After years of anticipation, Boeing’s CST-100 Starliner capsule has flown its first crew into area on the one hundredth flight of an Atlas V launch automobile. Capping off Starliner’s check marketing campaign, the Crew Flight Take a look at (CFT) has despatched Barry Wilmore and Sunita Williams on a trajectory to rendezvous with the Worldwide House Station (ISS) the place they may stay for a few week.
Launch was initially scheduled for Could 6, however was scrubbed slightly below two hours earlier than the flight resulting from a difficulty with an oxygen reduction valve on the Centaur higher stage. Liftoff was then scheduled for June 1 at 12:25 PM EDT (16:25 UTC). On this second try, the rocket entered a maintain at roughly T-3:50 resulting from a fault within the floor help gear that controls the launch automobile’s countdown. The launch happened on Wednesday, June 5 at 10:52 AM EDT (14:52 UTC).
Whereas CFT was the primary crewed flight on Starliner, it additionally marked the primary flight of people on the United Launch Alliance (ULA) Atlas V rocket, in addition to the primary crewed flight from Cape Canaveral House Drive Station since Apollo 7 in 1968.
Following this launch, Starliner will be part of SpaceX’s Crew Dragon within the rotation of automobiles contracted to carry crews to and from the ISS for long-duration stays.
First launch try
Throughout the countdown on Could 6, groups with ULA seen a valve on the Atlas V’s Centaur second stage that appeared to repeatedly open and shut.
Given the very fact it was a crew mission and that the automobile had been in a totally fueled state, groups determined to face down from the launch try. ULA famous that had this been a non-crew mission, it may have doubtless been resolved throughout the countdown. The valve, which vents strain from the liquid oxygen tank, was rated to no less than 200,000 cycles, which engineers consider it had surpassed previous to launch. This led to the automobile rolling again to the Vertical Integration Facility (VIF) the place it was changed.
Groups additionally seen a small helium leak within the service module of the Starliner spacecraft. Initially leaking at 7 kilos per sq. inch (psi), it reportedly grew to between 50-70 psi from an space smaller than a shirt button and roughly 10 sheets of paper thick in response to engineers.
That is positioned within one of many response management system thrusters onboard the automobile that assist with in-orbit maneuvers in addition to deorbiting. The difficulty reportedly solely impacts one of many 28 of such response management system (RCS) thrusters onboard the automobile.
Engineers additionally famous that helium leaks will not be unusual, having been current on different automobiles together with early Crew Dragon flights, and pose no hazard to the crew.
The Starliner capsule at SLC-41 previous to a Could 6 launch try. (Credit score: Max Evans for NSF)
Nevertheless, analyzing this situation did reveal a further “design vulnerability.” The manifolds for the thrusters are positioned inside housings often called a “doghouse.” 4 of them are positioned across the automobile. It was famous that if two of the doghouses skilled a failure that weren’t perpendicular to one another, it may take away the power of the spacecraft to make use of eight of its orbital maneuvering thrusters to carry out a deobrit burn, eradicating a layer of redundancy.
The opposite licensed deorbit maneuvers each contain firing the automobile’s orbital maneuvering and angle management (OMAC) thrusters, that are completely different from the RCS thrusters.
An extra deorbit methodology was examined and accepted as a backup that will see two deorbit burns, every utilizing 4 RCS thrusters. The crew, who’ve been quarantined in Houston, reportedly ran by way of these eventualities within the simulator between launch makes an attempt.
The 2 astronauts arrived again in Florida on Could twenty eighth, adopted by their journey rolling again out to the launch pad the following day. Following a particular Delta Flight Readiness Overview on the twenty ninth, meant to have a look at all anomalies found between makes an attempt, groups gave their approval for launch.
