Performance of the dragonfly mass spectrometer (DraMS) programmable UV laser source engineering test unit (ETU)

Abstract

NASA's Dragonfly mission will sample surface materials from multiple sites on Saturn's largest moon, Titan, in exploration of prebiotic chemistry. We report on the performance of our short-pulsed UV laser transmitter, developed for the Dragonfly's on-board Mass Spectrometer (DraMS). Our engineering test unit (ETU) has completed flight qualification and demonstrated its operational science requirements, such that the final spaceflight unit build can begin. The Titan Hydrocarbon Analysis Nanosecond Optical Source (THANOS) ETU laser produces 266 nm laser pulses at programmable energy levels to perform high resolution laser desorption mass spectrometry (LDMS) measurements. The laser operates in bursts of 1-50 pulses, each at < 2 ns pulse width with a pulse energy of 0 -200 uJ, at a 100 Hz repetition rate. This paper details the qualification process of the THANOS laser as well as the rigorous characterization performed to ensure consistent performance of the system during laboratory testing, while integrated onto the DraMS instrument and most critically, while operating on the distant surface of Titan.