1. Geophysical Institute, University of Alaska Fairbanks 1 Outline We will launch a sounding rocket north from PFRR. The final stage will include an attitude control system. The ACS would direct the delta-v from the final stage burn so that the payload ends up flying in the flattest possible parabolic trajectory. Say we want 200 km of trail. If the payload speed is 2 km/sec, this portion of the trajectory will take 100 sec. Consider just the “down-leg” portion of the trail. This takes 50 sec, with an initial vertical velocity of zero. In 50 sec, the payload will free-fall 0.5  9.8  50 2  12 km. At the end of the 50-second downleg, the payload vertical velocity would be 490 m/sec. This means the maximum off-horizontal angle for the trail would be 13 . This angle would occur at each end of the 200 km trail. Of course, we may not need the full 200 km. Shorter trails would be confined to the flattest part of the trajectory.

2. Geophysical Institute, University of Alaska Fairbanks 2 Example flight – Black Brant X (Lynch)

3. Geophysical Institute, University of Alaska Fairbanks 3 In-situ measurements The following parameters would be useful to measure in-situ, in approximate order of priority: N 2 and O densities, or [O]/[N 2 ] ratio Neutral temperature Magnetic zenith optical emission intensities Electric field Ion temperature Electron density

4. Geophysical Institute, University of Alaska Fairbanks 4 Personnel Project personnel and general area of responsibility: Science goals – Mark Conde, Roger Smith Flight instrumentation – John Craven Trajectory design and vehicle implementation – Gene Wescott Ground instrumentation – Hans Nielsen TMA canister – Miguel Larsen