NASA announced that the Discovery shuttle will launch on July 1 (3:48:15 p.m. EDT) despite the No-Go opinion of two senior officials. “There were many different viewpoints on the issue of whether we are ready to fly or not,” said NASA chief Michael Griffin. “We’ve decided that we are.” The two officials did not object to the agreed launch date.

The decision came after two days of “intensive and spirited exchange” during a Flight Readiness Review for NASA’s STS-121 shuttle flight aboard the Discovery orbiter. The two dissenting senior NASA managers – chief engineer Chris Scolese and Bryan O’Conner, the associate administrator of Safety and Mission Assurance – did have concerns over the potential risk of foam debris posed by a number of insulated ice frost ramps along Discovery’s external tank. 

A one-pound piece of foam insulation fell from a protective ramp from Discovery’s external tank during the STS-114 launch in July 2005. While it did not strike Discovery, a similar foam shedding event pierced Columbia's heat shield ultimately leading to its destruction and loss of seven astronauts in 2003.

NASA’s ability to inspect the spacecraft in orbit, conduct basic repairs, and keep the shuttle astronauts safely aboard the International Space Station (ISS) until a rescue comes contributed to the positive launch decision.