Second launch try
Throughout the try on June 1, a number of points appeared throughout the countdown, nonetheless all had been resolved previous to coming into the terminal rely at T-4 minutes. This consists of a difficulty with a sensor on the gasoline topping valves for the cryogenic Centaur higher stage, an inadvertent launch of 1,000 psi of nitrogen, and a difficulty with a fan inside one of many crewmember’s spacesuits.
Moments after coming into the terminal rely, the clock stopped at T-3:50 after a fault was detected in a number of the floor help gear. At a press convention following the scrub, ULA CEO Tory Bruno defined that out on the pad, there are three units of redundant computer systems, every stuffed with racks containing particular person playing cards associated to every portion of the countdown.
Groups at @NASA and @BoeingSpace confirmed on Monday that the #Starliner spacecraft, @ulalaunch Atlas V rocket, and floor help gear are wholesome and prepared for the ten:52am ET June 5 launch of the company’s Boeing Crew Flight Take a look at.
Meteorologists with @SLDelta45 predict 90%… pic.twitter.com/VEiYQlgHAy
— NASA Business Crew (@Commercial_Crew) June 3, 2024
Bruno famous that upon coming into the terminal rely, two of three redundant launch sequencers immediately enter flight configuration, whereas a 3rd took a further six seconds. These sequencers are in command of time-sensitive components of the launch together with disconnecting umbilical strains and commanding the discharge of the bolts that hold the rocket on the pad.
Whereas it did finally come as much as full velocity, Bruno stated the launch sequencer learn this as an issue and out of an abundance of warning auto-triggered the scrub.
Even if all three playing cards carry out the identical activity, including redundancy, Bruno famous that every one three of those playing cards must be absolutely powered on coming into the terminal rely given their significance to conserving observe of programs previous to the launch.
As soon as the rocket was detanked and the launch pad deemed protected, groups had been in a position to substitute the cardboard on the pad and check it, clearing the flight for its subsequent try on June 5.
Earlier flight assessments
In September 2014, NASA introduced that SpaceX and Boeing would every obtain a contract as a part of the Business Crew Transportation Functionality contracts. The plan was to get two unbiased spacecraft up and operating concurrently as a type of redundancy within the occasion one thing had been to occur to one of many automobiles, leaving it out of fee. The primary uncrewed check flight of Crew Dragon occurred in March 2019 with the Demo-1 mission, which docked to the ISS with out crew and returned safely.
Demo-2 noticed the return of US crew launch functionality launching on Could 30, 2020, safely bringing Bob Behnken and Doug Hurley to the ISS and again.
The Starliner OFT-1 Atlas V previous to first stage cutoff on Dec 20, 2019. (Credit score Joseph Navin for NSF)
Concurrently, Boeing was engaged on their check program for Starliner.
The primary flight check, initially named Orbital Flight Take a look at and later renamed Orbital Flight Take a look at 1 (OFT-1), lifted off on Dec. 20, 2019. Nicknamed Calypso, the spacecraft launched efficiently, nonetheless, it encountered a major problem whereas making an attempt to enter its deliberate orbit previous to an ISS rendezvous and docking.
A later investigation discovered that the mission elapsed timer had polled incorrectly, ensuing within the spacecraft not executing its orbit insertion burn on the deliberate time. This left it in a protected orbit, however unable to finish its main goal of docking to the Station, even after the burn was finally commanded manually.
As well as, a software program situation with the service module separation sequence was discovered throughout the mission, which may have resulted in a lack of automobile had it not been recognized and glued earlier than Starliner’s return to flight. The capsule landed safely on the White Sands Missile Vary in New Mexico after a shorter-than-planned mission.
Groups course of the OFT-1 Starliner automobile after touchdown. (Credit score: NASA)
This resulted within the want for an unplanned second uncrewed flight check, Orbital Flight Take a look at 2 (OFT-2), which confronted its personal points.
Initially scheduled to launch in August 2021, the try was scrubbed as soon as indicators on the spacecraft famous 13 valves within the service module’s propulsion system had been in an incorrect configuration.
