2016.B.1.3. The SunCube FemtoSat Platform: Pathway to Low-Cost Interplanetary Exploration

Author(s)

Jekan Thangavelautham (1)
Mercedes Herreras-Martinez (1)
Andrew Warren (1)
Aman Chandra (1)

Arizona State University, United States of America

Session

B.1

Keywords

femtosat, space system design, low-cost

Abstract

Space exploration can advance rapidly with widespread interest, participation and access by a large fraction of humanity. One major barrier to space exploration is the high launch cost. CubeSats offer a low-cost standard for designing, building and launching spacecraft. However, even these platforms cost $100,000 for a 1U (10 cm x 10 cm x 10 cm) and $300,000 for a 3U to ride to low earth orbit. The cost of sending 1 kg into Earth escape trajectory costs in excess of $1 million. We have seen significant advances in miniaturized, low-power, high-reliability electronics thanks to the widespread demand for smartphones. Thanks to these technological advances, we propose the SunCube FemtoSat platform, where a single unit (1F) spacecraft is a 3 cm x 3 cm x 3 cm cube and will have a mass of up to 35 grams. Commons configurations include the 1F and 3F (9 cm x 3 cm x 3cm) configuration with 100 grams mass. The FemtoSat is fully compatible with the CalPoly CubeSat standard. A single 1U CubeSat chassis can hold 27 SunCube 1F FemtoSats or 9 3F FemtoSats. We have developed reference designs of the 1F and 3F spacecraft comparable in capability to first generation CubeSats. The SunCube 1F spacecraft contains walls covered in 3TJ solar cells that provide 0.5 watts of power in LEO, a 1.5 Wh lithium ion battery, an onboard attitude control system consisting of IMU (Accelerometer, Gyro, Magnetometer) and magnetorquers, a CD&H board and a 3 MP pixel camera. Work is proceeding on developing a 3-axis miniature reaction wheel. A SunCube 3F will have nearly two thirds of its volume dedicated to user payload. Under current market prices, the 1F SunCube will cost $2,700 to launch into LEO, while the 3F SunCube will cost $8,100. For earth escape trajectories, the cost is $27k and $81k for the 1F and 3F respectively. A basic SunCube 1F spacecraft is expected to cost $300 in terms of parts. The use of space proven inflatable technologies can enable these systems to attain large antenna area for communication and tracking. Propulsion is enabed using several promising technologies, including cold gas systems, green mono-propellants and solar sails. Thanks to the reduction of mass and volume by the cube power, this enables low ISP, high thrust propulsion systems to provide high delta V. There is significant potential in developing a whole new generation of science and technology payloads.