‘Hold hold hold’: NROL-71 mission scrubbed
LOMPOC, Calif. — Just seconds before the planned liftoff of a Delta IV Heavy rocket with the NROL-71 payload for the National Reconnaissance Office, an automatic abort of the launch sequence was triggered.
With only a minor issue earlier in the countdown, the Dec. 8, 2018, launch attempt of United Launch Alliance’s Delta IV Heavy rocket seemed ready to fly with the classified NROL-71 payload at 8:15 p.m. PST (11:15 p.m. EST / 04:15 GMT Dec. 9) from Space Launch Complex 6 at Vandenberg Air Force Base.
However, just as the engines were about to start and excess hydrogen gas burn off began—a hold was called, which would ultimately scrub the launch.
“The launch of a United Launch Alliance Delta IV Heavy carrying the NROL-71 mission for the National Reconnaissance Office was scrubbed today due to an unexpected condition during terminal count at approximately 7.5 seconds before liftoff,” a ULA statement reads. “The team is currently reviewing all data and will determine the path forward.”
Within minutes, the launch team verified the rocket, launch pad and payload were in a safe configuration. Shortly thereafter, it was recommended that the 233-foot (71-meter) tall, triple-core rocket be emptied of its liquid oxygen and liquid hydrogen propellant.
This was the second attempt to get the NROL-71 mission off the ground (the first was on Dec. 7). ULA has not announced when its next launch attempt will occur. This was slated to be the company’s 38th Delta IV rocket (the 11th “Heavy” variant) since the vehicle’s debut in 2002.
Should the rocket launch before the end of the year, it will be the final flight for ULA in 2018, capping off with nine missions—five Atlas V’s, three Delta IV’s (two if NROL-71 is delayed to 2019) and the final flight of the venerable Delta II rocket.
Video courtesy of SciNews
Derek Richardson has a degree in mass media, with an emphasis in contemporary journalism, from Washburn University in Topeka, Kansas. While at Washburn, he was the managing editor of the student run newspaper, the Washburn Review. He also has a website about human spaceflight called Orbital Velocity.