For the first time since July 2011, astronauts are set to take off from United States soil and fly to the International Space Station. The last time astronauts left for the ISS from the U.S. it was on the Space Shuttle Atlantis, this was also the last flight of the Space Shuttle program which ended in 2011 after more than 30 years of service.
Now, almost nine years later, NASA, alongside commercial partner SpaceX, owned by Elon Musk, are set to launch the first manned rocket from the Kennedy Space Center this Wednesday. The rocket enters its first instantaneous launch window on Wednesday, May 27 at 4:33 p.m. EDT if the weather holds out. Additional instantaneous launch windows open on Saturday, May 30 at 3:22 p.m. EDT, and on Sunday, May 31 at 3:00 p.m. EDT.
For the most part, whether or not Houston can count down, all depends on what the weather will be like that day. The job of forecasting for any rocket launch at the Kennedy Space Center, falls to the 45th Weather Squadron, part of the 45th Space Wing, a division of the United States Space Force. The forecast is never an easy one, even more so this time around as a tropical wave of moisture is set to move onto the Space Coast this week bringing torrential rainfall to the region.
The latest forecast, labeled as L-2 (i.e. 2 days to launch), shows a “60% Probability of Violating Weather Constraints” namely they’re worried about “Flight Through Precipitation”, the “Thick Cloud Layer Rule”, and the “Cumulus Cloud Rule”. That’s great, but for the rest of us, what does that all mean? The best place to start is at NASA itself, here you can find a fact sheet detailing the various weather thresholds specifically for the Falcon 9 rocket. From this we can find the answers we’re looking for…
The forecast given by the 45th Weather Squadron forecast talks about a tropical wave moving through Florida on Memorial Day. Here is what that looked like (1st Image). Simply put it is a disorganized mass of showers and storms that are sitting over the Space Coast, and the entire East coast, of Florida. This will evolve into a coastal low over the next few days bringing rain along the Southeast U.S. coast but it also leaves behind some clouds and some lingering moisture. This is the primary concern as to whether the launch can go ahead or not; how thick are the clouds that day, are there any pop-up showers and storms, and with those possible storms how high are the cloud tops? Based on Predictor (2nd Image), seemingly all of those rules are broken. Forecasts change and Florida is known to be one of the more difficult places to forecast for a variety of reasons. But for now it looks like the weather may put a damper on the first launch from U.S. soil in nearly a decade. Fortunately there are two other instantaneous launch windows this week on Saturday and Sunday!