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plate and Lego brand wheels with rubber treads. The second category being the control logic. The CPU was a programmable Digispark USB Development Board (Attiny85 based micro-controller development board). The drive system utilized a Digispark Motor Shield Kit (Fig- ure 4) to drive two oppose-mounted micro servos modified to turn 360 degrees. Communications were handled by a KEDSUM ® Arduino Wire- less Bluetooth Transceiver Module connected to the Digispark micro- controller. This configuration provided wireless connectivity between the rover and the Samsung Galaxy Nexus, which in turn allowed "ground control" to remote control the rover. Custom software was written that provided "ground control" remote control capabilities of the rover and live video feeds from the phone's built-in camera. This software was installed onto the Galaxy Nexus. Onboard rover video was handled by a modified 720p keychain DVR video camera. The rover's onboard systems were powered by dual LG BF-45FNV cell phone batteries that provide over eight hours of continuous use. All-in the rover weighed just over 137g and was 3.5" long by 3" wide by 3" tall. These dimensions were used as the baseline for the design on the lander and launch vehicle. The com- pleted ANDRover can be seen in Figure 5. The Lander "Mestler" Arguably the most complex and challenging part of the project was the Mestler lander. The lander was responsible for safely and autonomously landing and deploying the rover—not to mention handling communications between the rover and "ground control." About 90% of the lander build was 3D printed due to the complexi- ties of the design requirements. Figure 6 shows the design diagram of the lander package. The lander was 5" in diameter and stood approximately 27" tall, weighing in at approximately 2,241 grams flight loaded with the rover inside. The lander "stack" consisted of a lower base assembly (leg at- tachments, battery packs, terrain sensors), a lower rover containment assembly (where the rover was stowed during launch), and an up- per assembly (electronics bay, pyro block, and recovery attachments). Figure 4. The Digispark Motor Driver— part of the rover control electronics. Figure 3. The Mestler project launch vehicle design was inspired by the SpaceX Falcon 9 aesthetic. 22 MAY/JUNE 2017 SPORT ROCKETRY