Lunar Escape: Development of Astronaut Recovery Rover Program Nicholas Wade-Mayhue, Dan Janke, Kyle Kilgore, Mohammed Alzohay, Samad Qureshi Colorado School of Mines Advisor: Dr. Knecht [email protected] March 30, 2009 Abstract each of the other subsystems in order for the astronaut As NASA looks into the future of lunar exploration, recovery system to be successful. the requirement of an astronaut recovery program must be recognized. As no other programs are currently in 2. Subsystem Design existence to fulfill this need, we must acknowledge the The SMART rover system itself consists of 4 major necessity of astronaut safeguards against possible volatile components: a panic button to summon the robotic rover, environments. It is with this need that the Sensory Moon sensory beacons to guide the rover to the astronaut, life Astronaut Recovery and Transport (SMART) rover has support and first aid kits on the rover to aid the astronaut, been established. The SMART rover will be physically and the SMART rover itself. attached to the existing Lunar Electric Rover (LER) or can be docked at the nearest Lunar Outpost. This innovative 2.1. SMART Rover Launch Button capability will trace and recover any lost/injured astronaut when remotely activated via a “panic button” placed on 2.1.1. Technical Specifications space suits which, when pressed, will establish a communication link with NASA headquarters, other astronauts on the lunar surface, as well as initiate the The SMART rover launch button is based on the rover’s recovery program. same principle as the LifeAlert system. As such, it is relatively small and not cumbersome to the astronaut. The 1. Introduction launch button is approximately 2 ¼ inches in diameter, and ¾ inch wide. Please see Figure 1 for dimensions and close-up. The safety of America’s astronauts are rapidly becoming a larger issue due to the fact that NASA prepares to return people to the moon in 2020. It is for this reason that we have proposed our designs of an astronaut recovery system. The focus of this structure is in the recovery of injured astronauts who are a considerable distance away from the Lunar Electric Rover (LER) or the lunar outpost. The best way we found to do this is with the Sensory Moon Astronaut Recovery and Transport (SMART) rover. The intent of the Lunar Escape project is that the Sensory Moon Astronaut Recovery and Transport (SMART) rover will be Figure 1. SMART rover launch button physically attached to the existing Lunar Electric Rover (LER). It can be activated by a means of remote control The launch button is made from Torlon polyamide- that the astronauts will have placed on their suits. The imide (PAI). This is a very high strength plastic which technology utilized for this remote control will be quite has the highest strength and stiffness of any thermoplastic similar to that of the Life-Alert system currently in place. up to 275°C (525°F). Not only is this plastic strong, it also Once activated, the SMART rover will then follow has excellent resistance to wear, chemicals, and is ideally sensors that are placed in the regolith to the suited for severe service environments, such as space lost/stranded/injured astronauts, retrieve them, and exploration. Since the material is a high grade plastic, this traverse back to the nearest LER or lunar outpost. It is price is relatively inexpensive, compared to that of a high- important that the SMART rover integrates grade metal. Quotes for molding and preparing this launch switch have been around $25. Given that this 1 launch switch is made of plastic, it is also quite light. We ease from greater distances and would be more cost believe that this switch will weigh no more than ½ pound. effective. The range provided when signal switching should be approximately 15-20 meters moving from the 5 2.1.2. Assembly and Operation meters provided with the product. The cost at the moment for changing this is unknown, but the beacons each cost The launch button is connected to the $33.10. The beacon’s purpose is not to emit the light, but Communications Carrier Assembly in the astronaut’s is focused on sending an electronic signal. It would use a helmet. The button is located on the display and control 5W max bulb with a max voltage of 250W. Switching module on the front of the suit for easy access. Power is signals would provide a robotic sensor with a greater provided to the button through the display and control range. module from the Primary Life Support System (PLSS). Please figure 2 for launch button specifics. Figure 3. Sensory beacon 2.2.2 Assembly and Operation The beacon allows the robot locate the injured Figure 2. Launch button connection astronaut once activated. The rover will follow the same path as the sensors are placed, allowing for decreased When the astronaut engages the launch button, it will chance for the rover to run into craters or encounter other signal an alert to the SMART rover, invoking the rover’s problems while navigating. The astronauts must drop the recovery program. The recovery program initiates the beacon at least every 20 meters or the chances of the rover SMART rover which follows sensors placed in the lunar failing to find the next sensor will certainly increase on regolith to the astronaut. Upon pushing this launch navigation. button, communication will be automatic to all other astronauts on the lunar surface, as well as with NASA Headquarters. 2.3. Life Support/First Aid 2.2. Sensory Beacons 2.3.1. Technical Specifications The immediate concern for a fallen astronaut is to 2.2.1. Technical Specifications make sure they remain able to breathe. It is for this reason that it is of utmost importance that air supply is on the We are basing our design of the beacon tracking as rescue rover. The design for this is as simple as adding an similar to that of Telemecanique’s product, XVDLS Mini additional air backpack strapped to the car. The pack that Beacons. See figure 3 for product identification. These will be strapped to the rover is the same as the one that is beacons are cost efficient, light, and portable. This strapped to the backs of the astronauts so there will be no specific product will have 1.75-inch diameter. The need for any additional hoses or equipment. Extra hoses materials this beacon is made out of will allow the beacon will be on the rover as well in the event that there is a to operate in space without any reactions. Because of the malfunction in one of the astronaut’s existing hoses. limited range of the beacon signal, it is recommended that The next concern deals with different scenarios. the astronaut carry multiple beacons with them on Because of the difficulties faced while on the lunar excursions. One solution may be to alter the beacon surface, the SMART rover will have the capability to signals to a more effective one; a free-space optics/radio swap out medical kits. One such kit would carry radiation frequency on each of these beacons would suffice. It blankets for thermal flare-ups, another would carry splints. would allow the rescue rover to track each beacon with It is with the rover’s ability to adhere to any situation that 2 makes this design practical. All components of this The rear of the rover has a remote controlled hookup subsystem are lightweight. The SMART rover is a fully to the LER. The hookup releases upon the push of the customizable system, which allows all the aforementioned SMART rover launch button by the astronaut. A winch is items to be added/removed. mounted above the stretcher on the steering console. This winch is capable of attaching to the stretcher, allowing for 2.4. The SMART Rover the injured astronaut, on the stretcher, to be pulled onto the SMART rover. A ramp stowed under the body of the chassis is able to be pulled out to assist in this process. 2.4.1. Technical Specifications See Figure 5 for SMART rover description. The SMART rover’s design is based roughly off of the design of the Apollo lunar roving vehicle. There is room on the rover for two astronauts, one injured astronaut on a detachable stretcher on the front of the rover and a second healthy astronaut standing up on the steering platform behind him. Each individual wheel has its own 1hp electric motor, mounted relatively close to the wheel and protected from dust by aluminum casing. These motors are powered by high-efficiency lithium ion batteries mounted in the rear of the rover. The wheels themselves are highly protected by dust guards, as this was a major problem on the Apollo moon missions. The steering mechanism, such as the one on the Apollo lunar roving vehicle, is a straightforward “joystick” which is responsible for not only steering but also acceleration and braking. See Figure 4 for steering mechanism. Figure 5. SMART rover description The dimensions of the SMART rover are important. The smallest the chassis can be to maintain effectiveness is 102 inches, allowing 73.5 inches for the stretcher and 18 inches for the standing astronaut. The front of the chassis (with the stretcher) may need to be extended to account for taller astronauts. The base of the chassis is 4 feet wide, with a three-foot stretcher that is centered on the top. The wheel axels are ten inches below the top of the chassis and extend eight inches out in both directions.