Seth Shostak Quotes
It's easy to reckon that the oomph to hurl even a Smart Car-size spacecraft to another star at, say, 20 percent the speed of light (and land it when it arrives) is the energy contained in 50 billion gallons of gasoline. The tank's not big enough.
Citations
Shostak, Seth. "Starship Century." HuffPost, 22 May 2013.
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Seth Shostak is an American astronomer and author, and is currently the senior astronomer for the SETI Institute.