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Remote sensing of methane fluxes has been highlighted as one of the measurement goals of the NASA 2017 Earth Science Decadal Survey. Measuring methane from space and airborne platforms with an active (laser) remote sensing instrument presents several technology and measurement challenges that need to be met in order to provide accurate and precise data. The instrument must be able to make continuous measurements day and night, over all seasons and at all latitudes. It must have a high signal-to-noise ratio and must be relatively immune to biases from aerosol/cloud scattering, spectroscopic and meteorological data uncertainties, and other systematic errors. In this paper, we will discuss the technology challenges, options and tradeoffs to measure methane from space and airborne platforms.

Europa is a high-priority astrobiology target due to the presence of liquid water, carbon-rich materials, and energy sources that may support complex chemistry and the emergence of biological activity. The CORALS (Characterization of Ocean Residues And Life Signatures) instrument—a transformative mass spectrometer that comprises a solid-state UV laser source, custom ion transfer optics, and a high performance Orbitrap™ mass analyzer—is capable of comprehensive analyses of planetary materials that can provide important context for the origin and evolution of potential biosignatures and geologic icy matrices on Europa. The CORALS laser source, ion inlet system, and mass analyzer constitute a highly versatile and low SWaP (Size: 11,000 cm3; Weight: 8.0 kg; and Power: 41 W peak) mass spectrometer. Here we report on the design of the CORALS engineering test unit (ETU), which will be qualified for spaceflight via random vibration testing and exposure to dry heat microbial reduction, and test results from the two pathfinding prototypes that have informed the development of the ETU. The demonstrated analytical performance of the CORALS instrument supports the wide range of science goals and planetary targets this spectrometer can access, highlighting the instrument's multidimensional strengths in the search for life signatures on Europa or elsewhere in the Solar System.

Mass spectrometers represent progressive analytical platforms for future in situ lander missions to explore the surface chemistry of planetary bodies. Europa (as an astrobiology objective) and the Moon (an extension of the terrestrial system) are two primary targets for future NASA missions to search for extraterrestrial life and potentially habitable environments beyond Earth, further our understanding of the timing and formation of the Solar System, and identify potentially viable economic resources such as water and/or valuable metal assets. The CORALS (Characterization of Ocean Residues And Life Signatures) and CRATER (Characterization of Regolith And Trace Economic Resources) instruments are laser-based Orbitrap™ mass spectrometers currently under development for prospective lander missions to Europa and the Moon, respectively. We report on the advancement of two compact, robust, and high technology readiness level (TRL) ultraviolet (UV) solid state lasers that serve as the sampling and ionization sources of these two investigations.

NASA Goddard Space Flight Center is developing a master oscillator power amplifier (MOPA) laser transmitter for the ESA-led Laser Interferometer Space Antenna (LISA) mission. Taking advantage of our space laser experience and the emerging telecom laser technology, we are developing a full laser system for the LISA mission. Our research effort has included both master oscillator (MO) and power amplifier (PA) developments, and their environmental testing and reliability for space flight. Our current baseline for the MO is a low-mass, compact micro non-planar ring oscillator (m- NPRO) laser. The amplifier uses a robust mechanical design based on fiber components. We have performed laser system noise tests by amplitude- and frequency-stabilizing the PA output. We will describe our progress and plans to demonstrate a TRL 6 laser system, which is an essential step toward qualifying lasers for space applications, by 2021.

The global and regional quantification of methane fluxes and identification of its sources and sinks has been highlighted as one of the goals of the NASA 2017 Earth Science Decadal Survey. Detecting methane from space and airborne platforms with an active (laser) remote sensing instrument presents several unique technology and measurement challenges. The instrument must have a single frequency, narrow-linewidth light source, and photon-sensitive detector at the right spectral region to make continuous measurements from orbit, day and night, all seasons and at all latitudes. It must have a high signal to noise ratio and must be relatively immune to biases from aerosol/cloud scattering, spectroscopic and meteorological data uncertainties, and instrument systematic errors. At Goddard Space Flight Center (GSFC), in collaboration with industry, we have developed an airborne instrument to measure methane. Our instrument is a nadir-viewing lidar that uses Integrated Path Differential Absorption (IPDA), to measure methane near 1.65 μm. We sample the absorption line using multiple wavelengths from a narrow linewidth laser source and a sensitive photodetector. This measurement approach provides maximum information content about the CH4 column, and minimizes biases in the XCH4 retrieval. In this paper, we will review our progress to date and discuss the technology challenges, options and tradeoffs to measure methane from space and airborne platforms.

