Abstract
SSTL has been studying the application of its highly successful Low Earth Orbit micro and mini-satellites for lunar and planetary missions since 1996, through in-house funded design exercises and supported by ESA through Lunar and inner planet mission studies. Technical feasibility of a minisatellite lunar orbiter has been demonstrated. SSTL has since developed a range of improved subsystems and more advanced platforms, many of which have gained heritage in-orbit. These include the GMP-MiniSat platform with deployable solar arrays, accurate 3-axis stabilized attitude control, high resolution and wide field-of-view multispectral cameras and low cost bipropellant propulsion systems. Low cost launch options range from a Proton auxiliary payload launch direct to geostationary orbit, to prime passenger on a PSLV, to secondary payload alongside larger lunar missions. While SSTL is focused on low cost lunar orbiter development, it is jointly considering affordable means of conducting lunar landing, and ultimately sample return with the University of Surrey Space Centre. Lunar landing and sample return would demonstrate the applicability of low-cost small spacecraft technology to reduce the risk of high profile and barely affordable missions such as Mars Sample Return, by demonstrating key technologies, offering secondary science, and increased mission frequency to build enthusiastic public and political support. A parametric study for a lunar sample return mission from the south polar Aitken basin is highlighted, which has shown that a 15kg rover can in principle be landed on the lunar surface for a maximum surface stay of 150hours, subsequently returning a 200g sample to Earth, for a total launch mass from Earth orbit of less than 500kg, using a mixture of chemical and electric propulsion. This paper briefly considers the technology requirements and COTS technology availability for the separate mission stages, in order to establish how SSTL's low cost approach may be applicable to this challenging mission. This study is an ongoing area of research between SSTL and the University of Surrey Space centre.