Garrett Skrobot is considered a hero in the cubesat community. Long before cubesats were widely adopted by universities, government agencies and nonprofit organizations as inexpensive tools for space-based research, Skrobot began searching for ways to enable the miniature satellites to piggyback on NASA launch vehicles.
In 2001, Skrobot began investigating whether the containers that hold three one-unit cubesats, known as Poly Picosatellite Orbital Deployers (P-PODs), could fly on Orbital Sciences Corp.’s Pegasus rocket. That effort failed due to a lack of funding. In 2007, however, managers of NASA’s Launch Services Program endorsed the idea of including P-PODs on agency-procured expendable rockets. At the time, the only option available to U.S. cubesat developers was to send payloads aloft on foreign rockets.
Even with that support, it took a couple of years to identify upcoming NASA launches with enough performance margin to accommodate P-PODs, establish procedures to ensure cubesats would not interfere with primary missions and integrate the first P-POD on a launch vehicle.
That first launch occurred on March 4, 2011. Three cubesats flew on the Orbital-built Taurus XL rocket, whose payload fairing failed to separate, destroying NASA’s Glory climate-monitoring satellite. Although the cubesats onboard also were lost, data obtained showed the P-POD deployed as planned. That effort laid the groundwork for NASA’s Educational Launch of Nanosatellites (ELaNa) program, an ongoing rideshare campaign designed to promote science, technology, engineering and math disciplines.
Since then, ELaNa has flown 13 cubesats on tworockets: the 2 that lofted NASA’s Suomi National Polar-orbiting Partnership satellite in October 2011 and an Atlas 5 that flew a classified U.S. National Reconnaissance Office payload in September 2012.
Skrobot, who participated in more than 50 launches while working at General Dynamics Corp. as a systems engineer on the Atlas-Centaur booster program, joined NASA Kennedy’s Launch Services Program in 2000. He spoke recently with SpaceNews correspondent Debra Werner.
What has ELaNa accomplished?
One of our greatest accomplishments was the development of the Cubesat Launch Initiative from NASA headquarters. Jason Crusan, director of NASA’s Advanced Exploration Systems Division, and Anne Sweet, NASA Launch Services Program executive, worked extremely hard to develop the process by which we select cubesats from U.S. nonprofit organizations, educational institutions and NASA as candidates for future launches. On our first mission, we struggled because we didn’t have that process in place. But when headquarters got involved with this initiative, the ball really started rolling.
Over the remainder of 2013, we have three more ELaNa missions planned. ELaNa 4 will launch 11 cubesats on a Minotaur rocket. ELaNa 5 has five cubesats on a Space Exploration Technologies Falcon 9 rocket. Then, toward the end of the year, we are looking at launching ELaNa 2 with four cubesats on an Atlas 5.
Why are the numbers out of order?
We planned to launch ELaNa 2 on a previous mission that did not materialize.
What is the plan for 2014?
We are scheduled to have up to four ELaNa missions carrying nine cubesats.
The next mission will be your largest to date. Is it challenging to integrate 11 cubesats on a launch vehicle?
It is because we still have to verify the requirements of every cube. We have a team within the Launch Services Program that oversees this.
Do you plan to continue flying cubesats as secondary payloads?
We will continue to fly as secondary payloads as long as we have missions to fly on. Where we can, we will partner with other government organizations like the U.S. National Reconnaissance Office, the U.S. Defense Department’s Space Test Program or even commercial missions.
Are you discussing plans for commercial rideshares?
We have the ability to work with companies on commercial missions. There are commercial companies that broker available space on those missions. We have discussions with them and talk about potentially working with them.
Are you also exploring dedicated launch vehicles for nanosatellites?
We will continue to look at expendable launch vehicles that have performance available for cubesats. However, with the increased popularity of cubesats, the orbital requirements are becoming more stringent and the secondary opportunities we have don’t allow for optimal science for some missions. So over the past year, I’ve been working with NASA’s Small Business Innovative Research program to identify nanolauncher technologies. If this continues to go forward, we would look at development of a nanolauncher system in the future.
Why are you interested in nanolaunchers?
The mission could be optimized for the science. And if we had our own launch system, we could schedule launches at specific points in time. Cubesat developers could plan around these flights. We also would know the environmental conditions of the nanolauncher so cubesats could start testing to those environmental conditions and be ready earlier in the flow. If a cubesat drops off a mission, we could backfill it. It would give us some versatility in the manifesting.
So developers of cubesats accepted for ELaNa don’t know the launch vehicle their mission will be flying on?
Not until about 15 months before launch. Every vehicle has a different environment. I don’t know which launch vehicle payloads will ride on until we get close to a date. Then, [cubesat developers] have to test. They may have to do some rebuilds and redesign.
Is the ELaNa program becoming more popular?
Yes. When we had our first unofficial call for payloads, we had seven responses. Today, we receive 32 to 34 proposals per call. Of those, about two-thirds are selected as candidates. Right now we have about 36 cubesats on a manifest for the next two-year period. We still have an additional 34 cubesats looking for launches. On top of that, we are expecting the next call, the fifth call of the Cubesat Launch Initiative, in early August. Once those missions are selected, they will add to the list.
And it’s not just universities anymore. We are seeing a lot more cubesats coming out of NASA. People within NASA see that they can do research with these because universities, the National Science Foundation and other government agencies have been doing it.
Are the cubesats becoming more capable and complex?
The cubesats come in a variety of complexities. When a university builds its first cubesat, it’s not very complicated. It may be something as simple as putting up four different types of solar panels to look at the efficiency of the solar arrays on orbit. Then, on the other hand, you get a spacecraft studying cosmic X-ray background in the 30-50 kiloelectron volt range. It takes time to develop those detectors. Cubesats also are focused on space weather, communications, processors.
What are the challenges the ELaNa program faces?
Obtaining the launches to meet the requirements of the cubesats. So far we have been very successful. I’d like to extend my deepest appreciation to the primary missions that allow cubesats to fly. Without them, the cubesats would not be collecting science. They would be on the ground.
The other challenge is cost. The cost of launches continues to increase. If my budget remains the same, the number of cubesats I’m going to be able to launch will be reduced.
Is it challenging to keep the cubesats on schedule?
Cubesats have problems and challenges like any spacecraft. But the developers seem to work it out and show up on the delivery day. We have a mission readiness review about four months before launch. That’s when we evaluate the readiness of the cubesats to go into final integration. There is some margin. It’s a good point to get more testing. Many cubesats go through a test profile environment and they do break. But they have a little bit of time to understand what happened, fix the problem, retest and be ready to integrate, fly and be successful.