[Satellite News 02-24-12] It has been known for years that space debris — or pieces of man-made, non-functional hardware — has been littering the Earth’s low, medium and geostationary orbits and threatening the sustainability of the satellite industry. In the United States, the Pentagon is responsible for tracking roughly 22,000 man-made objects in orbit — with hundreds of thousands, if not millions, more objects too small to track. After several years of inaction on the part of global governments, the risk to space assets coming from orbital debris has skyrocketed to create frightening scenarios for functioning spacecraft.
ATK, however, has been working on a solution to this problem for years in the form of a multi-layered shield — a small satellite that would work as a vacuum cleaner and trash compactor to protect valuable assets in a particular region. ATK Spacecraft Division’s Systems and Advanced Technology Group Chief Technologist Jose Guerrero talks with Satellite News about the latest developments in its quest to supply the government with a viable fix to the problem.
Satellite News: What is the basic concept behind ATK’s Multi-layered Shield?
Guerrero: Our technology protects high-value assets from orbital debris. These pieces of debris are up to 10 centimeters in size and can travel about 11 kilometers-per-second. It’s a tremendous force that would destroy anything it hits. When the debris hits the multi-layered shield, it vaporizes and breaks the debris down to a size less than 2 millimeters. In some areas on existing spacecraft, shielding is limited to protect against objects that are smaller than 3 millimeters. Greater shielding might protect you for up to 5 millimeters, but typically, any size above 3 millimeters presents a threat to those assets. There’s no technology available right now to keep track of these particles. That’s why we came up with this shield technology — to act as protection for a high-value asset and as a debris sweeper to reduce the debris field that is impacting a particular area. ATK also has been working on technology to deal with larger debris objects, such as dead satellites, where we would use a spacecraft to grab the object and bring it down to low-Earth orbit so that it can burn through the atmosphere.
Satellite News: ATK’s concept has been several years in the making. What are the latest technological developments for this project?
Guerrero: We’ve done a significant amount of physics analysis, which was the key to making this a sound solution. Initially, we were looking to deploy the multi-layered shield with the shape of an entire sphere, but after looking over models, we realized that it would be more sufficient in protecting the International Space Station to deploy half of the sphere and having three or four of them depending on the size of the threat. Certain high-value assets like the space station and other spacecraft have pretty good data to prepare for debris impact. That data allows us to create different sets of geometry for our multi-layered shield technology. The shape could be a half-sphere or a rectangle. These are all new things that we’ve learned by evaluating the latest debris models.
Satellite News: What benefits would ATK’s solution provide over similar solutions?
Guerrero: I think the fact that we can prove, with sound physics, that it is possible to destroy these high-velocity debris particles is the main selling point. The subsystem that we would need to use, as far as deployable structures, is existing technology that we already have. This makes the multi-layered shield concept economically and technically viable for users in a short period of time. It is not something that couldn’t be done in the next 10 years, depending on funding. If funded properly, we could probably do it in five years.
Satellite News: Have you received any response to your solution from the government or other space companies?
Guerrero: We’ve pitched the multi-layered shield concept to the Air Force, DARPA and NASA. We gave Nicholas Johnson, the chief technologist for NASA, and his lead staff a three-and-a-half-hour presentation that went into the project in detail. He was really happy with our approach. He said that we had a very viable method that we were using and that he hadn’t heard too many viable methods in this range since he had started working at NASA. So, we feel this opportunity is very promising for us. Moving forward, it’s a matter of getting direction, priorities and funding completed.
Satellite News: Why is the issue of space debris receiving so much attention now when it has been a critical problem for so long?
Guerrero: Space debris is now the number one threat to the International Space Station. I think the issue of space debris has gotten worse. We’re at a point now where potential impact with orbital debris impacts the scheduling of 50 percent of launch missions. Not too long ago, impact with debris would factor into about 25 percent of launch schedules. If we don’t do something to deal with this issue, that number is going to shoot much higher than 50 percent. Launch windows are going to shrink considerably.