S-Band Telemetry Link Lifetime Following a Hypervelocity Impact
Abstract
To better understand the effects of hypervelocity impact generated debris on S-band radio frequency (RF) transmission, a conical aeroshell was impacted by a Lexan projectile traveling at 6.7 km/s. RF signals from four transmitting patch antennas mounted on the target were used to measure the debris effects. The aft impact produced a back-scattered debris cloud that slowed as it moved through the 2 torr atmosphere in the evacuated blast chamber, and the debris attenuated S-band signals by 2 to 4 orders of magnitude from their preimpact values. The average velocity of the RF-inhibiting debris ranged from 0.7 to 1.1 km/s depending on the distance traveled. At an intercept altitude of 230 km, the atmospheric pressure is 10(exp -7) torr, there is no resistive force, and the debris should continue at its initial velocity. To gain better understanding of the chamber atmosphere effects, a simple momentum transfer model for debris slowing in a nonviscous media was used to model debris propagation. The resistive force is proportional to V2, and an initial (exoatmospheric) velocity of 1.5 km/s was calculated. Therefore, debris velocities measured at 2 torr will overestimate telemetry link lifetimes by Vexo/Vave which ranges from 1.4 to 2.1 in this experiment.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 2000
- Accession Number
- ADA381010
Entities
People
- D. Sandison
- Joseph Moore
- L. Marshall
- R. Franco
Organizations
- Sandia National Laboratories