“The Catcher in the Skye”: How To Catch A Retired Satellite

Before going big, DARPA started small. Participants in the Zero Robotics Autonomous Space Capture Challenge designed and recently demonstrated algorithms to control a bowling-ball-sized programmable SPHERES satellite aboard the International Space Station (ISS). Three finalist teams—based on high school teams that participated in previous Zero Robotics challenges—emerged from a series of four, one-week qualifying rounds: “y0b0tics!” (Montclair, NJ); “The Catcher in the Skye” (Sparta, NJ); and “Nitro”(Eagleville, PA). 

Now to scale this work: through its Phoenix program, DARPA intends to develop and demonstrate technologies to cooperatively harvest and re-use valuable components from retired, nonworking communications satellites in geosynchronous orbit. Success will require that the Phoenix spacecraft maneuver itself into position and synchronize with a tumbling object such that tools can be extended to remove or attach necessary parts. Future Zero Robotics competitions and other DARPA efforts will be aimed at further developing and refining the algorithms that enable these capabilities. 

“The latest competition on the ISS helped identify key attributes in how to optimize fuel use and time to match an object’s random tumble in space and be able to approach and dock with it safely,” said Dave Barnhart, DARPA program manager. “The control procedures that were developed for the Zero Robotics Challenge will certainly benefit the Phoenix program, but they also potentially have much wider implications for space-based technologies. Our efforts can help to reduce the risks and costs of future complex satellite-to-satellite interactions in space to lower the barrier of entry for future space operations and missions.” 

The next Zero Robotics High School Tournament starts on Sept. 8, 2012, offering high school students the opportunity to design experiments that will be tested in space on DARPA’s SPHERES. For more information and to register, go tohttp://zerorobotics.mit.edu/

The Phoenix program envisions developing a new class of very small ‘satlets,’ similar to nano satellites, which could be sent to the GEO region more economically as a “ride along” on a commercial satellite launch, and then attached to the antenna of a non-functional cooperating satellite robotically, essentially creating a new space system. A payload orbital delivery system, or PODS, will also be designed to safely house the satlets for transport aboard a commercial satellite launch. A separate on-orbit ‘tender,’ or satellite servicing satellite is also expected to be built and launched into GEO. Once the tender arrives on orbit, the PODS would then be released from its ride-along host and link up with the tender to become part of the satellite servicing station’s ‘tool belt.’ The tender plans to be equipped with grasping mechanical arms for removing the satlets and components from the PODS using unique space tools to be developed in the program. 

The traditional process of designing, developing, building and deploying space technologies is long and expensive. Through Phoenix DARPA seeks to hasten the insertion of emerging technologies into space system development at much lower cost. 

Critical to the success of the Phoenix program is active participation from the international and non-traditional space communities involved in vital technical areas such as: 

• Radiation tolerant micro-electronics and memory storage 
• Distributed “wireless” mobile platform solutions for ad-hoc connectivity and control Industrial electronic control systems 
• Terrestrial micro-miniature guidance and control measurement units 
• Industrial robotics end effectors and tool changeout mechanisms and techniques 
• Computer-assisted medical robotics micro-surgical tele-presence, tools and imaging 
• Remote underwater imaging/vision technologies used in the offshore oil and gas drilling industry 
• Terrestrial manufacturing of high volume micro-electronics and computer data storage 
• Terrestrial thermal management design technology of electronic devices and systems 
• Low-cost industrial manufacturing of high volume sheet metal and other structural materials 
• Additive manufacturing on various structural materials 

The first keystone mission of the Phoenix program in 2015 plans to demonstrate harvesting an existing, cooperative, retired satellite aperture, by physically separating it from the host non-working satellite using on-orbit grappling tools controlled remotely from earth. The aperture will then be reconfigured into a ‘new’ free-flying space system and operated independently to demonstrate the concept of space “re-use.”