How can humans clean up our space junk?
More than 500,000 pieces of debris, or “space junk,” are tracked as they orbit the Earth. They all travel at speeds up to 17,500 mph, fast enough for a relatively small piece of orbital debris to damage a satellite or a spacecraft. If that sounds dangerous, that’s because it it is. The rising population of space debris increases the potential danger to all space vehicles, but especially to the International Space Station, space shuttles and manned spacecraft. NASA takes the threat of collisions with space debris seriously and has a long-standing set of guidelines on how to deal with each potential collision threat.
How to deal with the simple fact that space junk isn’t going away? There is so much of it that even if we stopped launching rockets tomorrow, the space junk problem will persist for a couple of centuries and even get worse, according to a 2008 NASA study. “People have been taking about debris since the 1960s,” he said. “But until now nobody has actually funded missions to study and deal with it.” But now at least, new launches — at least those licensed in the US, Japan, and Europe — are required to have a plan for getting a satellite down when it’s at the end of its life. A good step forward, but that will hardly mitigate the problem. Swiss Scientists have a plan – CleanSpace One – to clean up space junk – it involves creating a ‘Janitor Satellite’ that will seek out pieces of space junk to drag back into the atmosphere causing them to burn up.
Switzerland, is well known for efficiency and cleanliness, hopes that it’s EPFL Labs in the Swiss Space Center hope the price will drop in the future. The project is dubbed the “janitor” satellite because it is being designed to grab pieces of trash and bring them back down to Earth.
Basically it uses small but powerful engines to attack and capture ‘space junk’ by grabbing the trash with four metal prongs that fold out from the satellite, and then both the janitor and its cargo would burn up upon reentry into the Earth’s atmosphere. So a ‘new’ janitor has to be sent each and every time…a tedious process and expensive!
Space Junk is getting significantly worse each year (See Videos below), and more dangerous. NASA FEARS that Space Debris Will Trigger World War III by having unwanted space junk fall out of the sky and provoke a hostile attack. It’s a real threat as falling debris can achieve speeds of more than 30,000 mph and even small pieces of spent rocket parts – even chips of paint can do a lot of damage at that speed. And the danger of it hitting a military satellite and being mistaken for a hostile act are huge! In 2011, NASA warned that the level of space junk had risen exponentially, and had reached a “tipping point” and suggests that falling space debris poses a “special political danger” that could trigger an international incident. The problem is identifying where it originated is another!
Space debris encompasses both natural (meteoroid) and artificial (man-made) particles. Meteoroids are in orbit about the sun, while most artificial debris is in orbit about the Earth. Hence, the latter is more commonly referred to as orbital debris. Orbital debris is any man-made object in orbit about the Earth which no longer serves a useful function. Such debris includes nonfunctional spacecraft, abandoned launch vehicle stages, mission-related debris and fragmentation debris. So how to clean it up since the risk is increasing exponentially.
The problem is that there is no “United Galaxy Sanitation Patrol.” And salvage rules don’t apply in space, according to Brian Weeden, technical advisor at the Secure World Foundation and author of expert in space debris. “[The launching state] has jurisdiction and control,” he said. “And yes, that means you have to get their permission to interact with a piece of space junk.”
“Keeping all this litter in space, it’s like litter on the floor,” said Jason Forshaw a research fellow at the University of Surrey. “It’s becoming more of a risk.” The next few missions are RemoveDebris from Britain, on which Forshaw is one of the lead scientists; Japan’s just-launched Kounotori 6 satellite, carrying the Kounotori Integrated Tether Experiment; and e.Deorbit from the ESA. Even the private sector is getting into the act: Japanese startup Astroscale is designing a debris-removal satellite. RemoveDebris is planned for 2017, while Astroscale plans to launch in 2018. e.Deorbit’s flight is scheduled for 2023 or 2024.
There some ideas for missions that focus on dead satellites, aiming to catch them with robotic arms, spear them with harpoons, or slow them with sails or tethers. Others aim for smaller pieces with lasers or stick to them with adhesive. It’s all an effort to keeping low-Earth orbit, the region up to 1,200 miles from the surface, usable.
The Verge also reported that:
e.Deorbit is after bigger fish. The target is the ENVISAT, a 8-ton remote monitoring satellite launched in 2002. The ESA hasn’t settled on a design yet; it is considering either a robotic arm which would grab the satellite, or a net. In the meantime the agency wants to demonstrate tracking, guidance, and capture technologies to see what will work best.
