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Highlighted Projects
Rovers to Mars?
The First Astronaut-Rover (ASRO) Interaction Field Experiment and Recommendations for Future Planetary Surface Exploration.
Nathalie A. Cabrol, Project Science Lead. SETI Institute, NASA Ames Research Center.
Recent research has investigated how humans and robot rovers could work together to explore the topography of Mars. The first Astronaut-Rover (ASRO) Interaction field test took place Feb. 22-27, 1999 at Silver Lake in California's Mojave Desert. This experiment is the result of a joint project between NASA Ames Research Center and the Johnson Space Center. In the context of the human exploration of the Solar System, the interaction of the astronaut and the rover as a complementary and interactive team is critical to assess. The objectives the project were:1) To identify the operational domains where the EVA astronauts and rovers are complementary and can interact, and thus can collaborate in a safe, productive and cost-effective way; 2) To identify preliminary requirements and recommendations for advanced spacesuits and rovers that facilitate their cooperative and complementary interaction; 3) To develop operational procedures for the astronaut-rover teams in the identified domains, 4) To test these procedures during representative mission scenarios during field experiments by simulating the exploration of a planetary surface by a human crew interacting with a rover; 5) To train test-subject, simulated Earth-based and/or Lander-based science teams, and automated vehicle operators in mission configuration; and 6) To evaluate and understand sociotechnical aspects of the astronaut-rover interaction experiment in order to guide future technology designs.
The test site of Silver Lake was selected for the 1999 ASRO experiment because of its resemblance to Martian planetary surface landscapes that astronauts and rover will have to explore during future missions as we can foresee them from the images sent back by the Pathfinder and Mars Global Surveyor missions (Fig. 1). The experiment included: the rover; a support rover team (engineers and technicians); the EVA suited test subject, who is a geologist by training and the test subject for Johnson Space Center planetary EVA suits; a support EVA team (engineers and technicians); an in situ Rover Operation Center (ROC) located 1.5 km from the exploration site. The rover was remotely controlled from the ROC. A remote Support Science Team (SST) was located in a simulated Mission Control Center (MCC1) at NASA Ames Research Center, 800-km from the test site. The role of the SST was to simulate a scientific support provided to the EVA astronaut by the crew in the lander and/or a scientific support provided from Earth. A team of observers was located at a simulated MCC2 at Johnson Space Center. The communications between the test site, the EVA suited test subject, the rover, the ROC, and the simulated MCC 1 and 2 sites were established through satellite communications, radios, cellular phones, fax and printer. The five days of experiment were fully video-documented.
Figure 1 - click to enlarge
Figure 1 - The test site as seen through the cameras on board the Marsokhod rover. This stereo-color panorama is a mosaic of several thousands images. From this panorama, the astronaut communicating with the remote science team decided which science targets and sites to explore. From (a) to (d), examples of single images that comprise the panorama. Image: NASA Ames, Marsokhod data, IMG.
Four main science scenarios and associated detailed operational procedures were tested during the ASRO Silver Lake field test: (1) the rover as a scout, where the rover is sent to pre-examine a traverse area, which gives an overview of the lander's environment and establishes potentially favorable sites for deploying stations and for science exploration (e.g. geology, biology) for the suited astronaut to conduct work in; (2) the Rover as a Video Coverage Assistant, where the rover was used to video document the EVA crewmember's activity in the field. This task was usually performed by the second EVA crewmember during the Apollo mission; (3) the rovers as a field science assistant. The astronaut explored a traverse. When he spotted an area of interest, he placed a color-coded flag to show that the target needed to be documented by the rover. Each flag color corresponded to a specific tasks. While the rover was sent to the designated targets, the suited astronaut continued his traverse and placed a flag on scientifically interesting targets that the rover reached and documented; and (4) The Rover as a Field Technician Assistant. In this last scenario, the rover was used to carry tools and samples for the suited-astronaut (Fig.2). The astronaut also used capabilities onboard the Marsokhod (e.g. its imagery system) to document sites of interest and communicate with the support science at MCC1. Two runs of this scenario were performed. During the first run, the video camera tracking was performed by the rover operator located at the ROC. During the second run, the video tracking was done automatically by the stereo tracking system that controlled the camera pointing.
Figure 2 - click to enlarge
Figure 2 - The astronaut and the Marsokhod rover exploring together the ancient shores of Silver Lake, California. This team of a new type couples the resistance of the robotics systems and the human ability to immediately integrate new information in the context of past experiences and background, and to rapidly recognize and reach the important sites and samples. Photograph: NASA-JSC, Marc Sowa.
These scenarios represent four possible mission scenarios of interaction between an astronaut and a rover in the field. The goal was to evaluate their feasibility, effectiveness and sequence of execution. During all the scenarios, the "Lander" designated a fixed position in the field test site from where all operations were started.
The ASRO experiment pointed out a series of domains where more research and testing need to be undertaken to make surface planetary exploration by an astronaut-rover team a reality, to produce a safe, and cost effective mission, and to design productive interactions between the EVA astronauts and rovers. The domains encompass: science; rovers; EVA; communications; mission operational procedures; mission duration and data volume; and information technology. The EVA astronauts and rovers interaction is a new, and critical, domain that requires new and better-adapted tools, as well as new exploration strategies that do not exist yet.