What Is NASA’s Commercial Crew Program?

The Nine-Year Gap

The End of the Shuttle Era

When the wheels of the Space Shuttle Atlantis came to a stop at NASA’s Kennedy Space Center on July 21, 2011, it marked the end of a thirty-year saga of American human spaceflight. The Space Shuttle program, a fleet of iconic winged orbiters, was a marvel of engineering. It had deployed satellites, repaired the Hubble Space Telescope, and, most importantly, served as the heavy-lift construction fleet that assembled the International Space Station (ISS) piece by piece. But the fleet was aging, and its operational costs were immense. Its retirement, a decision made years earlier, left the United States in a position it had not been in since the early 1960s: without any domestic ability to launch its own astronauts into space.

This void became known as “the spaceflight gap”. The International Space Station, a $100 billion orbital outpost built and largely funded by the United States, was now only accessible to American astronauts via one route: by purchasing seats on the Russian Soyuz spacecraft.

A Fateful Decision: The Augustine Commission

The gap was not an unfortunate surprise; it was the known, calculated consequence of a major policy pivot. NASA’s original replacement for the Shuttle was the Constellation program, a massive, government-owned effort to build the Ares I rocket and the Orion capsule to service the ISS before heading back to the Moon. But by 2009, Constellation was in deep trouble.

That year, the White House established the Review of U.S. Human Space Flight Plans Committee, which became widely known as the Augustine Commission. Its final report was a bombshell. The committee concluded that the Constellation program was not viable under the existing budget. It was underfunded, behind schedule, and would likely not fly its first crew until 2016 at the earliest, with a return to the Moon financially out of reach.

The commission offered a radically different path forward. It recommended that NASA scrap its plan to build its own LEO rocket and instead turn over the “taxi service” to and from the International Space Station to the growing U.S. commercial space industry. This, the report argued, would be far more cost-effective. It would free NASA to focus its talent and treasure on a “heavy-lift capability to get beyond Earth orbit”.

This recommendation provided the political and technical justification for a complete reset. In 2010, the Constellation program was officially cancelled. NASA’s human spaceflight ambitions were split in two. The agency would focus its traditional development efforts on deep space exploration with the new Space Launch System (SLS) rocket and Orion capsule. For low-Earth orbit, it would become a customer, not an operator. This decision was the genesis of the Commercial Crew Program (CCP).

The program was born from a perfect storm of programmatic, financial, and strategic pressures. The first pressure was the technical and financial reality of the Space Shuttle’s retirement. The second was the programmatic collapse of its intended replacement, Constellation. The third, and most immediate, was the strategic and financial vulnerability of relying on a foreign partner for all crewed launches. The Augustine Commission’s report provided the policy “permission slip” to solve all three problems with a single, radical move: betting on the private sector.

The Soyuz Dependency

Between the final Shuttle flight in 2011 and the first Commercial Crew flight in 2020, every single American astronaut launched to space from the Baikonur Cosmodrome in Kazakhstan, strapped inside a Russian Soyuz capsule.

This arrangement was not just a matter of national pride; it was a significant financial and geopolitical liability. With NASA as a captive customer, the Russian space agency, Roscosmos, had total pricing power. The cost for a single round-trip seat escalated dramatically.

In the 2006-2008 timeframe, a seat on the Soyuz cost NASA a relatively reasonable $21 to $23 million. After the Shuttle’s retirement in 2011, the price immediately jumped, first to over $60 million, then to $70.7 million in 2013. By the end of the gap, the price had ballooned to over $86 million. For astronaut Kate Rubins’ flight in October 2020 – the last contracted seat before CCP became operational – NASA paid $90.3 million.

From 2011 to 2020, NASA spent nearly $4 billion just to buy seats from Russia. This dependency became a pressing national security issue, especially as geopolitical relations between the U.S. and Russia soured. The White House and NASA leadership began to frame the Commercial Crew Program as a top-priority, non-negotiable national need. As then-NASA Administrator Charlie Bolden said, the program was essential to “end the nation’s sole reliance on Russia”. The nine-year gap was not just an engineering problem; it was a strategic vulnerability that needed to be closed.

A New Model for Spaceflight

From Cost-Plus to Fixed-Price

The Commercial Crew Program was built on a contractual and financial foundation that was a stark departure from NASA’s 60-year history. For decades, the agency’s grandest projects – from the Apollo Moon landings to the Space Shuttle and the in-development Space Launch System (SLS) – were built using “cost-plus” contracts.

Under a traditional cost-plus-award-fee (CPAF) contract, NASA pays its prime contractor for all “allowable” costs incurred during development. This includes every engineer’s salary, every sheet of metal, every test, and every delay. On top of those reimbursed costs, NASA pays an additional fee or bonus. This model is useful for projects with many unknown scientific and technical challenges, as it places all the financial risk on NASA. If a project is delayed by years or runs into engineering hurdles, the costs simply escalate, and the taxpayer foots the bill. NASA Administrator Bill Nelson would later refer to the cost-plus model as a “plague” on the agency for its history of steep cost overruns and chronic schedule delays.

CCP flipped this model on its head. It was built on “firm-fixed-price” contracts. In this arrangement, NASA and the commercial company agree on a total, fixed price for the entire job. This price covers everything: designing, developing, testing, certifying, and flying a set number of missions. If the company’s development effort proves more difficult, takes longer, or costs more than anticipated, the company – not NASA – must absorb the loss. This simple change shifted the bulk of the financial risk from the government to the private partner.

