A History of Steerable Parachutes in Space Exploration

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From Kites to Capsules

The final few minutes of any space mission are among the most perilous. Returning from the vacuum of space, a spacecraft carries an immense amount of kinetic energy, a consequence of traveling at speeds of 17,500 miles per hour or more. The Earth’s atmosphere, a life-giving blanket for the planet, becomes a formidable barrier, a wall of air that must be used to scrub off this tremendous velocity. For decades, the primary tool for this task has been the parachute, a simple and ancient concept of using fabric to create drag. From the earliest days of human spaceflight, capsules have descended beneath billowing canopies, their fiery reentry culminating in a splashdown in the ocean or a cushioned landing on land.

This method, while proven, has always been a compromise. A spacecraft under a traditional parachute is largely at the mercy of the winds, a ballistic object with a controlled rate of descent but very little control over its destination. It requires vast, empty recovery zones – either the open ocean or the remote steppes of Kazakhstan – and extensive recovery forces to retrieve the crew and their vehicle. From the very beginning of the Space Race, engineers dreamed of something better. They envisioned a spacecraft that could end its journey not with a plummet, but with a glide; a vehicle that could be steered through the atmosphere to a precise, gentle landing on a runway, just like an airplane.

This ambition to transform a falling capsule into a gliding aircraft sparked a decades-long quest for a steerable decelerator. The story of this quest is defined by two parallel and occasionally intersecting technological paths, each born from the mind of a visionary inventor. The first was the elegant and deceptively simple “flexible wing” conceived by NASA engineer Francis Rogallo. Born from a backyard hobby of kite-flying, his invention captivated the imagination of early space planners and came tantalizingly close to giving the Gemini spacecraft wings. The second was the more complex but aerodynamically superior “ram-air parafoil” created by Domina Jalbert. This invention, a true wing made of fabric and air, would ultimately fulfill the promise of guided flight, evolving from a tool for precision military airdrops to a key technology for the recovery of next-generation space vehicles. Their stories chart the evolution of an idea, a journey marked by ambitious failures, quiet successes, and the persistent drive to master the final, critical moments of returning home from space.

The Dream of a Controllable Landing: Francis Rogallo’s Flexible Wing

The story of the first serious attempt to give a spacecraft wings begins not in a high-tech laboratory, but in the home of an aeronautical engineer with a passion for kites. It’s a story of how a simple, elegant idea, born from a hobby, nearly altered the course of the Space Race, promising a future of runway landings that NASA is only now beginning to realize. The journey of the Rogallo wing is a case study in visionary thinking, technological hurdles, and the immense pressures that shaped the early days of space exploration.

A Backyard Invention

In the 1940s, Francis Rogallo was an engineer at the National Advisory Committee for Aeronautics (NACA), the predecessor to NASA. In his professional life, he worked in the agency’s wind tunnels, a world of rigid, precisely machined airfoils and powerful aircraft. But in his personal time, he and his wife, Gertrude, were avid kite-flyers. Their hobby led them to question a fundamental assumption of aeronautics: that a wing had to be stiff to generate lift. They observed how birds’ wings flexed and how sails billowed, and they began to imagine a lifting surface made not of metal and wood, but of flexible fabric.

This was a radical departure from conventional thinking. The prevailing wisdom held that a wing’s shape had to be fixed to create predictable aerodynamic forces. Rogallo’s idea was that the wing itself should conform to the flow of the wind, rather than forcing the wind to conform to a rigid structure. Working on their own time, without official backing from NACA, the Rogallos began experimenting. In their home, they constructed a small wind tunnel. Using simple materials, including fabric from Gertrude’s kitchen curtains, they built and tested a variety of small, flexible wing models.

By 1948, their persistence paid off. They had developed two working designs: a kite they called the “Flexi-Kite” and a gliding parachute they would later term a “paraglider.” The design was a V-shaped, self-inflating wing. Unlike a traditional parachute that primarily creates drag, this flexible wing was shaped to generate lift, allowing it to glide. When held into the wind, air pressure would inflate the fabric, giving it a stable airfoil shape without any internal spars or rigid members. The Rogallos received a patent for their “flexible square wing” in March 1951. To help finance their work and publicize the concept, they licensed the Flexi-Kite as a toy, and soon, their revolutionary design was being flown by children and hobbyists. But Francis Rogallo had a much grander vision. He dreamed of an aircraft so simple and inexpensive that anyone could own one, an aircraft you could fold up, put in the trunk of your car, and fly from the outskirts of town.

