Space Dynamics Lab Awarded NASA Contract

February 4, 2002

LOGAN — NASA's Johnson Space Flight Center has awarded Utah State University's Space Dynamics Laboratory (SDL) a contract worth $1.9 million to build a Floating

FPMU is comprised of four sensors that will monitor the electrostatic charging of the Space Station as well as the surrounding ionospheric plasma density and temperature. This information will be used to ensure the safety of the astronauts during their space walks, known as Extra Vehicular Activity (EVA).

Pat Patterson, Division Director at SDL said the Space Station has unique concerns when it comes to vehicle charging. The solar panels aboard the Space Station collect electrons faster than can be emitted, driving the Station to a negative potential relative to its surrounding space environment.

"A similar situation is created when a person walks across a carpet, building up static electrical charge," said Patterson. "When they touch an object that is at a different charge, such as a doorknob, there will be a discharge - shocking the person."

In much the same way, astronauts charge to a potential different than Space Station as they perform their EVA. This creates a voltage difference between them and the Station. If the differential charging becomes severe enough, it may discharge, upsetting spacecraft electronics, damaging surface coatings, burning holes in thermal blanketing or causing failure of the astronaut's space suit.

As the station continues to grow it will require more panels to provide power to its systems. These panels will greatly enhance the negative charging of the Space Station.

"FPMU is a critical piece of hardware that must be in place before more solar panels can be added," Patterson said.

The FPMU sensors will allow astronauts to know when it is safe to venture outside of the Space Station and will warn operators when differential charges need to be adjusted.

SDL has extensive experience building these types of sensors, but up until this point they have only been used in scientific research.

"It is a transition from technology in the science world to cutting-edge technology in the operational world," said Patterson. "We are excited to be involved in this program."

The project resulted from ongoing research by Charles Swensen, PhD, USU professor in the Electrical and Computer Engineering department. Swensen will be the principle investigator for FPMU and will be working with the NASA science team. It will be ready for launch in January 2003.