Technology development of a solid state 266 nm laser for NASA’s Dragonfly mission

Abstract

NASA’s Dragonfly mission is a rotorcraft lander which will explore several geologic locations on Saturn’s moon, Titan and investigate evidence of surface-level prebiotic chemistry as well as search for chemical signatures of water-based and/or hydrocarbon-based life. To perform molecular composition investigations in-situ, the payload includes the Dragonfly Mass Spectrometer (DraMS), being developed at NASA’s Goddard Space Flight Center (GSFC). DraMS will utilize laser desorption mass spectrometry (LDMS) to interrogate surface samples and measure the organic composition. Enabling this science capability is the Throttled Hydrocarbon Analysis by Nanosecond Optical Source (THANOS) laser being developed at NASA-GSFC. The THANOS laser is comprised of a solid state, passively Q-Switched Nd:YAG oscillator which is frequency converted to 266 nm and utilizes a RTP high voltage electro-optic for pulse energy control. The laser outputs <2.0 ns pulses with a maximum energy of approximately 200 uJ which can be emitted in 1 - 50 shot bursts at 100 Hz while performing LDMS science operations. The laser has the capability to throttle its UV pulse energy output from full attenuation to maximum energy to provide varying levels of fluence on samples in the DraMS instrument. We report on the THANOS’ laser technology development and space qualification effort including vibration, thermal vacuum cycling, radiation as well as optical damage testing due to Titan’s atmospheric composition, performed at NASA-GSFC from 2019 through 2022.

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

“…In 2022, the THANOS LOB and internal critical subcomponents passed environmental testing and achieved a Technology Readiness Level (TRL) of 6. 9 In 2023, the LD Enclosure needed to be environmentally tested for shock, vibration, and survival temperature cycling after a previous LD enclosure version failed a vibration test and damaged the LD mounted inside. The failure was caused by unforeseen modal coupling between the enclosure and the internal diode mounting feet.…”