A variety of issues, including a boat that strayed into a dangerous area, wind gusts and a valve problem, repeatedly put different launch times on hold this morning until NASA finally scrubbed today's launch attempt.
The space agency rescheduled the launch for Friday at 7:05 a.m. ET. Like today, there will be a two-hour and 39-minute launch window. Crews will have until 9:44 a.m. to get Orion off the ground.
Friday's launch attempt can be viewed on NASA's website.
Orion's first test launch was billed as a major step in the effort to reach Mars.
The spacecraft is the first that NASA has built since the Apollo missions of the 1960s and 1970s to carry astronauts into deep space. Unlike Apollo, Orion was developed to fly past the moon. NASA expects Orion to carry astronauts to an asteroid in the 2020s and then to Mars in the 2030s.
In a press conference on Wednesday, Mark Geyer, Orion's program manager, said the Orion mission is as important to the space agency, and to space exploration, as the Apollo and space shuttle missions. "It's the beginning of exploring beyond Earth orbit, and Orion is a key part of that," he said.
Orion didn't get off to a smooth start today. Sitting atop a United Launch Alliance Delta IV heavy rocket, the spacecraft was set to lift off from Cape Canaveral Air Force Station at 7:05 a.m. ET. The launch time was pushed off because of an issue with the rocket's second stage propellant and because a boat had strayed into the prohibited zone in the Atlantic close to the launch pad.
After those issues were resolved, the launch was set for 7:17 a.m., but that time was pushed off because of wind gusts. A 7:55 a.m. time was canceled for the same reason.
NASA then aimed for an 8:26 a.m. launch time but three minutes before liftoff, engineers found that the core booster valve for the hydrogen tank on the rocket wasn't functioning properly. After troubleshooting the problem, including open and closing all the fill-and-drain valves on the three-core boosters, the hitch was not resolved in time to launch before the 9:44 a.m. cutoff time.
NASA had specifically set the launch window to close at 9:44 a.m. ET so the spacecraft could fly for four-and-a-half hours, splash down into the Pacific Ocean and be recovered before sunset.
The space agency has not set a date for another launch attempt if Friday's efforts do not pan out.
When Orion launches on its first test flight, the uncrewed vehicle will carry 1,200 sensors set up to monitor conditions in the crew compartment, the heat shield and the onboard computer and navigation systems. The spacecraft will makes two orbits around the Earth, soaring 3,600 miles above Earth, or 15 times farther than the International Space Station.
The sensors also will collect critical data as the spacecraft plunges back to Earth, enduring temperatures around 4,000 degrees Fahrenheit as it hits 20,000 mph on re-entry.