How many rovers does it take to fly to the moon? For Andy, it looks like it'll be four.
For our development, we're going through four stages. These stages of development are a rough way to break down the story of the design of our rover:
Proof of Concept
Like most big projects, our story starts with a vision. That vision is of humans returning to space, and exploring the way with robots.
So how do you design any rover, never mind one going to the Moon?
The first step is to consider the task of the rover, and the challenges it will face. We're going to visit and map a pit, so we need to be able to get high definition cameras inside the pit. Our challenges are going to be a long traverse over rugged terrain, and the shedding heat in a literal vacuum. The first step was to investigate if our ideas had any merits at all; not perfectly realistic, it was supposed to give us a sense of whether we were on the right path. This proof of concept was rough, but to make a better version, we needed to have made a first version.
Next, we wanted to refine this design, and build the expertise about the challenges facing Andy. Like the proof of concept, this mechanical prototype doesn't really benefit from being space-grade. It's about being a close mechanical model so we can develop around it; software, electronics, testing, and so on. This is why we didn't use expensive, space-grade parts: radiation, heat, and vacuum aren't concerns yet. This mechanical prototype is what exists right now, and what won the Mobility Milestone in the Google Lunar XPrize.
Now, we're making the Proto Flight version. We know our mechanical prototype works, so now we need to practice making the final version. In any complicated project, when you do something new you're more than likely to make mistakes. We want to make those mistakes on Earth, so that they don't end up on the Moon.