Some 300,000 Pieces Of Space Junk Imperil Billions Of Dollars Worth Of Spacecraft; Exponential Risk Rise Seen
Spacecraft operators later this year may gain access to better warnings of space collision dangers posed by thousands of orbiting objects.
But it may be many years before a vehicle is developed and deployed to solve the underlying problem by removing deadly space debris and destroy it by shoving it into a fiery reentry into the atmosphere. (Please see separate story.)
Clearly, some action is required to mitigate the space junk threat, because both military and commercial spacecraft operators face sharply rising risks that their multimillion dollar investments will be obliterated in a nano-twinkling.
There currently are some 300,000 pieces of space junk orbiting Earth at 17,500 miles an hour (4.86 miles per second), and each time two larger pieces collide, they increase the amount of space junk by thousands.
Experts worry that each disastrous collision will make further collisions more likely, in a steadily accelerating spiral of mishaps.
Those were some of the key points during a House Science and Technology Committee space and aeronautics subcommittee hearing that probed accidental collisions, such as a dead Russian Kosmos 2251 satellite on Feb. 10 crashing into a working, expensive Iridium Satellite LLC craft called Iridium 33.
The hearing also focused on a 2007 Chinese anti-satellite test in which Beijing used a ground-based interceptor to demolish an aging Fengyun-1C Chinese weather satellite on orbit, creating thousands of pieces of debris.
These incidents have spacecraft operators wishing for warnings of impending collisions.
Better alerts on potential collisions (conjunctions) may be provided before the end of the year, according to Lt. Gen. Larry D. James, commander of the 14th Air Force in the Air Force Space Command and commander of the Joint Functional Component Command for Space
The current tracking system faces limitations, he indicated.
Out of an estimated roughly 300,000 objects in orbit, the Air Force tracks perhaps 19,000 of the more major objects, and has the ability to calculate conjunctions, or impending collisions, for only a subset of those 19,000.
But even an item an inch or less in size, if it travels at orbital speed, can cause immense damage.
In the Russian Kosmos-Iridium crash, the Air Force wasn’t in position to tell Iridium to maneuver the Iridium 33 out of the way, James said.
“On that day there was no data to tell the owner-operators there could be a collision,” he told the subcommittee.
Where a satellite or spacecraft can maneuver, the Air Force may be able to advise the owner-operator of the craft to take evasive action, with this capability in place by the end of the year, James said.
But just how comprehensive or sweeping this service might be is unclear. For example, it isn’t possible to track every last one of those 300,000 pieces of space junk, so the focus is on larger items. At the same time, even a tiny object of just an inch in size, streaking along at orbital speed, can cause devastating damage if it slams into a spacecraft or satellite.
Another witness, Scott Pace, noted that absolutes may not be necessary. For example, not every ship at sea is tracked as it steams across the ocean, he said. Pace, director of the Space Policy Institute at George Washington University, has held space-related policy posts at NASA, at the White House and at the Department of Defense.
Greater cooperation can be useful, such as expanding exchanges with allies, and also in information exchanges among spacecraft operators, he said.
Giving spacecraft/satellite operators tips on potential impending collisions would be helpful, though those tips would have to be confirmed with further checks, he said.
Witnesses also said space is becoming more crowded, and therefore some rules could be well advised, such as what to do with a satellite when its useful life ends, to move it out of the way so it doesn’t pose a hazard to other space vehicles.
Further, planning satellite and spacecraft operations so various craft don’t interfere with each others’ radio signals would be commendable, witnesses said.
Such rules shouldn’t be hard and fast, or adopted in haste, but rules also shouldn’t be delayed until it is too late, Pace said.
Formal rules may not be required, Johnson indicated, if satellite and spacecraft operators move voluntarily to follow common-sense procedures.
The Russian-Iridium collision demonstrated the fallacy of the long-held assumption that collisions are unlikely because space is so vast.
“It was such a surprise to me and many others when we heard the news that two satellites had collided in orbit in February of this year,” said Rep. Gabrielle Giffords (D- Ariz.), who chairs the subcommittee. “It was hard to believe that space had gotten that crowded. It was equally difficult to believe that nothing could have been done to prevent the collision, given that one of the satellites was active and by all accounts would have had the capability to maneuver out of harm’s way.”
While several nations such as Russia, France, Germany and Japan have some form of space surveillance capability, these systems are not interconnected and are neither as capable nor as robust as the U.S. Space Surveillance Network (SSN). SSN consists of a world-wide network of 29 ground-based sensors that are stated to be capable of tracking objects as small as five centimeters orbiting in low Earth orbit, below 1,250 miles.
For the last four years, the Department of Defense (DOD) has undertaken a Commercial and Foreign Entities (CFE) pilot program to make collision avoidance information available to commercial space users.
Users have found the service worthwhile, and thus they worry about uncertainty concerning the CFE program’s future. James said CFE would transition to an operational program later this year.
The committee described the problem:
Since 1957, there have been several thousand payloads launched into space. After the first fragmentation of a man-made satellite in 1961, there have been more than 190 fragmentations and four accidental collisions.
“One thing is already clear — the space environment is getting increasingly crowded due to the relentless growth of space debris. If the spacefaring nations of the world don’t take steps to minimize the growth of space junk, we may eventually face a situation where low Earth orbit becomes a risky place to carry out civil and commercial space activities,” Giffords said.
In written testimony provided to the committee, a major industry association agreed that space situational awareness is critical as potential collision hazards multiply in space.
Space debris is a current and growing threat to U.S. exploration activities, and leaders must make situational awareness a top national priority, Marion Blakey, Aerospace Industries Association, said.
She detailed challenges created by tens of thousands of man-made objects orbiting the Earth. These items, which include both functioning satellites as well as debris, must be carefully monitored to ensure the safety of humans traveling in space and aboard the International Space Station, as well as critical U.S. space assets.
“As the number of nations placing objects in space grows, risks to U.S. space systems and our ability to operate in space also” will rise, according to Blakey. “Space technology is a critical infrastructure that contributes to a strong and secure America. It needs to be adequately protected.”
Blakey called upon lawmakers to provide robust funding for space situational awareness and protection of U.S. space assets. This investment should advance capabilities, including hardening satellites from attack and establishing contingency plans to provide backup to space assets.
There should be a role for government in mitigating collision dangers, said a witness at the hearing table, Richard DalBello, the Intelsat General Corp. vice president of government relations. For example, private satellite operators cannot know locations of government-owned space vehicles.
But as for exchanging information about potential impending collisions, “We can do part of that ourselves,” he said. “We routinely share” such information.
While some subcommittee members asked whether satellites and spacecraft could be shielded from space junk collisions, witnesses said that would involve prohibitive cost.
While the International Space Station does have some shielding, comprising 10 percent of its mass, most satellite buyers and operators couldn’t afford heavy shielding, witnesses said.
“There are no good technologies for protection,” DalBello said.
Another problem is that even when a satellite operator knows where some other spacecraft is, if that spacecraft maneuvers or shifts in orbit, then the operator has no idea where it is, DalBello said.
The question of who should pay for gathering information on locations of spacecraft and space junk, and calculating potential collisions, arose in the hearing.
One question is whether the government or other provider of such services should charge those who use them.
“That is a national policy decision,” James said. While current law permits DOD to charge satellite operators for information about potential impending collisions, it doesn’t do so, he said.
The Space Based Space Surveillance System, that the Air Force will launch in the summer, aims to track spacecraft and space debris.
Giffords said more hearings will be held on the space debris and collision-danger problem.