Feasibility Study of Laser Air Data System

Abstract

The feasibility of spectroscopic measurements on board a small re-entry vehicle is discussed, focussing on laser based systems to detect temperatures, densities and flow velocities in the upper atmosphere. In ground test facilities many laser systems are in operation, which can tag N2, 02 and NO even in small concentrations. These systems are listed and checked for flight capability, keeping in mind the limited space, mass and power supply, and the availability of optical windows that can withstand the heat loads during re-entry. Stimulated spectroscopy is still ruled out because of excessive mass and power consumption,nevertheless a system of Nd: YAG plus THG plus OPO plus SHG might be a good candidate in the future. Only emission spectroscopy and absorption spectroscopy systems driven by diode lasers are ready to be installed on board.