A highly stable and long-lifetime laser system is a key component of the space-based Laser Interferometer Space Antenna (LISA) mission, which is designed to detect gravitational waves from various astronomical sources. We are developing such laser system at the NASA Goddard Space Flight Center (GSFC). Our baseline architecture for the LISA laser consists of a low-power, low-noise small Nd:YAG non-planar ring oscillator (micro NPRO) followed by a diodepumped Yb-fiber amplifier with ~2 W output. In this paper, we will describe our progress to date and plans to demonstrate a technology readiness level (TRL) 6 LISA laser system.

NASA-Goddard is developing a high-fidelity space-based remote sensor for atmospheric CO2. We report on a the instrument architecture and performance and the technology developments for a low earth orbiting instrument.

NASA's Goddard Space Flight Center has been developing lidar to remotely measure CO 2 and CH4 in the Earth's atmosphere. We have advanced the tunable laser technology to enable high-fidelity measurements from space. In this paper, we will report on the progress of a fiber-based, 1.57-micron wavelength, laser transmitter that has demonstrated the optical performance required for a low earth orbiting instrument. The Laser transmitter has been packaged and is undergoing environmental testing to demonstrate its technology readiness for space.

The high average power from pulsed good quality mode laser emitting at fundamental wavelength of 1066.3 nm is needed for obtaining of high-fidelity pulsed radiation with wavelength centered at 589.15 nm for spaceborne Na Doppler resonance fluorescence LIDAR. The conversion of radiation from 1066.3 nm to 589.15 nm can be achieved through one stage of Raman lasing and subsequent frequency doubling using qualified nonlinear crystals. Although efficient scaling of average power at 1064 nm using a-cut Nd:YVO4 to multiple of 10W was demonstrated for more than a decade ago, the efficient demonstration of 1066 nm power scaling from single Watt level to 10W level of average power is yet to be done. Multiple publications with a-cut Nd:YVO4 laser host with fundamental emission wavelength at 1064 nm showed good conversion efficiencies to both 1176 nm and to 588 nm using intracavity Raman lasing and frequency doubling. We experimentally demonstrated efficient lasing at 1066 nm with output average power in excess of 15W using single c-cut Nd:YV04 crystal end-pumped with 888 nm diode pump laser. The achieved optical-to-optical efficiency of converting absorbed 888 nm pump to 1066 nm with short linear test cavity and output coupler of 84% was in excess of 32% while maximum reached optical-to-optical slope efficiency 50%. We discuss challenges of efficient 1066 nm generation and overall electro-optical efficiencies reachable for potential spaceborne LIDAR Sodium transmitter laser.

High resolution time-of-flight mass spectrometers (TOFMSs) have broad potential application in space exploration. We propose a novel femtosecond electron ionization (EI) source which, when coupled to a compact TOFMS, could improve mass resolution of miniature instruments by orders of magnitude, enabling effective isobar identification in volatile and planetary atmospheres. The ionization source is an ultrashort pulsed electron gun triggered by a femtosecond UV laser. In addition, the ultrafast laser technology may also be used for other analytical capabilities like laser desorption/ionization on solid samples, therefore future developments may offer a novel compact instrument package for both atmosphere and surface analysis. Here, we show a series of advances toward this goal, including efficient (5%) generation of 105 fs UV pulses, production of electron bunches of up to 32 fC pC via UV photoemission, and calculations for an ultrafast EI source.

