SEV

SEV (left) with SECOR 5 (right) [NASA]

SEV (Scout Evaluation Vehicle) was a NASA launch vehicle evaluation payload to test a new version of the Scout launch vehicle and performing new maneuvers during launch. Primary purpose of the experiment was to demonstrate in flight the operation of a number of improved vehicle features which had been developed for the Scout program.

These included:

• The Scout's capability to fly a "dog-leg" course from Wallops Island by a guidance technique known as yaw torquing.
• The use of new second and fourth-stage rocket motors with improved thrust characteristics.
• Test in-flight performance of improved spin motors to stabilize the fourth stage of the vehicle.
• Demonstrate the Scout air transportability concept by launching a vehicle which after complete assembly at Wallops, has been airlifted from and returned to the launch site in simulation of a transcontinental trip.

Because engineering evaluation of the Scout system performance was the primary purpose of the flight, special instrumentation and telemetry packages had been provided for gathering a number of measurements in addition to those regularly made. A precision velocity meter made very accurate measurements of vehicle velocities through fourth-stage burning. Other instruments measured vibration, temperatures, motor pressures, spin-motor performance, ignition system voltages and other quantities needed for a complete engineering evaluation of the performance of the improved Scout. Electrostatic charge measurements were made on stages two and three. Improved solid-state telemetry systems were used to reduce weight and increase reliability. Finally, a new lightweight radar tracking beacon was carried on the vehicle.

Although it carried a heavy load of special engineering instrumentation, the SEV Scout made use of a small excess payload capability by carrying a 20.4 kg SECOR 5 satellite payload furnished by the U.S. Army. However, achievement of an orbit for the bonus experiment, SECOR, was not a primary objective of this mission.