Partnership and Milestone-Based Payments

This new model was structured as a true “public-private partnership”. NASA would not dictate how a company should build its spacecraft, a stark contrast to the thousands of detailed requirements it levied on the Space Shuttle. Instead, the agency set high-level safety and performance requirements. For example, the system must be able to safely ferry at least four astronauts to the ISS, stay docked for 180 days, and then return them safely to Earth.

The companies were then free to design, innovate, and manufacture their own systems in whatever way they deemed most efficient and cost-effective. The companies would own and operate their own hardware and infrastructure. NASA was essentially buying a ticket to ride, not the vehicle itself.

The payment structure was also new. Instead of monthly checks for expenses, NASA paid for performance. The total contract value was broken into a series of “milestones”. A company might have a milestone for a successful system design review, another for a pad abort test, and a major one for a successful uncrewed flight test. A company only received its payment after it successfully completed and verified the milestone. This “pay-for-performance” model incentivized tangible, verifiable progress and was a powerful motivator to stay on schedule. This approach was not brand new; it had been successfully pioneered by NASA’s Commercial Orbital Transportation Services (COTS) program, which had funded the development of commercial cargovehicles like SpaceX’s Dragon 1.

This fixed-price, milestone-based model was a high-stakes gamble for both sides. NASA had to be willing to give up direct, day-to-day control over design, a major cultural shift for an agency built on meticulous engineering oversight. The companies, in turn, had to be willing to take on immense financial risk. If their design failed or they missed a milestone, they wouldn’t get paid. If they ran over budget, they could lose hundreds of millions of their own dollars. This model forces efficiency and rewards innovation. This entire strategy hinged on one non-negotiable element: genuine competition. The model only works if NASA has multiple, viable options. This is why NASA, from the beginning, funded multiple companies through the development phases and ultimately selected two for the final flights, ensuring “dissimilar redundancy”. This redundancy was not just for crew safety but also for long-term cost control.

Legislating the Change

This new direction, championed by the Obama Administration, was cemented into law by the NASA Authorization Act of 2010. This legislation formally established the Commercial Crew Program, directing the agency to continue and expand the initial Commercial Crew Development (CCDev) activities. Those initial CCDev activities had begun with seed money from the American Recovery and Reinvestment Act. The law officially directed NASA to pursue this new public-private partnership model with the goal of achieving “safe, reliable, and cost-effective” access to the ISS.

NASA’s Evolving Role

In this new partnership, NASA’s role shifted from being a top-down manager to an expert partner and, ultimately, the certifier. This was not a hands-off approach. NASA engineers and technical specialists were “embedded” with the commercial companies, attending meetings, working alongside their teams, and providing access to NASA’s decades of human spaceflight expertise and resources.

This “insight” model allowed NASA to understand the company’s design and potential risks without “oversight,” which is the authority to dictate changes. This created what some participants called a “healthy tension” between the government’s rigorous, safety-first culture and the private sector’s focus on speed and cost.

NASA’s ultimate power was certification. Before the agency would put its astronauts on a commercial vehicle, that company had to prove, through a rigorous series of ground tests, flight tests, and data reviews, that its entire system – the rocket, the spacecraft, and the ground operations – met NASA’s stringent human-rating safety requirements.

The program’s execution reveals a clever “funnel” approach. The early development phases (CCDev1, CCDev2, and CCiCap) used Space Act Agreements (SAAs). These are flexible partnership agreements, good for co-funding development where the company also invests its own money. The final phase, CCtCap, was a formal Federal Acquisition Regulation (FAR) contract. This is a rigid procurement contract to buy a service. This two-step process allowed NASA to use flexible SAA “seed money” to nurture multiple ideas before committing to a formal, fixed-price FAR contract for the most mature systems.

The Competition Begins: From CCDev to CCiCap

Commercial Crew Development 1 (CCDev1)

The CCP’s competitive-funnel approach began in 2010. Using $50 million in stimulus funds from the American Recovery and Reinvestment Act, NASA awarded the first round of CCDev1 contracts. This phase was not about building a complete spacecraft. It was about investing “seed money” to mature key technologies and concepts that could one day lead to a crewed vehicle.

The awards were spread broadly to five companies to encourage a wide range of ideas:

• Sierra Nevada Corporation (SNC): Received $20 million, the largest award, for its Dream Chaser, a reusable, lifting-body “spaceplane” concept that looked like a miniature Space Shuttle.
• The Boeing Company: Received $18 million to advance its CST-100 spacecraft, a traditional capsule design.
• United Launch Alliance (ULA): Received $6.7 million to develop an emergency detection system for its existing Atlas V and Delta IV rockets, a key step in human-rating them.
• Blue Origin: Received $3.7 million to mature its “pusher” launch escape system (a safety system where abort engines push the capsule away) and a composite pressure vessel.
• Paragon Space Development Corp.: Received $1.4 million for an advanced, air-revitalization life support system.

Commercial Crew Development 2 (CCDev2)

The second round in 2011, CCDev2, was much larger, with $269.3 million in awards. This phase focused on maturing “end-to-end” crew transportation system designs. NASA’s goal was to have these systems available by the middle of the decade, a timeline that would prove optimistic.

The funding was concentrated on four main vehicle proposals:

• Boeing: Received $92.3 million to continue development of the CST-100 Starliner.
• Sierra Nevada Corporation: Received $80 million to continue work on the Dream Chaser, which was designed to launch on an Atlas V rocket and land on a conventional runway.
• SpaceX: Received $75 million to upgrade its existing Dragon cargo capsule into a crew-capable vehicle with an integrated launch abort system.
• Blue Origin: Received $22 million to further its biconic capsule design and test its BE-3 liquid-fueled engine.