NASA Takes Notice

For nearly a decade, the flexible wing remained largely a curiosity, a successful toy and a novel concept in the world of kites. That all changed on October 4, 1957, when the Soviet Union launched Sputnik 1. The beep-beep of the first artificial satellite ignited the Space Race and transformed the landscape of aerospace engineering. The newly formed National Aeronautics and Space Administration (NASA) was tasked with putting an American in space, and one of the most significant logistical challenges was figuring out how to get him back safely.

The default solution was the one that had been used for decades: a parachute descent culminating in a splashdown in the ocean. While reliable, this method was incredibly complex and expensive. It required the deployment of a massive naval fleet, including aircraft carriers and destroyers, to be stationed in the recovery zone. The prospect of landing a space capsule on a runway like a conventional aircraft was immensely appealing. It would simplify logistics, reduce costs, and represent a more advanced, elegant solution.

It was in this context that NASA’s engineers rediscovered Francis Rogallo’s invention. The flexible wing, which the agency renamed the “Parawing,” seemed to be the perfect answer. It was lightweight and could be packed into a small container within the spacecraft. After the capsule had endured the fiery heat of reentry and slowed to subsonic speeds, the Parawing could be deployed. It would inflate into a large, steerable wing, allowing the astronaut to glide their capsule for dozens of miles, select a landing site, and touch down on a designated runway. The potential was so great that the Rogallos released their patent to the government, allowing NASA to develop the technology without restriction.

NASA began to seriously study the Parawing as a recovery system. It was briefly considered as an alternative for Project Mercury, the first U.S. human spaceflight program, during a period of developmental issues with the capsule’s conventional parachutes. But its true promise seemed to lie with the next-generation program, Project Gemini. Gemini was designed to be a more advanced, two-person spacecraft capable of rendezvous, docking, and long-duration flight – all necessary precursors for a mission to the Moon. From the outset of the Gemini program in 1961, a controlled land landing was a primary goal, and the Rogallo Parawing was the initial choice to make it happen.

The Paresev Program: Learning to Fly a Kite

Before NASA could entrust the lives of its astronauts to a novel, inflatable wing attached to a multi-billion-dollar spacecraft, it needed to answer a fundamental question: how do you fly this thing? The Rogallo wing was unlike any conventional aircraft. It had no rigid control surfaces like ailerons or rudders. To understand its unique handling characteristics, NASA’s Flight Research Center (now Armstrong Flight Research Center) in the Mojave Desert initiated the Paraglider Research Vehicle, or Paresev, program.

Between 1962 and 1964, engineers at the center designed and built a series of simple, unpowered gliders. The Paresev was the very definition of a bare-bones aircraft. It consisted of a welded steel-tube frame that formed a basic fuselage, a single non-steerable nose wheel and two main landing gear wheels, and an open pilot’s seat. Suspended above this minimalist chassis was a Rogallo wing with a frame made of aluminum tubing and a sail made of linen or, later, more durable Dacron. There was no engine and no complex avionics. The first vehicle, Paresev 1, was rolled out on August 24, 1962, just seven weeks after the project was initiated.

Control was achieved through a simple and direct method: weight-shift. The pilot sat in a seat that was part of the hanging fuselage structure. A control stick extended down from the wing’s frame. By moving the stick forward and backward or side to side, the pilot would physically tilt the entire wing relative to the suspended fuselage. This shift in the center of gravity was enough to control the glider’s pitch and roll, allowing it to be steered during its descent.

