WASHINGTON — NASA and Boeing are planning no earlier than May 2022 for the rescheduled second uncrewed test flight of the CST-100 Starliner spacecraft after deciding to change service modules for that mission.

Under the revised plan, the service module that had been built for the Crew Flight Test (CFT) mission, the flight of that vehicle to carry people, will instead be used for the Orbital Flight Test (OFT) 2 mission. The CFT mission will instead use the service module for the first operational mission, called Starliner-1.

That approach could allow the OFT-2 mission to launch in the spring. Boeing will work United Launch Alliance, whose Atlas 5 will launch the spacecraft, and the Eastern Range to consider a launch opportunity in May. That date will depend on both the readiness of the spacecraft and the schedule of other vehicles visiting the International Space Station.

“Our objective was to get back to flight safely and as soon as possible. With this objective in mind, we set out on parallel paths: remediating valves to preserve the option of utilizing the existing service module (SM2), while also working to accelerate the build of the next service module (SM4),” John Vollmer, vice president and program manager for Boeing’s commercial crew program, said in a Dec. 13 statement. “Based on the results to date we’ve decided to fly SM4 next and continue longer-term tests with SM2 hardware, on the vehicle and in offline facilities.”

Boeing scrubbed an August launch of the OFT-2 mission when valves in the propulsion system of service module failed to open. The investigation has focused on nitrogen tetroxide oxidizer that permeated Teflon seals in the valves and reacted with moisture on the other side. That created nitric acid that corroded the seals and caused them to remain shut.

However, the exact nature of the problem — not seen on the original OFT mission in December 2019 — and how to fix it remain unclear. “Ongoing investigation efforts continue to validate the most probable cause to be related to oxidizer and moisture interactions,” NASA said in the statement, but didn’t elaborate on topics like the source of the moisture and how to resolve the problem.

NASA and Boeing said they were making “preventative remediation efforts” to the new service module for the OFT-2 mission. Engineers also tested the module to confirm it was in good condition before moving ahead with plans to swap out the service modules.

Steve Stich, NASA commercial crew program manager, said in the statement that the agency and Boeing have been working together to investigate the problem, including tests at NASA facilities. “Because of the combined work, we have a much better understanding of the contributors that led to the valve issues, and ways to prevent it from happening in the future,” he said. “Boeing remains diligent and driven by the data during its decision making, which is key to ensuring the Starliner system is ready when we fly our test missions in 2022.”

While that comment suggested NASA and Boeing still play to fly the CFT mission before the end of 2022, that schedule will be challenging even if OFT-2 flies in May 2022. For example, more than a year elapsed between SpaceX’s two Crew Dragon test flights, the uncrewed Demo-1 mission in March 2019 and the crewed Demo-2 launch in May 2020. In the statement, NASA said only that potential launch dates for CFT are under review.

Quelle: SN

----

Update: 27.02.2022

.

Boeing Starliner chief to retire, but staying on through next flight test

Boeing's Starliner program leader will soon retire from the company but stay on as an adviser through the capsule's test flight later this year, according to a memo sent out to employees this week.

With a 35-year career under his belt, John Vollmer, vice president and manager of Boeing's Commercial Crew Program, is slated to retire from the aerospace giant in early March. He was instrumental in the development of Starliner, one of two capsules chosen by NASA to return astronauts to the International Space Station after the space shuttle program ended in 2011.

The announcement was made Thursday by Jim Chilton, Boeing's senior vice president of space, and a copy of the memo was obtained by FLORIDA TODAY.

"John Vollmer is someone who has shown us what a 35-year Boeing career looks like," Chilton said in the memo (see the full text below). "Thankfully, John has offered to stay on board as an advisor to the program through Starliner’s (next) mission. This transition period will enable shared learning and strengthens program continuity."

Starliner flew its first uncrewed test flight in December 2019, but it failed to reach the ISS due to software and hardware issues, forcing a turnaround back to Earth and safe landing in New Mexico. Boeing has opted to pay out of its own pocket for a second test flight, known as Orbital Flight Test 2 or OFT-2, which is set to fly no earlier than May.

Once operational, Starliner will join SpaceX's Crew Dragon capsule in transporting astronauts to and from the ISS. SpaceX has so far hosted four crewed launches to the station.

Vollmer kicked off his space career as a space shuttle engineer, helped develop the ISS and eventually became its chief engineer, and has since led the Starliner team at Kennedy Space Center.