Commercial Crew Integrated Capability (CCiCap)

This was the first major down-selection, announced in August 2012. This phase, valued at over $1.1 billion, was designed to fund the development of fully integrated crew transportation systems. The field of competitors narrowed. Blue Origin decided not to compete for this round, choosing instead to continue development using its own private investment.

NASA selected three companies for CCiCap:

• Boeing: Awarded $460 million for the CST-100 Starliner.
• SpaceX: Awarded $440 million for the Crew Dragon.
• Sierra Nevada Corporation: Awarded $212.5 million for the Dream Chaser.

Each company was given a demanding list of paid milestones to complete over the next 21 months, designed to prove its system was safe, mature, and on a credible path to certification. This phase was the final “audition” before NASA would select its final partners to actually fly astronauts.

Throughout these early phases, NASA was deliberately managing its risk by funding technically diverse concepts. In the CCiCap “finals,” it wasn’t betting on one horse; it had three very different ones. It had a traditional capsule from an aerospace giant (Boeing), a next-generation capsule from a “new space” disruptor (SpaceX), and a reusable, winged spaceplane (Sierra Nevada). This technical diversity was a hedge. If one design philosophy ran into an insurmountable engineering problem, an alternative might still succeed.

And Then There Were Two

In September 2014, after the CCiCap phase concluded, NASA announced its final, momentous decision. The agency awarded the Commercial Crew Transportation Capability (CCtCap) contracts, the largest and final awards meant to fund the completion, certification, and first operational missions to the ISS.

This was the end of the competition. Sierra Nevada’s Dream Chaser, despite its popular winged design and strong technical progress, was not selected.

The winners were:

• The Boeing Company: Awarded $4.2 billion to certify and fly its CST-100 Starliner.
• Space Exploration Technologies (SpaceX): Awarded $2.6 billion to certify and fly its Crew Dragon.

The contracts were structured to cover the final design, a pad abort test, an uncrewed flight test, a crewed flight test, and then a minimum of two – and up to six – operational post-certification missions to the ISS.

The Dream Chaser Protest

The decision was immediately and forcefully challenged. Sierra Nevada Corporation filed a formal legal protest with the U.S. Government Accountability Office (GAO). SNC alleged that NASA’s evaluation was “flawed”, arguing that its Dream Chaser proposal was a higher-rated, better-value solution. The protest automatically halted all work on the newly awarded contracts, threatening to delay the entire program.

In January 2015, the GAO issued its ruling, denying the protest and upholding NASA’s selection. The GAO’s report explained NASA’s rationale. While SNC’s proposal had strengths, NASA’s selection board had rated its technical design as the “lowest level of maturity” of the three contenders. NASA had determined that both Boeing’s and SpaceX’s proposals presented a more credible path to achieving certification by the 2017 target date. The GAO also found that NASA’s analysis of SpaceX’s much lower price was reasonable and realistic.

The most glaring detail of the CCtCap award was the $1.6 billion price difference. This reflects NASA betting on two very different development philosophies. SpaceX’s $2.6 billion bid was seen as a lower-cost option because it was building on its existing, COTS-funded Falcon 9 rocket and Dragon 1 (cargo) capsule. They were upgrading a known system. Boeing’s $4.2 billion bid was for a brand-new capsule and the complex, expensive, human-rating modifications for the Atlas V rocket. NASA’s selection statement praised Boeing’s “highly effective technical interchange”, suggesting the agency saw them as a mature, thorough, and traditional (and thus more expensive) partner. NASA was, in effect, buying one system based on a disruptive, iterative model (SpaceX) and one based on a traditional, “heritage” aerospace model (Boeing).

From Cargo to Crew

The SpaceX system centered on the Crew Dragon, also known as Dragon 2. This was a significant evolution from the Dragon 1 capsule that was already flying cargo missions to the ISS. The new design was a futuristic leap. It included seats for up to seven astronauts (though NASA missions would fly with four), a full life support system, a cockpit of sleek touch-screen displays, and new windows for the crew.

One of the biggest operational changes was its docking system. The Dragon 1 cargo craft had to be “berthed” – a slow, methodical process where astronauts on the space station used the 57-foot-long Canadarm2 robotic arm to grab the capsule and manually attach it to a port. The new Crew Dragon was designed to dock autonomously, flying itself directly to the port and latching on, a capability similar to the Soyuz and the Space Shuttle.

An Integrated “Pusher” Abort System

A revolutionary element of its design was the launch abort system. For 60 years, crewed capsules like Mercury, Apollo, and Soyuz had used a “tractor” tower. This was a large, solid-fuel rocket mounted on a truss above the capsule. In an emergency, this tower would fire and pull the crew to safety, after which the tower was jettisoned.

Crew Dragon used a “pusher” system. Eight powerful SuperDraco engines were integrated directly into the sidewall of the capsule itself. These engines use hypergolic propellants, which ignite instantly when they mix, providing immediate, powerful thrust. This system could fire at any moment – from the launch pad to orbit – to push the crew safely away from a failing rocket. This design meant the abort system was available for the entire ascent, a safety feature no “tractor” tower, which was typically jettisoned after the first few minutes of flight, could offer.

The spacecraft would be launched on SpaceX’s own rocket, the Falcon 9. Specifically, it would use the human-rated “Block 5” version, a two-stage rocket whose first stage was designed to be rapidly reusable. After launch, the first stage would land itself on an autonomous droneship in the ocean or on a landing pad at Cape Canaveral. This reusability was the cornerstone of SpaceX’s entire low-cost business model.

