6 Technologies for Space Debris Removal

The human spirit for exploration has taken us to the top of Mt. Everest and beyond to the very threshold of the solar system. The price for such adventures has been paid in human lives and garbage – lots of garbage. We read recently that mountaineers hauled down some 24,000 pounds of waste from the world’s tallest mountain earlier this month, including empty oxygen cylinders, plastic bottles, cans, batteries, and several well-preserved human bodies. The situation way above Everest isn’t much better, as we recently noted in our article on tracking space junk from a tiny little island in the middle-of-nowhere Pacific Ocean using a Lockheed Martin (LMT) radar powered by some gallium nitride. Now we want to talk about what technologies are being developed for space debris removal.

It’s getting crowded up there. Credit: Astroscale

The motivation for cleaning up outer space is pretty obvious: There’s a lot of expensive equipment circling the Earth, beginning with the $160 billion International Space Station (ISS). Last year, a bit of space junk pierced the station, which astronauts literally patched with a piece of duct tape. The chances of more such collisions with orbital debris will only increase, as companies like SpaceX and OneWeb start pumping thousands of new satellites into space for global internet connectivity. Venture capital firm SpaceFund counts about 140 launch companies on top of that. Space junk could put a serious dent into the NewSpace economy before it ever really takes off. The issue made our list of the top NewSpace predictions for 2019.

Medieval Technology for Space Debris Removal

It turns out that a lot of smart people have devoted a lot of time to thinking about the problem of space debris removal. Our favorite option so far? Shooting a harpoon through the near-vacuum of space at about 45 miles per hour. It’s one of a number of technologies that are being tested by the Surrey Space Centre out of the University of Surrey in the UK. The agency is leading the nearly $19 million RemoveDEBRIS project that includes Airbus (AIR), which is behind the harpoon idea. While it looks like you could literally spear a whale with this thing, it’s actually the size of a writing pen.

The project has also tested other space debris removal technologies, including a net for capturing errant cubesats, modular satellites that have become increasingly popular for cheap access to space-based missions. Another technology under consideration is a dragsail that will help deorbit the RemoveDEBRIS spacecraft itself after it completes its mission. It’s like a bunch of engineers watched The Ice Pirates movie one too many times.

Can a bunch of scrappy scallywags startups do any better?

Tugboats for Space Debris Removal

Click for company websiteProbably the most well-funded of the bunch is a company based in Singapore, but with its main operations in Tokyo and a satellite office coming to Denver, Colorado – Astroscale, which we first came across a couple of years ago. Founded in 2013, the NewSpace startup has since raised $132 million, completing an extended Series D in March for $80 million. The company is betting that the maturing space-based economy will eventually require the services of a dedicated space debris removal service, and Astroscale is jockeying to be the leader in a yet-to-be-created market. The hope is that the international community will implement regulations requiring the removal of both space junk and defunct or malfunctioning satellites.

Astroscale space debris removal system.
Astroscale is looking to make a connection in space for space debris removal. Credit: Astroscale

Its main space debris technology in development involves a mission it calls End-of-Life Service by Astroscale demonstration (ELSA-d), which is scheduled for launch in 2020. The idea is that a chaser satellite will dock magnetically with a second target that it will tow into Earth’s atmosphere to burn up. The proposal would require all satellites in mid- to high-low earth orbit be pre-engineered with a lightweight docking plate that can interface with the Astroscale tugboat. The company says it will also address what’s called active debris – junk already floating in space – but few details have emerged aside from “innovative solutions for capture and removal of environmentally critical debris, such as rocket upper stages and defunct satellites that are already in orbit.” In other words, they’re still working on it.

Update 11/29/2021: Astroscale has raised $109 million in Series F funding to scale and dramatically accelerate their on-orbit servicing capabilities. This brings the company’s total funding to $313.2 million to date.

Dedicated Engine for Space Debris Removal

Click for company websiteAnother company that we’ve covered previously that has expanded its products and funding is D-Orbit. Founded in 2011, the startup out of Milan, Italy has raised about $7 million. D-orbit is dabbling in a little bit of everything – satellite propulsion systems, software for satellite command systems, and booking agent for launch services. However, its flagship product is the D3, an “independent, smart motor optimized for decommissioning maneuvers.” Again, the business model relies on the emergency booster being pre-installed on satellites before launch.

The D-Orbit satellite decommissioning engine.
The little engine that could. Credit: D-Orbit

While it develops the D3 and other hardware, the company is brokering launch service deals with other NewSpace startups, including a Swiss startup called Astrocast that has raised about $4.2 million, including from Airbus, to deploy a constellation of 80 cubesats for the Internet of Things, which could challenge bigger, more expensive IOT satellite networks like that operated by ORBCOMM. At the same time, D-Orbit is buying launch space from another NewSpace startup that is also interested in solving the problem of space debris removal – Firefly Aerospace.

