Scientists launch 'CubeSats' into radiation belts

The twin FIREBIRD CubeSats. 

Credit: MSU Space Science and Engineering Laboratory.

Twin, pintsized satellites built in part at the University of New Hampshire's Space Science Center by UNH graduate student Alex Crew were launched into orbit from Vandenberg Air Force Base in California just before midnight on December 5, 2013.

The two 4x4x6-inch Focused Investigations of Relativistic Electron Burst Intensity, Range, and Dynamics (FIREBIRD) satellites will now brave a region of space 400 miles above Earth, where they have begun probing a mysterious physical process within our planet's dangerous radiation belts.

That process, known as microbursts, involves electrons moving at nearly the speed of light during short-duration (100 milliseconds) events.

Microbursts are thought to be one of the primary mechanisms by which the outer radiation belt loses energetic particles to Earth's atmosphere after the occurrence of powerful solar storms.

Such storms can dramatically change the intensity of the radiation belts.

Alex Crew holds FIREBIRD's full-size engineering unit, which contains twin particle detectors. 

The boxy structure to Crew's left is a copy of the miniscule FIREBIRD spacecraft.

Photo by David Sims, UNH-EOS.

"We care about this because the belts' high-energy particles, particularly the electrons, pose a real risk to spacecraft," says Crew, who worked on FIREBIRD for over three years to recently earn his Ph.D.

"So if we understand these physical processes better, we'll be able to predict how the radiation belts will behave and both protect the satellites we depend upon for telecommunications, weather monitoring and prediction, etcetera, and design them to withstand this high-energy radiation," Crew adds.

FIREBIRD was among ten other CubeSats that shared a ride into space on a rocket dedicated to a larger mission - in this case, an Atlas 5 rocket launching a payload for the U.S. National Reconnaissance Office (NRO).

Such ridesharing is standard operating procedure for a program designed to put small, low-cost satellites into space much more quickly than typical satellite missions.

The little satellites are placed into a compartment known as a Poly Picosatellite Orbital Deployer, P-POD for short, and jettisoned from the rocket at the proper orbital height above Earth.

FIREBIRD was the first to be deployed and is the first CubeSat mission UNH scientists have been involved with.

Funded by the National Science Foundation (NSF), the CubeSat program is launching a new generation of tiny satellites outfitted with modern, smart-phone-like electronics and miniaturized scientific instruments to study highly focused science questions and go where bigger, more costly and complex satellite missions cannot.



"The tiny Firebird CubeSats are poised for big science discoveries, providing first-of-a-kind, multi-point observations of microbursts that will help answer crucial questions about radiation belt dynamics and processes," says Therese Moretto Jorgensen, program director in the NSF Division of Atmospheric and Geospace Science.

California Polytechnic State and Stanford universities first developed the CubeSat specifications in an effort to help universities worldwide perform space science and exploration, and NSF's program is providing students and young professionals with the opportunity to participate as never before in satellite missions end-to-end.

Crew's advisor and UNH mission lead scientist for FIREBIRD is astrophysicist Harlan Spence, director of the Institute for the Study of Earth, Oceans, and Space.

Says Spence, "In contrast to typical satellite missions, which can take over a decade from conception to launch, the CubeSat program provides invaluable opportunities for scholars like Alex to experience a complete spacecraft mission and to conduct high-quality scientific research as a graduate student."

UNH and collaborators have already been funded for the follow-up FIREBIRD II mission slated for launch in October 2014.

More information: For more information on the FIREBIRD mission, visit: firebird.unh.edu

NASA Van Allen Probes: Mysteries of Earth's radiation belts uncovered

The twin Van Allen Probes were launched on August 30, 2012 into elliptical, near-equatorial orbits around the Earth. 

Remarkably, rather than seeing just the well-known two-belt structure, the mission found almost immediate evidence of the clear three-belt structure portrayed in green in this diagram. 

Image courtesy of Andy Kale, University of Alberta.

Just over a year since launch, NASA's Van Allen Probes mission continues to unravel longstanding mysteries of Earth's high-energy radiation belts that encircle our planet and pose hazards to orbiting satellites and astronauts.

Derived from measurements taken by a University of New Hampshire-led instrument on board the twin spacecraft, the latest discovery reveals that the high-energy particles populating the radiation belts can be accelerated to nearly the speed of light in conjunction with ultra-low frequency electromagnetic waves operating on a planetary scale.

