The noted US military bonkers-boffinry bureau, DARPA, announced yesterday that it would like to hear from anyone with ideas for cleaning up the large amounts of space debris orbiting the Earth. Aerospace globocorp Boeing has already indicated that it is interested.
According to DARPA:
Since the advent of the space age over five decades ago, more than thirty-five thousand man-made objects have been cataloged by the U.S. Space Surveillance Network. Nearly twenty-thousand of those objects remain in orbit today, ninety-four percent of which are non-functioning orbital debris. These figures do not include the hundreds-of-thousands of objects too small to be catalogued, but still large enough to pose a threat... collisions between debris objects could potentially lead to a continuously growing debris population, thus increasing the risk to operational satellites.
Since January 2007 we have experienced a nearly fifty percent increase in the number of cataloged debris objects, largely due to the intentional destruction of an active satellite by the Chinese government in 2007, as well as the collision between an active Iridium satellite and a retired Russian communications satellite earlier this year.
Owing to the tremendous speeds of objects in orbit, and the fact that satellites and spacecraft must be as lightly built as possible to save on launch costs, even a tiny piece of debris can inflict disabling damage in a collision.
This isn't a good scenario for the US military, perhaps the organisation most heavily dependent on space. Hence DARPA would like to hear from anyone with "possible technical approaches for cost effective and innovative system concepts for the removal of orbital debris".
It seems that the Pentagon brainiacs particularly want to tackle drifting space rubbish from 1mm up to "derelict spacecraft" size in low orbit, and larger stuff up in geosynchronous orbit where the communications satellites are found.
DARPA is looking for information on the full spectrum of potential solutions, from quickly clearing a congested region in space of all types of debris to strategically removing large objects across a range of altitudes to manage the overall growth rate of debris.
It's noticeable that US aerospace and weaponry behemoth Boeing have already listed themselves as an "interested vendor" on the possible Orbital Debris Removal (ODR) project. Boeing is big in the military space industry. The firm is working on the so-called Space Based Surveillance System, a group of satellites intended to spy on enemy spy satellites. According to Boeing, the SBSS could also be used "to calculate orbital debris collision-avoidance measures for the International Space Station and Space Shuttle missions".
That said, however, the ODR effort is only a request for information for now. No funds have been set aside, and DARPA says it "does not intend to award a contract on the basis of this... or to otherwise pay for the information solicited".
Plus there's the fact that DARPA is institutionally a bit, you know... special. So there's every chance that orbital-debris sweepup is actually impossible or that they'll give up on it in the near future. ®