Filling his position on March 4 will be Mark Nappi, the current Boeing program director for NASA's Artemis I mission slated for launch no earlier than May. Boeing also builds the core stage of the massive Space Launch System rocket, a separate vehicle from Starliner designed to take astronauts to farther destinations like the moon and Mars. 

In that role, Chilton said, Nappi was responsible for "assembling the workforce, establishing operations processes, commencing production of the core stage, performing a full-flight duration hot fire test, and ensuring readiness for the upcoming wet dress rehearsal and launch of SLS on the Artemis I mission."

Before Boeing, Nappi led two contracts at KSC with United Space Alliance and Vencore. He also worked on the shuttle, ISS support, and the Ares I-X rocket that ultimately did not replace the shuttle as planned. He was on the team that made possible the shuttle program's last flight of Atlantis in July 2011.

"Mark’s extensive operations experience uniquely qualifies him for this position, especially as the program transitions from the design, development, test and evaluation phase toward operational flights," Chilton said.

Artemis I will include an uncrewed, Lockheed Martin-built Orion capsule that will fly to the moon, orbit it, then return back to Earth. Artemis II will run the same test but with astronauts, while Artemis III will eventually see two Americans set foot on the surface no earlier than 2025.

Quelle: Florida Today

----

Update: 13.03.2022

.

Boeing Starliner test flight next on ULA’s launch schedule

Boeing’s Starliner spacecraft inside the Commercial Crew and Cargo Processing Facility at NASA’s Kennedy Space Center in Florida. Credit: Boeing

The U.S. Space Force has postponed a multi-spacecraft mission that was booked to fly on a United Launch Alliance Atlas 5 rocket in April, moving a redo of a test flight for Boeing’s Starliner crew capsule to the front of the line on ULA’s launch schedule.

ULA announced the delay in the Space Force’s USSF 12 mission in a brief statement shared on social media. The launch company, a 50-50 joint venture between Boeing and Lockheed Martin, said the delay was ordered at the request of the Space Force’s Space Systems Command.

“We will continue to work with SSC to determine USSF 12’s next launch opportunity,” ULA said.

The Starliner test flight, delayed from last August, was tentatively scheduled to launch from Cape Canaveral on May 20 before the delay in the USSF 12 mission. The USSF 12 postponement is not expected to allow the Starliner mission to move forward significantly.

The USSF 12 mission was set to launch in the first half of April with two Space Force payloads heading for geosynchronous orbit, a location more than 22,000 miles (nearly 36,000 kilometers) over the equator.

The Space Force’s Wide Field of View, or WFOV, surveillance satellite is the primary payload on the USSF 12 mission. The WFOV satellite is a testbed for a next-generation space-based sensor designed to detect rocket launches and provide early warning of a missile attack.

Built by Millennium Space Systems, the WFOV testbed satellite will host an optical staring instrument to detect the exhaust plumes from missile launches, demonstrating the wide-area sensor for future use in the military’s operational early warning systems.

Boeing’s Starliner team at Kennedy Space Center is readying the crew-rated spacecraft for a launch opportunity in May, a mission that now becomes the next flight on ULA’s Atlas 5 schedule.

The Starliner mission is a redo of an unpiloted test flight in December 2019 cut short by software problems. The software issues prevented the spacecraft from docking with the International Space Station, and the capsule safely landed in New Mexico after an abbreviated mission.

After several hardware and software changes, Boeing readied for second attempt at the Starliner’s Orbital Flight Test mission — designated OFT-2 — last August. The spacecraft was rolled to the launch pad at Cape Canaveral atop its Atlas 5 rocket, but tests revealed stuck valves in the Starliner propulsion system.

Boeing and NASA, which manages the Starliner commercial crew contract, agreed to remove the Starliner from the Atlas 5 rocket and postpone the mission to investigate the valve problem. Engineers believe the valve components likely corroded from the interaction of nitrogen tetroxide propellant with moisture that seeped into the thrusters on the spacecraft’s service module, then permeated a Teflon seal inside the valve itself.

Technicians removed the service module from the Starliner’s crew module in January for shipment to a test facility in New Mexico, where teams are performing tests to better understand the valve problem. The OFT-2 mission will fly with a new service module, one originally assigned to the first Starliner mission with astronauts.

