Boeing’s historic Starliner launch

(CNN) — Boeing’s Starliner mission will make its third attempt to launch its first crewed test flight this Wednesday, marking a major milestone in a decade.

The new first human flight of the spacecraft is scheduled for 10:52 a.m. ET from Cape Canaveral Space Force Station in Florida, aboard an Atlas V rocket. The historic event will be streamed live on NASA’s website. broadcast begins at 6:45 a.m. ET.

Veteran NASA astronauts Butch Wilmore and Suni Williams are about to embark on a journey aboard the Starliner capsule that will take them to the International Space Station.

According to the U.S. Space Force’s 45th Weather Squadron, weather conditions were 90% favorable for Wednesday morning’s launch, with cumulus clouds the only concern.

If liftoff doesn’t happen this Wednesday, there is another opportunity at 10:29 a.m. ET this Thursday, according to NASA.

The mission, called the Crew Flight Test, is the culmination of Boeing’s efforts to develop a spacecraft capable of competing with SpaceX’s Crew Dragon capsule and expand the U.S.’s ability to fly astronauts to the space station under NASA’s Commercial Crew space program. The federal agency’s initiative aims to foster collaboration with private sector partners.

If successful, the flight would be the sixth maiden flight of a crewed spacecraft in U.S. history, NASA Administrator Bill Nelson said at a news conference in May.

“It started with Mercury, then Gemini, then Apollo, the space shuttle, then the Dragon capsule (SpaceX) and now Starliner,” Nelson said.

Williams will also make history as the first woman to complete such a mission.

A historic flight with ambitious goals

If Starliner takes off successfully, astronauts will spend just over 24 hours traveling to the space station.

After docking around 12:15 pm ET this Thursday, Williams and Wilmore will spend eight days in the orbiting laboratory, joining the seven astronauts and cosmonauts already on board.

Starliner is carrying a critical bomb needed to repair the space station’s urine processor assembly, which failed on May 29.

“This urine processor collects all crew urine and processes it in the first stage of the water recovery system,” said Dana Weigel, NASA program manager for the International Space Station. “It is then sent to a water purifier, which turns it into drinking water. “The station is designed as a closed circuit.”

Urine now has to be stored on board in containers, so Starliner’s expected arrival at the space station may not happen anytime soon.

The astronauts will test several aspects of Starliner’s capabilities, including the operation of the spacecraft’s engines, the operation of the spacesuits inside the capsule, and manual piloting in case the crew needs to disengage the spacecraft’s autopilot.

During the May 31 press conference, Williams and Wilmore will also test the feasibility of Starliner’s “safe haven,” designed to provide shelter for the space station crew in the event of a problem, according to Steve Stich, NASA’s commercial crew program manager.

When it’s time to return home, the astronauts will return on the same Starliner capsule and parachute to one of several designated locations in the southwestern United States.

Years of development delays, problems with test flights and other costly setbacks delayed Starliner’s path to the launch pad. Meanwhile, SpaceX, Boeing’s competitor in NASA’s commercial program, has become the transportation provider for the space agency’s astronauts.

The mission could be the final major milestone for NASA to deem Boeing’s Starliner spacecraft ready for routine operations and carrying astronauts and cargo to the space station.

Problem Solving Weeks

Due to a number of problems, previous attempts to launch a manned flight, on May 6 and June 1, were cancelled.

Two hours before the May 6 launch attempt, engineers identified a valve problem on the second, or upper, stage of the Atlas V rocket built by United Launch Alliance, a joint venture between Boeing and Lockheed Martin. The entire stack, including the rocket and spacecraft, was removed from the launch pad for testing and repairs.

The teams also worked on a small helium leak inside the spacecraft’s service module, a “structural vulnerability” in the propulsion system, and evaluated parachutes for the Starliner capsule.

Starliner was just 3 minutes and 50 seconds from liftoff this Saturday afternoon when the ground-based launch sequencer, or computer launching the rocket, activated an automatic hold.

Over the weekend, United Launch Alliance technicians and engineers assessed ground support equipment by examining three large computers located inside a shelter at the base of the launch pad. All computers are identical, providing triple redundancy to ensure safe launch of manned missions.

“Imagine a large rack that is a large computer, with the functions of the computer as a controller separated into individual cards or circuit boards,” said Tory Bruno, president and CEO of United Launch Alliance, during a press conference this week. Saturday. “They are independent, but together they form a single controller.”

The cards inside the computers are responsible for various key systems that must be performed before launch, such as unscrewing the bolts at the base of the rocket so it can take off once ignited.

During the last four minutes before launch, the three computers must communicate and negotiate with each other. But during Saturday’s countdown, the card on one of the computers responded six seconds later than the other two, indicating something was wrong, and an automatic hold was activated, Bruno said.

Over the weekend, engineers assessed the computers, their power supply, and the network communications between the computers. The team isolated the problem to a single ground power source inside one of the computers that supplies power to the computer boards responsible for key countdown events, including the rocket’s upper stage jettison valves, which also caused the problem during the countdown, according to the team. update provided by NASA.

Starliner crews reported finding no signs of physical damage to the computer, which was removed and replaced with a spare. According to the ULA team, other computers and their cards have also been tested and all are functioning normally as expected.

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