Demo-1: The First Flight

The first major test of the full, integrated system was Demonstration Mission-1 (Demo-1), an uncrewed flight to the ISS. On March 2, 2019, a Crew Dragon capsule lifted off from NASA’s historic Launch Complex 39A, the same pad used for the Apollo Moon missions and dozens of Space Shuttle flights. The mission was a comprehensive, end-to-end test of the vehicle’s avionics, propulsion, life support, and communications systems.

A little over 24 hours after launch, the capsule performed a flawless, first-ever autonomous docking with the International Space Station. This was a major milestone, proving the new docking and navigation systems worked perfectly.

“Ripley” and the Return

The capsule’s single “passenger” was an Anthropomorphic Test Device (ATD), a test dummy outfitted in SpaceX’s iconic white flight suit. The SpaceX team nicknamed it “Ripley,” a nod to the protagonist from the 1979 film Alien. Ripley was not just ballast; it was packed with sensors in its head, neck, and spine to capture data on the G-forces and environment that future astronauts would experience during the mission’s most dynamic phases.

After five days docked to the station, Crew Dragon undocked on March 8, 2019, and executed its deorbit burn. It blazed through the atmosphere, deployed its four main parachutes, and splashed down safely in the Atlantic Ocean. The Demo-1 mission was a complete and resounding success, providing NASA with a mountain of critical data needed for certification.

The Anomaly: A Fiery Setback

The triumph was short-lived. On April 20, 2019, the very same capsule that had successfully flown the Demo-1 mission was on a test stand at Cape Canaveral. It was being prepared for a static-fire test of its SuperDraco abort thrusters, a test needed to qualify them for the upcoming in-flight abort demonstration.

Moments before the planned ignition, an anomaly occurred, triggering a catastrophic explosion that completely destroyed the capsule. A plume of orange smoke, a telltale sign of burning hypergolic propellant, was seen for miles. No one was injured, but the accident was a major setback, destroying a flight-proven vehicle and casting doubt on the propulsion system’s design.

Finding the Fault

A joint NASA-SpaceX investigation dug into the telemetry. The problem, they found, was not the SuperDraco engine itself, which remained intact. The root cause was a subtle and dangerous chemical interaction. The investigation found that a leaking check valve had allowed liquid oxidizer (nitrogen tetroxide, or NTO) to seep into the high-pressure helium pressurization lines during ground processing.

During the test’s pressurization sequence, this “slug” of NTO was slammed at high speed and pressure into a titanium component in the helium line. The high-pressure NTO reacted violently with the titanium, causing it to ignite and leading to the explosion. SpaceX’s solution was a robust redesign of the propulsion system, replacing the problematic check valves with “burst discs,” a type of single-use, high-integrity seal that physically isolates the propellants and pressurant, eliminating the possibility of a similar leak.

This event was a perfect example of the SpaceX “test, fail, fix, fly” development philosophy. The explosion, while dramatic, occurred on a test stand, not with a crew on board. It revealed a deep and subtle design flaw – a chemical incompatibility under specific pressure and flow conditions – that could have been catastrophic. This event vindicated NASA’s “rigorous safety standards” and the necessity of thorough testing, while also validating SpaceX’s approach of finding and fixing failures rapidly.

The Final Test: In-Flight Abort

With the propulsion system redesigned and validated, SpaceX moved to its final major test: the In-Flight Abort Test (IFA). On January 19, 2020, a Falcon 9 rocket launched a Crew Dragon capsule from Kennedy Space Center. The mission’s goal was to prove the abort system worked under the most stressful conditions possible: “Max-Q,” the point of maximum aerodynamic pressure on the rocket.

At 1 minute and 26 seconds into the flight, with the rocket screaming skyward, the abort sequence was intentionally triggered. The eight SuperDraco engines fired with a combined 120,000 pounds of thrust, pushing the Crew Dragon away from the Falcon 9 with violent force. The now-uncontrolled rocket, as expected, broke apart under the intense aerodynamic forces. The capsule coasted to an apogee of 42 kilometers before jettisoning its trunk, deploying its parachutes, and splashing down safely in the Atlantic. The test was a complete success.

Demo-2: “Launch America”

With all developmental and test milestones finally complete, the stage was set for the first crewed flight, Demonstration Mission-2 (Demo-2). On May 30, 2020, NASA astronauts Bob Behnken and Doug Hurley – both veteran Space Shuttle pilots chosen for their extensive test-flight experience – strapped into a new Crew Dragon capsule. At 3:22 p.m. EDT, their Falcon 9 rocket thundered to life and lifted off from Launch Complex 39A.

It was a significantly historic moment. For the first time in 3,246 days – nearly nine years – American astronauts had launched into orbit from American soil on an American rocket. The mission, dubbed “Launch America,” was a massive morale boost for the agency and the nation, taking place during the global COVID-19 pandemic. Shortly after reaching orbit, the astronauts revived an old tradition from the Mercury and Gemini days, naming their capsule Endeavour in honor of the Space Shuttle they had both flown on their first spaceflights.

A New Era of Splashdowns

Endeavour performed a series of automated phasing burns, catching up to the ISS and docking autonomously about 19 hours after launch. Behnken and Hurley joined the Expedition 63 crew, spending 62 days on the station. They were not just passengers; they became full-fledged station crew members, conducting scientific experiments and maintenance. Notably, Behnken performed four spacewalks to upgrade the station’s external batteries.