Whereas they tried to repair the problems whereas nonetheless connected to the Atlas V rocket inside ULA’s Vertical Integration Facility (VIF), 4 valves remained caught. That resulted within the destacking of Starliner, which was then despatched again to Boeing’s facility for repairs.
The foundation reason for the valve situation was decided to be corrosion from nitric acid, which had shaped because of water vapor within the air reacting with the dinitrogen tetroxide that Starliner makes use of as an oxidizer. This led to the substitute of the service module, utilizing one initially deliberate for the CFT mission because it contained a nitrogen purge system meant to assist mitigate the issue together with different processing and fueling process modifications.
Starliner lifts off on the uncrewed OFT-2 mission from Cape Canaveral House Drive Station. (Credit score: Stephen Marr for NSF)
OFT-2 efficiently launched on Could 19, 2022, docking to the ISS simply in the future later. After slightly below six days in area, the capsule efficiently landed in New Mexico on its airbags, paving the best way for CFT.
The crew
The lineup for who would fly on the primary crew flight check of Starliner has modified over time. The unique lineup was to incorporate astronauts Nicole Mann and Eric Boe. Mann finally flew aboard SpaceX’s Crew Dragon on the Crew-5 mission in October 2022. Boe was discovered unable to fly resulting from a medical situation. He’s at present the chief of the Car Integration Take a look at Workplace at NASA’s Johnson House Heart, working intently with each Crew Dragon and Starliner crewmembers.
Spacecraft Commander Barry “Butch” Wilmore is making his third spaceflight. Chosen as an astronaut in 2000, Wilmore has greater than 8,000 flight hours in tactical jet plane. A graduate of the US Naval Take a look at Pilot Faculty, he accomplished 663 service landings, flying 21 fight missions throughout Operation Desert Storm.
Wilmore’s first flight was aboard House Shuttle Atlantis on the STS-129 mission in 2009. The ten-day mission to the ISS delivered two Specific Logistics Provider racks plus round 30,000 kilos of spare components to assist with Station orientation.
Barry “Butch” Wilmore and Sunita “Suni” Williams arrive on the Kennedy House Heart forward of the Boeing CFT mission. (Credit score: Max Evans for NSF)
His second flight noticed him spending 167 days aboard the Station as a member of the Expedition 41/42 crew, launching on Soyuz TMA-14M in September 2014 alongside two cosmonauts. Over the course of his missions, Wilmore additionally logged greater than 25 hours of spacewalking time throughout 4 EVAs.
Additionally getting her begin within the Navy, Sunita “Suni” Williams flew H-46 helicopters and noticed abroad deployments to the Mediterranean, Pink Sea, and the Persian Gulf throughout Operation Desert Defend. She later joined the US Naval Take a look at Pilot Faculty in 1993.
5 years later, Williams was chosen as a NASA astronaut. Her profession with NASA truly started in Russia working with Roscosmos to help Expedition 1, the primary long-duration mission aboard the ISS. Williams then performed science underwater throughout NEEMO2, happening in an underwater science laboratory, for 5 days.
Her first spaceflight project was as a member of Expedition 14/15. Initially launching aboard Discovery on the STS-116 mission in 2006, she remained for 192 days. Throughout the keep, she accomplished 4 spacewalks. She landed again on Earth aboard Atlantis on STS-117 in June 2007.
Williams returned to the ISS for Expedition 32/33, launching aboard Soyuz TMA-05M in July 2012. In addition to taking up as ISS Commander for Expedition 33, she additionally turned the primary particular person to finish a triathlon in area. Â Rather than the swimming portion, Williams used a resistive train machine to do weightlifting and resistance workout routines that approximate swimming in microgravity. The station already has a treadmill and recumbent bicycle to finish the complete triathlon.
Throughout her four-month keep, she accomplished a further three spacewalks, bringing her whole EVA time to 50 hours and 40 minutes, a file on the time.
