The Atlas V Rocket for Boeing’s CST-100 Starliner Launch

United Launch Alliance’s Atlas V rocket that will launch Boeing’s CST-100 Starliner to the International Space Station for NASA’s Commercial Crew Program was modified specifically for the agency’s Orbital Flight Test-2. This rocket configuration does not include a payload fairing. Instead, the Starliner’s own protective surfaces will take the place of the fairing to protect the uncrewed spacecraft during launch and ascent. The rocket has two solid rocket boosters (SRBs) and a dual-engine Centaur upper stage. Starliner is attached to the Atlas V using a launch vehicle adapter, which includes an aeroskirt to reduce the aerodynamic loads on the vehicle.

The Atlas V booster is 12.5 feet in diameter and 106.5 feet in length. The booster’s propulsion is provided by the RD-180 engine system, which delivers 860,200 pounds of thrust at sea level. The SRBs generate the additional power required at liftoff, with each providing 348,500 pounds of thrust.

The Centaur second stage is 10 feet in diameter and 41.5 feet in length. For this configuration, the Centaur is configured with dual RL10A-4-2 engines, each producing 22,600 pounds of thrust. The cryogenic tanks are insulated with a combination of helium-purge blankets, radiation shields, and spray-on foam insulation. The Centaur includes an Emergency Detection System that monitors for critical hazards. This system will provide critical in-flight data which supports jettison of the ascent cover and initiates CST-100 spacecraft separation.

Learn more at www.ulalaunch.com.

Boeing’s Orbital Flight Test-2 Objectives

On May 18, 2022, Boeing’s CST-100 Starliner spacecraft and the United Launch Alliance Atlas V rocket rolled out from the Vertical Integration Facility to the launch pad at Space Launch Complex-41 on Cape Canaveral Space Force Station in Florida.
On May 18, 2022, Boeing’s CST-100 Starliner spacecraft and the United Launch Alliance Atlas V rocket rolled out from the Vertical Integration Facility to the launch pad at Space Launch Complex-41 on Cape Canaveral Space Force Station in Florida. Photo credit: NASA/Kim Shiflett

NASA’s Boeing Orbital Flight Test-2 will test the end-to-end capabilities of the company’s CST-100 Starliner spacecraft from launch to docking to a return to Earth in the desert of the western United States. The flight test will provide valuable data toward NASA certifying Boeing’s crew transportation system for regular crewed flights to and from the International Space Station. OFT-2 will build on the objectives achieved during Starliner’s initial flight test, including:

  • In-orbit operation of the avionics, docking system, communications and telemetry systems, environmental control systems, solar arrays and electrical power systems and propulsion systems;
  • Performance of the guidance, navigation and control systems of the Starliner and Atlas V through ascent, on-orbit, and entry;
  • Acoustic and vibration levels, and loads across the Starliner exterior and interior;
  • Launch escape trigger monitoring; and
  • Performance of the Starliner system end-to-end mission operations.

These objectives are intended to demonstrate all of Starliner’s systems and capabilities except for those requiring a human onboard to test.

For this flight, Starliner will carry more than 500 pounds of NASA cargo and crew supplies to the space station. After a successful docking, the spacecraft will spend five to 10 days aboard the orbiting laboratory before returning to Earth. The spacecraft will return with nearly 600 pounds of NASA cargo, including reusable Nitrogen Oxygen Recharge System tanks that provide breathable air to station crew members.

Read more about OFT-2.

Live Coverage Begins for NASA and Boeing’s Orbital Flight Test-2

A United Launch Alliance Atlas V rocket with Boeing’s CST-100 Starliner spacecraft aboard is seen after being rolled out of the Vertical Integration Facility to the launch pad at Space Launch Complex 41 ahead of the Orbital Flight Test-2 (OFT-2) mission, Wednesday, May 18, 2022 at Cape Canaveral Space Force Station in Florida.
A United Launch Alliance Atlas V rocket with Boeing’s CST-100 Starliner spacecraft aboard is seen after being rolled out of the Vertical Integration Facility to the launch pad at Space Launch Complex 41 ahead of the Orbital Flight Test-2 (OFT-2) mission, Wednesday, May 18, 2022 at Cape Canaveral Space Force Station in Florida. Photo Credit: NASA/Joel Kowsky