On August 1, 2020, the duo boarded Endeavour and undocked. The following day, the capsule blazed through the atmosphere and splashed down in the Gulf of Mexico off the coast of Pensacola, Florida. A SpaceX recovery ship, GO Navigator, was quickly on the scene to hoist the capsule aboard with the crew still inside. It was the first-ever splashdown for a commercially built and operated crew spacecraft and the first water landing for NASA astronauts since the Apollo-Soyuz mission in 1975.

Certification

The flawless execution of Demo-2, from launch to recovery, was the final step. After months of meticulously reviewing all the data from the entire test campaign – from the abort tests to Demo-1 and Demo-2 – NASA officials formally certified the SpaceX Crew Dragon and Falcon 9 system for human spaceflight on November 10, 2020. This certification cleared the way for the first operational “post-certification mission,” Crew-1, to launch just days later. SpaceX had successfully and officially ended the nine-year gap.

The Starliner Struggle: Boeing’s Difficult Development

The CST-100 Starliner and Atlas V

Boeing’s path to the launch pad was longer and far more difficult. Its entry, the CST-100 Starliner, drew heavily on Boeing’s decades of experience as a prime NASA contractor for the Apollo, Space Shuttle, and ISS programs. The Starliner is a capsule designed to be reusable up to 10 times. It features an innovative “weldless” spun-metal structure to reduce mass and production time, along with modern, tablet-based crew interfaces.

Like Crew Dragon, Starliner uses a “pusher” abort system. Its four powerful launch abort engines are integrated into its expendable service module – the large cylindrical section that provides power and propulsion in orbit. A key design difference is its landing method. Instead of splashing down in the ocean, Starliner is designed to touch down on land in the American Southwest, cushioned by a set of large airbags.

Starliner’s launch vehicle is the United Launch Alliance (ULA) Atlas V, one of the most reliable rockets in the U.S. inventory. A new, human-rated variant, the “N22,” had to be created for the CCP. This version includes two solid rocket boosters and a unique, dual-engine Centaur upper stage. This dual-engine configuration was necessary to fly a flatter, lower-G trajectory, which would ensure the crew could safely abort at any point during the launch.

Pad Abort Test and a Parachute Failure

Boeing’s Pad Abort Test took place on November 4, 2019, at White Sands Missile Range in New Mexico. The uncrewed Starliner capsule’s four launch abort engines ignited, powerfully pushing the spacecraft off the test stand to an altitude of approximately 4,500 feet. The test appeared to go well until the parachute sequence.

Starliner is designed to land under three main parachutes. In the test, only two of them deployed. The capsule, by design, could land safely on just two, and it touched down on its airbags as planned. NASA and Boeing declared the test a success, as it met the minimum parameters for crew safety. The subsequent investigation found the failure was not a design flaw but a simple, costly human error in assembly: a “pin meant to connect the pilot chute to the main chute was not properly connected”.

OFT-1: The Failed Test Flight

On December 20, 2019, Boeing launched its uncrewed Orbital Flight Test (OFT-1). The Atlas V rocket performed perfectly, placing the Starliner on its intended suborbital trajectory. But just 31 minutes after launch, as the capsule was coasting on its own, a critical anomaly occurred.

The spacecraft’s Mission Elapsed Timer (MET) was wrong. The system had incorrectly polled the time from the Atlas V booster 11 hours before launch. As a result, the Starliner’s autonomous flight computer “believed” it was much later in the mission. It thought it had already completed the vital orbital insertion burn, so it never commanded the engines to fire.

The spacecraft began firing its smaller thrusters, trying to “correct” an attitude it thought was wrong, burning excessive fuel. On the ground, flight controllers saw what was happening but were delayed in sending commands by a separate, intermittent space-to-ground communications problem. By the time they could manually command the burn, Starliner had used so much propellant that it no longer had enough to reach the International Space Station. The primary mission objective was lost. Boeing controllers managed to get the vehicle into a stable, lower orbit and commanded it to return to Earth two days later, executing a successful landing at White Sands.

The “High-Visibility Close Call”

The mission timer failure was a public and embarrassing failure, but the post-flight investigation revealed something far worse. A joint NASA-Boeing team discovered a second, catastrophic software flaw that had been lurking in the code. This “valve-mapping error” was in the software that controlled the service module’s disposal sequence, just before re-entry.

If it had not been caught and patched while in orbit, this error would have caused thrusters to fire incorrectly. This could have sent the jettisoned service module crashing back into the crew module. Such a collision could have damaged the capsule’s heat shield, leading to the “Loss Of Vehicle” and any crew inside. This second, flight-critical error was only discovered because engineers, alerted by the first anomaly, ran an end-to-end simulation of the entire mission profile while the spacecraft was still in orbit. This full, integrated test had never been performed on the ground before the flight.

The Independent Review and the Valve Crisis

The joint investigation team identified an initial 61, and ultimately a total of 80, corrective actions that Boeing needed to implement. The findings pointed to “fundamental SE&I missteps” and systemic failures in Boeing’s software testing and verification process. NASA required a complete overhaul of the process, and Boeing announced it would re-fly the uncrewed test flight, OFT-2, at its own expense. This amounted to a write-off of hundreds of millions of dollars.

After implementing the extensive software fixes, Boeing prepared OFT-2 for an August 2021 launch. But during the countdown, on the launch pad, a new and completely different problem emerged. Thirteen of the 24 oxidizer valves in the service module’s propulsion system were “stuck” shut and would not open. The launch was scrubbed, and the rocket was rolled back.

The investigation found that moisture (likely humidity from the Florida air) had seeped into the valves and reacted with the nitrogen tetroxide oxidizer. This created nitric acid, which corroded the internal components and “fused” the valves shut. This was a new, deep-seated hardware problem that required another major redesign of the propulsion system and delayed the program for nearly a full year.

