Attitude control of an inflatable sailplane for mars exploration

Exploration of Mars has been made possible using a series of landers, rovers and orbiters. The HiRise camera on the Mars Reconnaissance Orbiter (MRO) has captured high-resolution images covering large tracts of the surface. However, orbital images lack the depth and rich detail obtained from in-situ exploration. Rovers such as Mars Science Laboratory and upcoming Mars 2020 carry stateof- the-art science laboratories to perform in-situ exploration and analysis. However, they can only cover a small area of Mars through the course of their mission. A critical capability gap exists in our ability to image, provide services and explore large tracts of the surface of Mars required for enabling a future human mission. A promising solution is to develop a reconnaissance sailplane that travels tens to hundreds of kilometers per sol. The aircraft would be equipped with imagers that provide that in-situ depth of field, with coverage comparable to orbital assets such as MRO. A major challenge is that the Martian carbon dioxide atmosphere is thin, with a pressure of 1% of Earth at sea level. To compensate, the aircraft needs to fly at high-velocities and have sufficiently large wing area to generate the required lift. Inflatable wings are an excellent choice as they have the lowest mass and can be used to change shape (morph) depending on aerodynamic or control requirements. In this paper, we present our design of an inflatable sailplane capable of deploying from a 12U CubeSat platform. A pneumatic deployment mechanism ensures highly compact stowage volumes and minimizes complexity. The present work attempts to describe expected dynamic behavior of the design and contributes to evolving an effective strategy for attitude control required for stable flight and high-quality imaging. The use of Dynamic Soaring as a means of sustained unpowered flight in the low-density Martian atmosphere will be studied through a point mass sailplane model. Using a linear wind gradient model of the Martian atmospheric boundary layer, numerical simulations of such trajectories will attempt to demonstrate that longer duration missions can be conducted using such hardware and flight characteristics.