The test protocol was straightforward. The Paresev would be towed into the air, either by a ground vehicle like a pickup truck speeding across the dry lakebed, or by a small tow plane like a Piper Super Cub. Once it reached an altitude between 5,000 and 12,000 feet, the tow line was released, and the pilot would glide the strange-looking craft back to a landing. Over the course of the program, the Paresev made nearly 350 flights. A cadre of legendary test pilots and astronauts got their turn at the controls, including future moonwalker Neil Armstrong, Mercury astronaut Gus Grissom, and famed NASA test pilot Milt Thompson. These flights were not always smooth; the vehicle had unusual handling qualities and could be difficult to control. But the program was a success. It proved that the Rogallo wing was fundamentally pilotable. The experience gained by the pilots and engineers in the desert was the necessary first step toward the dream of a gliding Gemini capsule.

An Ambitious Failure

While the Paresev program successfully demonstrated that a pilot could control a Rogallo wing in flight, translating that concept into a reliable, deployable system for the actual Gemini spacecraft proved to be a monumental challenge. The task of designing and building the full-scale system was contracted to North American Aviation, the same company behind the X-15 rocket plane. The theory was simple: the Parawing would be stowed in a container on the front of the capsule. After reentry, at an altitude of around 50,000 feet, it would deploy and inflate, turning the ballistic capsule into a glider.

In practice, the theory refused to work reliably. The primary technical hurdle was the wing itself. Engineers struggled to design and construct a full-scale inflatable wing that would deploy and inflate correctly every single time. The complex unfolding process, the stresses of inflation, and the aerodynamics of a large, flexible structure interacting with a heavy, blunt capsule created a host of problems that were difficult to solve. Failure to inflate properly was a persistent issue throughout the development program.

Beyond the deployment problems, the system had other significant drawbacks. The complete Parawing system, with its inflatable structure, gas canisters, and control mechanisms, weighed nearly 800 pounds more than a conventional parachute system. In the world of spaceflight, where every pound of payload requires a significant amount of extra fuel to launch, this was a massive penalty that deeply concerned mission planners.

Moreover, the very pilots and engineers at the Flight Research Center who had the most hands-on experience with the technology harbored serious doubts. While they had proven the Paresev could be flown, they were skeptical about the stability and controllability of the much larger and heavier Gemini-Parawing combination, especially during the violent and unpredictable deployment phase. Their concerns proved to be well-founded.

By early 1964, with the first Gemini flights looming and the Parawing program falling behind schedule, NASA faced a difficult choice. On February 20, 1964, NASA Associate Administrator George Mueller made the official decision to remove the paraglider from the operational Gemini program. The dream of a runway landing was put on hold. The program was downgraded to a technology demonstration, with North American continuing tests to gather data, but the ten manned Gemini missions would all end with a traditional parachute splashdown.

The test program that followed underscored the wisdom of this decision. In August 1964, test pilot Charles Hetzel, one of the veterans of the Paresev program, climbed into a full-scale Gemini boilerplate capsule for the first free-flight test. The capsule, with its wing already inflated, was lifted by a helicopter. Moments after Hetzel severed the towline to begin his glide, the entire vehicle entered a violent, uncontrollable spin. He was forced to eject and parachute to safety while the Gemini test article crashed into the desert floor. Although subsequent tests in late 1965, flown by pilot Donald McCusker, achieved a dozen successful, if rough, landings, this success came nearly two years too late to be incorporated into the Gemini program. The ambitious attempt to give the first maneuverable spacecraft wings had failed, not because the idea was wrong, but because the technology of the era was not yet capable of executing it with the flawless reliability that human spaceflight demands. NASA reverted to the proven, if less elegant, technology of round parachutes and water landings, a method that would see it through the rest of Gemini and all the way to the Moon with Apollo.

A New Shape for Flight: Domina Jalbert and the Ram-Air Parafoil

As NASA grappled with the complexities of the Rogallo wing in the early 1960s, a parallel evolution in flexible wing technology was taking place, driven by an inventor with a deep background in kites and aerostats. Domina Jalbert’s creation, the ram-air parafoil, represented a fundamentally different and ultimately more capable approach to generating lift from fabric. While the Rogallo wing was a single surface held in shape by tension, Jalbert’s invention was a true, double-surfaced wing inflated by air pressure. This design would solve many of the aerodynamic limitations that had hindered the Parawing and would eventually become the foundation for virtually all modern steerable parachutes and paragliders.

