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Space Systems Lab
University of Maryland

About the Space Systems Laboratory
The Space Systems Laboratory (SSL) is dedicated to making human beings more productive while working in space. We believe that both humans and robots, working together, are necessary to accomplish this goal. We are currently developing robotic systems capable of assisting astronauts in EVA (spacewalk) tasks, thus making EVA excursions shorter and safer, and in some cases allowing astronauts to perform tasks that would otherwise be impossible. We also study the ways the human body works in space, quantify human abilities in orbit, and design tools and systems to help astronauts work in space.

The SSL was established in 1976 at the Massachusetts Institute of Technology by MIT faculty members Renee Miller and J.W. Mar. Its early studies in space construction techniques eventually led to the EASE (Experimental Assembly of Structures in EVA) flight experiment which flew on Space Shuttle mission STS-61B in late 1985. EASE was designed to evaluate the ability of astronauts to build structures in space.

Other early SSL work with Richard Stallman and Marvin Minsky resulted in the Aramis study, an early influential paper on the use of automation in space exploration. In addition, the SSL developed the first neutral buoyancy version of a Manned Manuevering Unit, which allows astronauts to fly untethered around the Space Shuttle. NASA now uses SAFER, a similar device, to ensure the safety of astronauts during EVA excursions.

The success of EASE led to questions about how well robots could build structures in space. The SSL's first neutral buoyancy robot, the Beam Assembly Teleoperator (BAT), was built in 1983 specifically to construct the EASE structure. Over BAT's lifetime, SSL personnel accumulated a large database comparing human and robot performance in space. BAT also demonstrated the ability of robots to assist astronauts during EVA excursions and to service and repair satellites.

Since 1983, the SSL has built eight robots, including the Multimode Proximity Operations Device (MPOD), an orbital manuevering vehicle or "space tugboat"; the Secondary Camera and Maneuvering Platform (SCAMP), a "floating eyeball"; and Ranger, a robot designed to be capable of replicating a Hubble Space Telescope servicing mission.

Ranger will be used to study how best to design robotic manipulators for servicing and repairing satellites and spacecraft in orbit. There are three configurations of Ranger currently in existence at the SSL: Ranger Neutral Buoyancy Vehicle, an underwater prototype of a space robot designed to repair satellites and assist astronauts during EVA excursions; Ranger Telerobotic Shuttle Experiment (RTSX), a space robot designed to perform telerobotic servicing experiments while in the cargo bay of the orbiter; and Ranger Neutral Buoyancy Vehicle II, an engineering test unit for RTSX and advanced robotic manipulators.

In 1990, the lab director Dr. Dave Akin and the SSL moved from MIT to the University of Maryland at College Park. In 1992, the Neutral Buoyancy Research Facility (NBRF) was completed. The NBRF is the only neutral buoyancy facility located on a college campus, and gives the SSL world-class research facilities. We also work cooperatively with other UMCP facilities, including the Glenn L. Martin Wind Tunnel, the Human-Computer Interaction Lab, and the Autonomous Mobile Robotics Lab. In addition, many of our students have taken part in NASA Johnson's Reduced Gravity Student Flight Opportunities Program and we have worked with JSC's Neutral Buoyancy Laboratory. Before it was closed in July 1997, the SSL had the most accumulated test time at Marshall Space Flight Center's Neutral Buoyancy Simulator of any non-NASA group.

The SSL also has a long history of human factors research designed to improve the productivity of humans working in space, both inside a spacecraft and during EVA excursions. Current projects include the Maryland Advanced Research/Simulation (MARS) suit, a simplified neutral buoyancy spacesuit for use in EVA research; Power Glove, a prototype motorized spacesuit glove which will help reduce astronaut hand fatigue; and TSUNAMI, an apparatus to test human neuromuscular adaptation in different gravitational fields and different simulations of weightlessness.

The SSL also researches advanced spacecraft control systems. Control systems engineering is the study of using computers to control motion, in this case the motion of spacecraft and space-faring robots. Current spacecraft control systems such as those found on space telescopes are able to point a satellite at a stationary target very precisely but are not designed for human pilots and cannot change direction quickly. The SSL is developing control systems that work well with humans, and are also able to adapt to changing conditions that affect the spacecraft's motion, such as temperature extremes, hardware decay, and decreasing mass due to fuel loss. SCAMP SSV, an upgraded version of SCAMP, is a testbed for advanced control techniques.

Recently the SSL has begun to investigate techniques for spacecraft automation. Autonomous spacecraft will be vital for the exploration of other planets and for the operation of orbital satellite constellations, and are also useful for reducing the cost of routine spaceflight missions by alleviating the workload of human ground support crews. Development of orbital path planning algorithms, spacecraft vision systems, real-time planning for spacecraft and aircraft, and formation flying techniques is underway. SCAMP SSV is also supporting this research.

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