The 75-meter-high steel structure hosting systems for testing space-based solar power, at Xidian University in Xi'an, north China. Credit: Xidian University
HELSINKI — China’s Xidian University has completed what it calls the world’s first full-link and full-system ground test system for space-based solar power.
The 75-meter-high steel structure, located in the south campus of Xidian University in Xi’an, north China, hosts subsystems for testing a space-based solar power (SBSP) concept. It passed an acceptance inspection on June 5, according to a university statement, three years ahead of schedule.
The facility is designed to collect solar energy and convert it into direct current electricity. This is to then be converted into microwaves for transmission via an antenna over a distance of 55 meters.
It includes technologies for concentrating light and photoelectric conversion, conversion of energy into microwaves, microwave transmission and waveform optimization, microwave beam aiming measurement and control, and microwave reception and rectification.
The work was led by Academician Duan Baoyan, a leading Chinese expert in SBSP. Duan is a co-author of the proposed SSPS-OMEGA (Orb-Shape Membrane Energy Gathering Array) concentrator system for generating electricity in geostationary orbit. The new facility is designed to test and verify technology for the OMEGA system.
“The research on space solar power is currently a hot spot in the world,” Duan said in the press release. He noted however that the realization of SBSP would take generations.
“To use an analogy, heaven and earth transmission is like common prosperity,” Duan said, in a modified machine translation of the statement. “That is the ultimate goal and must take many years and many people to achieve it, but we can start working on it now and start from where it is most likely to be achieved.”
The OMEGA modular system is presented in comparison and contrast to NASA’s proposed SPS-ALPHA (Solar Power Satellite via Arbitrarily Large Phased Array) project.
Duan is part of a special expert team on SPS strategic research created by the China National Space Administration (CNSA) in 2014 which includes Long Lehao, a Long March rocket chief designer, who is involved in another Chinese SBSP concept.
The Multi-Rotary joints SPS (MR-SPS) is proposed by the China Academy of Space Technology (CAST), the country’s main, state-owned spacecraft maker. In contrast to the “orb-shaped” SSPS-OMEGA, it would involve numerous linear solar arrays with multiple rotary joints to avoid single-point failure. It would require in-space assembly using free flying robotic spacecraft.
Long last year presented a proposed reusable version of the under-development Long March 9 super heavy-lift launch vehicle which could be used for construction of large SBSP facilities in geostationary orbit.
Meanwhile CAST plans to conduct a “Space high voltage transfer and wireless power transmission experiment” in low Earth orbit in 2028, followed by tests in GEO in 2030.
CAST last year conducted microwave power transmission over a distance of 300 meters using a payload aboard a small airship and receivers aboard a maritime research vessel as part of its research.