The rockets are being launched to study winds in the upper parts of the atmosphere. Each of the rockets, launched a minute apart over five minutes, will ascend to an altitude of 50 to 90 miles above the surface and will release a chemical tracer contrail that will allow researchers to see wind speeds and trajectories in the high levels of the atmosphere. Our atmosphere extends out, theoretically, a few thousand miles with the exosphere but the outer edges (anything above 60-70 miles) is very space-like and with very limited molecules of hydrogen and helium.
The mission sets out "to study these high altitude winds and their intimate connection to the complicated electrical current patterns that surround Earth."
Below, from NASA, a video explains the mission in visual detail.
NASA hopes the experiment will help scientists better model wind impacts and speeds in this portion of the atmosphere, where damage to satellites and communication systems can occur from the turbulent winds that often exceed 200 or even 300 miles per hour.