OFT-2: A Troubled Success

Boeing’s second attempt at an uncrewed flight test finally launched on May 19, 2022. This time, the software worked. Starliner successfully performed its orbital insertion burn and, after a tense, delayed docking to check out its systems, it successfully latched onto the ISS.

But the flight was not clean. During its orbital maneuvers, two of the spacecraft’s main Orbital Manevering and Attitude Control (OMAC) thrusters failed, shutting down prematurely. A backup thruster had to compensate. Despite the thruster issues, the mission met its primary objectives. Starliner spent five days docked to the station, and its capsule successfully undocked, re-entered, and landed at White Sands. NASA and Boeing reviewed the data and, despite the new thruster anomalies, deemed the flight successful enough to proceed to the final step: the Crew Flight Test (CFT).

Crew Flight Test: The 2024 Mission

After numerous additional delays to address the OFT-2 thruster issue and other hardware concerns, the first crewed Starliner mission, CFT, was ready. On June 5, 2024, NASA astronauts and veteran test pilots Butch Wilmore and Suni Williams launched from Cape Canaveral. The launch itself, which had been scrubbed days earlier for an Atlas V valve issue and a ground computer failure, was successful.

Leaks and Lost Thrusters

As Starliner reached orbit, new, serious problems began to surface. A small helium leak in the propulsion system, which was known and “waived” for flight before launch, was suddenly joined by four new helium leaks. Helium is the pressurant gas used to push propellants into the thrusters; significant and multiple leaks threaten the propulsion system’s ability to operate.

Then, as the spacecraft made its final autonomous approach to the ISS, its thrusters began to fail. Five of the 28 Reaction Control System (RCS) thrusters went offline. The spacecraft’s computer automatically disabled them. Wilmore and Williams, both test pilots, were in a tense situation: they were “one additional failure away from losing six-degrees-of-freedom (6DOF) control”. Losing 6DOF control means being unable to steer, which would have forced an immediate, high-risk abort. Ground controllers instructed the crew to manually command resets, managing to recover four of the five failed thrusters and allowing a tense, delayed docking.

Stranded at the Station

The astronauts’ planned eight-day mission was extended. And then extended again. Weeks turned into months. Engineers on Earth were scrambling to understand what had gone wrong with the propulsion system. Analysis revealed the thruster failures were likely caused by overheating of internal Teflon seals. The repeated firing commands during the approach caused the seals to deform, restricting propellant flow. The helium leaks, while slow, were persistent and their cause was not fully understood.

The Unprecedented Decision

On August 24, 2024, after more than two months of docked investigations, NASA made an unprecedented and stunning announcement: Starliner was not safe to return its crew. The agency and its independent engineers could not achieve “expert concurrence” that the compromised propulsion system could be trusted to perform the critical, non-stop deorbit burn required for a safe re-entry.

The risk was too high. Wilmore and Williams, now effectively “stranded” 250 miles above Earth, would be integrated into the space station’s Expedition crew. Their new ride home would arrive months later: a SpaceX Crew Dragon.

The Autonomous Return

On September 6, 2024, three months after it arrived, the Starliner Calypso capsule undocked from the ISS – empty. It flew autonomously back to Earth, successfully landing at White Sands Space Harbor. The Crew Flight Test was officially over. It had successfully launched a crew, but it had failed to prove it could safely bring them home.

The Starliner development story is not one of a single, unlucky flaw. It’s a cascade of different, deep-seated failures at every phase. First, a human assembly error with the parachute. Second, a systemic software verification failure in OFT-1. Third, a hardware design and corrosion flaw with the valves. Fourth, an integrated thermal-propulsion failure with the thrusters on CFT. This pattern, warned about by NASA’s safety panels, points to a fundamental breakdown in Boeing’s systems engineering, quality control, and testing discipline.

This entire debacle was the ultimate vindication of the CCP programmatic strategy. The very reason NASA funded two competing companies was for “dissimilar redundancy”. The CFT failure was the exact nightmare scenario this policy was designed to mitigate. Because the SpaceX system was operational, NASA had a “lifeboat”. Without Crew Dragon, NASA would have faced an impossible choice: risk the lives of its astronauts on a compromised vehicle or negotiate an emergency, politically fraught Soyuz return. The CCP model, despite the failure of one of its providers, had worked.

The Commercial Crew Fleet in Operation

The SpaceX “Workhorse”

With its certification in November 2020, SpaceX’s Crew Dragon became the “workhorse” for crew transportation to the ISS. The first operational mission, SpaceX Crew-1, launched just days after certification, on November 16, 2020. It carried a four-person international crew – NASA’s Michael Hopkins (Commander), Victor Glover, and Shannon Walker, and JAXA’s Soichi Noguchi – for a 167-day mission.

This mission set the pattern for the program: regular, six-month crew rotation flights that would allow NASA to keep the ISS fully staffed at all times. SpaceX has since flown a steady cadence of these missions for NASA, each carrying a crew of four.

