Operation Credible Sport was a joint project of the U.S. military in the second half of 1980 to prepare for a second rescue attempt of the hostages held in Iran. The concept included using a Lockheed C-130 Hercules airlifter modified with the addition of rocket engines to make it a short take off and landing (STOL) capable aircraft able to land on the field within a soccer stadium in Tehran. Operation Credible Sport was terminated when on 2 November, the Iranian parliament accepted an Algerian plan for release of the hostages, followed two days later by Ronald Reagan's election as the U.S. president.