Williams landed in November 2012, marking the top of a 127-day mission. She at present has a complete of 321 days mixed in area.
The spacecraft
The Crew House Transport 100 (CST-100) capsule flying this mission is known as Calypso. Chosen by astronaut Suni Williams, it was named after Jacques Cousteau’s oceanography vessel, RV Calypso, and thus far, is the one Starliner capsule to obtain a reputation.
Boeing’s Starliner capsule named Calypso is moved to SLC-41 for the Boeing CFT flight. (Credit score: Max Evans for NSF)
Altogether, the automobile consists of a capsule and a service module. The capsule measures 4.5 meters (15 toes) in diameter, which is barely bigger than an Apollo capsule but smaller than the Orion capsule which NASA is utilizing as a part of the Artemis program. The capsule can carry a most of seven individuals into orbit. Whereas this flight solely has a crew of two, the plan is to launch operational missions with a crew of 4, with an non-obligatory fifth seat. Starliner is able to staying in orbit, in response to Boeing, for seven months.
Mixed with the service module, Starliner stands 5 meters (16.5 toes) tall. The service module, which stays connected to the capsule till simply previous to reentry, incorporates 4 launch abort engines designed by Aerojet Rocketdyne. These are supposed to pull the spacecraft away within the occasion of an on-pad or in-flight downside.
The service module can be geared up with 28 response management system (RCS) engines for on-orbit maneuvering. These are along with 20 orbital maneuvering and angle management (OMAC) engines used to maneuver and separate the capsule. The photo voltaic panels for Starliner are additionally positioned on the aft aspect of the service module.
The capsule is moreover geared up with 12 RCS thrusters of its personal.
When it comes time for reentry, the bottom warmth defend, fabricated from Boeing Light-weight Ablator, takes on the warmth of reentry. The warmth defend is a honeycomb-like construction that’s hand-filled with the ablator. In areas that obtain much less warmth, the capsule is roofed with a mixture of thermal blankets and warmth defend tiles, each of which have House Shuttle heritage.
As soon as by way of the thicker a part of the environment, the warmth shields are jettisoned, the parachutes deploy, and the airbags inflate to cushion the desert touchdown.
The launch automobile
The Starliner automobile and crew launched aboard ULA’s workhorse Atlas V rocket. Though Atlas V itself has not launched crew, early Atlas rockets flew the primary American astronauts into orbit. Initially starting improvement as a long-range ballistic missile launch automobile for the Military Air Drive in 1946, it was later tailored to fly Mercury missions. That included John Glenn’s Friendship 7 in 1962, marking the primary time an American astronaut orbited the Earth. Atlas additionally noticed later use within the launching of Agena goal automobiles for the Gemini program.
Starliner OFT-1 mission launches on Atlas V. (Credit score: Mike Deep for NSF)
Whereas nonetheless Atlas by title, the automobile launching Starliner has superior fairly dramatically. This specific Atlas, the one hundredth Atlas V, flew in what is called the N22 configuration. The Atlas V has its customary RD-180 engine, which incorporates two thrust chambers, serving to to raise the automobile off the pad. Atop the automobile was the capsule, which isn’t enclosed within a payload fairing, as denoted by the “N.” Two strap-on stable rocket boosters, manufactured by Aerojet Rocketdyne, present a further 1.55 meganewtons (348,500 kilos) of thrust. That is marked by the primary “2” within the configuration.
The second “2” represents the variety of second-stage RL-10A-4-2 engines. The pair energy the 12.6-meter-long (41.5 foot) Centaur higher stage. The Centaur is a cryogenic automobile, fueled by liquid hydrogen, completely different than the kerosene-based rocket propellant 1 (RP-1) used within the first stage.
Included for the Starliner flights is the Centaur Ahead Adapter (CFA) in addition to the automobile’s Emergency Detection System (EDS). The CFA supplies electrical interfaces with the spacecraft amongst different duties. The EDS screens for any indication {that a} failure is imminent. Because of this, that is additionally chargeable for the jettison of the ascent cowl and initiates Starliner spacecraft separation.
