At 7:28PM on October 4th, 1957 a rocket screeched into the sky above the Soviet Union, releasing its payload into low orbit and granting the world its very first artificial satellite.
Sputnik was revolutionary for any number of reasons – many of which we in America begrudgingly ignore, like successful Soviet trips to Venus, because we saw their victories as losses at the time, and because the United States ultimately took home the heavyweight title by sending six manned missions to the surface of the moon.
In the years since, however, manned missions to the outer reaches of space have been all but scrapped and we find ourselves, once again, looking at a manned mission to the moon like it’s something we’ll have to plan for decades in advance. The thing is, state-owned space programs may have stagnated over the past thirty years or so, but the private sector just got cooking – and in just a few short years they have nearly caught up with the capabilities of organizations like NASA and Russia’s Roscosmos. Having so many new names in the space game over the coming decades could likely mean a new era in space travel – but it will certainly mean more traffic in the skies above our heads.
While many of us aren’t familiar with the intricacies of planning a rocket launch and satellite deployment, or establishing a long-term orbit once the satellite is released… most of us are pretty familiar with traffic. At best, it can be frustrating, and at worst it can be incredibly dangerous.
Now imagine a traffic jam where every vehicle is traveling at 18,000 miles per hour and many aren’t able to perform any kind of course correction. See the problem? The United Nations does too. That’s why they released a forty-six-page document entitled “Guidelines for the long-term sustainability of outer space activities,” which was put together after years of discussion within the UN’s “Committee on the Peaceful Uses of Outer Space.”
These guidelines are intended to help establish a uniform methodology for the deployment, and perhaps more importantly, the disposal of orbital equipment like satellites. Satellites, like any spacecraft, have operational lifespans determined by their stored and absorbed energy capabilities, equipment longevity, and often, new technology sent up to replace them.
When a satellite becomes redundant, or simply dies, current guidelines established by the UN and accepted among most of the larger space-faring organizations calls for the old hardware to come out of the sky within 25 years. In most cases, that requires no real planning or course of action, as a dead satellite’s orbit will slowly degrade until it burns up as it begins to re-enter the atmosphere. Depending on how far up the satellite is and the state of its orbit, that could take anywhere from months to decades – which is fine according to the current set of rules… but those rules may not work for long.
Researchers at the Southampton University in the U.K. used software to simulate large bits of space debris already being tracked as well as the current artificial satellites in orbit around the Earth. They then added an artificial constellation of a thousand more satellites – which may sound significant, but is actually a fairly moderate guess as to how many small, medium and large pieces of equipment may be launched by governments and private ventures alike in the years to come. They then used the current guidelines for the destruction of redundant or failed spacecraft and let the simulation play for two hundred years.
Their simulation showed that, even if every space fairing organization over the next two hundred years adheres strictly to the current guidelines (with a 95% success rate allowing for unintentional failures) chances of catastrophic collisions between the satellites we use for everything from communications to GPS increase by a rate of 50% – and that’s assuming a veritable “best case scenario.”
In order to prevent this dangerous situation, the researchers at Southampton University are calling on the world’s space agencies to do away with the 25-year rule when it comes to disposing of old space gear, and replace it with a much more aggressive 5-year one. They also call on companies like SpaceX, Boeing, and OneWeb that have announced plans to launch thousands of small satellites intended to bring broadband and other telecom services to everywhere on the planet to plan to dispose of their own redundant or failed satellites within just two years.
“What we found was that when you put the constellation satellites on to a disposal orbit, they intersect with objects below them. And if they take 25 years to pass through those lower altitudes, there is a good chance that they will have collisions with objects in the background population on the way down. But by reducing the 25 years to five years, you greatly minimize the chances of those interactions taking place.” Southampton’s Dr. Hugh Lewis told the media.
Other changes they call on the international community to make for a safer future in space is to equip satellites with more fuel than current commercial norms to allow for extended maneuvering near the end of each satellite’s anticipated life span. OneWeb, who worked with Southampton in their study, also encourages manufacturers to add grapple fixtures to their platforms to allow for manual orbital corrections from other spacecraft. Of course, for any of this to work, it means governments and companies alike must adhere to the guidelines
“Spacefarers of today already fail to implement mitigation measures to a sufficient level,” Dr. Holger Krag, who heads the Space Debris Office at the European Space Agency said.
“My office regularly monitors space surveillance data in order to form statistics on how well we behave globally. One example is for post-mission disposal to remove spacecraft (from low-Earth orbit) in order to avoid long-term presence in space after the mission. Forty percent of all missions fail to implement this today.”
Clearly, there will need to be a shift in strategy for all space-faring organizations in the near future, otherwise the burgeoning businesses intent on populating the space around our little blue dot may find that just getting to space is the easy part – keeping our ships and satellites from becoming targets for a never-ending shotgun blast of debris could be the real challenge.
Image courtesy of the European Space Agency