This mode of action, as detailed in a paper recently published in the journal Nature Communications, is analogous to that of a cyclical particle accelerator like the Large Hadron Collider (LHC).

However, in this case, the Earth's vast magnetic field, or magnetosphere, which contains the Van Allen belts, revs up drifting electrons to ever-higher speeds as they circle the planet from west to east.

The recent finding comes on the heels of a related discovery—also made by the UNH-led Energetic Particle, Composition, and Thermal Plasma (ECT) instrument suite—showing similar particle acceleration but on a microscopic rather than a planetary scale.

Harlan Spence

"The acceleration we first reported operates on the scale size of an electron's gyromotion—it is a really local process, maybe only a few hundred meters in size," notes Harlan Spence, director of the UNH Institute for the Study of Earth, Oceans, and Space, principal scientist for the ECT, and coauthor on the Nature Communications paper.

"Now we're seeing this large-scale, global motion involving ultra low-frequency waves pulsing through Earth's magnetosphere and operating across vast distances up to hundreds of thousands of kilometers."

And, Spence adds, "in all likelihood both processes are occurring simultaneously to accelerate particles to relativistic speeds."

Understanding the complex dynamics of the particle acceleration will help scientists make better predictions of space weather conditions and, thus, offer better protections to orbiting satellites crucial to modern-day society.

Having twin spacecraft making simultaneous measurements in different regions of nearby space is a key part of the mission as it allows the scientists to look at data separated in both space and time.

"With the Van Allen Probes, I like to think there's no place for these particles to hide because each spacecraft is spinning and 'glimpses' the entire sky with its detector 'eyes', so we're essentially getting a 360-degree view in terms of direction, position, energy, and time," Spence says.

Van Allen Probes: Giant Electric Fields Supercharge Particles In Radiation Belts

Huge electric fields in the radiation belts around Earth may help explain how electrons surrounding the planet can be accelerated to speeds near that of light, researchers have found in a new study.

These findings, detailed Dec. 2 in the journal Physical Review Letters, could help shed light on the radiation belts of planets such as Jupiter, Saturn, Uranus and Neptune, as well as the behaviour of the sun during flares and of bodies beyond the solar system, such as stellar nurseries, neutron stars and incredibly energetic black holes known as quasars.

After humanity began exploring space, the first major find made there were the Van Allen radiation belts, zones of magnetically trapped, highly energetic charged particles discovered in 1958.

The Van Allen Probes aka Radiation Belt Storm Probes (RBSP) Mission, part of NASA's Living With a Star program, will provide unprecedented insight into the physical dynamics of the radiation belts. 

Credit: NASA

These belts generally consist of two rings: 

• an inner zone with both high-energy electrons and very energetic positive ions that remains stable in intensity over the course of years to decades; and
• an outer zone made up mostly of high-energy electrons whose intensity swings over the course of hours to days, primarily depending on the influence from the solar wind, the deluge of radiation streaming from the sun. 

Earlier this year, scientists also detected a third radiation belt temporarily surrounding Earth.

The gigantic amounts of radiation the Van Allen belts generate can pose serious risks for satellites. To learn more about them, NASA launched twin spacecraft, the Van Allen probes, in the summer of 2012.

The satellites are armed with a host of sensors to comprehensively analyze the plasma, energetic particles, magnetic fields and plasma waves in these belts with unprecedented sensitivity and resolution.

Two giant swaths of radiation, known as the Van Allen Belts, surrounding Earth were discovered in 1958. In 2012, observations from the Van Allen Probes showed that a third belt can sometimes appear. 

The radiation is shown here in yellow, with green representing the spaces between the belts. 

Credit: NASA/Van Allen Probes/Goddard Space Flight Center.

Now, using the Van Allen probes, scientists have detected structures that pop in and out of existence in the outer belt that could help explain the high-energy electrons seen in that zone.

The structures in question are known as "double layers." They are each made up of a pair of parallel layers of particles with opposite electrical charge that move along Earth's magnetic field.

The probes saw huge numbers of double layers in the outer belt —7,000 in the course of a minute, each lasting on the order of seconds.

These double layers were discovered "sort of by accident as the Van Allen probes passed through this region of space, and only captured a snapshot," said study lead author Forrest Mozer, a physicist at the University of California, Berkeley.

"The spacecraft will get back to this region maybe eight months, maybe 10 months from now, and we're setting up our instruments to do what we now know they should — to collect data at that site then with a continuous view, to really get definitive information on what is going on there."