The low earth orbit environment observed using CREAM and CREDO.

The Cosmic Radiation Environment and Dosimetry experiment (CREDO) has been operational on board the Advanced Photovoltaics & Electronics Experiment Spacecraft since August 1994. Extensive measurements of cosmic ray linear energy transfer spectra (using data to January 1996) and total dose (using data to November 1994) have been made, and compared with predictions of standard models. Detailed consideration of spacecraft shielding effects have been made. Predictions are shown to overestimate the measured linear energy transfer spectra. The CREAM experiment was flown on STS-63 in the SpaceHab module. Results show penetration of high energy electrons into the SpaceHab module.     

Tetrahedral Robotics for Space Exploration

A reconfigurable space filling robotic architecture has a wide range of possible applications. One of the more intriguing possibilities is mobility in very irregular and otherwise impassable terrain. NASA Goddard Space Flight Center is developing the third generation of its addressable reconfigurable technology (ART) tetrahedral robotics architecture. An ART-based variable geometry truss consisting of 12 tetrahedral elements made from 26 smart struts on a wireless network has been developed. The primary goal of this development is the demonstration of a new kind of robotic mobility that can provide access and articulation that complement existing capabilities. An initial set of gaits and other behaviors are being tested, and accommodations for payloads such as sensor and telemetry packages are being studied. Herein, we describe our experience with the ART tetrahedral robotics architecture and the improvements implemented in the third generation of this technology. Applications of these robots to space exploration and the tradeoffs involved with this architecture will be discussed.