Crew-6 Ready to Launch, Crew-5 Ready to Come Home

NASA and SpaceX will try again to launch the next crew to the International Space Station in a few hours at 12:34 am March 2. The first attempt was scrubbed early Monday morning due to a ground equipment issue. The four-person Crew-6 aboard SpaceX’s Crew Dragon Endeavour will replace Crew-5. In a post-departure news conference from the ISS today, Crew-5 shared what they are looking forward to most when they get back to Earth.

ISS has been permanently occupied with international crews rotating on roughly 4-6 month schedules for more than 22 years. Almost every crew rotation flight is composed of mixed crews from the ISS partners — the United States, Russia, Europe, Japan and Canada. Astronauts from many other countries also have been aboard.

Crew-6 includes NASA astronauts Steve Bowen and Woody Hoburg, Roscosmos cosmonaut Andrey Fedyaev, and United Arab Emirates astronaut Sultan AlNeyadi.  AlNeyadi will be the second UAE astronaut on the ISS and the first who gets to stay for a long-duration mission.

Crew-6’s launch attempt on Monday was scrubbed two minutes and 14 seconds before launch when the launch team could not confirm sufficient triethylaluminum-triethylborane or TEA-TEB had been loaded to ignite the Falcon 9 rocket’s kerosene/liquid oxygen Merlin engines. TEA-TEB sparks with oxidizer to allow the engines to fire.

NASA explained today that during launch preparations, the TEA-TEB liquid goes through a bleed-in process where it flows from a ground supply tank to the rocket’s interface and back to a catch tank to remove gas from the ground plumbing. That process is used to determine if TEA-TEB has been properly bled into the system so that it will ignite the engines at launch.

In this case, data showed there was a problem so the launch was scrubbed.

An investigation showed that a clogged ground filter reduced the flow back to the catch tank. The filter was replaced and the lines purged with nitrogen.

The system now is ready for launch at 12:34 am ET tomorrow morning. A post-launch news conference is scheduled for approximately 2:30 am ET.  NASA TV launch coverage begins at 8:45 pm ET tonight. The weather forecast is 95 percent favorable.

If launch takes place as planned this time, Crew-6 will arrive at the ISS at 1:17 am ET Friday morning with hatch opening at 3:27 am ET and a welcome ceremony about 3:40 am ET.

Welcoming them will be the seven members of Expedition 68: the four members of Crew-5 plus three who arrived on Russia’s Soyuz MS-22. Crew-5 is NASA’s Nicole Mann and Josh Cassada, Roscosmos’s Anna Kikina, and JAXA’s Koichi Wakata. The Soyuz MS-22 crew is Roscosmos’s Sergey Prokopyev and Dmitri Petelin and NASA’s Frank Rubio.

All four Crew-5 crew members talked today about how great it’s been to be on the ISS, but also how much they’re looking forward to reuniting with family and friends — and getting a hot shower and drinking tea from a cup instead of a plastic bag.

Those pleasures will be delayed an extra six months for the Soyuz crew members.

Their Soyuz MS-22 spacecraft suffered a coolant leak in December and is not safe to bring the three of them home. Russia just sent Soyuz MS-23 to ISS as a replacement and it docked on Saturday.

Soyuz MS-23 should have delivered two Russian cosmonauts and an American astronaut — Oleg Kononenko, Nikolai Chub and Loral O’Hara — to replace Propokyev, Petelin and Rubio, but it had to be launched empty so it can bring them back to Earth. Kononenko, Chub and O’Hara will have to wait for Soyuz MS-24 and the next crew rotation sometime this fall.

Prokopyev, Petelin and Rubio, who launched on September 21, 2022, are pulling a double-shift and will become the newest members of the select group of astronauts and cosmonauts to continuously spend a year or so in space.

Not surprisingly, astronauts love to be in space, so an extended mission is not a hardship for them. Just last year, NASA astronaut Mark Vande Hei and Russian cosmonaut Pyotr Dubrov also got to spend an extra six months on ISS when Roscosmos decided to fly two space tourists to the ISS instead of a replacement crew.

One of the benefits is the fantastic views of Earth. Cassada tweeted this spectacular view of the Northern Hemisphere auroras earlier this week.