When professors Jordi Puig-Suari of California Polytechnic State University and Bob Twiggs of Stanford University invented the cubesat a little more than a decade ago, they never imagined that the tiny satellites would be adopted by universities, companies and government agencies around the world. They simply wanted to design a spacecraft with capabilities similar to Sputnik that graduate students could design, build, test and operate. For size, the professors settled on a 10-centimeter cube because it was large enough to accommodate a basic communications payload, solar panels and a battery.
Since the first cubesats were launched in June 2003 on Russia’s Eurockot, approximately 75 cubesats have been sent into orbit. That number is growing rapidly as launch service providers and government agencies make room for cubesats on an increasing number of rockets. In addition, cubesats are finding new paths into orbit. The Japan Aerospace Exploration Agency (JAXA) plans to conduct the first release in September of cubesats from the international space station. JAXA plans to deploy cubesats from a robotic arm on the international space station’s Kibo module. Virgin Galactic announced plans in July to develop LauncherOne, an air-launched rocket designed exclusively for small satellites.
Puig-Suari spoke recently with Space News Correspondent Debra Werner.
Did you ever imagine cubesats would be so popular?
Nobody did. At the time we were hoping for an educational platform. The idea that cubesats would become something that the National Reconnaissance Office (NRO), the Department of Defense, the National Science Foundation (NSF) and NASA would be interested in was not on the radar screen.
Why do you think that happened?
There were a couple of things that happened that had nothing to do with us. One was the electronics revolution. The ability to do a lot in a small package with very low power consumption has changed dramatically.
The other thing was space access. For a lot of communities it was always a decade-long struggle to get their instrument to fly. Initially, a lot of those people were skeptical of cubesats because their ideal, perfect instruments were bigger. But people began designing 80 percent solutions, instruments that were good enough to provide some data.
Are you satisfied with the number of available launch opportunities?
It’s so much better than it was it would be inappropriate to complain. A lot of people at NSF, NASA’s Kennedy Space Center and NRO’s Office of Space Launch have worked very hard to help us.
When industry and government groups were getting interested in cubesats, I was concerned they would occupy all the launch capability. That has not happened. There is still room for the universities and students to get their experiments launched. It’s a very good situation. Could it be better, yes? But it’s much better than it was.
Is the price of a cubesat launch rising?
When we did the Russian launches a decade ago, it was $40,000 to launch a one-unit cubesat and $120,000 for a three-unit cubesat. The initial launches were on very low-cost flights using missiles as launch systems. Flying in the U.S., there is more quality assurance, testing and vetting of the system. That adds a little bit of cost. But it hasn’t gone up that much. I think the cost probably has doubled in a decade.
People seem eager to experiment with six-unit cubesats.
Yes. That’s the next phase. A lot of people have realized that a big part of what made cubesats successful was not that they were small or big or cheap or expensive or square or round, but that they were standardized. You build your satellite without having to worry about the interface with the launch vehicle or even which launch vehicle you would ride on. Rocket builders made accommodations for cubesats without knowing which ones would ride. That’s a different way of thinking about secondary payloads.
The six-unit and 12-unit cubesats are trying to use standardization for a new class of missions. There have always been things you cannot do on cubesats because of the size.
What technologies are making cubesats more capable?
There are many. Communications could be better. Power is always a problem. Attitude determination and control could always be better. But the one that has been holding us back a little bit was propulsion. That’s something we are working on right now because we see that as the next big improvement to actually have propulsion.
Why do you want onboard propulsion?
You can stay up longer because you can go to the right orbit. You can do proximity operations and swarms and constellations. There are a lot of benefits that come with propulsion.
New groups are talking about launching cubesats from the space station and from air-launched rockets. How do you view these developments?
We welcome them. It’s really a validation of the open-standard concept. When JAXA decided to fly cubesats from the space station, they grabbed the standard from the website and developed a system.
What Virgin is doing, catering to smaller satellites, is a very interesting development. We will see how the economics work out. It would be great if we could define our own launch date and our own orbit instead of always relying on a primary mission.
A lot of the developers of the higher-end platforms, such as the U.S. Defense Department, NSF and NASA would like to go to orbits where primaries are not going. It would be very exciting if they could use a small vehicle to go there. It also could be the big break for responsiveness. You could launch whenever you want. That is probably easier with a smaller vehicle than a larger vehicle.
Why did you establish Tyvak Nano-Satellite Systems in 2011?
When we started building cubesats at Cal Poly, we realized the big issue was the launch. So we spent the last decade focused on making launches available.
At the same time, we were working on compact avionics. We had a team looking at smart phones as the guideline by which to develop the electronics, connectors and components.
About a year and a half ago, we realized we had something interesting enough to commercialize. So we put together a small company. If a launch provider needs a commercial entity to handle launches, we can do it. If somebody is interested in very compact avionics packages, we have a commercial outlet to sell them. We also are supporting the new, high-end cubesat market. We can contribute to high-end cubesat development because we have the experience.
Were launch providers initially resistant to the idea of carrying cubesats?
Some were. Many people put their careers on the line to support this. They spent years talking to their management, saying flying cubesats was a good idea. Sometimes it seems like it just happened magically but there was a lot of work behind the scenes.
Are launch service providers willing to fly cubesats with onboard propulsion?
The people who buy the rocket are the ones who need to feel comfortable with the technologies. Those people took a long time to get comfortable with secondary payloads. It’s taken a decade to show them we add no risk to the mission. We have very secure systems.
People are starting to feel ready to talk about propulsion. We will probably start with very simple systems: cold gas, low specific impulse, low-pressure gases and electric propulsion. The key is to get the launch community and the primary payload community comfortable. We will work with them to define profiles and verification plans so that everyone is happy.