While interest in CubeSats—spacecraft as small as ten centimeters on a side and weighing one kilogram—has grown in recent years, one challenge facing the community of CubeSat developers is whether such spacecraft can perform useful missions, beyond education (many satellites are built by student groups) and technology development and demonstration. For one group at the University of Colorado, it appears that CubeSats can carry out research worthy of publication in scientific journals.
The question about the scientific utility of CubeSats came up in the very first presentation at a CubeSat workshop on the campus of Utah State University in Logan, Utah, on Saturday, a prelude to the 27th Annual AIAA/USU Conference on Small Satellites that starts on Monday. “For myself, I would like to see whether we can do publishable science with CubeSats,” said Stefano Rossi of the Swiss Space Center. That organization launched its first CubeSat, called SwissCube, in 2009; it was still operational today, but was primarily a technology demonstration. His organization has plans for follow-on CubeSat missions, but he said there are plenty of people in Switzerland who remain skeptical of the capabilities of CubeSats.
The answer of whether CubeSats can do “publishable science” came just two presentations later. David Gerhardt of the University of Colorado’s Laboratory for Atmospheric and Space Physics discussed the results from the Colorado Student Space Weather Experiment (CSSWE). That spacecraft is a 3U CubeSat (so named because it’s comprised of three cubes stacked together, forming a satellite 30 centimeters long) launched last September. It carries an space science experiment that examines solar energetic particles and how they interact with the Earth’s radiation belts. CSSWE, Gerhardt said, was designed to operate for 120 days but continues working to this day, 11 months after launch.
The spacecraft has been a scientific success as well. Data from CSSWE is being incorporated into three Ph.D. theses, including Gerhardt’s; the spacecraft was also part of masters degree projects for more than 50 students. Observations of a solar storm by CSSWE just a few weeks after launch are being used for a paper in work for the Journal of Geophysical Research (JGR), a major geophysics and space sciences journal. “So the answer is yes, you can make journal-quality measurements with a Cubesat,” he said.
Cubesats are now extremely popular and I feel are going to be developed still further. I do worry if they will become a future problem with regards to becoming more space trash orbiting the Earth a hazard to future space farers.
Could somebody put my mind at ease?
Stuart,
Most cubesats, CSSWE included, are in a relatively low altitude orbit. This means that with enough time atmospheric drag will slow the satellite down and it will fall out of orbit. If I remember right, one of our engineering requirements for CSSWE was that it would reenter within 25 years. The necessary analysis was done during the design phase and, CSSWE should meet that requirement.
In general you are right that space debris represent a major challenge for the future space industry.
While CubeSats are large, especially compared to most debris in space, there has only been a few hundred put into orbit. ( http://en.wikipedia.org/wiki/List_of_CubeSats ) I think you’re right that they’re part of the space debris problem. After all, everything that gets put into space becomes part of the space debris problem. But when one compares the few hundred CubeSats to the total number of space debris objects in orbit right now, they compose a very small fraction. ( http://www.spaceacademy.net.au/watch/debris/gsd/sonum.gif ).
Personally, I think we should take the debris problem seriously, and a good place to start would be at the large-scale collision events. The 2007 Chinese anti-satellite missile test and the 2009 satellite collision event created an estimated 4,000 new objects just between the two, increasing the total number of objects by ~50%. Operational satellites, such as CubeSats, I think should take a back-seat to the discussion.