Good afternoon from Kennedy Space Center in Florida, and welcome to live launch coverage of NASA’s Boeing Orbital Flight Test-2 (OFT-2) to the International Space Station, launching in a little over an hour. Boeing’s CST-100 Starliner spacecraft sits atop a United Launch Alliance Atlas V rocket poised on the launch pad ready to go at nearby Space Launch Complex-41 on Cape Canaveral Space Force Station.

OFT-2 is an uncrewed flight test of the company’s Starliner spacecraft for NASA’s Commercial Crew Program. Liftoff is scheduled for 6:54 p.m. EDT during an instantaneous launch window.

The countdown is currently proceeding according to schedule. Fueling of the Atlas V rocket began a little after noon EDT today. The first stage booster’s RD-180 engine, containing two thrust chambers, was fueled with Rocket Propellant-1, a highly purified kerosene. The Centaur second stage was fueled with liquid hydrogen and liquid oxygen. Fueling of the rocket was completed about two hours later.

Stay with us here for coverage as the countdown continues towards launch. Watch the coverage live on NASA TV starting at 6 p.m. EDT. More details about the flight test and NASA’s Commercial Crew Program can be found in the online press kit and by following the @commercial_crew on Twitter and commercial crew on Facebook.

Meteorologists with the U.S. Air Force 45th Weather Squadron continue to predict an 80% chance of favorable weather for launch this afternoon. The primary concerns for launch day are the cumulus and anvil cloud rules violations during the instantaneous launch window.

Orbital Flight Test-2 Starliner, Atlas V Roll to Pad, NASA Leaders to Brief Media

On May 18, 2022, Boeing’s CST-100 Starliner spacecraft and the United Launch Alliance Atlas V rocket roll out from the Vertical Integration Facility to the launch pad at Space Launch Complex-41 on Cape Canaveral Space Force Station in Florida.
On May 18, 2022, Boeing’s CST-100 Starliner spacecraft and the United Launch Alliance Atlas V rocket roll out from the Vertical Integration Facility to the launch pad at Space Launch Complex-41 on Cape Canaveral Space Force Station in Florida. Photo credit: NASA/Kim Shiflett

This morning, Wednesday, May 18, Boeing’s CST-100 Starliner spacecraft and the United Launch Alliance (ULA) Atlas V rocket rolled out of the ULA Vertical Integration Facility to the launch pad at Space Launch Complex-41 on Cape Canaveral Space Force Station in Florida ahead of the uncrewed launch of NASA’s Boeing Orbital Flight Test-2 (OFT-2) to the International Space Station. Liftoff is scheduled for 6:54 p.m. EDT on Thursday, May 19.

For a launch Thursday, meteorologists with the U.S. Space Force 45th Weather Squadron continue to predict a 70% chance of favorable weather. The primary weather concerns for launch day are the cumulus and anvil cloud rules violations during the instantaneous launch window.

NASA leaders will update members of the news media on OFT-2 during a briefing on Wednesday, May 18, at 1 p.m. The briefing will air live on NASA TV, the NASA app, and the agency’s website. Participants include:

  • Bob Cabana, NASA associate administrator
  • Janet Petro, director, NASA’s Kennedy Space Center
  • Kathryn Lueders, associate administrator, Space Operations Mission Directorate at NASA
  • NASA astronaut Suni Williams
  • NASA astronaut Butch Wilmore
  • NASA astronaut Mike Fincke

NASA TV will cover the upcoming prelaunch, launch, and docking activities. Mission coverage is as follows (all times Eastern):

Thursday, May 19

6 p.m. – NASA TV launch coverage begins for a targeted 6:54 p.m. liftoff. NASA TV will have continuous coverage through Starliner orbital insertion.

9 p.m. (approximately) – Postlaunch news conference on NASA TV

Friday, May 20

3:30 p.m. – NASA TV rendezvous and docking coverage begins.

