Abstract: Apparatus and methods for controlling a spacecraft for a transfer orbit. The spacecraft includes a propulsion subsystem with electric thrusters that are installed with two-axis gimbal assemblies. The spacecraft also includes a controller that identifies a target spin axis for the spacecraft, determines an actual spin axis for the spacecraft during the transfer orbit, determines gimbal angles for the electric thruster(s) that adjust the actual spin axis toward the target spin axis, and initiates a burn of the electric thruster(s) at the gimbal angles.

Abstract: Apparatus and methods for controlling a spacecraft for a transfer orbit. The spacecraft includes a momentum subsystem that stores angular momentum relative to a center of mass of the spacecraft, and a propulsion subsystem that includes electric thrusters. A controller identifies a target spin axis for the spacecraft, determines gimbal angles for electric thruster(s) that so that thrust forces from the electric thrusters are parallel to the target spin axis, and initiates a burn of the electric thruster(s) at the gimbal angles. The controller controls the momentum subsystem to compensate for a thruster torque produced by the burn of the electric thrusters. The momentum subsystem is able to produce a target angular momentum about the center of mass, where a coupling between the target angular momentum and an angular velocity of the spacecraft creates an offset torque to counteract the thruster torque.

Abstract: Apparatus and methods for controlling a spacecraft for a transfer orbit. The spacecraft includes a propulsion subsystem with electric thrusters that are installed with two-axis gimbal assemblies. The spacecraft also includes a controller that identifies a target spin axis for the spacecraft, determines an actual spin axis for the spacecraft during the transfer orbit, determines gimbal angles for the electric thruster(s) that adjust the actual spin axis toward the target spin axis, and initiates a burn of the electric thruster(s) at the gimbal angles.

Abstract: Apparatus and methods for controlling a spacecraft for a transfer orbit. The spacecraft includes a momentum subsystem that stores angular momentum relative to a center of mass of the spacecraft, and a propulsion subsystem that includes electric thrusters. A controller identifies a target spin axis for the spacecraft, determines gimbal angles for electric thruster(s) that so that thrust forces from the electric thrusters are parallel to the target spin axis, and initiates a burn of the electric thruster(s) at the gimbal angles. The controller controls the momentum subsystem to compensate for a thruster torque produced by the burn of the electric thrusters. The momentum subsystem is able to produce a target angular momentum about the center of mass, where a coupling between the target angular momentum and an angular velocity of the spacecraft creates an offset torque to counteract the thruster torque.

Abstract: A tracked vehicle produces a pressure no more than 3 psi on the ground by increasing the number of contact points on the inner surface of the track. The stiffness of the track is also selected to minimize bowing between the idler wheels or rollers. The track is therefore kept substantially straight between the rollers to increase the efficiency associated with transferring power to track. The drive sprocket is positioned above the ground so as to eliminate complexity in the design and yet effectively transmit power to the tracks. Positioning the drive sprocket above ground also prevents derailing of the track. The track is also held in a constant state of tension on the driver sprocket and the roller. This too prevents derailment. The undercarriage of the vehicle includes torsion axles and sealed bearings to provide for a lower maintenance track. Components associated with the undercarriage do not require constant greasing and cleaning of the idler wheels.

Abstract: A tracked vehicle capable of traversing a variety of surfaces without damaging the surface traversed. The vehicle is capable of light or heavy-duty applications. An embodiment of the vehicle includes a track with a substantially smooth outer surface, and an inner surface including a portion having lugs, a driver sprocket assembly engaging the lugs, and a plurality of wheels spaced to minimize flexing of the track between each wheel in contact with the track while the track contacts the traversed surface.

Abstract: A tracked vehicle produces a pressure no more than 3 psi on the ground by increasing the number of contact points on the inner surface of the track. The stiffness of the track is also selected to minimize bowing between the idler wheels or rollers. The track is therefore kept substantially straight between the rollers to increase the efficiency associated with transferring power to track. The drive sprocket is positioned above the ground so as to eliminate complexity in the design and yet effectively transmit power to the tracks. Positioning the drive sprocket above ground also prevents derailing of the track. The track is also held in a constant state of tension on the driver sprocket and the roller. This too prevents derailment. The undercarriage of the vehicle includes torsion axles and sealed bearings to provide for a lower maintenance track. Components associated with the undercarriage do not require constant greasing and cleaning of the idler wheels.

Abstract: A tracked vehicle produces a pressure no more than 3 psi on the ground by increasing the number of contact points on the inner surface of the track. The stiffness of the track is also selected to minimize bowing between the idler wheels or rollers. The track is therefore kept substantially straight between the rollers so increase the efficiency associated with transferring power to track. The drive sprocket is positioned above the ground so as to eliminate complexity in the design and yet effectively transmit power to the tracks. Positioning the drive sprocket above ground also prevents derailing of the track. The track is also held in a constant state of tension on the driver sprocket and the roller. This too prevents derailment. The undercarriage of the vehicle includes torsion axles and sealed bearings to provide for a lower maintenance track. Components associated with the undercarriage do not require constant greasing and cleaning of the idler wheels.

