The launch of the SpaceX Falcon 9 rocket carrying next one NASA officials said Wednesday that the crew to the International Space Station has been postponed as of Saturday, a ripple effect of weather delays in the return of a team of commercial astronauts from the outpost to Earth.
SpaceX’s first private astronaut mission, known as the Ax-1, launched on a SpaceX rocket and Dragon capsule on April 8 and docked with the space station on April 9, transporting a crew of four non-government personnel to the complex for research and educational experiments and public outreach events , sightseeing.
The crew of four was supposed to leave the space station on Tuesday and land off the coast of Florida on Wednesday. But mission managers have extended their stay at the outpost due to persistent bad weather in SpaceX’s recovery areas in the Gulf of Mexico and the Atlantic Ocean.
NASA and Axiom officials have not announced new target dates for the Ax-1 mission’s decommissioning and dispersal, but mission control sent the crew early Wednesday that the Ax-1 mission’s departure from the station would not occur until Thursday night.
“As the weather forecast remains unfavorable, we are still evaluating the best time to undocking the Ax-1 mission from the space station,” tweeted Kathy Luders, chief of NASA’s Space Operations Department. “We’ll be reviewing throughout the day. Really proud of the NASA, Axiom Space and SpaceX teams for staying focused while carrying out our mission.”
The launch date for NASA’s next crewed mission, designated Crew-4, will depend on when the Ax-1 can leave the station. Crew-4 was scheduled to launch before dawn Saturday from Platform 39A at NASA’s Kennedy Space Center in Florida.
SpaceX’s Dragon Endeavor spacecraft on the Ax-1 mission currently operates the docking port needed for the Dragon Freedom spacecraft to dock with Crew-4 astronauts.
“When Ax-1 departs, the space station has room to dock the Crew-4,” Lueders tweeted on Wednesday afternoon. “We want a two-day hiatus after going back for data reviews and preparing for asset release and phase recovery. We will make decisions about the new Crew-4 launch date based solely on our plans being safely executed.”
Despite the uncertainty of a Crew-4 launch date, SpaceX’s ground teams and four astronauts assigned to the flight continued their preparations at Kennedy.
Before dawn Wednesday, Commander Kjell Lindgren, pilot Bob Hines and mission specialists Jessica Watkins and Samantha Cristoforetti donned their SpaceX pressure suits and rode their Tesla SUVs from the Operations and Checkout Building in Kennedy to Platform 39A.
The astronauts rode the lifts atop the launch pad tower and walked through the crew access arm to the white room, where they climbed through the side hatch of the Dragon spacecraft and took their seats in the capsule. The crew then disembarked from the spacecraft to complete a so-called “dry dress rehearsal,” which provided the opportunity for astronauts and support teams to practice on launch day.
Later Wednesday morning, SpaceX filled a Falcon 9 rocket with kerosene and liquid oxygen thrusters to test launch the first stage of its Merlin main engines. The engines fired for seven seconds at 9:26 a.m. EDT (1326 GMT) as hydraulic clamps kept the 215-foot (65-meter) rocket on the ground.
Then SpaceX drained the Falcon 9 of propellant, and engineers began reviewing data from the launch test to make sure all rockets, spacecraft, and Earth systems were operating as expected.
The launch will be SpaceX’s seventh human spaceflight mission, and the fourth is an operational crew rotation flight to the space station under contract with NASA. Other SpaceX crew missions have included a NASA test flight in 2020, and two purely commercial flights — last September’s Inspiration4 mission and the Axiom astronauts’ special mission currently on the International Space Station.
The Falcon 9 booster for the Crew-4 mission will fly for the fourth time. The rocket stage – designated B1067 – previously launched the Dragon cargo mission, NASA’s Crew-3 astronaut flight, and the Turksat 5B communications satellite last year.
The booster originally assigned to the Crew-4 mission – tail number B1069 – was damaged during an attempt to land on a SpaceX drone ship on December 21.
“NASA and SpaceX jointly select primary and backup first-stage boosters before each manned mission,” a NASA spokesperson said. “We have jointly agreed to use the Crew-4 spare booster after an asymmetric landing of the originally planned booster due to sea surges.”
The Crew Dragon vehicle awaiting launch atop a Falcon 9 rocket is the fourth, and likely last, reusable Dragon capsule to join the SpaceX fleet. The Dragon Freedom spacecraft joins Endeavor, Resilience and Endurance in SpaceX’s rotation of the crew capsules.
Once the Crew-4 mission takes off from Earth, the Dragon Freedom spacecraft will transport Lindgren, Hines, Watkins and Cristoforetti to the space station for a five-month stay. They will replace the outgoing Crew 3 astronauts, who have been on the station since November.
Crew 3 astronauts currently live on the space station with four commercial Ax-1 astronauts and three Russian cosmonauts, giving the Research Laboratory a group of 11 crew members, at least for a short time. The station is usually staffed by seven crew members.
The delay in returning the Ax-1 mission to Earth and launching Crew-4 could also extend the mission of Crew-3 astronauts, who were due to leave the station on SpaceX’s Dragon Endurance spacecraft on April 30.
Send an email to the author.
Follow Stephen Clark on Twitter: Tweet embed.