Beyond the Flexible Wing

Domina Jalbert was an innovator in the world of kites and balloons, known for creating the “kytoon,” a hybrid kite-balloon that combined aerodynamic lift with buoyant lift. His deep understanding of fabric structures and airflow led him to a novel concept for a gliding parachute. Instead of a single, V-shaped canopy like the Rogallo wing, Jalbert envisioned a rectangular wing constructed from a series of individual cells. Each cell would be made from two layers of fabric – an upper and a lower skin – connected by vertical fabric ribs. The front, or leading edge, of these cells would be open, while the back, or trailing edge, would be sewn shut.

He filed a patent for this “Multi-cell Wing Type Aerial Device” in 1964. The principle behind it was ingenious and is now known as “ram-air inflation.” As the wing moves forward through the air, air is “rammed” into the open leading edges of the cells. Because the trailing edge is closed, the air becomes trapped, pressurizing the cells. This internal pressure forces the fabric into a stable, semi-rigid airfoil shape, with a curved upper surface and a flatter lower surface, just like the wing of an airplane.

This was a significant leap beyond the Rogallo concept. The Rogallo wing generated lift as a tension structure, much like a kite, with its shape determined by the pull of the suspension lines and the pressure of the wind against its single surface. The parafoil, in contrast, formed a true, pressurized airfoil. This double-surfaced, inflated structure was far more aerodynamically efficient. It could generate significantly more lift for a given amount of drag, resulting in a much higher glide ratio. While a Rogallo wing could glide, a parafoil could soar. This superior performance gave it the ability to travel long horizontal distances and to be steered with a high degree of precision, capabilities that would make it invaluable for future applications.

Taming the Opening Shock

The very aerodynamic efficiency that made the parafoil such a powerful glider also presented its greatest challenge. Because it was so effective at capturing air, the inflation process could be incredibly rapid and violent. When deployed at high speed, a parafoil could snap open with such force that it generated an enormous “opening shock.” This sudden deceleration could place immense stress on the canopy fabric, the suspension lines, and the payload, sometimes leading to catastrophic failure. This characteristic initially prevented the parafoil from being widely adopted as a parachute, which must be able to deploy safely from a fast-moving aircraft or spacecraft.

The solution to this problem was a simple but brilliant innovation known as the “slider.” The slider is a small rectangle of fabric, typically nylon, with reinforced grommets or rings at its four corners. Before the parachute is packed, the suspension lines are threaded through these grommets. The slider is then pushed all the way up the lines so that it rests near the bottom of the parachute canopy.

When the parachute is deployed, the pilot chute pulls the canopy and its lines from the deployment bag. As the canopy begins to inflate, the slider, positioned at the mouth of the canopy, catches the air. The force of the airflow prevents the slider from moving down the suspension lines instantly. By constricting the opening of the canopy, it effectively chokes off the airflow into the cells, forcing the parachute to inflate slowly and progressively. As the canopy gradually fills with air and the forward speed of the system decreases, the air pressure on the slider lessens, allowing it to slide down the lines toward the parachutist or payload. This process allows the canopy to open in a controlled, staged manner over several seconds, dramatically reducing the peak forces of the opening shock.

The invention of the slider was the key that unlocked the parafoil’s full potential. It tamed the violent opening, making the high-performance wing safe and reliable to use as a parachute. This breakthrough transformed the parafoil from a niche concept into a revolutionary technology that would go on to redefine the sports of skydiving and paragliding and become the go-to solution for precision aerial delivery systems used by military and space agencies around the world.

From Unmanned Cargo to Crew Return: The Parafoil in Space Applications

With the opening shock tamed by the slider, the ram-air parafoil was ready for practical application. Its unique combination of high glide performance, steerability, and reliable deployment made it an ideal candidate for tasks that required more than just simple deceleration. The military and NASA quickly saw its potential for delivering cargo with pinpoint accuracy, and this application drove decades of development, culminating in the most ambitious parafoil system ever conceived: a steerable canopy the size of a Boeing 747’s wing, designed to serve as the landing system for a space station lifeboat.

