For a half century, the Maui Space Surveillance System has been a prime component in the U.S. Defense program to monitor Earth's orbital space - identifying, characterizing and tracking satellites placed by other countries.
Over the past decade, the Defense Department's space situational awareness effort has had to take on a more prosaic duty, but one typically left to government. It's cleaning up after folks who don't take responsibility for their messes.
Since the Soviet Union first shot Sputnik I into orbit in 1957, there have been 6,000 successful launches of satellites and spacecraft from Earth and some that weren't successful. It all adds to the assortment of obsolete satellites, booster tanks and launch accessories littering orbital corridors.
For working satellites, orbital altitudes run from 125 miles to 22,000 miles up. Most satellites are positioned to serve specific purposes in the same orbital region. Communications and global positioning satellites, for instance, are placed where users can access signals with a certainty of their location.
While there have been only a few incidents of space debris damaging or destroying a working satellite, the increasing amount of litter is increasing the threat.
It's become a major topic for scientists at the annual Advanced Maui Optical and Space Surveillance Technologies Conference. This year's conference includes a panel session, "Space Debris Observation Status and Needs," as well as an afternoon devoted to reports on space debris (Sept. 12-17, www.amostechconf.com).
British astronomer and author Stuart Clark ("Big Questions: the Universe," July 2010, Quercus Publishing) warned last year of the increasing threat, citing findings of the European Space Agency, which set up an office on space debris.
"With satellites traveling at tens of thousands of kilometers per hour, any encounter with debris could be lethal," Clark says ("Junk Busters," New Scientist, Sept. 11, 2010).
There is an urgent need to clean up the litter, he said, "but this will take time, partly because technology needs to be developed and partly because the political and legal framework does not currently encourage removal of debris."
The political obstacle is the more difficult. A 1967 international treaty specifies that an object put into orbit belongs to the launch country, which is responsible for it. There is no national or international agency to enforce responsibility.
In 2007, China displayed the same concern for the orbital environment that it has for its earthly environment by destroying its Feng Yun satellite in orbit, spewing thousands of bits of satellite debris into low-Earth orbit. Two years later, a zombie (wandering dead) Kosmos satellite collided with the Iridium 33 communications satellite, generating 1,800 identifiable bits of debris across the orbital space used by communications satellites, as well as thousands of smaller bits that haven't been identified - millimeter-size metal fragments traveling at orbital speeds of 10 kilometers a second.
In 2009, the space shuttle Discovery took avoidance actions over unidentified debris approaching its flight path. Last year, satellite operators were forced to modify positions 126 times to avoid debris.
In March, Lt. Gen. Susan Helms of the U.S. Strategic Command said the U.S. needs to work with other nations "to enhance our shared ability to detect, warn of, characterize and attribute natural and man-made disturbances to space systems." The statement was in a report of 22,000 pieces of space junk being tracked today ("Space debris threat needs international response," www.space.com, March 22, 2011).
At the 2010 AMOS Conference, Darren McKnight of Integrity Applications argued for action to remove derelicts, saying the options on cleaning up space are high costs now or higher costs later.
"Only time will tell exactly when the debris hazard will cross into an untenable level, and how much more we will end up paying to clean up tens to hundreds of thousands medium-size 'lethal' debris rather than tens to hundreds of large objects," he said ("Pay me now or pay me more later: Start the development of active orbital debris removal now," McKnight, AMOS 2010).
* Edwin Tanji is a former city editor of The Maui News. He can be reached at hakumoolelo@earthlink.net. "Haku Mo'olelo," "writing stories," is about stories that are being written or have been written. It appears every Friday.