Boeing said the Starliner team designed a new purging system to help prevent moisture from getting into the valves during the upcoming launch campaign while the spacecraft is in the factory and at ULA’s launch site.

A Boeing spokesperson did not respond to questions from Spaceflight Now.

If successful, the OFT-2 mission will pave the way for Starliner’s Crew Flight Test, which will carry a team of three NASA astronauts to the space station. That will ultimately lead to operational crew rotation flights on the Starliner spacecraft, akin to SpaceX’s Crew Dragon missions to the space station, giving NASA two U.S. vehicles capable of ferrying astronauts to and from the orbiting research complex.

Quelle SN

----

Update: 16.04.2022

.

NASA Invites Media to Cover Boeing’s Orbital Flight Test-2 Mission

Media accreditation is open for prelaunch and launch activities for NASA’s Boeing Orbital Flight Test-2 (OFT-2) mission to the International Space Station, the second uncrewed flight test of the company’s CST-100 Starliner spacecraft for the agency’s Commercial Crew Program.

 

Liftoff on the United Launch Alliance Atlas V rocket with Starliner is targeted for Thursday, May 19, from Space Launch Complex-41 at Cape Canaveral Space Force Station in Florida.

 

NASA and Boeing will hold a joint media teleconference at 11 a.m. EDT Tuesday, May 3, to discuss the OFT-2 mission and provide an update on spacecraft readiness. The teleconference will include the following participants:

 

• Kathryn Lueders, associate administrator, NASA’s Space Operations Mission Directorate
• Steve Stich, manager, Commercial Crew Program, NASA’s Johnson Space Center in Houston
• Dr. Michelle Parker, vice president and deputy general manager, Space and Launch, Boeing
• Mark Nappi, vice president and program manager, CST-100 Starliner, Boeing

 

Audio of the teleconference will stream live on the agency’s website.

 

The uncrewed mission will test the end-to-end capabilities of the Starliner spacecraft and Atlas V rocket from launch to docking and return to Earth at one of five designated landing zones in the western United States. Following a successful completion of the OFT-2 mission, NASA and Boeing will determine a launch window for NASA’s Boeing Crew Flight Test (CFT), Starliner’s first flight with astronauts aboard.

 

OFT-2 and CFT will provide valuable data toward NASA certifying Boeing’s crew transportation system for regular flights with astronauts to and from the space station.

 

Media accreditation and mission overview teleconference participation deadlines for the OFT-2 launch are as follows (all times Eastern):

 

• Media interested in participating in the OFT-2 mission overview news teleconference must RSVP by 10 a.m. Tuesday, May 3.
• U.S. media interested in covering the OFT-2 launch must apply for credentials by 5 p.m. Sunday, April 24.
• All international media, including U.S.-based international media without U.S. citizenship, interested in covering the OFT-2 launch must apply by 5 p.m. Sunday, April 17.

 

All accreditation requests should be submitted online at:

 

https://media.ksc.nasa.gov

 

For questions about media accreditation, email: ksc-media-accreditat@mail.nasa.gov. For other questions, contact the newsroom at NASA’s Kennedy Space Center in Florida at: 321-867-2468.

 

Special logistical requests, such as space for satellite trucks, tents, or electrical connections, should be sent: ksc-media-accreditat@mail.nasa.gov by 5 p.m. Friday, May 6.

 

Para obtener información sobre cobertura en español en el Centro Espacial Kennedy o si desea solicitar entrevistas en español, comuníquese con Antonia Jaramillo: 321-501-8425.

 

NASA’s Commercial Crew Program is working with the American aerospace industry through a public-private partnership to launch astronauts on American rockets and spacecraft from American soil. The goal of the program is to provide safe, reliable, and cost-effective transportation to and from the International Space Station, which will allow for additional research time and will increase the opportunity for discovery aboard humanity’s testbed for exploration. The space station remains the springboard to NASA's next great leap in space exploration, including future missions to the Moon and eventually to Mars.

Quelle: NASA

----

Update: 23.04.2022

.

ULA begins stacking Atlas 5 rocket for Boeing’s Starliner test flight

An Atlas 5 first stage, with its Russian-made RD-180 engine, is prepared for stacking outside ULA’s Vertical Integration Facility on Wednesday morning. Credit: United Launch Alliance

Final assembly of a United Launch Alliance Atlas 5 rocket began Wednesday with the hoisting of a first stage booster onto a mobile launch platform at Cape Canaveral, kicking off a campaign to prepare for liftoff May 19 on a delayed unpiloted test flight of Boeing’s Starliner crew capsule.

