Global Low-Thrust Guidance Scheme for Disaggregated Spacecraft Architectures

Paper number

IAC-12,C1,2,9,x13764

Author

Prof.Dr. Pini Gurfil, Technion, I.I.T., Israel

Coauthor

Mr. Leonael Mazal, Israel Institute of Tecnology, Israel

Coauthor

Dr. Giorgio Mingotti, University of Strathclyde, United Kingdom

Year

2012

Abstract

The concept of disaggregated spacecraft reshapes the classic monolithic satellite into a network
of multiple free-flying wireless-communicating
modules. Compared to
a traditional spacecraft, the subsystems may no longer be connected;
therefore they can be developed, manufactured and launched
separately. Individual
modules can be added, removed or exchanged independently, offering a flexible space architecture. Disaggregated
satellites offer more flexibility, maintainability and
responsiveness compared to traditional designs.

This papers is concerned with the problem of keeping the modules within
prescribed bounded distances (typically less than 100 km) for the entire
mission lifetime (at least 1 year). Guidance and control techniques
are developed to enable cluster flight, assuming a disaggregated
spacecraft architecture. Moreover, the possibility that during the
overall mission at least one of the modules tracks a given reference
orbit is also addressed. It is assumed that each module is equipped
with a low-thrust chemical (cold-gas) propulsion system. With the need
of establishing the cluster after launch and maintaining it for the
entire mission lifetime, dedicated algorithms are proposed
considering continuous bang-off-bang thrust profiles.

In detail, once the disaggregated satellites are launched and
deployed, they start to drift apart because of differential external
disturbing forces. Thus, control strategies are developed in order
to balance the perturbations while minimizing the fuel
consumption for a long-term mission. 

The work is organized as
follows: First, a \textit{local} continuous low-thrust maneuver is
implemented in order to configure the cluster, starting from the
deployment conditions: the modules are taken -- within few orbital
periods -- to ideal initial relative conditions, which yield low-drift inter-module distances. Second, a \textit{global}
cooperative guidance strategy is derived to render the cluster
operational for long-term time intervals. Two different thruster
configurations are investigated: A single gimballed thruster and
six body-fixed thrusters. A general approach is proposed that enables
optimizing both thruster architectures under the
same mathematical formulation.

Abstract document

IAC-12,C1,2,9,x13764.brief.pdf

Manuscript document

IAC-12,C1,2,9,x13764.pdf (🔒 authorized access only).

To get the manuscript, please contact IAF Secretariat.