© NASA | Apollo 17: Returning to the rover
Science on the Moon and science of the Moon are two very interesting and upcoming fields of space exploration. Even if men stepped on the surface of the Moon more than 40 years ago, some lunar areas have not been explored until today. Science of the Moon is mainly driven by the exploration of the lunar interior, the lunar core and also the surface of the Moon. Therefore, seismic measurements and measurement networks on the Moon are essential to get a better understanding of our next neighbor. The main problem on the far side of the Moon is the lack of communication to Earth. But the far side of the Moon is a key target area for space exploration, e.g. for the construction of telescopes which are able to look into deep space without disturbances from Earth. Next to the lack of communication, there is a major problem due to the harsh thermal environment, since there are temperature cycles from 130° C down to -160°C. These challenges can only be solved by installation of supporting infrastructures able to protect the scientific measurement systems.
The work package 1200 comprises the design or conception of surface experiments and instruments for geophysics.
The investigation of the deep lunar interior requires setting up a suite of geophysical instruments or of a network of such instruments. A possible instrumentation comprises seismometers, gravimeters, tilt and strain meters, and geodetic instruments like Laser reflectors or beacons. A robotic mission with both a stationary and a mobile component (rover) will be investigated for a combined active/passive seismic experiment accompanied by geological investigations of rock composition and volatile content. The stationary component will consist of infrastructure modules for communication and power supply, and by a seismic sensor array that is deployed by the rover. The rover will travel to a distance up to 10 km between which it returns to the base station. To optimize the seismic efficiency of the experiment, the rover will also communicate with the central station in order to fire as many seismic sources as necessary to obtain a useful signal-to-noise ratio. Suitable source types still need to be identified. The following study tasks arise from this concept:
- Reappraise the Apollo Active Seismic Experiment data in the light of refined impact positions and determine its depth resolution and limitations
- Optimize seismic array design: trade-offs between sensor type, sensor number, array geometry, and sources
- Optimize experiment protocols: minimize energy consumption of seismic source, repeatability, limitations by day/night cycle
- Develop camera technology for geological observations
The concept for a lunar autonomously conducted experiment suite described above will require the development/improvement of several system components:
- Scalable power sources (or different types of powers sources) for use in central stations, small instrument packages, navigation beacons, mobile units
- Module system e.g. for power, communication, science experiments
- Navigation beacons e.g. for positioning mobile components
- Autonomous mobility e.g. for inspection of remote sites, transporting of components
- Communication between stationary and mobile components (e.g. for optimizing the signal to noise ratio while firing seismic sources)
- Manipulation abilities, e.g. to set up infrastructure, deploy instruments, handle samples
