Automaton Rover for Extreme Environments (AREE)

Mechanical automata and computers have not been considered a serious avenue of scientific research since before early work on computers in the 1950s. Even then, much of the prior research into mechanical computers did not make it into the literature as it was related to the war effort and considered classified. The first phase of the project was to create a point design and exhaustively research the literature on the varied topics requiring greater refinement. At every opportunity, subject matter experts were engaged to provide input on the feasibility of various ideas and brainstorm for creative solutions to novel problems. The Jet Propulsion Laboratory employs many individuals who specialize in varied topics ranging from materials science, mechanism design, extreme environments, radar, science, spacecraft systems, and mission architectures, and the names of those consulted are listed in the end of this report. The concept was showcased at forums within JPL, such as the Mechanical Systems Division Seminar, and external, including the Venus Exploration Analysis Group (VExAG), IEEE Aerospace Conference (paper submission), and AIAA SciTech (featured presentation). This exposure allowed for the generation of additional ideas and knowledge of what has been done before and where there are holes in current capabilities. Midway through the project an A-team Study (an early formulation team in the JPL Innovation Foundry) was used help to leverage the breadth and depth of experience at JPL and collate ideas and concerns from various disciplines. The study incorporated a presentation of the point design and shorts talks from relevant experts in various relevant fields. Through discussion, the workshop narrowed down the primary science objectives (seismic and geologic), provided insight on the most robust architecture, and provided guidance on next steps. The final phase of the project involved comparing what we think could be done with an automaton to the current state of the art in fields like high temperature electronics 2.2 Assessment Against Phase One Goals The goal of the Phase One study was to generally determine the feasibility and value of using an automaton to explore Venus. Three main questions were brought forth in the original proposal and are repeated below along with an assessment of the Phase One finding. 1) Can an automaton explore and record data from the surface of a hostile world? A viable systems architecture was developed for the automaton rover, however, it is not practical to make a purely mechanical rover. High temperature electronics are incorporated where they have sufficient maturity and application, such as instrumentation. A system by system breakdown is provided in Section 4.0. 2) Can information gathered be communicated to Earth? An in depth trade was performed to determine the feasibility of getting information back to Earth and understand how to communicate science data using the limited resources. See Section 4.5. 3) What science questions can most effectively be answered with low bit rate communication? Radar scientists and engineers at JPL were brought on to determine the value of low bit rate longitudinal science on Venus and the question was addressed as part of the workshop held on the automaton concept. Science return is discussed in Section 3.0. 2.3 Key Findings The Phase 1 study showed that there are no technological or physical barriers preventing an automaton rover within the Venus context. The key areas investigated were computing elements, mass and volume constraints from the EDL system, power generation, power storage, communication link to Earth, science instruments, materials, and control, which are all discussed later in this document. The study also revealed that a fully mechanical rover, while feasible, is not practical. This conclusion resulted from an A-team Study held to explore AREE in more detail combined with a review of high temperature electronic technologies. Fundamentally, building a mechanical computer with 1,000+ transistors would require a technology investment similar to if not greater than high temperature electronics already in development without significant increase in performance. With input from MEMS experts at Sandia National Laboratories, it was determined that mechanical computing elements would not be lower mass, lower power, or smaller than high temperature electronics under development. However, mechanisms are still an enabling technology in a Venus mission context. Clever mechanisms can be combined with high temperature electronics to enable a platform that is more capable than either technology by itself. For example, one may consider simple addition. An electronic adder requires 576 transistors to combine two 16-bit numbers11. To add numbers larger than 16 bits, multiple iterations through software would be required. However, a mechanical analog differential adder can solve the same problem using only 5 gears. By finding these areas where mechanical solutions are relatively simple, the load on the computer can be reduced, thereby enabling a mission. Of course, a differential adder can only perform the adding operation, whereas a processor made up of many transistors can perform many other functions. But for an automaton, where the system is designed to carry out a specialized series of actions, this flexibility is not required.