Less than 20 minutes before SpaceX's first crew flight, weather conditions remained miserable and forced meteorologists from the Air Force's 45th Weather Squadron, NASA and SpaceX to deliver bad news.
"It definitely hurts, especially when we have tough requirements that we can't do anything about it when it hits," said Captain Jason Fontenot. said the flight commander of Space Lift Weather Operations at the 45th weather squadron during a press briefing. "And we just have to pass on the information somehow and say:" Even if we are not yet at the start window, it is very unlikely that we will see this today. "
Military personnel who work in the squadron in Cape Canaveral, Florida are used to canceling the show. Fontenot and his team from Patrick Air Force Base are responsible for monitoring the weather around all launches from the Cape, where the busiest spaceport in the United States is located.
"It definitely hurts, especially when we have these tough requirements."
This can be difficult because the weather in Central Florida is unpredictable. During the summer, hot, humid air rises, creating large, swollen clouds and storms that are bad for flight. Space engineers often joke before the start and ask the 45th launch weather officer, Mike McAleenan, to keep the clouds at bay. "The only thing we have to do is figure out how to control the weather," said Kathy Lueders, program manager for NASA's Commercial Crew Program, during a pre-launch press conference on Monday, May 25. "And I hope Mike will help us when he starts talking."
McAleenan later joked, "First of all, I would like to point out that we are in the weather sales business, not production. So you have to talk to someone else about this part of it."
According to Fontenot, a team of five from the 45th weather group monitors the conditions surrounding a start. The lead start weather officer McAleenan coordinates current information between the start customer – in this case SpaceX – and the 45th customer. One officer monitors the weather via radar around the Cape, while another coordinates with a weather reconnaissance plane. "We are in constant contact with this aircraft so that it can be our eyes in the sky, flying around clouds and giving us heights, bases and cloud strengths," said Fontenot. The other two places are reserved for the oversight team, which ensures that everyone is at the top of their checklist. Fontenot is part of the supervisory group.
Members of the 45th Weather Squadron monitor the weather before takeoff in 2016.
Photo by Sean Kimmons / U.S. Air Force
The 45th follows strict guidelines that go back to 1987. This year, an Atlas Centaur rocket launched from Cape Canaveral and rose in thick clouds and heavy rain. The highly electrified environment in the clouds triggered a lightning strike that hit the vehicle and destroyed its control system. "It started to go off course and we actually had to blow up the rocket," said Fontenot.
It was not the first time that lightning was a problem for a start. Over the years, engineers have learned that a launch rocket can actually fire a flash during flight, even if there is no flash in the area. All it took was a highly charged environment. During the ascent to Apollo 12 – the second time humans landed on the moon – the lightning struck NASA's Saturn V rocket twice, although the mission remained unscathed.
Engineers have learned over the years that a rocket can actually fire a flash
After the Atlas-Centaur incident, NASA and the Air Force formed a committee called Lightning Advisory Panel, which was composed of weather experts from across the country. They finally came to the rules of what conditions are acceptable for a rocket launch. This includes certain criteria for what types of clouds may and may not be in the region. Cumulus clouds and anvil clouds, which are highly charged, are of particular importance. There is also a criterion known as the electric field mill rule that limits the strength of the electric field in the atmosphere.
This rule was one of the biggest show stops for SpaceX's attempt to launch on Wednesday, along with some other restrictions. "Unfortunately, we won't start today," said one engineer from the crew. "It was a great effort by the team and we understand and we will meet you there," said NASA astronaut Doug Hurley, one of the astronauts on the flight.
The 45th Weather Squadron is primarily looking for conditions that would violate these lightning rules. If one of the 10 lightning-related rules is violated, a launch provider absolutely cannot start from the Cape Canaveral area. "This is a tough and quick requirement for a go / no-go weather decision," said Fontenot.
The squadron also monitors other conditions – particularly how fast winds blow on the ground and over the launch site, as well as the activity of the sun and temperature. All of these factors can hinder a start, but the rules for these conditions are specific to each start provider. Some missiles can handle different wind speeds depending on how they are built and configured for flight.
These so-called user restrictions are ultimately decided by the organizations that launch the missiles. The 45th will continue to provide guidance on these conditions, but launch providers will call whether, for example, higher-level winds are suitable for flying their missiles. Usually, however, the start provider listens to the Air Force. "I've never seen it where we say we're hurt because of something and they decide to leave," said Fontenot. “Usually these criteria exist for a reason. So when we say that we are injured because of this specific limitation, they usually don't fly for safety reasons. "
"I would rather not launch and avoid any threat to the missile or crew."
For the upcoming launch of SpaceX, the weather around the launch site is not the only problem. The SpaceX Crew Dragon capsule has an emergency escape system that allows the spaceship to be removed from the missile during flight if something goes wrong. This means that the Crew Dragon could land in a large part of the Atlantic Ocean after launch. SpaceX and NASA monitor conditions in up to 50 potential landing areas from Florida to Ireland, so that astronauts do not accidentally get into rough seas. The 45th Weather Squadron gives some clues about the weather in these demolition zones, although NASA and SpaceX closely monitor these forecasts.
Overall, the weather remains a very restrictive factor when the first SpaceX crew takes off into space. However, Fontenot argued that it was important to be careful as something could go wrong – even if the call to scrub on Wednesday was painful.
"I would prefer not to launch and bypass any threat to the missile or crew and scrub myself for another day when we have a better opportunity," said Fontenot. "So yes, it was a little disappointing, but I would rather start in better weather and hopefully we'll give him a chance on Saturday."