NASA, still reeling from a political decision to cancel its Constellation program that would have returned a human to the moon by the end of the decade, has called on firms to provide new technology to power rovers or even future manned missions.
Hopes are now pinned on firms like Chang-Diaz's Texas-based Ad Astra Rocket Company.
"In the early days... NASA support for the project was rather minimal because the agency did not emphasize advanced technologies as much as it's doing now," Chang-Diaz told AFP.
NASA was focused instead on the series of Apollo missions that delivered men to the moon for the first, and so far last, times.
"They were mesmerized by the Apollo days and lived in the Apollo era for 40 years, and they just forgot developing something new," he said.
Chang-Diaz, 60, hopes that "something" is a non-chemical rocket that eventually allow for a manned trip to Mars - long the Holy Grail for Apollonians.
His rocket would use electricity to transform a fuel - likely hydrogen, helium or deuterium - into plasma gas that is heated to 51.8 million degrees Fahrenheit (11 million degrees Celsius). The plasma gas is then channeled into tailpipes using magnetic fields to propel the spacecraft.