Precision from the Sky

The first and most widespread application of parafoil technology was in autonomous aerial delivery. The ability to steer the canopy gave it a capability that traditional round parachutes could never match: precision. When paired with a Guidance, Navigation, and Control (GNC) system, a parafoil could transform a simple airdropped payload into a smart, guided vehicle.

The first autonomous flight tests of such systems were performed as early as 1966, shortly after Jalbert patented his invention. The concept was straightforward. The payload would be equipped with a GPS receiver to determine its position, a flight computer to calculate a path to a pre-programmed target, and an actuation system to control the parafoil. This control mechanism typically consists of a pair of electric winches or servos. By pulling on a control line attached to the trailing edge of one side of the canopy, the system could induce a turn. By pulling on both lines symmetrically, it could slow the parafoil’s forward speed or execute a “flare” maneuver just before landing. The flare dramatically increases both lift and drag for a short period, bleeding off speed for a gentle touchdown.

In the early 1990s, the U.S. Army and NASA began major programs to develop these guided parafoil systems. The technology matured rapidly, enabling the delivery of thousands of pounds of cargo from high altitudes to landing zones the size of a football field. This capability for the rapid and precise deployment of supplies to remote or inaccessible locations became a cornerstone of modern military logistics and demonstrated the parafoil’s robustness and reliability in demanding operational environments.

The X-38 and the Promise of a Space Station Lifeboat

The ultimate expression of the parafoil’s potential in space applications came in the 1990s with NASA’s X-38 program. The program’s objective was to develop a Crew Return Vehicle (CRV), a dedicated “lifeboat” for the International Space Station (ISS). In the event of a medical emergency, a fire, or other catastrophe that required the immediate evacuation of the station’s crew, the CRV would provide a means of safe return to Earth.

The X-38 vehicle was a lifting body, a wingless craft that generated aerodynamic lift from the shape of its fuselage. This allowed it to fly and maneuver during hypersonic reentry. a lifting body has a very high landing speed, requiring a long runway. To solve this problem, NASA turned to parafoil technology. For the final phase of its descent, from an altitude of about 15,000 feet, the X-38 was designed to deploy the largest parafoil ever constructed.

With a surface area of 7,500 square feet, the X-38’s parafoil was as large as the wing of a Boeing 747. This massive, steerable canopy would slow the 25,000-pound vehicle and allow its autonomous GNC system to guide it to a soft, precise landing on a conventional runway. The development program was extensive, involving over 300 drops with subscale parafoils and more than 30 drops with full-scale 5,500-square-foot and 7,500-square-foot canopies. These tests, conducted over the Mojave Desert, successfully demonstrated the feasibility of the concept. The autonomous system proved capable of steering the heavy test articles through complex maneuvers and bringing them to a gentle touchdown.

Although the X-38 program and the associated CRV were canceled in the early 2000s due to budget constraints, the project was a landmark achievement. It proved that large-scale parafoil systems were a viable and reliable technology for the recovery of heavy spacecraft. The lessons learned, the hardware developed, and the GNC software written during the X-38 program would provide a deep well of experience for future efforts in guided aerial delivery and vehicle recovery.

European Ambitions: Parafoils for Reusable Spaceplanes

The pioneering work done by NASA on large-scale parafoils did not go unnoticed by other space agencies. The European Space Agency (ESA) recognized the technology’s potential for enabling the land-landing of its own reusable space vehicles. To build confidence and expertise, ESA initiated the Parafoil Technology Demonstration (PTD) program. This effort involved a series of drop tests in Europe to study the performance of large canopies and to develop and validate GNC algorithms. The tests confirmed the parafoil’s excellent steerability and its ability to perform flare maneuvers to reduce landing shocks to less than 3.5 g.

This research has fed directly into one of ESA’s flagship future programs: Space Rider. Space Rider is an uncrewed, robotic spaceplane designed to be launched on a Vega-C rocket. It will operate as an orbital laboratory, carrying experiments for weeks or months before returning to Earth. Critically, the Space Rider is designed for reusability. After reentering the atmosphere as a lifting body, it will deploy a large parafoil to manage its final descent. The GNC system will then guide the vehicle to a gentle, horizontal landing on a runway, allowing for quick refurbishment and relaunch.

