The Google Lunar XPrize (GLXP) is offering a Grand Prize of $20 million for safely landing a privately-funded spacecraft on the Moon, driving 500 meters, and sending HD video back to Earth by the end of 2015. Carnegie Mellon University is developing a lunar rover in partnership with Astrobotic Technology, Inc. to compete for this prize.
The rover’s avionics bay houses all of its electronics. A computer is needed to coordinate a variety of tasks including communication with the lunar lander, motor control, camera control, image processing, and telemetry management. The current rover program uses UDOO boards for developing technologies critical to winning the GLXP. If space-hardened to endure the extreme thermal, vacuum, and radiation environments, an UDOO board could fly to the Moon in 2015.
The UDOO was chosen as a development tool for several reasons. First, it has two processors, so it can handle processing critical commands and camera data independently. It is also lightweight (113g), low-power (~2.2W), and user friendly, enabling students to design and build a fully functioning rover prototype in 90 days. These features are difficult to find in other commercially available computer boards (15 others were evaluated).
Figure 1. Carnegie Mellon University’s prototype lunar rover, “Andy.”
During testing, thermal images of both the dual-core and quad-core UDOO boards were used to map out their heat distributions and design a viable thermal solution for vacuum, where convection-based heat dissipation (normally used on Earth) does not work.
Figure 2. Thermal images of UDOO Dual-Core & Quad-Core boards taken at 0% and 100% CPU usage levels running a CPU/IO stressing script.
The UDOO Dual-core board was stress tested in multiple vacuum tests, reaching a “medium” vacuum at a pressure of 2.2×10-2 torr and lasting for 6 hours. While this is not the extreme “hard” vacuum of the Moon (10-8 torr), it is equivalent to the atmospheric pressure at 75 km above the Earth’s surface. The UDOO board performed excellently in these conditions, never exceeding 40°C.
Figure 3. Vacuum test chamber at Carnegie Mellon University.
Figure 4. Left: Partial avionics system setup with motors and a motor control board commanded by the UDOO. Right: Avionics vacuum test setup with the UDOO, motor control board, and camera. Each board uses a metal cylinder to transfer heat from the processor to the radiator plate.