DAYTONA BEACH, Fla. – Yet again, NASA had to change its plans in space because of space debris, likely the leftovers of a damaged satellite.
This time, the astronauts on board the International Space Station couldn’t step outside for a spacewalk because NASA felt the risk of debris hitting an astronaut was too great.
Two weeks ago, astronauts had to hunker down and close all hatches onboard the ISS after Russia used a missile to shoot down a satellite, splintering it into thousands of pieces.
On Tuesday, Elon musk tweeted that his company SpaceX had to move some of its micro-satellites in low earth orbit “to reduce the probability of collision.”
We had to shift some Starlink satellite orbits to reduce probability of collision. Not great, but not terrible either.— Elon Musk (@elonmusk) November 30, 2021
Station & Dragon have micrometeorite shields (ultra high velocity impact absorption), but EVA suits do not, hence higher risk for spacewalk.
Satellites, including Musk’s Starlink constellation providing high-speed internet to the world, are required to deorbit themselves within 25 years so they don’t create space junk. But most don’t have a backup system to do that.
Another batch of those Starlink satellites are expected to launch from Cape Canaveral Space Force Station at 6:20 Wednesday night.
Embry-Riddle Aeronautical University Professor Riccardo Bevilacqua, Ph.D., said NASA approached him with a challenge.
“The whole idea is can you guarantee to us that (a satellite) will come down at 25 years and you can control where?” Bevilacqua said.
Dr. Bevilacqua, who teaches aerospace engineering at ERAU, put together a team of Ph.D. students and even some undergraduates.
Over the course of four years, they invented the DD3 -- the Drag De-Orbit Device -- and the algorithms to steer it.
The 10x10x5 cm device looks similar to a tape measure. It attaches to the bottom of a micro-satellite and when it’s ready to deorbit the satellite, the metal boom deploys and the the algorithms calculate how to move the boom to slow down, or drag, the satellite and drop it back through the atmosphere in an unpopulated spot where it can safely burn up.
“Right now countries of different regulations, the U.S. and European countries, are pretty clean in a sense of requiring satellites to be removed at end of life,” Bevilacqua said. “But not everybody is, and so having the technology that allows you to be sure that you’re not going to become space debris, it’s absolutely a must. Especially with SpaceX launching thousands of satellites in the future into low-earth orbit.”
Eventually all satellites in low-earth orbit will fall back through the earth’s atmosphere, but in some cases that could take hundreds if not thousands of years.
“I would say this is definitely a way to mitigate exponential growth that has been projected,” Bevilacqua said. “Trying to stop the trend. For sure.”
Some scientists predict that if countries continue to use old satellites for target practice, like Russia, China, India and even the U.S., or defunct satellites continue to smash into each other, eventually low-earth orbit will become unusable.
“I can’t imagine my kids in the future not being able to use GPS on their smart devices,” Bevilacqua said. “If we end up having too many dead or uncontrolled satellites, it may become impossible to ever place another satellite into orbit.”
Bevilacqua said the DD3 is being patented and has already been licensed.
It will fly on a SpaceX rocket to the ISS likely in May, according to Bevilacqua, and be inserted into low-earth orbit by astronauts as early as June. Bevilacqua should know if the test succeeded weeks after.
Bevilacqua hopes and expects the DD3 to enter into commercial use. He, the students and ERAU jointly own the invention. It should sell to a satellite builder for less than $10,000, according to Bevilacqua.