Ralph: A Visible/Infrared Imager for the New Horizons Pluto/Kuiper Belt Mission

TL;DR

Ralph is a compact, robust visible/infrared imager designed for the New Horizons mission to map Pluto and Kuiper Belt objects' surface geology, composition, and temperature with high sensitivity and reliability.

Contribution

This paper introduces Ralph, a multi-spectral imager with unique design features optimized for long-duration space exploration missions.

Findings

High sensitivity and excellent imaging quality

Low mass and power consumption suitable for spaceflight

Robust design with no moving parts

Abstract

The New Horizons instrument named Ralph is a visible/near infrared multi-spectral imager and a short wavelength infrared spectral imager. It is one of the core instruments on New Horizons, NASA's first mission to the Pluto/Charon system and the Kuiper Belt. Ralph combines panchromatic and color imaging capabilities with IR imaging spectroscopy. Its primary purpose is to map the surface geology and composition of these objects, but it will also be used for atmospheric studies and to map the surface temperature. It is a compact, low-mass (10.5 kg), power efficient (7.1 W peak), and robust instrument with good sensitivity and excellent imaging characteristics. Other than a door opened once in flight, it has no moving parts. These characteristics and its high degree of redundancy make Ralph ideally suited to this long-duration flyby reconnaissance mission.