Abstract: A tracked vehicle produces a pressure no more than 3 psi on the ground by increasing the number of contact points on the inner surface of the track. The stiffness of the track is also selected to minimize bowing between the idler wheels or rollers. The track is therefore kept substantially straight between the rollers so increase the efficiency associated with transferring power to track. The drive sprocket is positioned above the ground so as to eliminate complexity in the design and yet effectively transmit power to the tracks. Positioning the drive sprocket above ground also prevents derailing of the track. The track is also held in a constant state of tension on the driver sprocket and the roller. This too prevents derailment. The undercarriage of the vehicle includes torsion axles and sealed bearings to provide for a lower maintenance track. Components associated with the undercarriage do not require constant greasing and cleaning of the idler wheels.

Abstract: A tracked vehicle produces a pressure no more than 3 psi on the ground by increasing the number of contact points on the inner surface of the track. The stiffness of the track is also selected to minimize bowing between the idler wheels or rollers. The track is therefore kept substantially straight between the rollers so increase the efficiency associated with transferring power to track. The drive sprocket is positioned above the ground so as to eliminate complexity in the design and yet effectively transmit power to the tracks. Positioning the drive sprocket above ground also prevents derailing of the track. The track is also held in a constant state of tension on the driver sprocket and the roller. This too prevents derailment. The undercarriage of the vehicle includes torsion axles and sealed bearings to provide for a lower maintenance track. Components associated with the undercarriage do not require constant greasing and cleaning of the idler wheels.

Abstract: A tracked vehicle produces a pressure no more than 3 psi on the ground by increasing the number of contact points on the inner surface of the track. The stiffness of the track is also selected to minimize bowing between the idler wheels or rollers. The track is therefore kept substantially straight between the rollers so increase the efficiency associated with transferring power to track. The drive sprocket is positioned above the ground so as to eliminate complexity in the design and yet effectively transmit power to the tracks. Positioning the drive sprocket above ground also prevents derailing of the track. The track is also held in a constant state of tension on the driver sprocket and the roller. This too prevents derailment. The undercarriage of the vehicle includes torsion axles and sealed bearings to provide for a lower maintenance track. Components associated with the undercarriage do not require constant greasing and cleaning of the idler wheels.

Abstract: A tracked vehicle produces a pressure no more than 3 psi on the ground by increasing the number of contact points on the inner surface of the track. The stiffness of the track is also selected to minimize bowing between the idler wheels or rollers. The track is therefore kept substantially straight between the rollers so increase the efficiency associated with transferring power to track. The drive sprocket is positioned above the ground so as to eliminate complexity in the design and yet effectively transmit power to the tracks. Positioning the drive sprocket above ground also prevents derailing of the track. The track is also held in a constant state of tension on the driver sprocket and the roller. This too prevents derailment. The undercarriage of the vehicle includes torsion axles and sealed bearings to provide for a lower maintenance track. Components associated with the undercarriage do not require constant greasing and cleaning of the idler wheels.

Abstract: A tracked vehicle produces a pressure no more than 3 psi on the ground by increasing the number of contact points on the inner surface of the track. The stiffness of the track is also selected to minimize bowing between the idler wheels or rollers. The track is therefore kept substantially straight between the rollers so increase the efficiency associated with transferring power to track. The drive sprocket is positioned above the ground so as to eliminate complexity in the design and yet effectively transmit power to the tracks. Positioning the drive sprocket above ground also prevents derailing of the track. The track is also held in a constant state of tension on the driver sprocket and the roller. This too prevents derailment. The undercarriage of the vehicle includes torsion axles and sealed bearings to provide for a lower maintenance track. Components associated with the undercarriage do not require constant greasing and cleaning of the idler wheels.

Abstract: A tracked vehicle produces a pressure no more than 3 psi on the ground by increasing the number of contact points on the inner surface of the track. The stiffness of the track is also selected to minimize bowing between the idler wheels or rollers. The track is therefore kept substantially straight between the rollers so increase the efficiency associated with transferring power to track. The drive sprocket is positioned above the ground so as to eliminate complexity in the design and yet effectively transmit power to the tracks. Positioning the drive sprocket above ground also prevents derailing of the track. The track is also held in a constant state of tension on the driver sprocket and the roller. This too prevents derailment. The undercarriage of the vehicle includes torsion axles and sealed bearings to provide for a lower maintenance track. Components associated with the undercarriage do not require constant greasing and cleaning of the idler wheels.

Abstract: A method and an apparatus useful as a secondary level assaying tool for qualitative and quantitative confirmation of results obtained by primary separation techniques and their correlation with a specific function or property of the tested sample. An apparatus is useful for the post-transfer development assaying on the solid support of the biological samples already assayed by standard separation techniques such as blotting or chromatography.

Abstract: An all seasons vehicle has a hydraulic control circuit that is used to make the vehicle highly maneuverable in which the rear treads are controllable through a speed control driving or controlling the speed of each of the hydraulic motors from a pair of hydraulic pumps connected to the motors in proportion to the position of a control element that is changed through the steering wheel of the vehicle. The control over the hydraulic motors may be increased or decreased by overriding the position of the control element and increasing the hydraulic flow of fluid to one motor or the other without interfering with the direction being imparted to the vehicle.