No abstract

No abstract

Absfract-The objective of the Terrestrial Planet Finder (TPF) mission is to find and characterize earth-like planets orbiting other stars. Three architectural options are under consideration for this mission: a formation-flying interferometer (FFI), a structurally-connected interferometer, and a coronagraph. One of these options will be selected as the TPF baseline design in 2006. This paper describes the technology tasks underway to establish the viability of precision formation flying for the FFI option. In particular, interferometric science observations require autonomous precise control and maneuvering of five spacecraft to an accuracy of 2 cm in range and 1 arc-minute in bearing. This precision must be maintained over interspacecraft ranges varying ftom a few meters to hundreds of meten. Autonomous operations, ranging kom formation acquisition and formation maneuvering to high precision formation flying during science observations, are required. Challenges lie in meeting the demanding performance requirements as well as in demonstrating the long-term robustness of the autonomous formation flying system. These challenges are unprecedented for deep space missions. To address them, research is under way in the areas of formation control algorithms, relative sensor technologies, system design, end-to-end real-time system simulation, and ground-based and micro-g end-to-end system demonstrations. Four interrelated testbeds are under development concurrently with the FFI system design.

This paper documents a software package for solving the Sylvester matrix equation (1) AXB T + CXD T = e All quantities are real matrices; A and C are m x n ; B and D are m x n ; and X and E are m x n . The unknown is X . Two symmetric forms of Eq. (1) are treated separately for efficiency. They are the continuous-time symmetric Sylvester equation (2) AXE T + EXA T + C = 0 and the discrete time equation (3) AXA T + C = 0, for which A , E , and C is symmetric. The software also provides a means for estimating the condition number of these three equations. The algorithms employed are more fully described in an accompanying paper [3].

No abstract