ULA’s ground team raised the Atlas first stage off its trailer transporter, and a crane lifted the rocket into the Vertical Integration Facility Wednesday morning. The 107-foot-tall (33-meter) rocket stage was then lowered onto the Atlas 5’s mobile launch platform inside the integration building just south of ULA’s launch pad at Space Launch Complex 41.

The milestone event Wednesday, known as Launch Vehicle On Stand, will be followed in the coming days by the addition of two strap-on AJ-60A solid rocket boosters made by Aerojet Rocketdyne. Then a dual-engine Centaur upper stage will be raised on top of the Atlas first stage to complete the initial build-up of the launcher.

In early May, Boeing and ULA will move the Starliner spacecraft from its hangar at the Kennedy Space Center to the VIF for stacking atop the Atlas 5.

The launch preparations will culminate in rollout of the Atlas 5 rocket and Starliner spacecraft to pad 41 on May 18. Liftoff to begin Boeing’s Orbital Flight Test 2 mission to the International Space Station is scheduled for 6:54 p.m. EDT (2254 GMT).

The mission is scheduled to last approximately one week, with docking at the space station scheduled the day after liftoff. The Starliner capsule will return to Earth for a parachute-assisted, airbag-cushioned landing at one of Boeing’s recovery sites in the Western United States.

The Starliner demo, known as OFT-2, mission is a redo of an unpiloted test flight in December 2019 cut short by software problems. The software issues prevented the spacecraft from docking with the International Space Station, and the capsule safely landed in New Mexico after an abbreviated mission.

After several hardware and software changes, Boeing readied for second attempt at the Starliner’s Orbital Flight Test mission — designated OFT-2 — last August. The spacecraft was rolled to the launch pad at Cape Canaveral atop its Atlas 5 rocket, but tests revealed stuck valves in the Starliner propulsion system.

Boeing and NASA, which manages the Starliner commercial crew contract, agreed to remove the Starliner from the Atlas 5 rocket and postpone the mission to investigate the valve problem. Engineers believe the valve components likely corroded from the interaction of nitrogen tetroxide propellant with moisture that seeped into the thrusters on the spacecraft’s service module, then permeated a Teflon seal inside the valve itself.

Technicians removed the service module from the Starliner’s crew module in January for shipment to a test facility in New Mexico, where teams are performing tests to better understand the valve problem. The OFT-2 mission will fly with a new service module, one originally assigned to the first Starliner mission with astronauts.

Teams inside Boeing’s Starliner hangar mated the crew module with the new service module March 12. Filling of the service module with propellant is expected to occur this month, before the spacecraft rolls over to ULA’s rocket integration building for stacking atop the Atlas 5.

Boeing said the Starliner team designed a new purging system to help prevent moisture from getting into the valves during the upcoming launch campaign while the spacecraft is in the factory and at ULA’s launch site.

If successful, the OFT-2 mission will pave the way for Starliner’s Crew Flight Test, which will carry a team of three NASA astronauts to the space station. That will ultimately lead to operational crew rotation flights on the Starliner spacecraft, akin to SpaceX’s Crew Dragon missions to the space station, giving NASA two U.S. vehicles capable of ferrying astronauts to and from the orbiting research complex.

Following the grounding of the OFT-2 last year, ULA removed the Atlas 5 rocket’s dual-engine Centaur stage and solid rocket boosters, but kept the launcher’s core stage in position on its mobile platform. Ground teams added a different version of the Centaur upper stage for the launch of NASA’s Lucy asteroid explorer last October.

The solid rocket boosters and dual-engine Centaur upper stage were kept in storage for the last eight months until Boeing engineers could ready the Starliner spacecraft for another launch campaign.

A new Atlas first stage was delivered to Cape Canaveral last week from ULA’s factory in Decatur, Alabama, on NASA’s Pegasus rocket barge, a vessel originally built to ferry space shuttle external tanks between their manufacturing site in New Orleans and the Kennedy Space Center.

Since the retirement of the shuttle, the Pegasus barge has been modified to carry the core stage of NASA’s Space Launch System moon rocket. ULA’s rocket ferry, named the R/S RocketShip, is currently in a routine dry dock period and river locks on the typical route from Decatur to Cape Canaveral are closed for maintenance, ULA said.

