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A Hitchhiker’s Guide to CubeSats
- Published on Friday, 08 August 2014 17:23
- Jenny Woodman
- 0 Comments
While it sounds ambitious, that’s exactly what Adam Kemp set out to do in 2006, then in his first year of teaching at the prestigious Thomas Jefferson High School for Science and Technology in Alexandria, Virginia.The project took seven years, and in November of 2013, Kemp and his students watched as their satellite, TJ3Sat, launched from NASA’s Wallops Flight Facility.
“The thing that I try to bring home is that this was a student project, and I made sure that it wasn’t done by engineers, or me, or anyone else. We’re calling this the first high school, student-built satellite and it really was – it was a hands on, student project every step of the way. That’s what made it special.
TJ3Sat was not alone; 27 other CubeSats from NASA and universities across the country shared space as secondary payloads on the ORS-3 mission. But what exactly are CubeSats?
The evolution of CubeSats is an unusual story about a technological innovation that has transformed the way many scientists, universities, and private industries are thinking about doing research in space. In 1999, Bob Twiggs of Stanford and Jordi Puig-Suari of Cal Poly San Luis Obispo were frustrated by the challenges of teaching spacecraft design and engineering to students who would graduate before most projects could ever be seen through to completion. Together, they developed a standard platform based on a lightweight 10 centimeter cube utilizing COTS, or commercial-off-the-shelf, parts. If the nanosatellite is built with these specifications, you can put anything you want inside the cube – cameras, radio transmitters, data processers, and so on. By relying on an open standard, they able to keep it simple, opening up the doors for others to do research in a cost-effective and timely manner.
In a lecture given at Caltech’s Keck Institute for Space Studies in 2012, Puig-Suari explained that the dimension standard allowed researchers the freedom to develop unique experiments. “If you can fit in this box, you can go fly; we didn’t really tell people what to do,” he said.
Puig-Suari describes designing and building the first CubeSat with pizza-fueled students (he noted humorously that pizza is a lot cheaper than engineering salaries). They were trying to build something that most people thought would never work with no funding. When their second attempt to launch a CubeSat ended up creating a crater in Kazakhstan, Puig-Suari thought it might be time to give up. He described the project at the time as a potential “tenure catastrophe,” because critics believed CubeSats were just toys that would never be capable of handling complex payloads and experiments.
To Puig-Suari, the lack of support was a key factor in the eventual success of CubeSats. Since they were unfunded and few people thought the nanosatellites could work, no one bothered them; this afforded them the freedom to focus on the educational side of the project. Ultimately, universities were able to demonstrate capabilities that drew interest from government and industries, and this interest led to an explosion of CubeSat development. Add in the rapid innovations in electronics and solar power over the last decade, and you end up with a perfect vehicle for a range of diverse experiments that far exceed what skeptics thought these little boxes could ever accomplish.
Today, CubeSats are used in a wide variety of ways from testing new technologies to imaging and remote sensing for important Earth observations that will provide rich data about climate change and weather patterns. In the future, CubeSats could be used to go into deep space to explore planets, stars, and phenomena we have yet to observe up close.
Once the CubeSat standard was established, Twiggs and Puig-Suari needed a way to safely launch the CubeSats in space without damaging the expensive rockets and equipment they were hoping to share rides with. Mike Pasciuto, manager of In-Space Validation for NASA’s Earth Science Technology Office (ESTO), explains, “You don’t put some grapefruit-sized thing on something that costs a billion dollars, which may not work or turn into orbital debris.” In space, an object the size of a BB can do a great deal of damage. The United States launch industry is justifiably risk-averse, and providing a mechanism to safely launch the CubeSats would allow access to rockets as secondary payloads on much larger missions.
Twigg and Puig-Suari’s first CubeSats had to share rides on Russian rockets.
So Puig-Suari and his students designed the Poly Picosatellite Orbital Deployer, P-POD, which is essentially a rectangular box with a mechanical spring and a magnetic latch on the door. The P-POD can hold up to three 10 centimeter CubeSats, or a combination of larger ones
“It’s extremely simple; it’s the world’s most expensive jack-in-the-box” Puig-Suari joked.
Pasciuto believes CubeSats worked, in large part, because of one really important factor. “In addition to these nutty, driven, visionary people, it is the use of standards,” said Pasciuto. The standard size of the CubeSat and the P-POD can be thought of like the Internet. Everybody is able to use the Internet because of an open standard available to all. In this simple analogy, the CubeSat is the data being transmitted over the Internet, and the P-POD is the vehicle, or the protocol (HTTP), for transmitting data. Anybody who is consistent with the CubeSat standard will fit in the P-POD, and rockets will deliver the deployment device and nanosatellites to space – with a little help.
A Hitchhiker’s Guide
Developing a safe mechanism for launching CubeSats didn’t guarantee transport on launch vehicles. It turns out that if you really want to hitch a ride to space, you need someone passionate who is willing to navigate the many challenges of convincing folks to attach these quirky little satellites to multi-million dollar rockets and billion dollar spacecrafts.
