With proliferating space debris jeopardizing equipment and astronaut safety, scientists are sounding the alarm. Researchers, meanwhile, continue their search for effective ways to clean up the mess.
And while it's the large pieces of space junk that grab headlines, scientists believe tiny, non-trackable debris may pose a more significant overall hazard. Even tiny paint flecks can destroy shielding, spacecraft windows, camera lenses and other vital equipment.
“The greatest risk to space missions comes from non-trackable debris,” Nicholas Johnson, NASA chief scientist for orbital debris, said in late 2013.
At Capitol College's Aerospace Research Lab (ARL), where astronautical engineering (AE) students collaborate with their counterparts in other disciplines, members of the TrapSat team are busy exploring an innovative way to address the debris problem.
TrapSat, founded and led by students with the support of Capitol faculty, aims to harvest minute fragments of space junk with the help of small form factor satellites.
"Our focus is on using them for debris capture," said TrapSat founder and lead engineer Ryan Schrenk, a Capitol senior. "We’re going to use a substrate that will allow particulate to enter into the material, and then it will be trapped and will burn up when the satellite re-enters the earth."
Stopping Particles in Their Tracks
The substrate in question is aerogel, an ultralight material created by removing liquid from gel and replacing it with gas.
"We are developing a passive way of clearing out the debris problem using the aerogel material," explained Mikus Bormanis, a TrapSat member and the team's resident 3-D printing expert. "Scientists discovered that gel is actually a solid structure that was filled with liquid bubbles. You can dry them out and create a substrate that has a lot of surface area, so you can slow down these hypervelocity particles that are travelling at 7 or 8km per second. In a lower earth orbit you can slow them down using just about 1 to 3cm of this gel."
"These are really small particles, we're talking about less than a millimeter in size," Bormanis said. "But there's a lot of them out there, and currently there is no way of removing them.”
TrapSat's work builds on earlier experiments involving aerogel, including a Mir space station environmental study that tested the material's ability to capture small debris, as well as NASA's Stardust mission, which used aerogel to gather comet particles and interstellar dust.
“We are trying to fully flesh out this concept so it could be used to finally remove all this debris that’s collected up there, just rotating around the earth,” Bormanis said.
Harnessing Expertise From Across Disciplines
According to Schrenk, the lead engineer, what started out as a small research project has blossomed into a much larger, collaborative endeavor.
"It’s evolved into a multidisciplinary group where we have business, information assurance and computer science students in addition to AE master's students and undergraduates. We've received great support and success from the college in getting the materials we need to move along. We have stuff we can demonstrate with now and show how it works." he said.
The group plans to conduct its first high-altitude balloon launch in April or May 2014. That will be followed by a preliminary design review later in the year. Beyond that, the team could propose a satellite launch, work with governmental or corporate partners, or put the collection system on the market.
Angela Walters, an astronautical engineering professor at Capitol, says the team effort is typical of the hands-on approach to science and technology education that is emphasized at the college.
"It exemplifies the dedication the students have to gaining experience for their careers and boosting their expertise in astronautical engineering," Walters said, noting that that the students' participation in TrapSat comes on top of an already rigorous schedule of classes, homework and exams.
"They have demonstrated teamwork, the ability to use what they're learning in the classroom and put it into the project, and the willingness to reach out to students in other disciplines," Walters said.