On previous occasions when the RocketShip vessel was unavailable, ULA has used Ukrainian-built Antonov An-124 cargo planes to fly Atlas booster stages from Alabama to the launch site. Those aircraft are owned and operated by Russia’s Volga-Dnepr Airlines. Russian aircraft are banned from U.S. airspace in the aftermath of Russia’s military invasion of Ukraine.

Without the Antonov cargo planes, ULA turned to NASA to use its rocket barge to deliver the Atlas first stage to Cape Canaveral and keep the Starliner’s OFT-2 mission on track for launch in May.

Quelle: SN

----

Update: 30.04.2022

.

Boeing to launch 2nd test flight of Starliner spacecraft for NASA on May 19

The company will take a second try to reach the International Space Station during an uncrewed mission

Boeing is finally ready to test Starliner again in space. 

The commercial crew spacecraft is set for a test launch, dubbed OFT-2 (Orbital Flight Test-2) no earlier than May 19 as Boeing seeks to certify its Starlinervehicle for future NASA astronaut flights.

Liftoff will take place from Space Launch Complex-41 at Cape Canaveral Space Force Station in Florida, NASA said in a recent release. Liftoff is scheduled for 6:54 p.m. EDT (2254 GMT).

The test will be an opportunity for Boeing to once again simulate a mission to the International Space Station. Starliner will ride atop a United Launch Alliance Atlas V rocket as Boeing seeks to ready the spacecraft for launch, docking and return-to-Earth operations. 

This mission will be the second attempt for Starliner after a flawed OFT-1 mission in December 2019 and numerous technical problems with OFT-2's development.

A July 2020 NASA review of Boeing's first problematic test flight, which failed to reach the orbiting laboratory, identified 80 necessary corrections to deal with the glitches and software issues that underlay the mission's difficulties. 

Addressing these issues took time, and the process was compounded by issues such as the ongoing coronavirus pandemic, widespread power outages in Texas during testing. But on July 22, 2021, the system appeared to be almost set to go after it passed its flight readiness review (FRR) for an expected launch July 30.

That July 30 date was aborted due to a a mishap with Russia's Nauka module, which docked with the International Space Station and tilted the orbiting complex so severely that it caused a spacecraft emergency. Following that, teams encountered a valve issue with Starliner on the launch pad that required investigation, standing down from a backup launch date of Aug. 3.

Ground teams ultimately decided Aug. 5, 2021 to roll the Atlas V rocket back into the Vertical Integration Facility at Launch Complex-41 to access Starliner more directly to fix the valve issue.

Ongoing troubleshooting of the valves, along with a busy launch schedule to the ISS, both contributed to pushing the mission back into 2022. But by the end of 2021, engineers were able to say the leading cause of the anomaly was moisture interactions with the oxidizer, creating corrosion that sealed the valves. 

The Starliner team in part addressed the valve issue by switching out the service module with one from an upcoming flight, originally planned for its Crew Flight Test (CFT) that would have had astronauts on board. That said, the current May 2022 launch date aligns with the expected timing the team predicted by end of 2021.

Quelle: SC

----

Update: 6.05.2022

.

Boeing’s Starliner crew capsule meets Atlas rocket for long-delayed test flight

Boeing’s Starliner crew capsule moves toward ULA’s Vertical Integration Facility. Credit: Stephen Clark / Spaceflight Now

 

Ready for another try at launching on a test flight to the International Space Station, Boeing rolled a repaired Starliner crew capsule to United Launch Alliance’s seaside rocket hangar at Cape Canaveral Wednesday to prepare for a liftoff scheduled for May 19.

The test flight will not carry astronauts, but could set the stage for the first Starliner crew mission to the space station late this year or in early 2023, NASA and Boeing officials said in a press conference Tuesday.

The upcoming mission, known as Orbital Flight Test 2, is set for liftoff May 19 at 6:54 p.m. EDT (2254 GMT) aboard a United Launch Alliance Atlas 5 rocket. The Starliner spacecraft, carrying a mannequin and about 500 pounds of supplies, is scheduled to link up with the space station the next day to begin several days of cargo transfers and checkouts while docked at the complex.

Then the spacecraft will depart the station and jettison its expendable propulsion module. The crew module section, designed for reuse, will target a landing under parachutes at White Sands Space Harbor in New Mexico. Undocking and landing are scheduled for May 25, assuming the mission takes off May 19.