7:10 p.m. (approximately) – Docking

Friday, May 21

11:30 a.m. – NASA TV hatch opening coverage begins

11:45 a.m. – (approximately) Hatch opening and welcoming remarks

Learn more about station activities by following @space_station and @ISS_Research on Twitter as well as the ISS Facebook and ISS Instagram accounts.

Starliner Returns to Factory, Preparations Underway to Resolve Valve Issue

OFT-2 Starliner spacecraft
Boeing’s Starliner spacecraft returned Aug. 19, 2021, from the United Launch Alliance Vertical Integration Facility to the Commercial Crew and Cargo Processing Facility at NASA’s Kennedy Space Center in Florida, where teams will work to diagnose and resolve a valve issue detected during the Aug. 3 launch attempt of NASA Boeing’s Orbital Flight Test-2. Photo credit: Boeing

Teams from Boeing and United Launch Alliance (ULA) safely returned the CST-100 Starliner to its production facility in Florida on Aug. 19 for continued work on the spacecraft’s service module propulsion system.

The Starliner Orbital Flight Test-2 spacecraft was removed from its Atlas V rocket inside the Vertical Integration Facility at Space Launch Complex-41 on Cape Canaveral Space Force Station in Florida and returned to the Commercial Crew and Cargo Processing Facility on NASA’s Kennedy Space Center.

The team now will perform propulsion system checkouts inside the factory’s hazardous processing area and determine the appropriate vehicle configuration for accessing and analyzing the system further. NASA and Boeing will recommend forward work as part of a formal process designed to aid in determining root cause and remediation steps.

In the weeks ahead, engineering teams from NASA and Boeing will work to diagnose and ultimately resolve a valve issue detected during the Aug. 3 countdown for NASA’s Boeing Orbital Flight Test-2, and resulted in the decision to postpone the launch destined for the International Space Station.

NASA, Boeing, and ULA will establish a new launch date once the issue is resolved.

NASA, Boeing to Move Starliner to Production Facility for Propulsion System Evaluation

Boeing's CST-100 Starliner spacecraft is in view in the United Launch Alliance Vertical Integration Facility at Space Launch Complex 41 on Aug. 9, 2021.
Boeing’s CST-100 Starliner spacecraft is in view in the United Launch Alliance Vertical Integration Facility at Space Launch Complex 41 on Aug. 9, 2021. Photo credit: Boeing

NASA and Boeing have decided to postpone the launch of Orbital Flight Test-2 to the International Space Station as teams continue work on the CST-100 Starliner propulsion system.

Engineering teams have been working to restore functionality to several valves in the Starliner propulsion system from inside United Launch Alliance’s Vertical Integration Facility that did not open as designed during the launch countdown for the Aug. 3 launch attempt. The valves connect to thrusters that enable abort and in-orbit maneuvering.

“We made a lot of progress to open the valves from inside the Vertical Integration Facility, and the NASA-Boeing teams did a great job doing everything we could to get ready for this launch opportunity,” said Kathryn Lueders, associate administrator for NASA’s Human Exploration and Operations Mission Directorate. “Although we wanted to see Starliner fly in this window, it’s critical that our primary focus is the safety of the crew transportation system – for the safety of the space station and the crew members that will be flying on these vehicles. We’ll only fly this test when we think we are ready, and can complete the mission objectives.”

Inside the VIF, Boeing was able to prompt nine of 13 valves open that previously were in the closed position using commanding, mechanical, electrical and thermal techniques. Teams will now begin the process to move Starliner back to Boeing’s Commercial Crew and Cargo Processing Facility in Florida for deeper-level troubleshooting of four propulsion system valves that remain closed and more detailed analysis on the spacecraft.

“Mission success in human spaceflight depends on thousands of factors coming together at the right time,” said John Vollmer, vice president and program manager, Boeing’s Commercial Crew Program. “We’ll continue to work the issue from the Starliner factory and have decided to stand down for this launch window to make way for other national priority missions.”

