Abstract: A method is provided for controlling the attitude of a momentum biased spacecraft about all three mutually orthogonal axes during a thruster firing maneuver without separately sensing angular displacement, angular rate, or angular acceleration about the spacecraft yaw axis. The method includes a transient phase during which a yaw feedforward torque is computed based on the known pitch/yaw coupling due to thruster geometry, and a steady state phase, during which feedback gains are adjusted to estimate yaw attitude based on coupling of a steady state disturbance torque about the roll axis of the spacecraft and a steady state disturbance torque about the yaw axis of the spacecraft.

Abstract: A device for use as a meter pit or a traffic barrel, having double-walled construction in which one wall is a substantially smooth inner wall and a second outer wall is a corrugated wall, wherein the corrugated wall may be a singular wall extending from one end of the inner wall to the other end of the inner wall or a plurality of exterior walls attached sequentially at various points to the inner wall, the exterior corrugated walls may be linked to one another by a series of smooth walls. The corrugated wall has small, individual corrugations with the individual corrugations including a pair of trough walls and a crest, the small size of the individual corrugations making the device light-weight and impact resistant. The drum device is extruded and contains a polyolefin mixture, which preferably contains recycled and virgin polyethylene materials.

Abstract: A device for use as a meter pit or a traffic barrel, having double-walled construction in which one wall is a substantially smooth inner wall and a second outer wall is a corrugated wall, wherein the corrugated wall may be a singular wall extending from one end of the inner wall to the other end of the inner wall or a plurality of exterior walls attached sequentially at various points to the inner wall, the exterior corrugated walls may be linked to one another by a series of smooth walls. The corrugated wall has small, individual corrugations with the individual corrugations including a pair of trough walls and a crest, the small size of the individual corrugations making the device light-weight and impact resistant. The drum device is extruded and contains a polyolefin mixture, which preferably contains recycled and virgin polyethylene materials.

Abstract: An electrical pulse generator comprising a closed magnetic circuit made up of permeable iron and permanent magnet material having a cup-shaped portion, a central rod shaped portion extending upwardly from the inside bottom of the cup portion and a generally flat disc-shaped removable keeper making contact with the cup-shaped portion and the upper end of the rod-shaped portion, an electric coil wound on a portion of said magnetic circuit such that on movement of the keeper away from the rest of the structure an electrical voltage pulse is generated in the coil, mechanical means such that on activation by a predetermined level of shock severity it forces the keeper away from the rest of the structure.