June 21, 2013
NASA Using Sounding Rockets To Study Our Ionosphere
Brett Smith for redOrbit.com - Your Universe Online
Way up in the Earth’s atmosphere is a layer of charged particles called the ionosphere, which plays a crucial role in the transmission of radio and other signals.
Through a mission called Dynamo, NASA scientists are planning to study the currents that pass through this charged section of the atmosphere found between 30 and 600 miles above Earth. Launching from NASA’s Wallops Flight Facility in Virginia, Dynamo is expected to take a five-minute trip into the ionosphere to study a global, electrical current called none other than the dynamo.
“The dynamo further south at the magnetic equator is particularly strong and is called the equatorial electrojet,” said Robert Pfaff, a Dynamo principle investigator at NASA’s Goddard Space Flight Center in Greenbelt, Md. “The mid-latitude dynamo is less understood and is actually more complex, since here Earth’s magnetic field is at an angle.”
In conjunction with the Japan Aerospace Exploration Agency (JAXA), the Dynamo mission will launch two sounding rockets, 15 seconds apart. The first is a Black Brant V rocket that will collect information about the ionosphere’s neutral and charged particles. The second rocket is a Terrier-Improved Orion that will study the upper atmospheric winds believed to drive the dynamo currents.
Understanding the movements of neutral and charged particles in the upper atmosphere is crucial to understanding the dynamo, since it is affected by both.
“The simple picture of the dynamo involves two giant circles of current – one in the northern hemisphere and one in the south,” said Doug Rowland, a co-investigator for Dynamo at Goddard. “At its most basic, the electric current is caused simply because the sun heats the upper atmosphere during the day causing the gas to rise up, which in turn causes movement, a wind. The neutral wind pushes the heavier charged particles and that drives an electric current. So both the neutral and the charged material must be understood.”
Dynamo is only expected to reveal small details regarding how the ionosphere works as many other factors around the planet impact the dynamo. While activity on the Sun can affect Earth’s magnetic fields, the lower parts of the ionosphere can also influence currents based on the collisions between different types of ions and neutral gases found there.
NASA scientists expect that understanding the dynamics of the ionosphere could lead to learning how it affects radio signals. Data from the Dynamo project could also shed light on similar processes that may be happening on other planets throughout the Solar System.
“The manner in which neutral and ionized gases interact is a fundamental part of nature,” said Pfaff. “There could very well be a dynamo on other planets. Jupiter, Saturn, Uranus and Neptune are all huge planets with huge atmospheres and huge magnetic fields. They could be setting up dynamo currents galore.”
The sounding rockets allow for NASA scientists to access areas of the upper atmosphere that are too low for orbiting satellites. Wallops Flight Facility, located on Virginia’s Wallops Island, is where the rocket payloads are designed, built and tested.