Search

Planetary Instrument for X-ray Lithochemistry (PIXL) is a micro-focus X-ray fluorescence spectrometer mounted on the robotic arm of NASA’s Perseverance rover. PIXL will acquire high spatial resolution observations of rock and soil chemistry, rapidly analyzing the elemental chemistry of a target surface. In 10 seconds, PIXL can use its powerful 120 μm-diameter X-ray beam to analyze a single, sand-sized grain with enough sensitivity to detect major and minor rock-forming elements, as well as many trace elements. Over a period of several hours, PIXL can autonomously raster-scan an area of the rock surface and acquire a hyperspectral map comprised of several thousand individual measured points. When correlated to a visual image acquired by PIXL’s camera, these maps reveal the distribution and abundance variations of chemical elements making up the rock, tied accurately to the physical texture and structure of the rock, at a scale comparable to a 10X magnifying geological hand lens. The many thousands of spectra in these postage stamp-sized elemental maps may be analyzed individually or summed together to create a bulk rock analysis, or subsets of spectra may be summed, quantified, analyzed, and compared using PIXLISE data analysis software. This hand lens-scale view of the petrology and geochemistry of materials at the Perseverance landing site will provide a valuable link between the larger, centimeter- to meter-scale observations by Mastcam-Z, RIMFAX and Supercam, and the much smaller (micron-scale) measurements that would be made on returned samples in terrestrial laboratories.

A commercial position sensing detector (PSD) has been used to measure mast deflections on a space based X-ray telescope (NuSTAR). This paper describes the space qualification process for utilizing a commercial PSD sensor in space. This discussion includes packaging, environmental testing, selection of flight candidate devices, calibration and alignment.

Reliability and lifetime of diode lasers is critical to space missions. 12Rigorous tests were conducted on diode lasers to qualify them to be deployed on the Nuclear Spectroscopic Telescope Array (NuSTAR) mission. This mission includes a metrology system that is based upon 2 laser diodes. This paper discusses the different laser diode failure mechanisms that can arise, as well as laser diode reliability requirements set forth by the NuSTAR space mission. In addition, the space qualification procedures and results on 120 laser diodes from two different vendors will be presented. Also, the results of an accelerated laser lifetime test of 20 laser diodes, along with the flight laser diode selection process will be described in this paper.

Laser-based metrology has been identified as an enabling technology in the deployment of large, spaceborne observatories, where nanometer-level knowledge of fiducial displacement drives overall system performance. In particular, Nd:YAG NPRO (non-planar ring oscillator) based lasers have received considerable attention in this application because of their inherent high coherence at wavelengths of interest (1064 and 1319nm). However, the use of NPRO based lasers in decade long space missions is limited by typical 800nm-band pump laser diode wearout and random failure rates. Therefore, reliably achieving multi-hundred milliwatt NPRO power over prolonged mission lifetimes requires innovative pump architectures. In this paper we present a pump architecture capable of supporting continuous NPRO operation over 5.5yrs at 300mW with reliability exceeding 99.7%. The proposed architecture relies on a low-loss, high port count, all-fiber optical coupler to combine the outputs of multiple single-mode pump laser diodes. This coupler is capable of meeting the exacting environmental requirements placed by a space mission, such as SIM Lite.

We have designed and built a hollow-core fiber frequency reference cell, filled it with CO2, and used it to demonstrate frequency stabilization of a 2.05 μm Tm:Ho:YLF laser using frequency modulation (FM) spectroscopy technique. The frequency reference cell is housed in a compact and robust hermetic package that contains a several meter long hollow-core photonic crystal fiber optically coupled to index-guiding fibers with a fusion splice on one end and a mechanical splice on the other end. The package has connectorized fiber pigtails and a valve used to evacuate, refill it, or adjust the gas pressure. We have demonstrated laser frequency standard deviation decreasing from >450MHz (free-running) to

A metrology system designed and built for the NuSTAR mission is described. The NuSTAR mission is an orbiting X-ray telescope with a 10 meter focal length. The system consists of two laser pointers mounted rigidly together with a star tracker and the X-ray optics. The focused laser beams illuminates two metrology detectors mounted rigidly with the X-ray detectors. The detectors and optics/lasers are separated by a ∼10 meter deployable (and somewhat flexible) carbon fiber mast. Details about the implementation of the metrology system is discussed in this paper. 12

A simple method for evacuating, refilling and connectorizing hollow-core photonic crystal fiber for use as gas reference cell is proposed and demonstrated. It relies on torch-sealing a quartz filling tube connected to a mechanical splice between regular and hollow-core fibers.

A laser radar system has been constructed. It is based on a commercial PC with digitizer, pulse delay instrument, National Instruments IO card and an optical head from a previous laser radar program. The laser radar was mounted on a gyro stabilized gimbal on the nose of a helicopter and flown in the Mojave Desert in September 2006. The collected data will be used to test algorithms for future precision lunar landers, which may be utilizing a laser radar as the primary landing sensor. This paper will describe the laser radar and PC based acquisition system used for the data collection, and provide an overview of the supporting test sensors and architecture. Preliminary data collected during the helicopter field testing will also be presented.

A metrology system to measure the on-orbit movement of a ten meter mast has been built for the Nuclear Spectroscopic Telescope Array (NuSTAR) x-ray observatory. In this paper, the metrology system is described, and the performance is measured. The laser beam stability is discussed in detail. Pre-launch alignment and calibration are also described. The invisible infrared laser beams must be aligned to their corresponding detectors without deploying the telescope in Earth’s gravity. Finally, a possible method for in-flight calibration of the metrology system is described.