NASA’s Interest in Removal of Orbital Debris Limited to Tech Demos
SAN FRANCISCO — NASA’s policy of paying companies to develop technology designed to eliminate orbital debris but not to pay for in-flight demonstrations has space companies searching for new backers.
NASA adopted a policy in June 2014 to support development of orbital debris removal technology but not of operational systems. Specifically, the space agency backs projects with Technology Readiness Levels (TRL) 1 through 4, which means NASA’s support for projects ends once components or prototypes work in a laboratory setting.
“At present, there is no viable technological or economically affordable approach that is sufficiently mature to justify technology demonstration,” NASA spokesman Joshua Buck said June 8 in an emailed response to a question about the policy.
Some space industry officials counter that assessment. “The challenge of active debris removal requires capabilities for orbital rendezvous, capture of noncooperative objects and affordable disposal,” said Robert Hoyt, chief executive and chief scientist for Tethers Unlimited of Bothell, Washington. “The required propulsion and control technologies for orbital rendezvous capability have been demonstrated by many prior missions.”
To capture spent rocket boosters or defunct satellites, Tethers Unlimited developed a deployable net technology called Grapple, Retrieve and Secure Payload, or GRASP. Through microgravity testing on commercial parabolic aircraft flights, GRASP is now at TRL-5, Hoyt said. TRL-5 means components or prototypes work in the appropriate environment.
Busek Co. has another debris-capturing technology it calls Satellite on an Umbilical Line, or SOUL. Natick, Massachusetts-based Busek won a grant in April under NASA’s Small Business Innovative Research program to take SOUL, a 10-kilogram satellite equipped with a tool and linked by a 100-meter cord to a larger spacecraft, from TRL-4 to TRL-5. The U.S. Air Force and Navy funded early development of SOUL to retrieve space debris weighing approximately 1,000 kilograms and tow it to another orbit. NASA also is interested in SOUL’s ability to gather asteroid samples, inspect spacecraft and repair orbiting satellites.
In addition, many companies are developing devices designed to be launched on small satellites or attached in orbit to debris to increase drag and speed its re-entry into Earth’s atmosphere.
Tethers Unlimited sells the Terminator Tape, a $7,000 deorbit module for cubesats that includes a 250-meter-long conductive tape designed to unfurl at the conclusion of the mission and produce enough drag to lower the satellite’s orbit. Two orbiting cubesats are equipped with Terminator Tapes. When those cubesats complete their missions and deploy Terminator Tapes next year, the technology will be at TRL-8, meaning the system has been tested, demonstrated and qualified for flight, Hoyt said.
Similarly, two dragNET De-orbit Systems, produced by MMA Designs of Boulder, Colorado, are currently flying. In 2013, the U.S. Air Force launched two inflatable dragNET sails on the Space Test Program Satellite-3 and on the Minotaur 1 rocket upper stage that launched that satellite. The 14-square-meter dragNET on the Minotaur upper stage, the first to deploy, is expected to bring the rocket body into Earth’s upper atmosphere later this year.
“We have demonstrated on-orbit success (TRL 9) so our technology is certainly viable and economically feasible to implement on every space vehicle immediately,” Mitchell Wiens, MMA’s president and chief operating officer, said by email.
Given those examples of ongoing technology demonstrations, many NASA observers in industry and academia say a key reason the space agency is limiting its orbital debris removal work to research and development is concern among senior officials that successful flight demonstrations would push NASA into the role of space garbage collector.
“No one wants to get saddled with the responsibility without the budget to back it up,” said Raymond Sedwick, director of the University of Maryland’s Center for Orbital Debris Education and Research.
NASA’s Orbital Debris Remediation guidelines allude to those concerns. “NASA’s recognition of the importance of Orbital Debris Remediation technology coupled with limited resources provides the basis for guidance on Orbital Debris Remediation technology investments and activities,” reads a memo signed June 19, 2014, by Associate Administrator Robert M. Lightfoot.
U.S. President Barack Obama’s National Space Policy published in 2010 does not specify which U.S. agency should take the lead in cleaning up orbital debris. It simply directs NASA and the Defense Department to “perform research and development of technologies and techniques … to mitigate and remove on-orbit debris, reduce hazards, and increase understanding of the current and future debris environment.”
NASA has a robust strategy to perform those activities in coordination with other U.S. government agencies, international partners and international organizations, Buck said. “The problem of orbital debris is too large for any single agency or nation to solve alone,” he added.
International organizations are preparing to demonstrate their ability to clean up space debris.
Astroscale, a startup based in Singapore, is preparing to launch a dual-satellite Active Debris Removal System in 2017. The German Aerospace Center, DLR, plans to begin servicing spacecraft in orbit and removing debris through its Deutsche Orbital Servicing Mission scheduled to launch in 2018. In Switzerland, engineers at the École Polytechnique Fédérale de Lausanne are designing Clean Space One, a spacecraft to catch a cubesat and move it to Earth’s atmosphere.
International coordination would be required for any sustained effort to capture and remove debris because many nations have contributed to the problem and the United Nations 1967 Outer Space Treaty states that space-based objects, including spent rocket boosters and satellite fragments, belong to the nation or nations that launched them. Still, that should not be a deterrent to debris removal activities because U.S. agencies could begin testing new technology by capturing garbage left behind by U.S. government missions, Sedwick said.
“We could spend years cleaning up our own stuff,” he said. “If we did that and the technology advanced, I think we would be permitted to bring down the junk of other countries.”