On February 12, 2001, the NEAR Shoemaker spacecraft made its historic descent to the surface of the asteroid 433 Eros, becoming the first spacecraft to soft land on a small celestial body. Development of the final descent activity offered the NEAR team a difficult technical challenge as the spacecraft had been designed solely as a free flyer, not as a lander. The NEAR Shoemaker spacecraft rende...

Studies of the Earth with the ATS-5, ATS-6, and SCATHA spacecraft led to the development of several simple tools for predicting the potentials to be expected on a spacecraft in the space environment. These tools have been used to estimate the expected levels of worst case charging at Jupiter and Saturn for the Galileo and the Cassini spacecraft missions. This paper reviews those results and put...

This paper investigates the problem of synchronizing the chaotic attitude dynamics of multiple spacecraft is investigated based on the distributed predictive control approach. Kinematic and dynamic equations are used to describe the spacecraft system according to the Modified Rodriguez Parameters representation. The respective method follows the sequential and cooperative structure of distribut...

This paper describes spacecraft formation control and sensing research with application to a Separated Spacecraft Interferometer. A multi-layer control design that achieves very accurate alignment between spacecraft is described. Sensing for this control architecture is based on a global real-time relative position and orientation estimator that uses Carrier Di erential-phase GPS measurements. ...

This paper discusses analytical approaches to evaluating performance of Spacecraft On-Board Computing systems, thereby ultimately achieving a reliable spacecraft data communications systems. The sensitivity analysis approach of memory system on the ProSEDS (Propulsive Small Expendable Deployer System) [I] as a part of its data communication system will be investigated. Also, general issues and ...

spacecraft potential could interfere with the low energy (a few tens of eV) plasma measurements, by biasing the particle distribution functions measured by the detectors. If the spacecraft charges to large negative potentials, the problem will be more severe as low energy electrons will not be seen at all. The Solar Probe Plus and Solar Orbiter cases will be presented in details and extended to...

This paper presents the design of a multi-spacecraft system for the deflection of asteroids. Each spacecraft is equipped with a fibre laser and a solar concentrator. The laser induces the sublimation of a portion of the surface of the asteroid, and the resultant jet of gas and debris thrusts the asteroid off its natural course. The main idea is to have a formation of spacecraft flying in the pr...

Introduction NASA's and JPL's future missions of deep space exploration face the challenge of designing, building, and operating progressively more capable autonomous spacecraft and planetary rovers. Given the latencies of spacecraft-Earth communication for such missions, the need for enhanced autonomy becomes obvious. Earthbased mission controllers will be unable to directly control distant sp...

Secondary electron (SE) emission from spacecraft surfaces as a result of energetic electron bombardment is a key process in the electrical charging of spacecraft. It has been suggested that incorporating more complete knowledge of the energyand angular-distributions of secondary electrons is necessary to fully model how SE emission and spacecraft charging are affected by re-adsorption of low en...