Years late, Boeing’s Starliner crew capsule program is ready for a crucial unmanned test flight to the International Space Station on Thursday, the end of a 2019 demo mission that cost the contractor nearly 600 million.
The Starliner crew capsule is scheduled to take off for the Orbital Flight Test 2, or OFT-2, from Cape Canaveral at 6:54 p.m. EDT (2254 GMT) on Thursday over a United Launch Alliance Atlas 5 rocket.
ULA, Boeing and NASA, which oversees the Starliner commercial crew contract, gave the green light on Tuesday to proceed with the final launch preparations. Managers gathered for a launch readiness review and gave a “go” to continue the mission.
The review “went very well,” said Steve Stich, director of NASA’s Commercial Crew Program. “It was short. It was very clean. “There are no real problems that ULA, Boeing or NASA are working on launching.”
The test flight is intended to gather data and demonstrate the readiness of the Boeing Starliner spacecraft to transport astronauts to and from the space station. It is a repeat of the OFT-1 mission in December 2019, which was shortened by software problems that caused the Starliner capsule to burn through a propellant shortly after launch.
Developed in a public-private partnership, the Starliner spacecraft will give NASA a second human capsule capable of transporting astronauts to and from the space station, along with the SpaceX Dragon spacecraft, which was first launched by a crew in May 2020. .
Problems with the 2019 flight prevented the Starliner spacecraft from reaching the space station, and Boeing ordered the capsule to re-enter the atmosphere and land in New Mexico two days later.
After rewriting parts of the Starliner software code and running it through more extensive testing, Boeing and NASA began preparations for the OFT-2 mission – a test flight added to the Starliner program at Boeing’s expense.
The spacecraft landed on the launch pad last August at Cape Canaveral over the Atlas 5 rocket. But on the morning of the scheduled launch, tests revealed 13 stuck shut-off valves in the Starliner propulsion system.
Boeing and NASA have agreed to remove the Starliner from the Atlas 5 rocket and postpone the mission to investigate the valve problem. Boeing says the tests showed corrosion inside the valves – caused by a chemical reaction between moisture, nitrous oxide propellant and the aluminum housing of the valves – caused the components to get stuck in the hydraulic unit in the spacer unit.
For the OFT-2 mission, engineers improved the seals on the valves to prevent moisture ingress and added nitrogen discharges to keep atmospheric moisture out of the propulsion system. Boeing also changed the balky service unit from last summer’s launch effort with a brand new propulsion unit, with a new set of valves and propellers.
The company says it is considering design changes to the oxidizer shut-off valves – possibly reducing the amount of aluminum in the valve housing – for future Starliner shipments, but officials are “confident” of the intrusions introduced to prevent moisture intrusion. launch of OFT-2.
Boeing received $ 595 million in accounting costs to pay for delays, reprocessing and unscheduled OFT-2 shipments. NASA’s fixed-price contracts for the Starliner commercial crew program amount to about $ 5 billion, an agreement where the government and the contractor shared the cost of developing the spacecraft.
NASA signed a similar, less expensive contract with SpaceX in 2014 for the development, testing and operation of the Dragon-rated manned spacecraft. After its own series of shorter delays, SpaceX launched its first astronaut mission to the space station in 2020.
While Boeing has struggled with delays in the Starliner program, SpaceX has carried out seven crew missions to its fleet of reusable Dragon capsules – five for NASA and two for private customers.
Boeing’s contract with NASA covers the OFT-1 and OFT-2 unmanned missions and a crew flight test that could explode with a team of two or three astronauts later this year or early next year, with provided that it has a successful outcome on the upcoming test flight. Following the completion of the test flights, NASA has closed six operational rotation crew battles with Boeing using the Starliner spacecraft.
Mark Nappi, Boeing’s Starliner program director, said the delays had not strained the Starliner team’s focus.
“It’s very difficult to build, develop and launch this type of vehicle, so they focus on lasers to do it right, and that’s where their minds really are,” said Nappi, adding that Boeing wants to do the project. the “safest and best possible quality.”
“When we start, we start,” Nappi said.
