David H. Rodgers

Pluto integrated camera spectrometer (PICS) instrument

Abstract We describe an integrated instrument that will perform the functions of three optical instruments required by a Pluto Fast Flyby mission: a near-IR spectrometer (256 spectral channels, 1300–2600 nm), a two-channel imaging camera (300–500 nm, 500–1000 nm), and a UV spectrometer (80 spectral channels, 70–150 nm). A separate port, aligned in a direction compatible with radio occultation experiments, is provided for measurement of a UV solar occultation and for spectral radiance calibration of the IR and visible subsystems. Our integrated approach minimizes mass and power use, and promotes the adoption of integrated observational sequences and power management to ensure compatible duty cycles for data acquisition, compression, and storage. From flight mission experience, we believe the integrated approach will yield substantial cost savings in design, integration, and sequence planning. The integrated payload inherently provides a cohesive mission data set, optimized for correlative analysis. A breadboard version of the instrument is currently being built and is expected to be fully functional by late summer.

Kuiper Express: A Sciencecraft

The Kuiper Express is a mission to achieve the first reconnaissance of one of the primitive objects that reside in the Kuiper Belt. The objects in the Kuiper Belt are the remnants of the planetesimal swarm that formed the four giant planets of the outer Solar System. These objects, because they are far from the Sun, have not been processed by solar heating and are essentially in their primordial state. This makes them unique objects and their study will provide information on the composition of the solar nebula that cannot be extracted from a study of other objects in the Solar System. The Kuiper Express is a sciencecraft mission. A sciencecraft is an integrated unit that combines into a single system the essential elements (but no more) necessary to achieve the science objectives of the mission, including science instruments, electronics, telecommunications, power, and propulsion. The design of a sciencecraft begins with the definition of mission science objectives and cost constraint. An observational sequence and sensor subsystem are then designed. This sensor subsystem in turn becomes the design driver for the sciencecraft architecture and hardware subsystems needed to deliver the sensor to its target and return the science data to the earth. Throughout the design process, shared functionality, shared redundancy, and reduced cost are strongly emphasized. The Kuiper Express will be launched using a Delta vehicle and will use solar electric propulsion to add velocity and shape its trajectory in the inner Solar System, executing two earth gravity-assist flybys. It will also execute flybys of main belt asteroids, Mars, Uranus, and Neptune/Triton en route to its target in the Kuiper belt, where it will arrive about ten years after launch. It will use no nuclear power. The surface constituents and morphology of the objects visited will be measured and their atmospheres will be characterized. The cost of the detailed design, fabrication, and launch of the Kuiper Express is consistent with the

Planetary Integrated Camera Spectrometer (PICS): a new approach to developing a self-sequencing, integrated, multiwavelength instrument

150M limit set by the NASA Discovery Program.

Light weight, highly integrated optical systems for the new millennium program

The planetary integrated camera-spectrometer, PICS, is a highly integrated sensor system which performs the functions of three optical instruments: a near infrared (IR) spectrometer, a visible imaging camera, and an ultraviolet (UV) spectrometer. Integration serves to minimize the mass and power required to operate a complex suite of instruments, and automatically yields a comprehensive data set, optimized for correlative analysis. This approach is useful for deep space missions such as Pluto Express and will also enable Galileo/Cassini class remote observations of any object within the solar system. In our baseline concept, a single set of lightweight multiwavelength foreoptics is shared by a UV imaging spectrometer (80 spectral channels 70 - 150 nm), a two-CCD visible imaging system (shuttered in two colors 300 - 500 nm and 500 - 1000 nm), and a near-IR imaging spectrometer (256 spectral channels 1300-2600 nm). The entire structure, including its optics, is built from silicon carbide (SiC) for thermal and dimensional stability. In addition, there are no moving parts and each spectrometer covers a single octave in wavelength. A separate port is provided for measurement of a UV solar occultation and for spectral radiance calibration of the IR and visible subsystems. The integrated science that the PICS will yield meets or exceeds all of the Priority-1A science objectives, and many Priority 1-B science objectives as well, for the Pluto Express Mission. This paper provides details of the PICs instrument design, fabrication and testing, both at the sub-assembly and the instrument level. In all tests, including optical, thermal vacuum, and structural/dynamics, the PICS hardware prototype met or exceeded functional requirements.

Development of the second generation Wide-Field Planetary Camera for Hubble Space Telescope service mission

Over the past four years SSG has been working with the support of JPL to develop light weight, high performance optical systems for earth orbit and deep space missions. These programs, which include both ground demonstrations and flight instruments, achieve the improved weight and performance through a combination of two main features: multifunctional design and silicon carbide optics and structures. Multifunctional designs include aperture sharing telescopes and spectrometers that not only perform science, but can be used for optical navigation and laser communication. SiC, in monolithic form for optics and in composite form for fracture-tough structures, enables very light weight systems that are passively athermal to cryogenic temperatures. Ground demonstrations of several of these technologies have led to the upcoming flight demonstrations on DS-1 and EO-1, as well as candidate telescopes for other technology flights. These advances are currently being extended to the next level of multifunctionality ...

NEPTUNE regional observatory system design

The Wide Field and Planetary Camera (WFPC) is the principal instrument of the Hubble Space Telescope (HST), occupying the central portion of the telescopes focal plane. The Wide Field Camera meets the originally conceived requirement for an imaging device that covers a square field of view 2.67 arc minutes on a side with a pixel size of 0.1 arc second. The so-called Planetary Camera of WFPC offers a longer effective focal length over a smaller field (yielding 0.043 arc second per pixel) to better sample the point spread function of the telescope for critical definition imaging. The first generation WFPC (WFPC-1) was initiated in late 1977 and launched with the HST in April, 1990. A second generation backup instrument (WFPC-2) currently scheduled for launch in late 1993 will carry corrective optics to restore the flawed vision of the HST. The present paper traces the history of these developments.