We are working at the moment to integrate a ½ Gram (!) Video Camera (with near Broadcast image quality) into our 25 gram “Space Probe”. We have an adequate, similar mass video transmitter. This probe was originally planned as an “FAA Exempt”, “Weather Probe”, capable of being guided into a selected portion of a tornado or other violent storm system. With no customers for this experimental system, we are reconfiguring it as a “PicoSat” or Pico Spacecraft. It will probably be the first of our systems to approach the Moon, as less than a kilogram in LEO would allow acceleration of this guided probe to Lunar Orbit.

Video sensors massing no more than a gram are capable of delivering the GLXP required HDTV images. The required optics will weigh much more than this, but possibly still only a few grams. As mentioned earlier, the minimum mass necessary to WIN the Google Lunar X PRIZE has yet to be determined!

The ½ gram camera is certainly able to serve as a sun and star tracker, with a small cluster covering the entire sky. I will return to the navigation topic soon, but have been working to integrate images with these BLOG texts, since that makes them more interesting and understandable.

It has been noted by some that existing “Star Trackers” could serve for Lunar navigation, and this is true. However, the “Proven” units mass 2 to 5 kg, use 5 to 20 watts of power, and have significant stabilization and glare problems. (Data from “SMAD”, Third Edition). These are not things one wants to mount on top of a helmet! More pointedly, these are expensive enough that they are not used without very good reasons, and have never been used on very small satellites (like CubeSats, whose total mass is less than the listed star sensors.)

It is a good idea to rethink the systems we need to use, because the “Proven” units may be far from optimum and may even hide operational realities behind old habits. I won't consider using the 8088 processor for my spacecraft (the engine of the 1981 IBM PC and the Space Shuttle's main computer). I prefer the fractional gram, up to 50 MIPS, low power processors I am using.