Friday, August 12, 2011

Recovery landing velocity tips

Via Bob Krech on TRF.  Good basic stuff, now easier to find.

  1. Smaller, lighter model rockets can normally descend at a higher velocity than a heavy high power rocket.
  2. The surface is important. At grassy field will support a higher descent rate than a sun baked playa or asphalt.
  3. Smaller rockets landing on grass fields can handle 20-25 fps landings.
  4. Smaller rocket landing on hard surfaces and larger rockets ideally should have a final descent speed of ~15 fps.
  5. Drop test your rocket over the same type surface as your LZ before you launch.
    • A rocket dropped from 4' has a terminal velocity of 16 fps.
    • A rocket dropped from 6.25' has a terminal velocity of 20 fps.
    • A rocket dropped from 10' has a terminal velocity of 25.3 fps.
    • To determine the drop high, ft. for a velocity, fps: d=(v/8)^2
    • Drop from all orientations. If nothing breaks, you're good to go with landing speed comparable to the velocities obtained in the drop test.