The human race has a seemingly unlimited capacity for producing waste, and this most unwelcome trait extends beyond our planet.
Space junk, all those defunct satellites and miscellaneous debris that no longer serve a purpose, is growing at an alarming rate.
This is something that the Ad Astra Rocket Company of Costa Rica is looking into.
The issue of too much junk orbiting Earth is getting attention thanks to two recent films: the terrifying Gravity, masterfully directed by Mexican filmmaker Alfonso Cuaron, and the educational IMAX documentary Space Junk 3D by Melrae Pictures.
Space Junk 3D explains the problem:
Since humans have ventured into space, we’ve embraced “The Big Sky Theory.” The Theory holds that space is so big, you could launch anything into orbit, and it wouldn’t collide with anything else.
Over the last 50 years, we’ve launched several thousand satellites into space. Once an object stops functioning, we simply leave it in orbit.
That’s a whole lot of junk: It’s estimated that low Earth orbit (LEO) contains 6,000 tons of space [debris].
The image in this article is from NASA’s Orbital Debris Program Office. It represents the current amount of space junk floating in LEO. The debris produced by these discarded objects includes satellites, paint, bolts, solar panels, scientific instruments for measurement, waste from previous space missions, and more. In the film Gravity, these objects pose a grave danger to two stranded that become untethered and stranded in space. In reality, collisions between space junk and functional objects, such as the International Space Station, are also extremely dangerous.
Although most space junk ends up getting ignited and burned down in the atmosphere before it reaches Earth, there is still a risk that debris may come crashing down to Earth. In the 21st century, a handful of people have being injured by pieces of spy satellites from the former Soviet Union and rockets used to put U.S. Air Force satellites in space.
In 2011, NASA Hall of Fame Austronaut Franklin Chang Diaz –founder and CEO of the Ad Astra Rocket Company in Costa Rica- mentioned the issue of space junk in an
interview with the University of Barcelona:
Near-Earth orbits are teeming with space vehicles moving at very high speeds. There are tens of thousands of satellites, most of which have run out of fuel and are no longer operational, making them extremely dangerous to other satellites and crewed flights. We need to begin clearing these objects from their orbits, which have become highly coveted paths for new spacecraft.
There are two options for clearing the debris. The first would be to move these objects into lower orbits where atmospheric friction would eventually cause them to disintegrate. The second option, which is possibly the more ecologically sound, would be to push the debris into higher orbits to release it from Earth’s gravitational force and allow it to move towards the Sun, where it would also be destroyed.
Franklin Chang Diaz hopes to use Ad Astra’s Variable Specific Impulse Magnetoplasma Rocket (VASIMR) to help remove orbital debris from LEO. Ad Astra has been tracking the movements of 19 very large objects, among them pieces of Soviet Zenit rockets that weigh eight tons. Here’s how Ad Astra explains its Space Cleaner mission, which seeks to improve the safety of future space missions and clean up our orbits:
[A] 200 kW SEP VASIMR® space tug to lower the orbital altitude of the Zenit targets for a controlled chemical deorbit over the Pacific Ocean. To accomplish this, the reusable tug is fitted with a specialized service module (SM) consisting of a solid rocket motor (SRM) tray, loaded with 20 SRM units (19 plus a spare) and a detachable, short-range, “chemical robotic pod” (CRP) for proximity operations near the target body.
For each of the 19 targets, the tug first climbs to the orbit of the drifting Zenit (~800 km) where the CRP is released to capture, stabilize, and bring the target back to a hard docking with the tug. At capture, the CRP also robotically installs a fresh SRM unit onto the Zenit rocket nozzle. With the Zenit attached, the tug brings it down to approximately 400 km for release at a point where the newly fitted SRM ignites, bringing the Zenit to a controlled atmospheric re-entry. The VASIMR® tug then climbs back, making a plane change, as required, to capture the next target and repeat the process.
Although removal of space junk should be a priority of governmental space agencies, Franklin Chang Diaz and Ad Astra’s executives recognize the potential of aerospace firms to handle this task. In 2011, Franklin Chang Diaz told the Costa Rica Star that:
[…] commercial space initiatives are more than welcome, and they tell us that innovation is still very much alive and strong. Besides, VASIMR serves to complement these space systems with a propulsion method designed to be operated exclusively in outer space.
The VASMIR propulsion system is scheduled to undergo space trials by 2015. Scientists and technology students in Costa Rica have been involved in making VASMIR a reality, which NASA hopes to use in future missions, including a possible manned mission to Mars.
Article by Costa Rica Star