NASA’s Goddard Space Flight Center has been developing lidar to remotely measure CO2 and CH4 in the Earth’s atmosphere. The ultimate goal is to make space-based satellite measurements with global coverage. We are working on maturing the technology readiness of a fiber-based, 1.57-micron wavelength laser transmitter designed for use in atmospheric CO2 remote-sensing. To this end, we are building a ruggedized prototype to demonstrate the required power and performance and survive the required environment. We are building a fiber-based master oscillator power amplifier (MOPA) laser transmitter architecture. The laser is a wavelength-locked, single frequency, externally modulated DBR operating at 1.57-micron followed by erbium-doped fiber amplifiers. The last amplifier stage is a polarization-maintaining, very-large-mode-area fiber with ~1000 μm2 effective area pumped by a Raman fiber laser. The optical output is single-frequency, one microsecond pulses with >450 μJ pulse energy, 7.5 KHz repetition rate, single spatial mode, and < 20 dB polarization extinction.

We are developing a Q-switched narrow linewidth intra-cavity Raman laser for a space based sodium lidar application. A novel Raman laser injection seeding scheme is proposed and is experimentally verified. A Q-switched, diode pumped, c-cut Nd:YVO4 laser has been designed to emit a fundamental wavelength at 1066.6 nm. This fundamental wavelength is used as the pump in an intra-cavity Raman conversion in a Gd0.2Y0.8VO4 composite material. By tuning the temperature of the crystal, we tuned the Raman shifting to the desired sodium absorption line. A diode end pumped, T-shaped laser cavity has been built for experimental investigation. The fundamental pump laser cavity is a twisted mode cavity to eliminate the spatial hole burning for effective injection seeding. The Raman laser cavity is a linear standing wave cavity because Raman gain medium does not suffer spatial hole burning as traditional laser gain medium. The linewidth and temporal profile of the Raman laser is experimentally investigated with narrow and broadband fundamental pump emission. We have, for the first time, demonstrated an injection seeded, high peak power, narrow linewidth intra-cavity Raman laser for potential use in a sodium resonance fluorescence lidar.

We propose a nadir-pointing space-based Na Doppler resonance fluorescence LIDAR on board of the International Space Station (ISS). The science instrument goal is temperature and vertical wind measurements of the Earth Mesosphere Lower Thermosphere (MLT) 75-115 km region using atomic sodium as a tracer. Our instrument concept uses a high-energy laser transmitter at 589 nm and highly sensitive photon counting detectors that permit range-resolved atmospheric-sodium-temperature profiles. The atmospheric temperature is deduced from the linewidth of the resonant fluorescence from the atomic sodium vapor D2 line as measured by our tunable laser. We are pursuing high power laser architectures that permit limited day time sodium lidar observations with the help of a narrow bandpass etalon filter. We discuss technology, prototypes, risks and trades for two 589 nm wavelength laser architectures: 1) Raman laser 2) Sum Frequency Generation. Laser-induced saturation of atomic sodium in the MLT region affects both sodium density and temperature measurements. We discuss the saturation impact on the laser parameters, laser architecture and instrument trades. Off-nadir pointing from the ISS causes Doppler shifts that effect the sodium spectroscopy. We discuss laser wavelength locking, tuning and spectroscopic-line sampling strategy.

NASA is developing a highly stable, robust and reliable master oscillator power amplifier laser transmitter. We will discuss our technology development and progress on a spaceborne laser transmitter for the LISA mission.

NASA Goddard Space Flight Center has been developing an integrated path differential absorption (IPDA)lidar instrument concept to measure the column concentrations of atmospheric carbon dioxide (CO 2 )from space. We will discuss the development effort of a space-qualified, single frequency, fiber-based master oscillator power amplifier with >450 μJ pulse energy, 7.5 kHz repetition rate, single spatial mode, and > 20 dB polarization extinction.

NASA GSFC is developing a space-based sodium resonance fluorescence lidar for the International Space Station (ISS). We discuss the technology, prototypes, risks and trades for two laser architectures - Raman laser and sum frequency generation.

