Low-Cost Launches May Boost Chances For Space Solar Power
Like California-based SpaceX, the Japan Aerospace Exploration Agency (JAXA) is conducting research into reusable launch as a way to cut the cost of space launch drastically. Japan is the only nation that has made beaming solar power collected in space back to Earth a goal of its space policy.
JAXA engineers calculate reusable launch is one way to reduce the up-front investment needed to put gigawatt-class power stations in geostationary orbit.
“We need a reusable launch system,” says Susumu Sasaki of Tokyo City University, a professor emeritus at JAXA who has studied the relationship between launch costs and the cost of power delivered from space.
Using a 2003 JAXA reference model with a 1-gigawatt station weighing 10,000 tons, Sasaki says power would cost a prohibitive $1.12/kwh at a launch cost to low Earth orbit (LEO) of $10,000 per kilogram.
That is in the ballpark of what space launch costs today. Cut that to $1,000 a kilogram, in the ballpark for a reusable launch vehicle (RLV), and electricity from space drops to 18 cents/kwh.
The SpaceX RLV work, which includes prototype landing legs on the current Falcon 9 taking cargo to the International Space Station (see photo on page 25) and using the rocket's engines to control the first stage's return to a splashdown in the Atlantic, is but one development in the fast-changing worldwide spaceflight endeavor that holds promise for space solar power.