Abstract

The use of solar radiation force for reconfiguration of spacecraft formations beside one of the collinear sun- Earth liberation points is examined. Specifically, it is advised if spacecraft that are equipped with sunfacing thermal protects can exploit the solar radiation force that actions on them to present stepwise relation manoeuvring. Small protect off-pointing twists give increase to differential solar radiation force forces that are vitally perpendicular to the sun line: The result of these little differential forces on the relation action of the spacecraft in the formation is, thus, rather distinct from that of the total (down-sun) solar force on the unconditional orbital movement. First, the linearized formulas of relation action for liberation issue formations under differential solar radiation compelling are set up, with the sun protect off-pointing bend taken as the command input variable.

Formation Flying of Spacecraft at Sun-Earth Libration Points L2 Using Solar Radiation Pressure

Introduction

The variety of validity of these formulas is examined. The result of solar radiation force on the unconditional action is furthermore investigated, and the station-keeping topic is bypassed by moving the initial liberation issue to a new equilibrium point. These formulas are then utilised to study the reality and properties of answer trajectories that take the spacecraft from granted primary formation geometry to a yearned last one. When the vector command made by solar radiation force is decreased to a scalar one, the reality and properties of time-optimal trajectories founded on bang-bang command idea are analyzed. Comparisons made between these two kinds of move trajectories display that the previous own easier guiding of sun protects, while the last cited have a shorter move time and more reachable points in the goal orbit.

There is actually substantial concern in missions that engage air journey about a liberation issue of either the sun-Earth or Earth-moon system. Several of these suggested missions engage multiple spacecraft soaring in formation, often accomplishing astronomical interferometer from the vantage issue of the sun-Earth L1 or L2 point. Two specific demonstrations of such missions are the NASA MicroArcsecond X-Ray Imaging Mission (MAXIM) Pathfinder design.

MAXIM Pathfinder comprises of a hub spacecraft and a formation of likely six telescope spacecraft, with the last cited equally positioned about a around of radius 100-500 m centralised on the hub. In supplement, a detector spacecraft is positioned 20,000 km out of the telescope/hub plane. DARWIN likewise comprises of a centered hub spacecraft, six infrared telescope spacecraft soaring at accurate places in a plane encompassing the hub, and a expert spacecraft positioned some century meters behind this plane.

The function of the hub vehicle is to blend optically the pointers assembled by the telescopes and that of the expert is both to convey out communications with Earth and to supervise the relation positioning of the telescope spacecraft. Because DARWIN observes at infrared wavelengths, the telescope spacecraft are equipped with somewhat large sun protects, alike to that of the JamesWebb Space Telescope (JWST) (more data accessible online at URL: http://www.jwst.nasa.gov/FastFacts.htm [cited 12 Aug. 2004]), to hold the sensor temperatures ...