Garrett Skrobot, NASA’s project manager for Educational Launch of Nanosatellites (ELaNa), started pushing to get CubeSats on launches as secondary payloads in 2001; it wasn’t until 2011 that the first CubeSats were actually launched. Sadly, that launch failed when the Taurus rocket didn’t separate from the spacecraft, Glory. With roadblocks like that, most people might consider giving up at some point, but not Skrobot.
For Skrobot, it was the educational aspect that sparked his passion and kept him working at it. “Man, when I was in college we didn’t have opportunities to fly payloads in space. Today, we are seeing students designing, building and coming up with great ideas. When I see a student’s face light up about something new and exciting, its hard to not want to do something about it.”
Project ELaNa is managed under NASA’s Launch Services Program; the project partners NASA with universities and schools that are trying to get their CubeSats to space. According to Skrobot, ELaNa has facilitated the launch of 32 CubeSats with 18 scheduled to launch over the next 18 months. Currently, there are 53 CubeSat initiatives on backlog. “Just about everyday I am trying to figure out how to get the other 53 onto a launch,” said Skrobot.
What can we learn with CubeSats?
In light of CubeSats’ research and development potential, NASA’s Science Mission Directorate has allocated $5 million per year for the next five years for CubeSat projects with several expected to launch as early as 2016.
David Klumpar, research professor of physics and director of Space Science and Engineering Lab at Montana State University, is currently on two-year loan to NASA under the Intergovernmental Personnel Act.
At Montana State, Klumpar and his students collaborated with University of New Hampshire, Los Alamos National Laboratory, and Aerospace Corp. to launch FIREBIRD in 2013. (The acronym stands for: Focused Investigations of Relativistic Electron Burst Intensity Range, and Dynamics.) A second FIREBIRD mission is expected to launch in October 2014. The mission involves two CubeSats that will work in concert to measure rapid bursts of radiation emissions from the Van Allen Radiation Belts, an area in the Earth’s atmosphere where radiation is trapped by the planet’s magnetic field.
Each satellite is flying with the same instrumentation; they will fly a couple hundred kilometers apart from each other in order to see how big the radiation bursts are. Klumpar explains what they are hoping to observe: “Are the bursts dynamic in time and space? It’s like you and your friends are in two separate cars; the first car gets into a rainstorm and calls the second car, but they aren’t getting any rain yet. That’s what this pair is going to do.” He believes that these missions will add to our understanding of fundamental physics processes.
“Small, low-cost spacecraft open up potential to see things in a whole new light. It’s like being a mechanic and having certain tools – you need all of those tools to do your job completely. CubeSats are new tools that give us another capability to do new things,” said Klumpar.
CubeSats are also a perfect platform for testing new technology. On Earth, it is difficult to replicate the extreme environments that instruments will be exposed to in space. NASA ESTO funds missions to validate technology through its In-Space Validation of Earth Science Technologies (InVEST) program. ESTO is currently funding several CubeSat missions through this program. One mission, IceCube, will launch in 2016 or 2017.
IceCube is an 874-gigahertz receiver that offers new potential for measuring ice particles in clouds and, subsequently, climate change. Virginia Diodes Inc. developed the receiver via a Small Business Innovative Research Contract with NASA.
This CubeSat mission will advance the space flight readiness of the technology for future missions. “The goal is to substantially reduce the cost of flight instruments by paving the way to using newly developed, commercially available submillimeter-wave receivers,” said Paul Racette, senior engineer at NASA and co-investigator on the IceCube team.
In the middle and upper troposphere, clouds are composed of ice crystals that both reflect solar radiation and trap infrared radiation. To date, we still don’t know enough about these processes because it is difficult to measure ice in the atmosphere.
According to Racette, “Because we don’t have good measurements of ice clouds, the amount of ice in the atmosphere is used to tune climate models for balancing the energy and hydrologic cycles.” IceCube is a step toward making accurate measurements of ice clouds that will enable us to improve climate models.
As these examples demonstrate, CubeSats dramatically reduce the cost of testing new technology and observing a variety of phenomena on Earth and in space. They offer researchers new tools and reduce the time needed to develop, build, and launch instruments to space.
Additionally, the educational benefits are difficult to ignore. For students, getting to see projects like these through from beginning to end means that they will enter the aerospace industry with invaluable practical knowledge beyond theory learned in a classroom or lab. For the industry, these students are showing up for work, armed not just with technical knowledge, but also with a realistic understanding of how to get things done out in the real world.
Thomas Jefferson High School’s TJ3Sat project took seven years to complete, and along the way Kemp and his students learned about systems engineering and design, about government bureaucracy and politics, about the demands of academia and, for many of the students, about the demands of their future careers.
For TJ3Sat student project leader, Rohan Punoose, who will be heading off to University of Michigan’s Aerospace Engineering program in the fall, the benefits are clear, “To work on a project on such a huge scale is inspiring. Nobody actually thought we would actually get a satellite that would go up in space — everybody doubted us and we did it.”