Conceptual Design of a Mars Rotorcraft for Future Sample Fetch Missions

This paper describes a conceptual Mars rotorcraft designed to assist a notional Mars sample return mission by providing high resolution terrain mapping, science images, and sample fetch capability when paired in tandem with a conventional rover or lander. The concept of operations is similar to the Ingenuity Mars Helicopter flown as part of the Mars 2020 mission with the fetch rotorcraft stowed on a lander or rover through entry, decent, and landing at Mars, followed by deployment to the surface and operation as a standalone spacecraft. The payload capability of the rotorcraft is 280 grams when outfitted with a manipulator arm and wheeled mobility system; this payload could take the form of samples being collected for retrieval, stereo camera pairs for terrain mapping, high-resolution cameras for imaging science targets inaccessible to rovers, MEMS sensors such as gravimeters or soil humidity sensors. The concept being presented is a coaxial helicopter based heavily on the system developed and validated through the Ingenuity technology demonstration program; key components are modified based on lessons learned from Ingenuity's flights at Mars to increase the endurance and payload capability of the helicopter while maintaining the majority of the flight heritage. Modifications to the baseline Ingenuity design include an updated battery with higher specific energy, a lighter collective-only upper rotor control system, updates to the propulsion motor, and a larger solar array. To accomplish separation from the lander prior to flight and safe operation around the primary mission assets, the helicopter includes a wheeled mobility system mounted to the landing gear which has been prototyped and tested in representative conditions on Earth. In this paper, the authors will present the concept of operations for the system, the conceptual design for the helicopter, several options for accommodation and egress from the lander or rover, and aerodynamic design and performance estimates for the rotors and power system. In addition, prototypes of the wheeled mobility system and a 90 g robotic arm for sample collection will be presented and discussed.