Upon completion of the launch readiness review, the ULA ground team prepares to launch the 172-foot (52.4-meter) Atlas 5 rocket from the 30-story Vertical Integration Facility at 10 a.m. EDT (1400 GMT) on Wednesday. Two trackmobile units will carry the Atlas 5 spacecraft and the Starliner on rail for the 1,800-foot (550-meter) journey from VIF to pad 41 in Cape Canaveral.
The teams have stacked the main stage of the Atlas 5 rocket, two solid-state rocket boosters, the upper Centaur stage and the Starliner capsule within the VIF in recent weeks.
Once on the launch pad, the Atlas 5 and its portable launch pad will be connected to automatic couplings to load propellants on the rocket. The kerosene fuel will be pumped in the first stage on Wednesday afternoon, prepared for the start of the launch countdown at 7:34 a.m. EDT (1134 GMT) Thursday.
The launch team will be loading cryogenic propellants into Atlas 5 starting early Thursday afternoon, followed by an extended booking. In future astronaut missions, crew members will board the Starliner spacecraft through the capsule hatch during the four-hour countdown.
The Starliner spacecraft that will be launched on Thursday in the Boeing OFT-2 mission will not have an astronaut crew. A test dummy named “Rosie the Riveter” from World War II sits as commander of the spacecraft.
The Starliner will also carry more than 500 pounds (227 kilograms) of food and other supplies for the space station’s seven-member crew, according to NASA. At the end of the mission, the spacecraft is expected to return to Earth with a payload of over 600 pounds (272 kg).
There is a 70% chance of favorable weather for the launch of the Atlas 5 rocket with the Starliner spacecraft on Thursday. The main weather concerns are related to storms that could occur west of Cape Canaveral. Anvil clouds at the top of the storm hives could be launched at the launch site, creating a thunderbolt threat that could be triggered by the rocket as it ascends into the atmosphere.
On Friday, the backup launch opportunity, there is a 40% chance of good weather for launching, with greater chances of thunderstorms in the area of the launch site.
The Starliner team will also assess wind and sea conditions along the Atlas 5 runway northeast of Cape Canaveral. The capsule could be launched into the Atlantic Ocean along the offshore flight route if an emergency triggers a launch cancellation, in which Starliner cancellation engines would propel the ship away from the Atlas 5 rocket.
The capsule launch cancellation system will be active for the first time in the OFT-2 mission. It operated in “shadow” mode during the launch of OFT-1 in 2019, collecting data for analysis by post-flight engineers.
For a Starliner mission with astronauts on board, cancellation weather restrictions will influence the decision on whether to launch. On this unmanned test flight, teams would monitor the conditions but would not launch if out of bounds.
If the OFT-2 mission does not take off on Thursday, the next launch opportunity will be on Friday at 6:31 p.m. EDT (2231 GMT). Launch times are determined by when the Earth’s rotation brings the launch pad to Cape Canaveral below the space station’s flight path.
After takeoff, the two Atlas 5 belt boosters and the Russian-made core engine will generate 1.6 million pounds to send the Starliner spacecraft into space. Once completed, the boosters and center stage will be launched to land in the Atlantic, leaving two RL10 hydrogen engines in the upper stage of the Centaur to push the Starliner into an arc orbit just below the speed required for speed. on a steady orbit around the Earth.
The Atlas 5 is programmed to fly with a flatter, less steep trajectory that flies in standard satellite delivery missions, increasing the chances for the Starliner crew capsule to escape safely from the rocket in the event of a failure.
Once free from the Centaurus’ upper tier, the Starliner’s four maneuvers on board will complete the task of placing the spacecraft in orbit with a burn about 31 minutes after takeoff. This combustion is the first of multiple engine launches to guide the Starliner spacecraft to an automated connection to the space station’s Harmony unit.
The orbital connection is scheduled for 7:10 p.m. EDT (2310 GMT) on Friday, assuming that the OFT-2 mission will take off on Thursday.
The astronauts at the space station will open hatches and enter the Starliner spacecraft on Saturday, remove the cargo under pressure from the crew cabin and conduct cockpit communication checks.
If all goes according to plan, and assuming good weather in the landing zone, the Starliner will disconnect from the space station on May 25 and head for re-entry, aiming for a parachute-assisted touchdown at White Sands Space Harbor in New. Mexico.
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