In space, invisible, fast-moving particles from the Sun and other sources in deep space zip around, their behavior shaped by dynamic electric and magnetic fields. There are so few of these particles that space is considered a vacuum, but what’s there packs a punch. Together, we call all of this invisible activity space weather — and it affects our technology both in space and here on Earth.
This month, two new missions are launching to explore two different kinds of space weather.
Scrambled signals
Many of our communications and navigation systems — like GPS and radio — rely on satellites to transmit their signals. When signals are sent from satellites down to Earth, they pass through a dynamic zone on the upper edge of Earth’s atmosphere called the ionosphere.
Gases in the ionosphere have been cooked into a sea of positive- and negative-charged particles by solar radiation. These electrically charged particles are also mixed in with neutral gases, like the air we breathe. The charged particles respond to electric and magnetic fields, meaning they react to space weather. Regular weather can also affect this part of the atmosphere.
Influenced by this complicated web of factors, structured bubbles of charged gas sometimes form in this part of the atmosphere, particularly near the equator. When signals pass through these bubbles, they can get distorted, causing failed communications or inaccurate GPS fixes.
Right now, it’s hard to predict just when these bubbles will form or how they’ll mess with signals. The two tiny satellites of the E-TBEx mission will try to shed some light on this question.
As these CubeSats fly around Earth, they’ll send radio signals to receiving stations on the ground. Scientists will examine the signals received in order to see whether — and if so, how much — they were jumbled as they traveled through the upper atmosphere and down to Earth.
All together, this information will give scientists a better idea of how these bubbles form and change and how much they disrupt signals — information that could help develop strategies for mitigating these bubbles’ disruptive effects.
Damaged satellites
The high-energy, fast-moving particles that fill space are called radiation. Every single spacecraft — from scientific satellites sprinkled throughout the solar system to the communications satellites responsible for relaying the GPS signals we use every day — must weather the harsh radiation of space.
Strikes from tiny, charged particles can spark memory damage or computer upsets on spacecraft, and over time, degrade hardware. The effects are wide-ranging, but ultimately, radiation can impact important scientific data, or prevent people from getting the proper navigation signals they need.
Space Environment Testbeds — or SET, for short — is our mission to study how to better protect satellites from space radiation.
SET aims its sights on a particular neighborhood of near-Earth space called the slot region: the gap between two of Earth’s vast, doughnut-shaped radiation belts, also known as the Van Allen Belts. The slot region is thought to be calmer than the belts, but known to vary during extreme space weather storms driven by the Sun. How much it changes exactly, and how quickly, remains uncertain.
The slot region is an attractive one for satellites — especially commercial navigation and communications satellites that we use every day — because from about 12,000 miles up, it offers not only a relatively friendly radiation environment, but also a wide view of Earth. During intense magnetic storms, however, energetic particles from the outer belt can surge into the slot region.
SET will survey the slot region, providing some of the first day-to-day weather measurements of this particular neighborhood in near-Earth space. The mission also studies the fine details of how radiation damages instruments and tests different methods to protect them, helping engineers build parts better suited for spaceflight. Ultimately, SET will help other missions improve their design, engineering and operations to avoid future problems, keeping our space technology running smoothly as possible.
For more on our space weather research, follow @NASASun on Twitter and NASA Sun Science on Facebook.
Meet the other NASA missions launching on the Department of Defense’s STP-2 mission and get the latest updates at nasa.gov/spacex.
Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com.
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