Operational Missions: A New Cadence

• SpaceX Crew-2 (April – Nov 2021): Carried NASA’s Shane Kimbrough (Commander) and Megan McArthur, JAXA’s Akihiko H_oshide, and ESA’s Thomas Pesquet. This was the first mission to fly with two international partners.
• SpaceX Crew-3 (Nov 2021 – May 2022): Carried NASA’s Raja Chari (Commander), Tom Marshburn, and Kayla Barron, and ESA’s Matthias Maurer.
• SpaceX Crew-4 (April – Oct 2022): Carried NASA’s Kjell Lindgren (Commander), Bob Hines, and Jessica Watkins, and ESA’s Samantha Cristoforetti.
• SpaceX Crew-5 (Oct 2022 – Mar 2023): This was a landmark flight, as it was the first mission under a new “seat-swap” agreement with Roscosmos, designed to ensure mixed crews on both Soyuz and Dragon. It carried NASA’s Nicole Mann (Commander) and Josh Cassada, JAXA’s Koichi Wakata, and Russian cosmonaut Anna Kikina.
• SpaceX Crew-6 (Mar 2023 – Sep 2023): Carried NASA’s Stephen Bowen (Commander) and Warren Hoburg, UAE’s Sultan Al Neyadi, and Roscosmos’s Andrey Fedyaev.
• SpaceX Crew-7 (Aug 2023 – Mar 2024): A highly international crew, commanded by NASA’s Jasmin Moghbeli and including ESA’s Andreas Mogensen, JAXA’s Satoshi Furukawa, and Roscosmos’s Konstantin Borisov.
• SpaceX Crew-8 (Mar 2024 – Oct 2024): This crew’s mission was extended to a record-breaking 235 days to accommodate the Starliner CFT crisis. The crew included NASA’s Matthew Dominick (Commander), Michael Barratt, and Jeanette Epps, and Roscosmos’s Alexander Grebenkin.
• SpaceX Crew-9 (Sep 2024 – Mar 2025): This was the “rescue” mission for the Starliner crew. It launched with only two crew members, NASA’s Nick Hague (Commander) and Roscosmos’s Aleksandr Gorbunov, leaving two seats empty. It returned to Earth with four: Hague, Gorbunov, and the stranded CFT astronauts, Butch Wilmore and Suni Williams.
• SpaceX Crew-10 (Launched Mar 2025): The current crew rotation on the ISS, carrying NASA’s Anne McClain (Commander) and Nichole Ayers, JAXA’s Takuya Onishi, and Roscosmos’s Kirill Peskov.

To ensure the ISS remains staffed through its 2030 retirement, NASA has extended SpaceX’s contract, which now includes a total of 14 operational missions.

The CCP was created to end U.S. dependency on Russia. But its operational success with Crew Dragon led to a new, more stable relationship. The “seat-swap” agreement, which began with Crew-5, ensures that at least one U.S. astronaut flies on every Soyuz and one cosmonaut flies on every Dragon. This isn’t about dependency; it’s about interdependency. It ensures that both nations can operate their respective segments of the ISS and provides a “lifeboat” for both sides, insulating the partnership from the grounding of any single vehicle – a policy that was proven essential by the Starliner failure.

A New Capability, A New Market

The certification of the SpaceX Crew Dragon did something NASA’s previous vehicles never could: it created a commercial market for human spaceflight. The Space Shuttle was government-owned and operated. But because the Crew Dragon is commercially owned and operated by SpaceX, the company is free to sell seats – or entire flights – to any private customer, completely separate from its NASA contract. This “private astronaut mission” (PAM) market exploded into existence almost immediately.

Inspiration4: The First All-Civilian Mission

The first-ever all-private, all-civilian orbital mission was Inspiration4, which launched on September 15, 2021. The mission was funded and commanded by billionaire entrepreneur Jared Isaacman, the founder of Shift4 Payments. He was joined by three other private citizens, selected to represent mission “pillars”: Hayley Arceneaux (Hope), Sian Proctor (Prosperity), and Christopher Sembroski (Generosity).

The crew did not go to the ISS. Instead, they spent three days in free-flight, orbiting the Earth in their Crew Dragon Resilience. For this mission, the capsule’s docking port was replaced with a massive, domed-glass “cupola,” providing 360-degree views. The mission orbited at an altitude of 585 km, higher than any human had flown since the final Shuttle mission to the Hubble Space Telescope in 1999. The flight also served as a massive fundraiser for St. Jude Children’s Research Hospital, raising over $240 million.

Axiom Space: The Private ISS Broker

While Inspiration4 focused on free-flight, a new company, Axiom Space, built a business model around brokering private trips to the ISS. Axiom buys a full Falcon 9 launch and Crew Dragon capsule from SpaceX, then sells the seats to a mix of wealthy tourists, philanthropists, and national space agencies that don’t have their own launch capability.

• Axiom Mission 1 (Ax-1): Launched in April 2022, this was the first all-private crew to ever visit the space station. The 17-day mission was commanded by a former NASA astronaut hired by Axiom, Michael López-Alegría, who escorted three paying customers: Larry Connor (U.S.), Eytan Stibbe (Israel), and Mark Pathy (Canada).
• Axiom Mission 2 (Ax-2): Launched in May 2023, this mission was commanded by former NASA astronaut Peggy Whitson, Axiom’s Director of Human Spaceflight. It flew two mission specialists from Saudi Arabia – Ali AlQarni and Rayyanah Barnawi, who became the first Saudi woman in space.
• Axiom Mission 3 (Ax-3): Launched in January 2024, this was billed as the “first all-European” commercial mission. Its crew was composed of national astronauts from Turkey (Alper Gezeravcı), Italy (Walter Villadei), and Sweden (Marcus Wandt), all flying to the ISS for the first time.
• Axiom Mission 4 (Ax-4): Launched in June 2025, this mission continued the trend, flying national astronauts from India (Shubhanshu Shukla), Poland (Sławosz Uznański-Wiśniewski), and Hungary (Tibor Kapu).

