Mars Atmosphere Sounding Balloon: Science Case and System Design

Kurzfassung

Measurements of the state and the variability of the Martian atmosphere significantly contribute to the scientific goal to understand the atmospheric processes on Mars and the engineering goal to prepare for and to de-risk entry, descent and landing operations for future large landing crafts. Balloon-borne instruments could bridge the gap in both temporal and spatial resolution in mesoscale distances between local, stationary landers and global orbiter observations in a similar way as balloon-radiosondes still used today on Earth. The idea to use balloon systems on Mars is not new in essence and has already been proposed in past decades. While those concepts considered an aerial deployment during entry and descent, the concept outlined here revisits a launch off the payload deck of a lander from the Martian surface. This deployment option profits today mainly from the technological advances in micro-electronics and sensor miniaturization which enable designing a balloon-probe significantly smaller than earlier proposed systems. The primary components of the proposed balloon instrument have been subject to testing to mature the concept's critical functions. Particularly, the hull inflation was tested with a sub-scale model in a low speed wind tunnel to determine the hull's aerodynamic properties in ground proximity and inflation characteristics under wind load. The basic avionic and sensor package has been flown as a radiosonde payload. This paper presents the development status for this instrument and gives further details on the scientific and operational concept, its technical components. It is complemented by the assessment of the risks involved in automatically launching such balloon-system off the Martian surface.