90-day flight of ST5 validated several devices crucial to space buoys: miniature magnetometers, high-efficiency solar arrays, and some strange-looking but effective micro-antennas designed from principles of Darwinian evolution. Also, ST5 showed that three satellites could maneuver together as a âconstellation,â? spreading out to measure complex fields and currents.
âST5 was able to measure the motion and thickness of current sheets in the magnetosphere,â? says Le, the missionâs project scientist at Goddard. âThis could not have been done with a single spacecraft, no matter how capable.â?
The ST5 mission is finished but the technology it tested will key future studies of the magnetosphere. Thanks to ST5, hopes Le, lonely buoys will soon be a thing of the past.
Learn more about ST5âs miniaturized technologies at nmp.nasa.gov/st5. Kids (and grownups) can get a better understanding of the artificial evolutionary process used to design ST5âs antennas at spaceplace.nasa.gov/en/kids/st5/emoticon.
This article was provided by the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration.
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Caption:
The Space Technology 5 micro-satellites proved the feasibility of using a constellation of small spacecraft with miniature magnetometers to study Earthâs magnetosphere.