Boeing and ULA transferred the spacecraft to the Atlas 5 rocket’s Vertical Integration Facility on Wednesday, a few hours later than planned due to a hydraulic leak on the capsule’s transporter. The convoy, which included security and support personnel, briefly stopped near the Vehicle Assembly Building at Kennedy after a protective cover blew off the Starliner’s window.

A Boeing spokesperson said the cover is intended to be removed before launch, and its absence was not an issue for the spacecraft to continue to the Atlas 5 hangar. Once in position, a crane hoisted the spacecraft on top of the Atlas 5 rocket, which was assembled inside the VIF last month.

ULA and Boeing will run the Atlas 5 and Starliner spacecraft through integrated checkouts over the next two weeks. The 172-foot-tall (52-meter) rocket will roll to the launch pad May 18, the day before liftoff.

Developed in a public-private partnership, the Starliner spacecraft will give NASA a second human-rated capsule capable of ferrying astronauts to and from the space station, alongside SpaceX’s Dragon spaceship, which launched with a crew for the first time in May 2020.

“It’s very important for commercial crew to have our second transportation system up and operational to continue our assured access to ISS, and also to grow our low Earth orbit economy,” said Steve Stich, NASA’s commercial crew program manager.

But the program has encountered a series of delays and setbacks, including an orbital test flight in December 2019 that ended prematurely due to a software programming error. The software glitch, associated with the spacecraft’s on-board timer, prevented  the Starliner from docking at the space station as planned, and the capsule made a safe landing in New Mexico.

The Starliner spacecraft also ran into problems with its communications system on the two-day demonstration mission in 2019. Boeing engineers had to solve a second software problem detected in flight, which could have caused the spacecraft’s service module to collide with the crew module after the two elements separated just prior to re-entry.

Engineers completed an in-depth review of the Starliner’s software code, and added more extensive tests of the software programming before trying another test flight last year, called OFT-2.

The spacecraft was rolled to the launch pad last August at Cape Canaveral atop its Atlas 5 rocket, but tests revealed 13 stuck isolation valves in the Starliner propulsion system.

Boeing and NASA, which manages the Starliner commercial crew contract, agreed to remove the Starliner from the Atlas 5 rocket and postpone the mission to investigate the valve problem. Officials said Tuesday that testing showed corrosion inside the valves — caused by a chemical reaction between moisture, nitrogen tetroxide propellant, and the valves’ aluminum housing — caused the components to stick inside the plumbing on the spacecraft’s service module.

Nitrogen tetroxide, or NTO, is a toxic liquid used as an oxidizer on the Starliner spacecraft’s propulsion system. Hydrazine fuel ignites when mixed with the oxidizer, generating thrust from the spacecraft’s rocket jets — supplied by Aerojet Rocketdyne — for in-space maneuvers and docking at the space station.

The stuck valves are used to isolate the thrusters from the nitrogen tetroxide tank, and need to open in flight to operate the thrusters for maneuvers or a launch abort.

Engineers from Boeing, NASA, Aerojet Rocketdyne, and Marotta, which produced the valves, honed in the cause of the problem during an eight-month investigation.

Technicians detached the service module from the Starliner’s crew module in January for shipment to a test facility in New Mexico, where teams performed tests to better understand the valve problem. The OFT-2 mission will fly with a new service module, one originally assigned to the first Starliner mission with astronauts.

The investigation revealed nitrogen tetroxide vapors seeped through Teflon seals in the valves, an occurrence that was known to happen in similar systems on other spacecraft. But moisture from the humid Florida air — not from rainfall, officials said — somehow made its way into the service module and reacted with the nitrogen tetroxide to create nitric acid.

The nitric acid then reacted with aluminum material in the valve housings to create aluminum nitrate deposits, leading to corrosion.

“Those corrosion products then resulted in preventing valve motion,” said Michelle Parker, Boeing’s vice president and deputy general manager for space and launch programs.

Engineers have not redesigned the valves on the new Starliner service module, but added “mitigations” to help prevent moisture from entering the propulsion system.

“If you eliminate the moisture from the valve, you won’t have this reaction and it won’t lead to corrosion,” Parker said.

The valves will be purged with nitrogen gas to prevent moisture build-up, and Boeing added sealant around an electrical connector that provided a path for humidity to get into the valves.

“Those two things will prevent the moisture from getting into the valve to start that reaction at all,” Parker said.