These Axiom missions demonstrate how the Commercial Crew Program inadvertently created a new arm of U.S. foreign policy. Nations like Saudi Arabia, Turkey, India, and Poland are now customers of a U.S. company to fly their astronauts. This gives them access to space and membership in the “space-faring” club without needing to build their own rockets or rely on Russia or China. This, in turn, binds their national space programs to the U.S. commercial ecosystem.

Polaris Dawn: Pushing the Envelope

Jared Isaacman, who funded Inspiration4, created a follow-on “Polaris Program” to push the boundaries of what commercial spaceflight could do. The first mission, Polaris Dawn, launched on September 10, 2024.

This mission had two groundbreaking objectives. First, it flew to a record-breaking apogee of 1,408.1 km (870 miles), intentionally flying the crew through portions of the Van Allen radiation belt to study the health effects. Second, the mission conducted the first-ever commercial spacewalk. The crew, wearing new EVA suits designed by SpaceX, depressurized their capsule, opened the forward hatch, and two crew members stood in the open hatch, exposed to the vacuum of space. The mission also tested Starlink laser-based communications, providing valuable data for future deep space missions.

This mission shows that the unlocked private market is now creating demand for new capabilities that go beyond NASA’s original requirements. NASA’s CCP contract certified Crew Dragon for a specific, conservative mission: a 400-km flight to the ISS. The private Polaris Dawn mission took that same vehicle and flew it to 1,400 km, tested brand new EVA suits, and conducted the first commercial spacewalk. SpaceX is no longer innovating just for NASA; it’s innovating for a new, private market.

Summary

Assessing the New Model: A Tale of Two Companies

The Commercial Crew Program’s fixed-price, milestone-based model has been both a spectacular success and a objectiveing cautionary tale. It was a test of two companies, and the results could not be more different.

For SpaceX, the model worked exactly as intended. NASA’s $2.6 billion investment, combined with hundreds of millions of SpaceX’s own funds, produced a highly reliable, reusable, and low-cost transportation system. A 2019 NASA Office of Inspector General (OIG) report estimated the average cost-per-seat on the first six Crew Dragon missions at approximately $55 million. Even with later contract extensions, the price has remained highly competitive, rising to around $72 million per seat. This is well below the final $86M-$90M cost of a Soyuz seat.

For Boeing, the model exposed deep-seated, systemic failures. NASA’s $4.2 billion award was $1.6 billion larger than SpaceX’s from the start. Furthermore, the OIG reported in 2019 that NASA had paid Boeing an additional $287.2 million outside the fixed-price contract to “mitigate a perceived 18-month gap in ISS flights” and ensure Boeing remained a second provider. This payment undermined the “fixed-price” principle. The OIG estimated Boeing’s per-seat cost at approximately $90 million. Because of the massive delays and the two required re-flights (OFT-2 and potentially a second CFT), Boeing has been forced to take on enormous financial losses, with total write-offs for the program now exceeding $2 billion.

The Geopolitical and Scientific Dividends

Despite the failure of one provider, the program as a whole has been a strategic success. Its primary goal was met: the United States has independent, reliable access to the International Space Station. The vulnerable, sole reliance on Russia is over.

The program also triggered a renaissance in ISS research. The new commercial vehicles are designed to carry four astronauts, allowing the standard ISS crew size to increase from six to seven. This one extra person, no longer needing to spend most of their time on station maintenance, nearly doubled the amount of crew time available for science – from ~35 hours a week to ~70. The operational missions are now packed with experiments in medicine, biology, and materials science, directly benefiting life on Earth.

The Future of Starliner

As of 2025, the future of Boeing’s Starliner is in serious jeopardy. The spacecraft is uncertified. NASA and Boeing are conducting extensive ground tests at White Sands to replicate and fix the thruster and helium leak issues, a process expected to last well into 2025.

Boeing’s next flight, now delayed until early 2026 at the soonest, may be an uncrewed cargo mission, not a crewed certification flight. With the ISS scheduled to be deorbited in 2030, there is a real possibility that Starliner will only fly a few, if any, of its six contracted missions. The staggering financial losses have led to reports that Boeing is exploring a sale of its space division.

The CCP Legacy

The true legacy of the Commercial Crew Program is not just a spacecraft; it’s the creation of a market and a new template for exploration. The fixed-price, pay-for-performance model is now NASA’s default for its most ambitious future programs.

• Artemis: The Human Landing System (HLS) program, which will land astronauts on the Moon, is not building a government-owned lander. It is using a CCP-style fixed-price contract to buy a “landing service” from SpaceX’s Starship and Blue Origin’s Blue Moon lander.
• Post-ISS Future: NASA is not planning to build a “Space Station 2.” Instead, it is actively funding private companies – like Axiom Space, Blue Origin, Sierra Space, and Vast – through its Commercial LEO Destinations (CLD) program to build their own private space stations. The goal is for NASA to be just one of many customers renting lab space on these commercial platforms after the ISS is retired. Even the Dream Chaser, which lost the crew competition, was later awarded a NASA cargo contract and is being developed as a key component of Blue Origin’s “Orbital Reef” station concept.

The CCP’s final lesson is that “fixed-price” contracts are not a magic bullet. They are a tool. They are a powerful mirror that, rather than hiding a contractor’s problems under cost overruns, exposes them. For a company like SpaceX, with a culture of rapid, iterative innovation, the model was an accelerant. For a company like Boeing, struggling with systemic process and quality issues, the same model became a financial anchor. The program successfully transformed NASA from being the sole architect of human spaceflight into the anchor tenant of a new, competitive, and expanding American space economy.