Understanding what lies beneath the lunar surface could be critical for future exploration. A number of missions have already mapped some regions below the Moon’s surface. Despite all this, few have dived deep inland where large lava caves or potentially valuable water or mineral deposits are found. But that can change. NASA’s Institute for Advanced Concepts (NIAC) has funded new technology developed by a team at the Jet Propulsion Laboratory (JPL) that could solve the age-old problem of observing what’s in the middle of the Moon.

The Passive Expandable Dipole Array for Lunar Detection (or PEDALS) project uses a self-deployment technique to place a large-scale antenna on the lunar surface. Once docked, it can collect subterranean moon data up to several kilometers away, comparable to the deepest data we’ve ever collected.

So far, the deepest data has been collected by the lunar radar orbiting SELENE (better known as Kayuga). However, it deliberately crashed into the moon in 2009, and although it could track signals up to 5km away, it didn’t produce anything resembling a high-resolution image.

Lava tubes are one of the most intriguing parts of the lunar surface. Other sounds, some from later Apollo missions, had higher resolution, but could reach depths to provide a better understanding of the structure of the lunar surface. A presentation by the JPL team outlined five scientific challenges that can be overcome with PEDALS, from mapping 3D volcanic interfaces to understanding the density of rocks in a given area.

So how will the system achieve these goals? PEDALS landed using the tradition of falling to the surface in a cushion of air. Once there, it will launch a spiral explosion, a concept that has been the focus of NASA research for several years. Theoretically, there is no real limit to the size of the pedal boom, but the volume of the airbag and the surface area that the antenna must cover will have an effect.

Once deployed, PEDALS collects data using its antenna. How this antenna will look remains a topic of research, as the presentation detailed two potential configurations – a loop antenna or a dipole. Both have their pros and cons, but the JPL team needs to do more research to determine which would be more useful for use per month.

The lava tubes on the Moon are of particular interest.

An obvious question is where can you deploy this thing? A passive view of the Apollo missions shows that the Moon is not very flat, and huge boulders are randomly scattered. By calculating the size of the rocks (they estimate a maximum diameter of 50 cm) and the amount of space they would need to deploy many times the area of ​​a deployed antenna, according to the JPL report.

Since there are areas on the Moon that fit the criteria, and perhaps at best, they could enlist the help of an autonomous rover to get some rocks out of the way. However, this idea appears to be pending for now, as it is unclear whether PEDALS will receive a Phase II grant after funding in 2021. However, the deployment of a large-scale antenna on the Moon’s surface is likely to become important one day. Source