At ICRA in 2012, researchers from JPL presented a paper on a new type of robotic gripper that uses microspines to adhere to rough surfaces in microgravity. In a follow-up paper at IROS 2013, the gripper made an appearance on a JPL robot, which was really cool to see. And now that it's 2014, it's time for the next step: seeing how a gripper designed for microgravity actually works in microgravity. To do that, NASA is sending it up on some parabolic test flights, along with several other robotic systems destined for space.
When groups apply for NASA's Flight Opportunities Program, they have to include some "maturation objectives," which are sort of like a "here's what this research may be leading to" type of thing. Here's where JPL imagines their microspine grippers ending up:
This technology could be used in the upcoming asteroid redirect mission to grip large boulders during the robotic mission or acquire core samples from rocks that are too large for the crew to transport back to Earth in their entirety. In the long term, the technology could enable the robotic exploration of lava tubes that have been observed on Mars and the Moon.
For smooth surfaces, JPL will also be testing a gripper that uses gecko-type adhesives:
Multiple spacecraft surface types will be tested including solar panel, composite panel, anodized aluminum, and Kapton thermal blanket. Multiple tests will characterize performance in terms of variables like applied preload, misalignment, and pull off vector.
The parabolic aircraft environment will allow a full 6 degree of freedom zero-g test, which will provide critical data on the performance of the tool as well as give the team invaluable operational experience that may influence the design, development, and test program for the tool as it advances toward multiple flight opportunities, including opportunities aboard the International Space Station.
For a while now, NASA has had little experimental robots jetting around the International Space Station called SPHERES (Synchronized Position Hold Engage Reorient Experimental Satellites ). They're evolving slowly with hardware and software upgrades, and this round of the Flight Opportunities Program will be adding a few more:
MIT has developed a Universal Docking Port (UDP) designed to enable multiple (SPHERES) to rigidly dock and undock. With this capability, spacecraft reconfiguration and modularity technical challenges can be addressed, including performing relative sensing and characterization for docking, reconfiguring the system controller to account for the new dynamics of the docked vehicles, and reconfiguring the actuation and sensing subsystems of the new system. The knowledge gained from ISS test sessions will help inform the Phoenix mission.
The Phoenix mission is DARPA's plan to test on-orbit robotic satellite servicing and repair "for the purposes of harvesting retired communications satellites." Yep, harvesting. It's scheduled to happen sometime next year.
SPHERES are also intended to eventually be able to take over some of the more tedious regular inspection and maintenance tasks aboard the ISS from astronauts, who'd much rather spend their time doing more productive things. To do this, they'll need some extra sensors:
The SPHERES INSPECT (Integrated Navigation Sensor Platform for EVA Control and Testing) program aims to augment the existing three SPHERES satellites on the ISS with additional sensors and actuators to take advantage of the environment within the station to provide risk reduction for a future IVA/EVA system capable of inspection, navigation, and health monitoring. The INSPECT program hardware includes an optical rangefinder, thermographic camera, optical vision system, and control moment gyroscopes (CMGs).
The last robot taking part in microgravity experiment comes from Stanford and JPL. It's internally-actuated, and designed to hop and tumble around low gravity environments like asteroids and small moons:
Researchers at Stanford University and at the Jet Propulsion Laboratory have recently been investigating low-mass surface platforms that can traverse the rugged and soft terrains of small bodies, where gravity is extremely low. These platforms impart mobility by generating a reaction force through simple internal actuation mechanisms, enabling them to traverse by hopping (for large surface coverage) and tumbling/shuffling (for fine mobility and instrument pointing). These platforms would position science instruments through a sequence of tumbling and shuffling maneuvers.
Via [ JPL ]
Evan Ackerman is a senior editor at IEEE Spectrum. Since 2007, he has written over 6,000 articles on robotics and technology. He has a degree in Martian geology and is excellent at playing bagpipes.