NASA SBIR 2003 Solicitation


PROPOSAL NUMBER:03-A2.06-9450 (For NASA Use Only - Chron: 033555)
SUBTOPIC TITLE:Modeling and Control of Complex Flows Over Aerospace Vehicles and Propulsion Systems
PROPOSAL TITLE:Terahertz Quantum Cascade Laser-Based Sensors for Hypersonic Flows (7274-050)

SMALL BUSINESS CONCERN (Firm Name, Mail Address, City/State/Zip, Phone)
Physical Sciences Inc
20 New England Business Ctr
Andover ,MA 01810 - 1077
(978) 689 - 0003

PRINCIPAL INVESTIGATOR/PROJECT MANAGER (Name, E-mail, Mail Address, City/State/Zip, Phone)
Joel M Hensley
20 New England Business Ctr
Andover ,MA  01810 -1077
(978) 689 - 0003
U.S. Citizen or Legal Resident: Yes

Ground test facilities are used by NASA to simulate the conditions present during flight at hypersonic velocities, to test thermal protection materials for existing spacecraft and develop new hypersonic aircraft. To ensure the accuracy and usefulness of ground test results, the state of the gas in the ground test facility must be known. Key components of the test gas, such as atomic oxygen and atomic nitrogen, can be monitored today using pulsed laser sources operating in the ultraviolet region of the spectrum. However, this measurement scheme is not fast enough to detect rapid fluctuations which may be present. Our innovation is a sensor based on compact, portable source of tunable laser radiation in the far-infrared (terahertz) region of the spectrum which can be used to measure the number density and velocity of atomic oxygen continuously during a ground test. During Phase I we will prove feasibility by showing that a laser with the required wavelength, tuning range, and linewidth can be constructed. During Phase II we will prove practicality by optimizing the properties of the laser, building a prototype sensor, demonstrating the detection of atomic oxygen, and delivering the sensor to an appropriate NASA test facility.

The laser-based diagnostic developed during this project will increase the accuracy of test results at hypersonic wind tunnel facilities used to simulate atmospheric re-entry. Using these test results, NASA will be able to optimize the amount of thermal protection material used in the Space Shuttle and other vehicles, so that safety can be ensured without reducing the payload unnecessarily. The diagnostic will also provide more accurate results in facilities which simulate combustion at hypersonic speeds, thus facilitating the design of engines for future hypersonic aircraft.

Compact, tunable terahertz lasers will be useful for container-penetrating detection of dangerous substances for homeland defense applications, detecting contraband substances for law enforcement applications, and detecting trace amounts of moisture for industrial process control.