Zip line to lifeline: @ULALaunch + #Starliner emergency egress system covers 1,300+ toes, reaches 40 mph in 30 seconds #SS33 #BoeingSpace pic.twitter.com/7NxTfNrA9v
— Boeing Protection (@BoeingDefense) April 2, 2017
The launch pad can be geared up with an Emergency Egress System (EES). Located on degree 12 of the Crew Entry Tower (CAT), the identical degree the place the crew enters Starliner, it consists of zipline-style wires and a harness for crew and pad workforce members to make use of in case of an emergency.
Every harness consists of handles that permit the particular person to manage their velocity, together with coming to a clean cease on the finish. Within the occasion the crewmember forgets to brake, 30 toes of springs assist sluggish the particular person to the touch down within the touchdown zone. The system is able to supporting as much as 20 personnel.
Launch Profile
Ambient temperature RP-1 gasoline was loaded onto the launch automobile two days earlier than scheduled liftoff. Loading of cryogenic propellants for the automobile, together with liquid oxygen for each phases and liquid hydrogen for the Centaur , begins six hours earlier than the scheduled liftoff time and takes one hour and 55 minutes to finish. Only one minute after the automobile is loaded with propellant, at L-4 hours 4 minutes, the countdown enters a maintain. Whereas referred to as the T-4 minute maintain, it stops the T- clock for 4 hours. Throughout that point, the L- clock repeatedly counts all the way down to liftoff.
About three hours earlier than launch, the crew departed the Neil A. Armstrong Operations and Checkout Facility, earlier than being pushed to SLC-41. The 2 astronauts rode an elevator as much as degree 12 of the CAT. The astronauts then walked throughout the Crew Entry Arm (CAA) and thru the white room to be strapped inside Calypso.
Hatch closure happened round one hour and 25 minutes earlier than launch, adopted ten minutes later by prelaunch cabin leak checks. The cabin pressurization was accomplished earlier than the L-1 hour mark.
The nominal flight profile for the Boeing CFT launch aboard Atlas V N22. (Credit score: ULA)
At L-20 minutes, the launch conductor begins the terminal rely briefing, adopted two minutes later by the ballot for Starliner to enter its terminal rely. At L-Quarter-hour, CST-100 switched to inside energy.
The CAA retracts at L-10 minutes leaving one last go/no-go ballot. At L-8 minutes, the Atlas V workforce conducts its readiness ballot to proceed with the terminal rely. Assuming all groups are go, Starliner is configured for the terminal rely at L-4 minutes 45 seconds.
At 4 minutes to launch, the T- clock resumes, which means that the T- and L- clocks are synchronized.
At T-1 minute, Starliner is formally configured for launch.
At T-2.7 seconds, the RD-180 engine ignites, adopted by the ignition of the SRBs, with liftoff anticipated at T+1.1 seconds.
The automobile then started its pitch/yaw maneuver to put it on a trajectory to rendezvous with the ISS. The automobile is predicted to achieve max Q at T+1 minute 1 second, passing the velocity of sound 4 seconds later.
At two minutes 20 seconds into flight, the 2 SRBs jettisoned, leaving the RD-180 to fireside by itself for an additional two minutes and eight seconds.
Then comes just a few occasions in speedy succession. Booster engine cutoff (BECO) happens 4 minutes 28 seconds after launch. Six seconds later, the Atlas booster separates from the Centaur higher stage. The ascent cowl is jettisoned six seconds after that, adopted by Centaur’s first principal engine begin (MES-1) at T+4 minutes 44 seconds.
