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...

This paper describes the Automated Scheduling and Planning Environment (ASPEN). ASPEN encodes complex spacecraft knowledge of operability constraints, flight rules, spacecraft hardware, science experiments and operations procedures to allow for automated generation of low level spacecraft sequences. Using a technique called iterative repair, ASPEN classifies constraint violations (i.e., conflic...

25 years of continuous operation-now renamed Voyager Interstellar Mission Can operate until 2020 based on available power and attitude control propulsion With some loss of subsystem redundancy, operates with full science payload Spacecraft has extensive autonomous fault-detection and protection capabilities covering multitude of possible failures. Designed using radiation hard parts and extensi...

The problem of reorienting a spacecraft in to acquire a moving target is investigated. The spacecraft is modeled as a rigid body with N axisymmetric wheels controlled by axial torques, and the kinematics are represented by Modified Rodriques Parameters. The trajectory, denoted the reference trajectory, is one generated by a virtual spacecraft that is identical to the actual spacecraft. The open...