The orbits around Earth are cluttered with chunks of space junk ? high-speed riffraff that poses a growing threat to robotic satellites and human-carrying spacecraft.
There are currently hundreds of thousands of pieces of space debris greater than 1 centimeter wide whizzing around in space. But while this space litter may be out of sight, out of mind for most of us, a new report on orbital debris has flagged potential solutions to deal with the threat.
The report anchors its space cleanup thinking and approaches to more down?to-Earth woes like acid rain, hazardous waste, chlorofluorocarbon and oil spills.
The same superfund approach to those earthly pollution problems could be reworked to tackle space junk, according to the report, which is titled "Confronting Space Debris - Strategies and Warnings from Comparable Examples Including Deepwater Horizon." Superfund is the federal government?s program to clean up the nation?s uncontrolled hazardous waste sites.
The monograph, compiled by the nonprofit global policy think tank RAND, was prepared for the Defense Advanced Research Projects Agency.
The organization recently completed its "Catcher?s Mitt" study, an assessment that, in part, explores technically feasible solutions for debris removal. [Worst Space Debris Moments in History]
Superfund for space
At the core of the RAND report is an analysis of how industries on Earth have approached their pollution problems, and how those lessons can be applied to cleaning up orbital debris.
A set of comparable problems that share similarities with orbital debris were identified in the RAND study, related because they all share the following set of characteristics:
- Behavioral norms (past and/or present) do not address the problem in a satisfactory manner.
- If the problem is ignored, the risk of collateral damage will be significant.
- There will always be an endless supply of "rule-breakers."
- The problem will likely never be considered solved because the root cause is difficult to eliminate.
One observation from the report is that the space Superfund could serve as an effective model for orbital debris cleanup.
A Superfund for space would make space polluters pay for cleanups while creating strong incentives for nation-states and private industry to take appropriate preventative steps to avoid creating additional space debris.
Also, the report stresses that the entire space community needs to agree that purposely creating orbital debris is not acceptable behavior.
"We tie orbital debris to things that were more intuitive, things that people sort of run into on a daily basis," said Dave Baiocchi, co-author of the report. "We purposely tried to tie the space debris problem to some environmental issues?to start making some connections in people?s heads," he told SPACE.com.
Baiocchi said that the environmental calamity of the 2010 Deepwater Horizon oil spill in the Gulf of Mexico was a saga that brings a key message home.
"We didn?t quite have our act together for Deepwater Horizon," Baiocchi said, citing technological trial-and-error that dogged attempts to curb the underwater hemorrhaging of oil. "Maybe we don't quite have our act together for the space debris problem either."
Perhaps the biggest lesson of that oil spill, as pointed out in the report, is that simply having a remedy available, or several, is not sufficient. They must be tested and proven to work in the expected operating conditions.
Likewise, any future orbital debris removal tactic must be tested to make sure that it will work in the operating environment of space.
Space debris wake-up calls
RAND co-author, William Welser IV, added that nobody has a good idea of what the environment looks like up in space.
The report explains that when a problem?s effects are not directly observable, a community is likely to misjudge the risk posed by the effects.
"You can have millions and millions of gallons of oil that has spilled. But you can't see it?until you see those birds that are covered with oil or you see the actual spill come to the surface. Until that happens, the public is not excited or worried about it," Welser told SPACE.com.
"As soon as a DIRECTV satellite gets knocked out ? or a GPS satellite or some other space asset we use ? then you?re going to have a lot of people up in arms about space debris," Welser said.
What about the inadvertent February 2009 space collision between a defunct Russian weather satellite and an active Iridium satellite? Or China?s purposeful 2007 anti-satellite test that spewed so much lingering debris that ? now over three-and?a-half years later ? poses distinct hazards to hundreds of operational satellites?
They weren't very good wake-up calls, responded Welser.
"The level of impact was not there," Welser said, in terms of public awareness or loss of commerce, whereas loss of a major asset in a war and a thousand troops die as a direct result ? that's a tangible wake-up.
However, as the report explains, these two events are likely the cause for the increased interest ? including the RAND research ? in the orbital debris problem. In addition, remedies are needed to clean up the consequences of such shattering events.
Developing the pathfinder technology now for such a remedy "may prove to be a wise decision" because on-orbit collisions are likely to continue to occur in the future, the report states.
There are a number of space cleanup ideas floating about ? such as using garbage scows, tethers, laser beams, giant foam balls and such.
While outside the scope of their report, Baiocchi said, "it's really a matter of devoting resources. Eventually, you?re going to get something. The hard part is convincing your friends in other countries that whatever you stick up there isn?t a weapon."
As for an orbital debris tool kit, RAND researchers warn not to put all your technological eggs in one basket.
"You?re probably going to need more than one of them," Baiocchi said. "You absolutely have to test your technologies in the environments in which they are going to be used."
"The biggest warning," Welser added, "is not to lull yourself into a false sense of security just because you think you have a tool set" ? a tool set that hasn't been tested under actual operating conditions.
Welser noted that the group of people in the orbital debris research field is still very small. "That community has stayed small over time while the community that?s been affected on a day-to-day basis by space systems has grown exponentially," he said.
There's a need to do a better job of relaying to the common person that relies on space that the problem of orbital debris is getting worse, Welser concluded. "We need to be concerned about this."
- Worst Space Debris Moments in History
- How Much Junk is in Space?, Video
- A Real Mess in Orbit: Space Junk to Hang Around Longer Than Expected
Leonard David has been reporting on the space industry for more than five decades. He is past editor-in-chief of the National Space Society's Ad Astra and Space World magazines and has written for SPACE.com since 1999.