Try the mission profile video to find out how ULA’s #AtlasV rocket will launch @BoeingSpace‘s #Starliner #CFT mission for @NASA‘s @Commercial_Crew Program. pic.twitter.com/NPYMgY5kdh
— ULA (@ulalaunch) Could 2, 2024
20 seconds after that, the aeroskirt is jettisoned. The RL-10A engines fired for the rest of the ascent, reaching principal engine cutoff (MECO) at T+11 minutes 52 seconds.
The Centaur with Starliner connected coasted for about three minutes, with Calypso and her crew let loose from the launch automobile at T+14 minutes 52 seconds.
The automobile was then launched on a suborbital trajectory of 157 by 62 kilometers (98 by 39 miles) inclined 51.6 levels to the equator. The capsule carried out its orbital insertion burn at 31 minutes into the flight.
Rendezvous and docking
As soon as in a steady orbit and heading in the right direction for the ISS, Starliner started its rendezvous process. In a check distinctive to the CFT, astronauts examined out the guide flight management system on the best way to the ISS, along with the automated programs already flown by the capsule on the 2 earlier Orbital Flight Take a look at missions.
Roughly two days after launch, the crew closed in on the station, performing two top adjustment and aircraft change maneuvers adopted by a coelliptic and aircraft change burn. Yet another burn positioned the spacecraft contained in the ISS strategy ellipsoid, an imaginary 4 by 2 by 2-kilometer (2.5 by 1.2 by 1.2-mile) ellipsoid, centered on the ISS heart of mass.
Starliner needed to pause 200 meters away from the station earlier than coming into what is called the “hold out sphere.” This imaginary sphere formally positioned the spacecraft inside the realm managed by Station flight controllers on the bottom.
Starliner previous to ISS docking on the OFT-2 flight. (Credit score: Bob Hines/NASA)
The capsule continued towards the Worldwide Docking Adapter positioned on the forward-facing port of the Concord module. The port was beforehand occupied by SpaceX’s Crew Dragon Endeavour, which delivered the Crew-8 astronauts to the ISS following a launch on March 3, 2024. That automobile was moved on Could 2 to Concord’s space-facing zenith port to make room for Starliner.
Calypso missed the primary docking window after troubleshooting points with response management thrusters on the service module. It stopped 10 meters from the docking goal awaiting one last go to proceed. As soon as given, the capsule autonomously docked to the station, with preliminary contact confirmed at 12:34 PM CDT. This marked the primary time a crewed Starliner capsule was connected to the ISS.
Undocking and touchdown
As soon as prepared and cleared to depart the ISS, Wilmore and Williams will enter the capsule and start the undocking course of. The capsule will carry out a fly-around maneuver, getting distinctive views of the ISS, earlier than exiting the strategy ellipsoid to start preparations for deorbit.
Whereas positioned over the Pacific Ocean, the service module will conduct the deorbit burn, slowing the automobile down sufficient to interface with Earth’s environment and start re-entry. Following the burn, the service module will detach and expend.
Drogue chutes deploy from a Starliner check article throughout a parachute reliability check. (Credit score: Boeing)
The crew module’s descent by way of the environment will see the outside attain temperatures of 1,650 levels Celsius (3,000 levels Fahrenheit). As soon as the automobile reaches 9 kilometers (30,000 toes) above the bottom, Starliner will jettison the ahead warmth defend which protects the parachutes throughout reentry.
First to deploy are two drogue chutes to start slowing the spacecraft down. As soon as these are jettisoned, the three principal orange and white parachutes will deploy and inflate, dramatically slowing the automobile down.
As soon as over its touchdown goal in White Sands, New Mexico, airbags will inflate 0.9 kilometers (3,000 toes) above the bottom, permitting them to cushion the crew for a softer touchdown as soon as they contact the bottom.
If all goes nicely, the primary operational mission to the ISS, Starliner-1, will launch on a six-month mission no sooner than 2025.
(Lead picture: The Atlas V with Starliner rolls out to the launch pad forward of the CFT mission. Credit score: Sawyer R for NSF)
