Jose I. Rodriguez

Performance of the MISR instrument during its first 20 months in Earth orbit

The Multi-angle Imaging SpectroRadiometer, one of five science instruments aboard NASAs Terra spacecraft, was launched into Earth orbit in December 1999. Acquisition of Earth imagery began in February 2000, and the quality of the data is excellent. Overall, MISR has been performing superbly, though the instrument exhibits several idiosyncrasies, some of which were anticipated prior to launch. Details regarding the in-flight performance of the instrument system are presented.

Ultra-compact imaging spectrometer for remote, in situ, and microscopic planetary mineralogy

Abstract The ultra-compact imaging spectrometer is a miniature imaging spectrometer that has been designed for compatibility with operation in a Martian environment. The spectrometer can be mated to a variety of front optics, both telescopic and microscopic. With a miniature telescope, it can serve as a rover mast instrument that surveys the surrounding area from a distance of ∼ 1     m to infinity and produces full spectral data (500 to 2500 nm) of a wide panoramic scene in order to find the most mineralogically promising targets for further analysis and for directing subsequent rover activities. With a microscopic front lens, it can serve as an analytical tool for determining types of minerals in a rock and their spatial relations at a scale of tens of micrometers in order to make detailed interpretations of geological history. A realization of the instrument, adapted for operation in the Earth’s atmosphere, has been produced and tested both in the laboratory and in the field. The results prove the ability of the instrument to detect and map minerals of interest in both modes of operation.

The Orbiting Carbon Observatory instrument: performance of the OCO instrument and plans for the OCO-2 instrument

NASAs Orbiting Carbon Observatory (OCO) was designed to make measurements of carbon dioxide concentrations from space with the precision and accuracy required to identify sources and sinks on regions scales (~1,000 km). Unfortunately, OCO was lost due to a failure of the launch vehicle. Since then, work has started on OCO-2, planned for launch in early 2013. This paper will document the OCO instrument performance and discuss the changes planned for the OCO-2 instrument.

TPF-Emma: concept study of a planet finding space interferometer

A novel space interferometer design originating in Europe has been studied. The interferometer uses the technique of starlight nulling to enable detection of earth-like planets orbiting nearby stars. A set of four telescope spacecraft flying in formation with a fifth, beam-combiner spacecraft forms the interferometer. This particular concept shows potential for reducing the mission cost when compared with previous concepts by greatly reducing the complexity of the telescope spacecraft. These spacecraft have no major deployable systems, have simplified propulsion and a more rugged construction. The formation flying geometry provides for greater average separation between the spacecraft with commensurate risk reduction. Key aspects of the design have been studied at the Jet Propulsion Laboratory with a view to collaborations between NASA and the European Space Agency. An overview of the design study is presented with some comparisons with the TPF-FFI concept.

Design Study for a Planet-Finding Space Interferometer

The characterization of earth like planets that may be orbiting nearby stars will require large observatories capable of detecting a small number of planet photons and separating them from the much larger flux from the parent star. One approach to this is to employ nulling interferometry on a space-based platform utilizing a number of spacecraft. At the Jet Propulsion Laboratory, a linear dual chopped Bracewell array design was studied in depth while in Europe various two-dimensional designs were discussed. This study looks in a little more depth at the design issues for one of the European concepts and concludes that the concept has promise for a significant reduction in spacecraft complexity and mass and therefore would result in a lower cost mission.

NGST MIRI instrument

The MIRI is the mid-IR (5-28μm) instrument for NGST and provides for imaging, cororographic, high- and low-resolution spectroscopic capabilities. Unlike to the other instruments on NGST, the MIRI must be cooled - to reduce the thermal background from the optics and because the detectors require an operating temperature of about 7k.. In this paper we summarise the science goals, the proposed overall opto-mechanical concept, the thermal design aspects, the detectors and the expected sensitivity of the instrument.

Optical Design and Performance of the Ultra-Compact Imaging Spectrometer

We present the optical design and performance of the Ultra-Compact Imaging Spectrometer (UCIS) currently under development at Caltechs Jet Propulsion Laboratory. The new instrument demonstrates a low optical bench mass of less than 0.5 kg and compact size that enables Mars Rover or other in situ planetary applications. UCIS is an F/4, wide field (30°) design, covering the spectral range 600-2600 nm and is enabled by a simple all aluminum two-mirror telescope and Offner spectrometer. We discuss here the optical design and alignment method that enables this compact and low mass imaging spectrometer and demonstrate successful spectrometer alignment with smile and keystone levels at 2-3% of a pixel width.

On‐Orbit Performance of the TES Pulse Tube Coolers and Instrument — A First Year in Space

Launched on NASA’s Aura spacecraft on July 15, 2004, JPL’s Tropospheric Emission Spectrometer (TES) instrument has completed a successful first year in space and captured a number of important lessons. The instrument contains four focal plane arrays in two separate housings cooled to 65 K by a pair of NGST pulse tube cryocoolers. The instrument includes a two‐stage passive cooler to cool the optical bench to 180 K. The cryocooler system design is tightly coupled with the overall thermal control design to maximize performance. Soon after cooling the optical bench and focal planes to their operating temperatures on August 20, 2004, ice contamination of the focal planes led to the need of a decontamination cycle. Ice buildup of cryogenic surfaces led to increased cryocooler heat loads. After six months of successful science operations, plans were developed to increase the optics temperature to 187 K to improve the interferometer optical alignment and obtain higher quality science data. The plan is in place a...

Investigation of Transient Temperature Oscillations of a Propylene Loop Heat Pipe

This paper reports on the transient characterization testing results showing low frequency temperature oscillations.

Portable Remote Imaging Spectrometer (PRISM): Laboratory and Field Calibration

We report the characteristics of the Portable Remote Imaging Spectrometer, an airborne sensor specifically designed for the challenges of coastal ocean research. PRISM has high signal to noise ratio and uniformity, as well as low polarization sensitivity. Acquisition of high quality data has been demonstrated with the first engineering flight.