Clearing Space Junk for Future Missions
Imagine launching a delicate spacecraft through a field of orbital debris, traveling at speeds of over 15,000 miles per hour. You just imagined a perfectly normal spacecraft launch. This, of course, is not a far-fetched scenario but the reality for every spacecraft that launches through the earth’s atmosphere.
The Department of Defense’s Global Space Surveillance Network is tracking over 27,000 pieces of orbital debris, more commonly known as “space junk.” Some are traveling as fast as 17,500 mph. NASA estimates that approximately 500,000 marble-sized objects are in orbit, along with perhaps 100 million even smaller debris.
The risk of impacting one of these objects is more than theoretical. In 1996, a French satellite was hit and damaged by space junk from a previous French satellite’s explosion. In 2009, an Iridium commercial satellite was hit and destroyed by a defunct Russian satellite.
Collisions like that one, and deliberate explosions such as China’s 2007 anti-satellite missile test, can also add tremendous amounts of space debris in a short time.
And, as more satellites are launched into orbit every year, the problem increases.
Reduction & Removal
There are two ways to meet the challenge of space junk. The first is to reduce the amount of debris being created. The second is to remove debris already in orbit.
In 1979, NASA launched its Orbital Debris Program, which, among other things, looks for ways to reduce the amount of debris created by operations in space. In `1995, NASA issued the world’s first comprehensive guidelines for reducing the amount of debris created in space. In 2002, the ESA and space agencies from 10 countries adopted a shared set of guidelines.
While these reduction efforts have been effective in slowing the creation of additional debris, they don’t remove the debris already in orbit.
A 2005 study found that even if no future space launches occurred, collisions between existing satellites would increase the number of debris in orbit faster than atmospheric drag would remove them.
It’s clear that fully addressing the challenge of space junk will require actively removing debris from orbit, a concept sometimes called active debris removal or ADR.
Several private companies and government agencies are working on this challenge. Orbital Prime, a program funded through the Space Force’s SpaceWERX program, has targeted awards at private companies developing solutions for removing space junk. But, some experts say that the U.S. is far behind other space agencies when it comes to space junk removal.
“It’s embarrassing to me hearing people talk about the need for active debris removal and the need for debris mediation as if it’s something that’s going to be decades out,” said Darren McKnight, a member of the International Academy of Astronautics’ Space Debris Committee. “The European Space Agency and Japan’s space agency are way ahead on those sorts of things.”
By way of example, the Space Force’s Orbital Prime program promises awards of $250,000 to $1.5 million, while the European Space Agency recently awarded a $104 million contract to launch a mission to remove a piece of space debris from orbit in 2025.
Why Space Debris Removal & Mitigation Requires Cost-Effective Robotics
The actual process of removing space debris can be complex and will almost certainly require advanced robotics. Space debris comes in many shapes and sizes and often needs robotic arms and other advanced robotic systems to capture them.
But, capturing and de-orbiting isn’t the only way to mitigate space debris: Extending the life of existing satellites can prevent them from becoming additional space debris. In line with initiatives like the White House’s recently announced ISAM strategy, satellites can be refueled, serviced, and even reconfigured for new purposes on-orbit. This process could both prevent them from becoming space junk and reduce the need for new launches.
However we attack the problem of space junk, it’s clear that robotics will play a significant role and that cost-effectiveness and timing will be significant factors.
That’s where systems like Motiv’s ModuLink Modular Robotics platform can help. They allow advanced robotic components like robotic arms, connectors, sensors, and modules to be quickly and easily fitted to a wide variety of spacecraft.
The entire system was designed with repairs, replacements, refueling, and space junk removal in mind. It could help to speed the development and lower the cost of spacecraft designed for those applications.
Whether ModuLink components are used to develop on-orbit servicing capabilities, refueling spacecraft, or developing spacecraft that capture and de-orbit space junk, we’re happy to be a part of the larger space junk solution.