One thought on “Power-Sats may yet be a reality”

  1. Interesting article, but…

    The figures claimed are jaw-dropping. A 17 MW powersat that only masses 10,000 kg? A power density of 1,700 watts per kilogram? I don’t think so. The energy density claimed is not credible and is either an error or, more disturbingly, a fraud.

    For example, look at the SAFE-400 space power reactor that was under development recently (wikipedia has a short article on it). The 1,200 kg reactor core generates 400 kilowatts of thermal energy. That is an energy density of only 333 watts per kilogram, or only 1/5 of the claimed power density of the solarsat!

    And consider that number is just the thermal power density of the reactor core. The hoped for electric power output is only 100 kilowatts out of the 400 kilowatts of thermal energy. And then there is the mass of the stirling generator power system and the mass of the heat rejection radiator system to be considered.

    A solar electric powersat which uses electric propulsion such as ion drive to reach geosynchronous orbit would resemble very much the Deep Space-1 spacecraft in all the various systems it must contain. (in addition the powersat would also require a microwave power beaming system) And the electric power density of the DS-1 was only 6.7 watts per kilogram, despite the fact DS-1 used the most advanced systems available at the time since it was a technology testbed.

    I would dearly love to believe commercial power from space solar power satellites is viable, but the math convinces me otherwise.

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