In response to the expanding population of the earth and the depletion of the fossil fuels, alternative forms of energy must be accessed to sustain the present way of life in the near future. It is estimated that there will be 10 billion people on earth by the year 2050. More than three-fourths of the population now living on the earth uses less than 15% of the energy used by the inhabitants of the developed nations. Once this population advances technically to the level enjoyed by developed nations there will be an immense increase in the need for power produced. Production of power would have to increase to 60,000 GW, six times the power currently produced annually. Providing this amount of energy requires alternative forms of power production.1
The demand for electricity has grown exponentially since the 1950's. It is estimated that oil resources burned to make electricity will be depleted by 2025. Coal and shale will be gone by 2075. It is conceivable that the current generation will witness the depletion of our natural resources. These are resources that could be used and reused for petroleum and chemical engineering of new products. Burning our natural resources for electric power is not a reusable technique.1
One alternative form of power is solar power. However, collecting solar power on the surface of the earth is not efficient as solar power from space. On Earth, solar collectors must be large and take up immense plots of land. Out of the 12 hours of sunlight that could reach solar collectors on the earth each day, obstructions such as clouds, dust, volcanic ash, rain, fog, storms, or local climate changes further reduce the density of sunlight at the surface. If the collectors were placed in space, however, the solar collection would be greatly increased. Placing solar collectors in space was first suggested in 1968 by Peter Glause. Mr. Glause suggested solar collectors be placed in geostationary orbit and the power beamed down to earth via microwaves, as shown in Figure 1. These collectors have become known as Solar Power Satellites (SPS).2
The Texas Space Grant Advanced Design Project seeks to challenge students to explore the use of extraterrestrial power production to supply electrical power to Earth. Large solar arrays in geosynchronous orbit will collect the sun's rays. The solar cells will convert the solar energy to electrical energy. The power produced must be converted to microwaves for transport to terrestrial based antennas. The system should produce approximately one gigawatt of electrical power from the microwave reception at the rectennas. The SPS design project focuses on the many challenges of producing power in space and transporting the power to Earth. The Texas Tech University design team has chosen to develop a deployment and support mechanism for a one square kilometer solar array on an SPS.
Figure 1: Overall System Diagram