Form 9.B Project Summary

Chron 970921

Proposal Number 97-1 09.05-5000B

Project Title Moisture and Oxygen Content Sensor Suite for Nutrient Delivery Systems

Technical Abstract

This project will develop a small, low power instrumentation package which includes a two

part sensor suite: 1) sensor for monitoring profiles of moisture content, and 2) sensor to

detect O2 concentration in porous substrate nutrient and water delivery systems designed to

support plant growth in space. Long-term plant growth experiments aboard the Mir Orbital

Station have demonstrated that management of water and O2 in porous substrates is

substantially more difficult than in similar systems on earth. The instrument package will

consist of several pairs of moisture-oxygen sensors used to measure concentration profiles

simultaneously. The substrate moisture content sensor will use the thermal pulse method,

which detects changes in thermal conductivity as the substrate moisture content changes.

Significant innovations exist in the concept and design of each sensor as well as the

integration of the sensor into a usable electronics module with calibrated control.

Innovative improvements in moisture sensor construction, reliability, and improved sensor

design will allow calibration transfer from earth to microgravity. The companion O2

concentration sensor will monitor O2 in close proximity to the moisture content sensor to

allow the two profiles to be compared simultaneously. The innovative design of the O2

sensor includes features permitting the miniaturization of an existing commercial sensor

core to provide safe use in wet, O2 diffusion limited environments.

Potential Commercial Applications

The moisture content and wet oxygen sensors will be important additions to advanced plant

nutrient system maintenance and control for space and ground applications. Near-term space

applications include the Biomass Production System and the Plant Research Unit. These

Sensors could become standard sensor additions to commercial growth chambers, be used in

all types of commercial growth systems where monitoring of appropriate moisture content and

aeration are important. The market is significant, especially in ornamental and more

expensive plant materials. Also markets exist for commercial maintenance plantscapes.

Name and Address of Offeror

Firm: Orbital Technologies Corp

Name:Dr. Eric Rice

Street: 1212 Fourier Drive

City: Madison

ST: WI ZIP: 53717

Name and Address Of Principal Investigator

Firm: Orbital Technologies Corp

Name: Jon Frank

Street: 1212 Fourier Drive

City: Madison

ST: WI ZIP: 53717