Launching from NASA’s Wallops Flight Facility, a Terrier-Improved Malemute suborbital sounding rocket will carry the Vlf trans-Ionospheric Propagation Experiment Rocket, or VIPER. The mission is scheduled for at 9:15 p.m. EDT. The launch may be visible in the mid-Atlantic region.
VIPER is studying very low frequency radio, or VLF, waves that are produced by both natural (e.g. lightning) and artificial means. During the day these waves are trapped or absorbed by the Earth’s ionosphere. At night, however, some of the waves escape through the ionosphere and accelerate electrons in the Van Allen Radiation Belt.
“At night, the lower layers of the ionosphere are much less dense, and more of the VLF can leak through, propagate along the Earth's magnetic field lines,” said John Bonnell, the project’s principal investigator from the University of California, Berkeley.
“Those belts of intense energetic electron fluxes cover a range of distances from the Earth, from as close as 14,300 miles altitude out to 23,500 miles altitude. GPS satellites and geosynchronous satellites orbit the Earth at these altitudes. So, satellites in those orbits are often engulfed by the Van Allen Radiation Belts and have to tolerate the effects those energetic particles have on electronics and materials,” said Bonnell.
In addition to the in-situ measurements made by VIPER as it flies through the area of interest, the mission also will employ numerous ground-based systems, including those in Maine, North Carolina, Georgia, Colorado and Virginia.
“It was surprising to find that while lots of ground-based and orbital observations of the VLF absorption/reflections/transmission had been made, there's not been any measurements right in the region where all the action happens. While we have good models of what to expect in such regions, actual measurements are key to pin down the details of those models, as well as to develop the instruments required to explore more challenging regions,” said Bonnell.
The two-stage Terrier-Improved Malemute rocket will carry the VIPER payload to an altitude of about 94 miles before descending and landing in the Atlantic Ocean. The payload will not be recovered.