Boeing also made process changes, and loaded the nitrogen tetroxide into the service module closer the time the spacecraft rolled out of the factory at the Kennedy Space Center. Teams will also command valve cycles every two to five days through launch day to ensure that the valves remain operational, Parker said.

The final pre-launch valve cycle test will occur during the countdown May 19.

“We are confident that we have the right mitigations in place,” said Mark Nappi, Boeing’s program manager for the Starliner. “We’ve also cycled the valves several times. We’ll continue to cycle the valves until we get to launch day to boost the confidence that we have a system that’s working.”

Stich, a former space shuttle flight director, said valves on the shuttle’s reaction control system jets were also susceptible to moisture causing corrosion.

“These prop iso valves, especially with NTO, they’re the bane of our existence,” said Kathy Lueders, associate administrator of NASA’s space operations mission directorate. “This is something that is not a new phenomenon on the spacecraft side.

“If you’ve been Florida in July, just imagine being outside,” Lueders said. “It’s just the ambient humidity. This is kind of an insidious thing because you have a vehicle on the pad.”

With SpaceX now providing regular crew transportation services to the space station, there’s no rush to make the Starliner spacecraft operational. Nevertheless, NASA is eager to have two crew transportation providers to avoid again relying on Russia’s Soyuz spacecraft for astronaut flights in the event SpaceX runs into any significant delays.

NASA has signed a series of contracts with Boeing, valued at more than $5 billion, since 2010 for Starliner development, test flights, and operations. The contracts include agreements for six crew rotation flights to the space station — each with a four-person crew — following the completion of the OFT-2 mission and the short-duration Crew Flight Test, or CFT, with three NASA astronauts on-board.

NASA and Boeing officials declined to set a target schedule for the Crew Flight Test, only saying that preparations on the capsule for the first astronaut mission were on track to have the vehicle ready for launch by the end of this year.

“The best path to CFT is a successful OFT-2 flight because this is the time that the vehicle is put through its paces in the space environment, through the complex rendezvous and docking sequence with the navigation sensors,” Stich said. “And really the only way to test that, we’ve found, is in the space environment.”

Quelle: Spaceflight Now

----

Update: 11.05.2022

.

NASA, Boeing to Discuss Readiness of Uncrewed Flight Test

The Boeing CST-100 Starliner spacecraft is lifted at the Vertical Integration Facility at Space Launch Complex-41 at Florida's Cape Canaveral Space Force Station on May 4, 2022. Starliner will be secured atop a United Launch Alliance Atlas V rocket for Boeing's second Orbital Flight Test (OFT-2) to the International Space Station for NASA's Commercial Crew Program. The spacecraft rolled out from Boeing's Commercial Crew and Cargo Processing Facility at NASA's Kennedy Space Center earlier in the day.

Credits: NASA/Frank Michaux

Audio of the teleconference will stream live on the agency’s website.

The teleconference will focus on the readiness of the flight test and is targeted to begin approximately one hour after the readiness review concludes with the following participants:

• Kathryn Lueders, associate administrator, NASA’s Space Operations Mission Directorate
• Steve Stich, manager, NASA’s Commercial Crew Program 
• Joel Montalbano, manager, NASA’s International Space Station Program
• Emily Nelson, acting chief flight director, NASA’s Flight Operations Directorate  
• Mark Nappi, vice president and program manager, Boeing Commercial Crew Program  

Media wishing to participate in the teleconference must RSVP by 5 p.m., Wednesday, May 11, by emailing the newsroom at NASA’s Kennedy Space Center in Florida at: ksc-newsroom@mail.nasa.gov. A copy of NASA’s media accreditation policy is online.

OFT-2 is targeted to launch at 6:54 p.m. Thursday, May 19, from Space Launch Complex-41 at Cape Canaveral Space Force Station in Florida. Starliner will launch on a United Launch Alliance Atlas V rocket for its uncrewed test to the International Space Station.

Starliner is expected to arrive at the space station for docking about 24 hours after launch with more than 500 pounds of NASA cargo and crew supplies. After a successful docking, Starliner will spend five to 10 days aboard the orbiting laboratory before returning to Earth in the western United States. The spacecraft will return with nearly 600 pounds of cargo, including reusable Nitrogen Oxygen Recharge System (NORS) tanks that provide breathable air to station crew members.

Quelle: NASA