Scavenging Space Debris for Resources

Click for company websiteFounded in 2013, Firefly is based out of Austin, Texas and had raised a reported $21.6 million by 2016. The Texas-based startup was nearly an early casualty of the budding NewSpace economy, as it almost crashed and burned in 2017 when a key investor pulled out. A venture firm called Noosphere Ventures swooped in and saved the company, which was founded by rocket scientist Tom Markusic who has worked at SpaceX, Blue Origin, and Virgin Galactic. The resurgent startup is building rockets for the small satellite market, competing against more mature companies like Rocket Lab out of New Zealand and even SpaceX. Firefly maintains it can launch its Alpha rocket for the bargain price of $15 million per mission, about a quarter the cost of a full ride on a SpaceX Falcon. Noosphere appears to be putting up the bucks to give Firefly a fighting chance, with news earlier this year that the rocket company will build a factory and launch site at Florida’s Cape Canaveral Spaceport as part of a $52 million deal.

Firefly Aerospace Alpha rocket.
Firefly Aerospace Alpha rocket. Credit: Firefly

Apparently, Markusic has the bandwidth to think beyond his first launch, as he’s reportedly been making the conference circuit with speeches about his own ideas on space debris removal. His proposal involves using “solar electric propulsion-powered space tugs to capture spent satellites and transport them to Mars’ over-sized asteroid moon, Phobos, transforming it into a staging base for a future human presence on Mars,” Inc. reported. In other words, Firefly wants to turn Mars into the new China, where we can send children in little spacesuits to scavenge satellites for valuable electronic bits.

Update 03/24/2022: Firefly Aerospace has raised $75 million in Series B funding to fund more Alpha rocket launches, further develop its larger rocket Beta, finance its Blue Ghost lunar lander, and continue work on a space utility vehicle – also known as a “space tug” — to transport satellites into unique orbits after a launch. This brings the company’s total funding to more than $271.6 million to date.

Getting a Grip on Space Debris

Click for company websiteFounded in 2011, Altius Space Machines only has about $87,000 in funding listed, so the Boulder, Colorado-based startup must be living off NASA grants or food stamps. One of its core technology areas is developing robotic arms systems for grabbing active debris. It developed a “sticky boom” with gecko-like abilities to grasp just about any material using electrostatic charges. Think rubbing a balloon against your head and then sticking it against the wall, but a little more sophisticated than that. It has also completed work for that shadowy government agency called DARPA, turning the sticky boom into an articulating selfie stick for space.

Venus Fly Trap for Space Debris

Click for company websiteA spin-out from Swiss technical university EPFL, ClearSpace is looking to commercialize technology that has been in development for about seven years. The company’s satellite, reportedly similar in design to a drone, uses a net that shoots out and grabs a piece of debris before retracting the space junk, like a metal-eating Venus flytrap. The startup’s long-term plan is to build a future piece of space debris platform from where it can deploy multiple satellites predators.

Gas Stations in Space

Click for company websiteFinally, we bring you gas stations in space. Or, more accurately, a Silicon Valley startup called Orbit Fab has raised an undisclosed amount of pre-Seed money to flesh out the idea of building a satellite refueling station in space. That means satellites wouldn’t necessarily be as disposable as oxygen canisters on Everest. The company has already developed the hardware of pumps, valves, and plumbing for such a fueling system and recently tested it by transferring water to the ISS in microgravity.

Orbit Fab satellite refueling system.
It’s either the Orbit Fab fueling depot or an Ikea instruction manual. Credit: Orbit Fab

Orbit Fab plans on offering a variety of storable propellants on orbit that include water, and more dangerous-sounding propellants such as xenon, green monopropellants, hydrazine, NTO, and hydrogen peroxide.

Update 09/07/2021: Orbit Fab has raised roughly $10 million in funding to further its goal to be the go-to source for orbital refueling. This brings the company’s total funding to $16.3 million to date. 


Space debris removal is a solution in need of a market. While the long-term health of the NewSpace economy likely hinges on clearing the space junk traffic jam, the situation will probably have to get much worse – i.e., the destruction of some really expensive stuff – before the industry decides to pay for these services. However, expect the sector to expand, especially as competition heats up in the launch sector. Experts and industry insiders alike are predicting a serious reckoning soon among the dozens of startups trying to build launch capabilities for what is still a pretty finite demand despite rapid growth in the smallsat market, so “garbage collector in space” might sound like an attractive pivot soon.


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