**1. Introduction**

Dielectric elastomer actuators (DEAs) are currently used in a variety of applications such as robots and medical devices. Since a DEA is very light and capable of high output, it is expected to be able to control the output of the planetary exploration ship and the solar panels loaded on exploration ships.

We are developing a DEA related to the output and control of Mars probes that observe the surface of Mars. Mars Airplane is a new Mars observation platform that enables a wide range of observations from low altitudes. Since 2010, the Japanese Mars spacecraft working group has been working on the conceptual design of Mars airplanes and various basic researches [1–5]. Mars exploration is performed with a weight of 6 kg, a wing width of 2.4 m, and a maximum cruising speed of 70 m/s. We are developing such a machine, as shown in **Figure 1** [6].

We would like to take this airplane down from the Mars exploration spacecraft with a parachute, disconnect the parachute at a high altitude (30 km) on Mars, control its flight remotely, and then gradually lower the altitude to fly a distance of about 300 km. Therefore, it is necessary to avoid high mountains on flights after the middle stage.

This Martian plane can obtain more detailed data than satellites and can observe a wider range than rovers. Also, one of the unique features of the Mars plane is to observe the formations of the canyons. Satellites cannot see the formation from the sky, and rovers cannot approach them.

Flight exploration by Martian planes has some difficulties, as detailed below:

These planes are not mass-produced and are very expensive due to their special payload and avionics for academic research. In addition to this, Mars planes must be

**Figure 1.** *Image of the Mars exploration airplane.*

lightweight to fly in the thin atmosphere of Mars. It also has to be fairly lightweight to carry this spacecraft to Mars as well as to even be transported to Mars itself.

DEAs have the potential to be used as actuators for control surfaces (i.e. ailerons, rudder, and elevator) and as a propeller for the Mars airplane, since it is light and has high output and high efficiency. Another advantage of the DEA is that it is linearly driven, making it less susceptible to dust. This research investigated the feasibility of the DEA for the application of control surfaces (i.e., ailerons, rudder, and elevators) on the Mars airplane. A structural model of a wing having the control surface, the DEA, and a linkage was built, and a wind tunnel test of a control surface actuation using a DE actuator was carried out to investigate the feasibility of the DE actuators for the Mars airplane.

The results obtained in this study will be useful not only for the development of Mars exploration airplanes, but also for the structure and aerodynamic design of lightweight airplanes where large aerodynamic deformation is expected. The study also provides valuable examples of some of the expensive custom-made airplanes for academic research, airplanes that are not capable of many flight tests, and airplane development processes for which conducting flight tests are difficult.