We present a laser technology development with space flight heritage to generate laser wavelengths in the near- to midinfrared (NIR to MIR) for space lidar applications. Integrating an optical parametric crystal to the LOLA (Lunar Orbiter Laser Altimeter) laser transmitter design affords selective laser wavelengths from NIR to MIR that are not easily obtainable from traditional diode pumped solid-state lasers. By replacing the output coupler of the LOLA laser with a properly designed parametric crystal, we successfully demonstrated a monolithic intra-cavity optical parametric oscillator (iOPO) laser based on all high technology readiness level (TRL) subsystems and components. Several desired wavelengths have been generated including 2.1 µm, 2.7 μm and 3.4 μm. This laser can also be used in trace-gas remote sensing, as many molecules possess their unique vibrational transitions in NIR to MIR wavelength region, as well as in time-of-flight mass spectrometer where desorption of samples using MIR laser wavelengths have been successfully demonstrated

We present modeling and performance of a solid, fused silica, 3-mirror Fabry–Perot-type etalon. 3-mirror etalons have been known for decades to have superior theoretical performance but for the first time we demonstrate an etalon with sufficient quality to realize the benefits of the more complex design. 3-mirror etalons have better passband shape and higher contrast ratio enabling significantly improved wavelength separation. We show the optical cavity design and construction of the new etalon and show >95% peak transmission, improved passband shape and 20 dB better out-of-band rejection than a similar 2-mirror etalon.

We are developing a multi-wavelength laser for the two-step laser time-of-flight mass-spectrometer (L2MS). The L2MS is designed to detect hydrocarbons in organically-doped analog minerals, including cryogenic Ocean World-relevant ices and mixtures for future astrobiology missions.

Future astrobiology missions will focus on planets with significant astrochemical or potential astrobiological features, such as small, primitive bodies and the icy moons of the outer planets that may host diverse organic compounds. We have made significant progress in the laser desorption/ionization mass spectrometry area with advancement in the two-step laser tandem mass spectrometer (L2MS) instrument to deconvolve complex organic signatures. In this paper we will describe our development effort on a new laser architecture for the L2MS instrument. The laser provides two discrete mid-infrared and ultraviolet wavelengths on a single laser bench with a straightforward path toward space deployment.

We describe an etalon spectrometer with a novel light recirculation scheme to generate simultaneous parallel wavelength channels with no moving parts. We present results from a system to resolve the 1651 nm absorption feature of methane. We present results from a prototype and a corresponding model. We also show results from a solid, 3-mirror etalon that has >95% peak transmission and significantly better out-of-band rejection than its 2-mirror counterpart. We show application of this system to methane laser spectroscopy.

The advent of several key enabling electro-optics technologies afford advanced, non-topographic remote sensing instruments for space. We will present progress on several new, space-based laser instruments that are being developed at NASA GSFC. Long Abstract: In the past 20+ years, NASA Goddard Space Flight Center (GSFC) has successfully developed and flown lidars for mapping of Mars, the Earth, Mercury and the Moon. As laser and electro-optics technologies expand and mature, more sophisticated instruments that once were thought to be too complicated for space are being considered and developed. We will present progress on several new, space-based laser instruments that are being developed at GSFC. These include lidars for remote sensing of carbon dioxide and methane on Earth for carbon cycle and global climate change; sodium resonance fluorescence lidar to measure environmental parameters of the middle and upper atmosphere on Earth and Mars and a wind lidar for Mars orbit; in situ laser instruments include remote and in-situ measurements of the magnetic fields; and a time-of-flight mass spectrometer to study the diversity and structure of nonvolatile organics in solid samples on missions to outer planetary satellites and small bodies.

We describe a Fabry-Perot etalon spectrometer with a novel light recirculation scheme to generate simultaneous parallel wavelength channels with no moving parts. This design uses very simple optics to recirculate light reflected from near normal incidence from the etalon at successively higher angles of incidence. The spectrometer has the full resolution of a Fabry-Perot with significantly improved photon efficiency in a compact, simple design with no moving parts. We present results from a conceptual prototype and a corresponding model.