New Mission and Spacecraft Design Enabled Using MSAC

Abstract

A new attitude control system (ACS) called Multifunctional Structures for Attitude Control (MSAC) utilizes structures onboard a spacecraft to provide active noise cancellation and large-angle slewing capabilities. Previous studies have detailed the system trades and physical and control designs that maximize the pointing performance of an MSAC system. As a result, the MSAC system can provide sub-milli-arc-second(mas)/nano-radian level pointing stability and accuracy. Traditional spacecraft design is formulated based on conventional spacecraft bus systems, of which conventional ACSs are a significant driver for the mass and volume of the spacecraft. MSAC relaxes these requirements and enables a new class of spacecraft missions. This paper details the new spacecraft architectures with large area-to-mass ratios that can be enabled using the MSAC system, such as solar sails, Disksats, ChipSats, etc. In addition to standalone spacecraft, MSAC can also be used to provide independent actuation capabilities to different subsystems onboard a spacecraft, such as self-steering antennas, solar panels, and thermal radiators. These new spacecraft busses and subsystems are made possible using MSAC, which can profoundly impact constellation mission development and deployment. Currently, MSAC exists as three main variants for use with different mission types and varying design complexity levels. This paper compares the different variants, and the control authority obtained using the different implementations. In addition to rotational control, MSAC also offers translational position control. These translational positioning capabilities are best at small scales (micrometer-level positioning). The position control can be utilized for internal translational active noise cancellation and formation flying missions that are sensitive to a spacecraft's position. Using the fine pointing and positioning accuracy and stability offered by MSAC can increase communication data rates for deep space optical communication, as well as enable missions such as distributed swarms and LISA.