Some technologies will use the magnetic field of the Earth itself to get the satellites down; that’s the aim of JAXA’s Kounotori Integrated Tether Experiment. The craft will trail a long conductive cable, and run current through it. As satellites and cables pass through the Earth’s magnetic field, the interaction of the field and current generates a small force on the tether. (This is the same way electric motors work). The tests will occur in January, as the KITE ship is currently docked with the ISS doing double duty as a supply run.
All three missions are geared toward sending satellites plummeting to a watery graveyard in the South Pacific, east of New Zealand.
For hunting smaller pieces, Astroscale plans is to launch a satellite called ELSA-1, that will track debris and stick to it with glue. Other more out-there proposals include using ISS- or satellite-mounted lasers to vaporize the surfaces of small pieces and force them down, but that will take more technical development of the lasers so they could maximize the amount of energy delivered to the debris.
It’s a start, but we have a long ways to go.
Here is a Q & A from NASA:
Orbital debris is any man-made object in orbit about Earth which no longer serves a useful purpose.
What are examples of orbital debris?
Derelict spacecraft and upper stages of launch vehicles, carriers for multiple payloads, debris intentionally released during spacecraft separation from its launch vehicle or during mission operations, debris created as a result of spacecraft or upper stage explosions or collisions, solid rocket motor effluents, and tiny flecks of paint released by thermal stress or small particle impacts.
How much orbital debris is currently in Earth orbit?
More than 22,000 objects larger than 4 inches (10 cm) are currently tracked by the U.S. Space Surveillance Network. Only about 1,000 of these represent operational spacecraft; the rest are orbital debris. The estimated population of particles between .4 inches and 4 inches (1 to 10 cm) in diameter is approximately 500,000. The number of particles smaller than .4 inches (1 cm) probably exceeds tens of millions.
Are orbital debris uniformly distributed about the Earth?
Most orbital debris reside within 1,250 miles (2,000 km) of Earth’s surface. Within this volume, the amount of debris varies significantly with altitude. The greatest concentrations of debris are found near 500-530 miles (800-850 km).
How fast are orbital debris traveling?
In low Earth orbit (below 1,250 miles, or 2,000 km), orbital debris circle the Earth at speeds of between 4 and 5 miles per second (7 to 8 km/s). However, the average impact speed of orbital debris with another space object will be approximately 6 miles per second (10 km/s). Consequently, collisions with even a small piece of debris will involve considerable energy.
How is the International Space Station protected against orbital debris?
The International Space Station, or ISS, is the most heavily shielded spacecraft ever flown. Critical components such as habitable compartments and external high pressure tanks normally will be able to withstand the impact of debris as large as .4 inches (1 cm) in diameter. ISS also can maneuver to avoid tracked objects. ISS executes a collision avoidance maneuver once a year on average.
How long will orbital debris remain in Earth orbit?
The higher the altitude, the longer the orbital debris will typically remain in Earth orbit. Debris left in orbits below 370 miles (600 km) normally fall back to Earth within several years. At altitudes of 500 miles (800 km), the time for orbital decay is often measured in decades. Above 620 miles (1,000 km), orbital debris normally will continue circling Earth for a century or more.
Is re-entering debris a risk to people and property on Earth?
A significant amount of debris does not survive the severe heating which occurs during re-entry. Components which do survive are most likely to fall into the oceans or other bodies of water or onto sparsely populated regions like the Canadian Tundra, the Australian Outback, or Siberia in the Russian Federation. During the past 50 years an average of one cataloged, or tracked, piece of debris fell back to Earth each day. No serious injury or significant property damage caused by re-entering debris has been confirmed.
What can be done about orbital debris?
The most important action today is to prevent the unnecessary creation of additional orbital debris. This can be done through prudent vehicle design and operations. Cleaning up the environment remains a technical and economic challenge that is currently being investigated by the United States and other countries.
What is the U.S. policy on orbital debris?
Since 1988 the official policy of the United States has been to minimize the creation of new orbital debris. The most recent National Space Policy (June 28, 2010) contains a section entitled “Preserve the Space Environment” that addresses orbital debris mitigation for both the near term and long term. In 2001 the United States adopted a set of measures for government agencies and departments called orbital debris mitigation standard practices. These standard practices became the foundation for the development of international orbital debris mitigation guidelines.
Do other countries have guidelines on orbital debris?
Yes, Russia, China, Japan, France, and the European Space Agency have all issued orbital debris mitigation guidelines. In addition, in 2007 the United Nations, through its Committee on the Peaceful Uses of Outer Space, created a set of orbital debris mitigation guidelines.
Where can I read more about orbital debris?
Visit the NASA orbital debris website at www.orbitaldebris.jsc.nasa.gov.