The CubeSat community is diverse. Interested parties include government agencies like the NRO and NASA as well as artists working on their own to build a spacecraft and 8th graders who built a non-flyable but functioning CubeSat for a science fair project. All these groups came together for four days at the beautiful Cal Poly campus for a group of 15-minute presentations and lots of networking time. The conference format included on-scene continental breakfast and boxed lunches that helped keep everyone local and talking.

There were a few interesting foci of the conference. In one case, Dr. Bob Twiggs, an early mover in the CubeSat effort, proposed a new size for picosatellites, in the form of a PocketQub: a satellite that fits in your pocket. 8 PocketQubs fit in the space taken up by one CubeSat, and they could then fly in a P-Pod launcher with other CubeSats or a mix of CubeSats and PocketQubs. He proposed this idea to address his concern that other big players getting involved in CubeSat flights (like the NRO, NASA, etc) are driving the launch price out of range of most universities. He feels that $40k per kilogram to fly is the breakpoint. Recent discussions between The Mars Society and Cal Poly indicated that $70k per kilogram is a better planning number for a flight out of the US.

Another focus that came up is the lack of launch opportunities within the US. While kind of at odds with the cost argument, there hasn't been a standard method of integrating CubeSats on US flights as of yet. That may be changing in the near future, as the Naval Postgraduate School (NPS) has developed a system called the NPS CubSat Launcher (NPSCuL)that will allow up to 24 single-sized CubeSats to fly using one of six spaces on an Evolved Expendable Launch Vehicle (EELV) Secondary Payload Adapter (ESPA) ring. The ESPA ring can fly on any Delta IV or Atlas flight with a satellite that weighs less than the maximum lift mass of the booster, and the NRO representative at the conference said that eventually there will be an ESPA ring and NPSCul on every NRO flight that can handle it. This would open many launch opportunities, though the cost factor may still be an issue.

The Mars Society talk took place as part of "New CubeSat Missions" track and gave an overview of the project, including background as to why artificial gravity was important for Mars missions. Since the talk took place near the end of the conference, there wasn't a lot of time where people knew the meat of the TEMPO project in order to stop and ask questions about it. A good idea would have been to submit TEMPO as a poster session as well, since the poster sessions were well attended.

Many teams are really pushing the limits of what's possible with a CubeSat bus, and this effort is driving some pretty clever designs. The Pumpkin company, that builds CubeSat kits for sale, unveiled a hinge mechanism for a 3U (30 cm) length cubesat that would double the solar cell area and allow power utility on the order of 10s of watts with high-capacity solar cells. This design was in support of an imaging system designed to achieve 7.5 meter ground resolution from orbit with a CubeSat.

Another effort underway by many teams is trying to increase the amount of data that can be downlinked by a CubeSat in flight. While power will always be a limiting factor, and the 'brute force' method of having a larger antenna on the ground is always an option, others are looking at creative ways to bring back more data by doing things such as switching the data rate throughout a pass, either through direct ground command or on-board scheduling, and this appears to provide some excellent results.

One concern that will grow with the number of CubeSats on orbit is the creation of a ground network to control them. Separate efforts are underway to address this issue, including creating a database of ground stations capable of commanding and downlinking data from CubeSat satellites with the goal of eventually allowing people from around the world the ability to talk to their CubeSat anywhere around the world.

Saturday morning brought about technical exchanges, including such topics as integration, power, and attitude determination and control. These discussions got very involved pretty quickly, such as which pin on a power board people with a particular transmitter could use to gain additional power. The talk had a very "Home Brew Computer Club" feel to it, and bodes well for our needs as we get closer to flying.

One lesson learned from the conference is that most other CubeSat developers are very localized, all at the same school or institution. A general guideline for university efforts is that a team is too big if you can't feed them with two pizzas. As an international organization with a few very active chapters, The Mars Society TEMPO team will have to integrate its efforts over long distances. This is certainly doable, but will require a different approach than most other CubeSat teams.

To sum things up, the CubeSat community is aware of our project now. While we're not pushing the bleeding edge of what CubeSats can do, there was an excitement to see CubeSats doing something related to human exploration of space. That is unique, and The Mars Society is in the lead.

Further discussion of the CubeSat conference and TEMPO project overall will take place at the Mars Society Convention near Washington DC on July 30th - Aug 2nd.