NASA, Boeing and ULA will establish a new launch date once the issue is resolved.

NASA, Boeing Continue Starliner Data Analysis

Atlas V rocket with Starliner on launch pad
A United Launch Alliance Atlas V rocket with Boeing’s CST-100 Starliner spacecraft onboard is seen on the launch pad on Thursday, July 29, 2021, at Space Launch Complex 41 in preparation for the Orbital Flight Test-2 (OFT-2) mission at Cape Canaveral Space Force Station in Florida. Photo Credit: (NASA/Aubrey Gemignani)

NASA and Boeing are continuing to work through steps to determine what caused the unexpected valve position indications on the CST-100 Starliner propulsion system.

The United Launch Alliance Atlas V with the Starliner spacecraft on top will be returned to its Vertical Integration Facility (VIF) at Launch Complex-41 on Cape Canaveral Space Force Station Thursday where engineers will have direct access to Starliner for continued troubleshooting.

The data will drive any corrective measures that may be necessary to ensure Starliner is ready for launch. When NASA’s Commercial Crew Program and Boeing Space agree the issue is resolved, a new launch opportunity will be selected, taking into account the readiness of all parties involved.

“The Boeing and NASA teams are working methodically to understand what caused the valve indications on the Starliner service module propulsion system,” Steve Stich, manager of the Commercial Crew Program, said. “The troubleshooting in the Vertical Integration Facility will help focus on potential causes and next steps before we fly the OFT-2 mission.”

Early in the launch countdown for the Tuesday, Aug. 3 launch attempt, engineers detected indications that not all of Starliner’s propulsion system valves were in the proper configuration needed for launch of the company’s second uncrewed orbital flight test to the International Space Station, a mission designed to test the end-to-end capabilities of the crew-capable system as part of NASA’s Commercial Crew Program.

Mission teams decided to halt the countdown to further analyze the issue, which was conducted later Tuesday via several steps to troubleshoot the incorrect valve indications, including cycling the service module propulsion system valves.

After presenting the data to NASA and Boeing managers, it was decided to relocate the Atlas V and Starliner to the VIF for further inspection and testing where access to the spacecraft is available. Engineering teams have ruled out a number of potential causes, including software, and the direct access is required to continue the assessment.

“This mission is extremely important for the Commercial Crew Program on the path to the Boeing Crewed Flight Test,” Stich said. “We will fly the mission when we are ready. I am extremely proud of the NASA and Boeing teams for their professionalism, perseverance, and methodical approach to solving complex problems.”

NASA and Boeing will take whatever time is necessary to ensure Starliner is ready for its important uncrewed flight test to the space station and will look for the next available opportunity after resolution of the issue.

NASA, Boeing Standing Down on Aug. 4 Starliner Launch Attempt

NASA and Boeing are standing down from the Wednesday, Aug. 4, launch attempt of the agency’s Orbital Flight Test-2 to the International Space Station as mission teams continue to examine the cause of the unexpected valve position indications on the CST-100 Starliner propulsion system.

Early in the launch countdown for the Aug. 3 attempt, mission teams detected indications that not all valves were in the proper configuration needed for launch. Mission teams decided to halt the countdown to further analyze the issue.

NASA and Boeing worked through several steps to troubleshoot the incorrect valve indications, including cycling the service module propulsion system valves, within the current configuration of the Starliner and United Launch Alliance Atlas V rocket at Space Launch Complex-41 on Cape Canaveral Space Force Station in Florida.

Mission teams have decided to roll the Atlas V and Starliner back to the Vertical Integration Facility (VIF) for further inspection and testing where access to the spacecraft is available. Boeing will power down the Starliner spacecraft this evening. The move to the VIF is expected to take place as early as tomorrow.

Engineering teams have ruled out a number of potential causes, including software, but additional time is needed to complete the assessment.

NASA and Boeing will take whatever time is necessary to ensure Starliner is ready for its important uncrewed flight test to the space station and will look for the next available opportunity after resolution of the issue.

