SpaceX Crew Dragon Launch Scrubbed

Launch Day

Due to unfavorable weather in the flight path on Wednesday, May 27, the Falcon 9 Launch of the Crew Dragon Demo-2 mission was scrubbed.

Missions to the International Space Station such as this one have an instantaneous launch window, meaning that the launch must take place at that exact scheduled second because their mission is designed to catch up to the ISS which is traveling overhead at over 27,000 kilometers per hour (17,500 miles per hour) or 7500 meters per second.

Because the weather was very dynamic as it often is in Florida at this time of year, the countdown proceeded normally in the hopes that the weather would clear enough to allow a launch.

At T-minus 4h:00m, the crew began the suit-up operations. They donned their pressurized flight suits which were also manufactured by SpaceX and pressure tested them. SpaceX founder and chief engineer, Elon Musk, met with them in the suit-up room and spoke with them briefly during this time.

All the while, as the countdown ticked on, the 45th Weather Squadron's Launch Weather Officer was monitoring the conditions at the launch site, flight path, booster landing site, and possible abort splashdown sites.

At T-minus 3h:22m, the crew was loaded into a Tesla Model X to begin the journey to the launchpad. Accompanying them were several escort vehicles, a S.W.A.T. security detail, and security helicopter giving aerial support.

Upon arrival at the launch pad, Bob and Doug exited the Telsa and got a look at their rocket from ground level. After a short peak, they got back into the car and drove to the launch tower elevators. Their suits are not really designed for walking so they went by car even though it would have been a pretty short walk.

At the top of the elevator, they each took a turn using the telephone located near the top of the elevator tower. This is a tradition that began during the Shuttle era, where astronauts would make a call to loved ones before entering the capsule for flight.

Throughout the day, the best probability of favorable weather conditions for the launch was about 50-60% but they allowed the countdown to continue. Lightning was seen in the area and there was even a brief tornado warning which expired after a short time, but all launch preparations continued to move forward. The two crew members entered the capsule and were strapped into their seats. After pressure testing their suits once again, they moved their seats into the launch position and the support crew closed the hatch.

The countdown proceeded as normal and fueling of the fuel and oxidizer began. This is the first time that the United States has ever fueled a rocket with crew on board. Prior to this, NASA viewed boarding before fueling as more hazardous to the crew because of the risk of explosion during fueling. In fact, SpaceX had a Falcon 9 explode on the pad while fueling back in 2016, but thanks to the ability to escape from the pad using the proven abort system and several other convincing arguments, SpaceX was able to demonstrate that their system was the safer alternative.

The countdown proceeded up until t-minus 17 minutes, at which time the final weather status report came in and the Launch Weather Officer reported "No-Go" conditions for flight. At that time, SpaceX and NASA decided to scrub the launch attempt and stand-down. Crew remained on-board during the fuel de-tanking process and safing of the launch vehicle and systems.

While it was a let-down to not see this historic launch go up yesterday, it is important to make sure it does so safely. This ended up being a valuable wet dress rehearsal for the crew, SpaceX mission control, and launch personnel.

The next launch attempt is scheduled for Saturday 5/30/2020 at 15:22 Eastern Standard Time (UTC-5).

View from Dragon Capsule of crew access arm retracting