NASA reveals why its historic ISS mission had to be postponed

28 May 2020

Sunrise over the SpaceX Falcon 9 and Crew Dragon capsule. Image: NASA/Bill Ingalls

Despite millions tuning in to watch the historic space flight for NASA and SpaceX, the weather had other ideas.

Astronauts Bob Behnken and Doug Hurley will have to wait a little while longer before they can make their historic journey to the International Space Station (ISS) after the Demo-2 mission was called off just 17 minutes before take-off. Originally scheduled for yesterday evening (27 May), the flight would have seen SpaceX’s Falcon 9 rocket and Crew Dragon capsule carry the astronauts to the ISS.

This would have been the first time that a private company had ferried people into orbit, but NASA and SpaceX feared that weather conditions may have posed a risk to crew and equipment during launch.

In addition to rain and clouds, lightning and field mill data – which measures the amount of electricity in the atmosphere – were identified as meteorological dangers that made it too unsafe for launch.

“There was a concern that if we did launch, it could actually trigger lightning,” said NASA administrator Jim Bridenstine. “There’s a lot of disappointment today.

“But it was a great day for NASA,” he added. “It was a great day for SpaceX. Our teams worked together in a really impressive way, making good decisions all along.”

‘Everybody’s probably a little bummed out’

Prior to launch, the US Air Force’s 45th Weather Squadron predicted there was a 60pc chance of “unfavourable weather conditions” including thick clouds. The Demo-2 mission is now schedule to go ahead on Saturday 30 May at 8.22pm Irish time.

No technical hiccups were recorded prior to the flight, with Behnken and Hurley already suited up in their SpaceX spacesuits and strapped into the Crew Dragon spacecraft a few minutes ahead of schedule.

Speaking after postponement was confirmed, Hurley said: “Everybody’s probably a little bummed out, but that’s part of the deal. It was a good practice, and we’ll do it again on Saturday.”

Bridenstine, meanwhile, said yesterday’s events were still important as a “wet dress rehearsal”.

Should Saturday’s launch go ahead as planned, NASA will certify SpaceX’s Crew Dragon pod for the space agency’s Commercial Crew Programme to launch astronauts further into space.

Once in orbit, the crew and SpaceX mission control will verify the spacecraft is performing as intended by testing things such as the environmental control system, the displays and the manoeuvring thrusters. Behnken and Hurley will then spend a number of weeks aboard the ISS before another commercial crew can come and replace them. Once fully operational, the Crew Dragon spacecraft would be able to last 210 days in orbit.

Colm Gorey was a senior journalist with Silicon Republic