The Lunar Radio Observatory will be built in a crater on the far-side of the moon called Daedalus. This observatory is equipped with a massive, 300m diameter, highly efficient antenna that points into deep space. The spectrum from 1-4 GHz will be sampled in ~244 KHz chunks by downconverting to baseband, sampled, and sent up to a satellite in geostationary orbit around the moon that has line-of-sight of both Daedalus and the Earth. This will require an enormous array of downconverters and processing hardware. However, because the equipment is relatively low speed and the savings in transmitted power is so great, the overall cost of the project should be considerably lower using this
The Moon Satellite is a simple Bent-Pipe Transponder that blindly amplifies and transmits the spectrum over which it is sampling in the direction of Earth.
The Earth Satellite constellation is comprised of three geostationary satellites equally spaced around the Earth. From the moon's perspective, the satellites will be rotating along with the Earth. However, the Moon Satellite knows nothing about the exact location of the satellites and simply illuminates the entire Earth. As each Earth Satellite comes into view of the Moon Satellite, it will begin collecting data as one of the other Earth Satellites moves out of sight of the Moon Satellite and stops collecting. Because the data collected is timestamped by the Earth Satellites against a time standard, any redundant data will be easily thrown out.
Although there are three Earth Satellites, only one of the satellites will serve as a Downlink. The other two satellites will simply relay their collected data to the Downlink-capable satellite, where the data will either be linked with another broadcast satellite or directly beamed to an undisclosed NASA facility in the North-Western hemisphere.
System Components
The Lunar Radio Observatory and link is described in further depth in each one of the design sections below.
Satellite Constellation -- The geometry of the links is a critical aspect of the link budgets and antenna design.
Telescope Architecture -- The nature of the data collected defines how we send the data over our links.