NASA’s Boeing OFT-2: Launch Scrubbed for Aug. 3. Attempt

The United Launch Alliance Atlas V rocket with Boeing's CST-100 Starliner atop is on the pad at Space Launch Complex-41 on Aug. 3, 2021.
The United Launch Alliance Atlas V rocket with Boeing’s CST-100 Starliner atop is on the pad at Space Launch Complex-41 on Aug. 3, 2021. Photo credit: NASA

NASA, Boeing and United Launch Alliance (ULA) have scrubbed the Aug. 3 launch attempt of the agency’s Orbital Flight Test-2 to the International Space Station due to unexpected valve position indications in the Starliner propulsion system. ULA will begin removing propellant from the Atlas V rocket.

Pending resolution of the forward work, our next available launch opportunity would be 12:57 p.m. EDT on Wednesday, Aug. 4.

For more information on the technical issue, click here.

Follow along with launch activities and get more information about the mission at: https://blogs.nasa.gov/commercialcrew/.

Learn more about commercial crew and space station activities by following @Commercial_Crew@space_station, and @ISS_Research on Twitter as well as the Commercial Crew FacebookISS Facebook and ISS Instagram accounts

Orbital Flight Test-2 Starliner, Atlas V Roll Return to Launch Pad

A United Launch Alliance Atlas V rocket with Boeing’s CST-100 Starliner spacecraft onboard is seen as it is rolled out of the Vertical Integration Facility to the launch pad at Space Launch Complex 41 ahead of the Orbital Flight Test-2 (OFT-2) mission, Thursday, July 29, 2021 at Cape Canaveral Space Force Station in Florida. Boeing’s Orbital Flight Test-2 will be Starliner’s second uncrewed flight test and will dock to the International Space Station as part of NASA's Commercial Crew Program.
A United Launch Alliance Atlas V rocket with Boeing’s CST-100 Starliner spacecraft onboard is seen as it is rolled out of the Vertical Integration Facility to the launch pad at Space Launch Complex 41 ahead of the Orbital Flight Test-2 (OFT-2) mission, Thursday, July 29, 2021 at Cape Canaveral Space Force Station in Florida. Boeing’s Orbital Flight Test-2 will be Starliner’s second uncrewed flight test and will dock to the International Space Station as part of NASA’s Commercial Crew Program. Photo credit: NASA/Aubrey Gemignani

This morning, Aug. 2, Boeing’s CST-100 Starliner spacecraft and the United Launch Alliance (ULA) Atlas V rocket rolled out of the ULA Vertical Integration Facility (VIF) to return to the launch pad at Space Launch Complex-41 on Cape Canaveral Space Force Station in Florida ahead of NASA’s Boeing Orbital Flight Test-2 mission to the International Space Station. Liftoff is scheduled for 1:20 p.m. EDT on Tuesday, Aug. 3.

Starliner and the Atlas V rocket made the first trip to the launch pad on July 29, but rolled back to the VIF on July 30 to avoid potential inclement weather.

For a launch Tuesday, meteorologists with the U.S. Space Force 45th Weather Squadron are predicting a 60% chance of favorable weather. The primary weather concerns for launch day are the cumulus cloud rule, lightning rule, and thick cloud rule violations during the instantaneous launch window.

NASA TV will cover the upcoming prelaunch, launch, and docking activities. Mission coverage is as follows (all times Eastern):

Tuesday, Aug. 3

12:30 p.m. – NASA TV launch coverage begins for a targeted 1:20 p.m. liftoff. NASA TV will have continuous coverage through Starliner orbital insertion.

3:30 p.m. (approximately) – Postlaunch news conference on NASA TV.

Wednesday, Aug. 4

10:30 a.m. – NASA TV rendezvous and docking coverage begins.

1:37 p.m. (scheduled) – Docking

Thursday, Aug. 5

8:30 a.m. – NASA TV hatch opening coverage begins

8:40 a.m. – Hatch opening

9:40 a.m. (approximately) – Welcoming remarks

Learn more about station activities by following @space_station and @ISS_Research on Twitter as well as the ISS Facebook and ISS Instagram accounts.