The adoption of parafoil technology for Space Rider highlights its essential role in the modern vision of reusable space infrastructure. Furthering this trend, NewSpace Systems, a UK-based company, is working under an ESA contract to develop its Glide2 system. This is a GPS-guided parafoil system specifically designed for the precision recovery of payloads and, significantly, reusable rocket boosters weighing up to 2,500 kg. This work demonstrates a clear trajectory: the parafoil, once a novel concept, has become a mature and indispensable tool for bringing valuable space assets safely and precisely back to Earth.

The Workhorses: Parachute Systems of the Manned Spaceflight Era

While NASA and other agencies explored the tantalizing prospect of steerable, gliding landings, the practical reality of human spaceflight demanded a different approach. After the ambitious Gemini Parawing program was canceled, the imperative shifted from precision to absolute, unquestionable reliability. For the next four decades, every American and Soviet/Russian crewed mission would rely on systems of conventional, unguided parachutes. These systems were not designed for pinpoint landings but for controlled, predictable deceleration. They were the robust, dependable workhorses of the Space Race, successfully bringing dozens of astronauts and cosmonauts home from orbit and the Moon.

Controlled Descent, Not Guided Flight

The landing systems for the Mercury, Gemini, and Apollo programs were all variations on a theme: a carefully sequenced deployment of parachutes designed to slow the capsule for a splashdown in the ocean. The Apollo Command Module, returning from the Moon at lunar-return velocities, employed the most sophisticated of these systems. The sequence began at an altitude of 24,000 feet with the jettison of the forward heat shield, which pulled out two 16.5-foot drogue parachutes. These drogues were essential for stabilizing the capsule and slowing it from supersonic speeds. At around 11,000 feet, the drogues were released, and three small pilot parachutes were deployed to pull out the three main parachutes.

The main parachutes were massive, 83.6-foot diameter “ringsail” canopies. The ringsail design, featuring concentric rings of fabric separated by open slots, is exceptionally stable and resistant to oscillations. The system was not steerable; the capsule’s landing point was determined by its reentry trajectory and the prevailing winds. it did provide a important form of orientation control. The parachutes were rigged to hold the conical Command Module at a specific 27.5-degree angle relative to the water’s surface. This ensured that the capsule’s slanted corner would strike the water first, maximizing the effectiveness of the impact attenuation and minimizing the forces on the crew. Redundancy was the cornerstone of the system’s safety philosophy. The capsule could land safely even if one of the three main parachutes failed to deploy, a design feature that was proven during the return of Apollo 15 when one main chute collapsed, resulting in a slightly faster but perfectly safe splashdown.

The Soviet Union’s Soyuz spacecraft, which has been in continuous service since the 1960s, was designed from the outset for land landings. Its recovery zone is the vast, flat, and sparsely populated steppes of Kazakhstan. The Soyuz landing sequence is similar in principle to Apollo’s. It involves a series of pilot and drogue parachutes to stabilize and slow the descent module, followed by the deployment of a single, large main parachute. Like its American counterparts, the Soyuz capsule’s descent under the main canopy is largely ballistic, meaning it drifts with the wind and targets a large, general landing area rather than a specific point.

The key difference in the Soyuz system is the final touchdown. Because a landing on hard ground is much less forgiving than a splashdown in water, the Soyuz incorporates an active landing attenuation system. A radar altimeter measures the capsule’s height above the ground, and at an altitude of just one meter, it triggers the firing of several solid-fuel retro-rockets embedded in the base of the heat shield. This last-second burst of thrust provides a final cushion, dramatically softening the impact. The system is robust, but the absolute necessity of parachute reliability was tragically underscored in 1967 during the Soyuz 1 mission. A failure of the main parachute to deploy, followed by the tangling of the reserve chute, led to the death of cosmonaut Vladimir Komarov, the first in-flight fatality in the history of spaceflight.

Recovering the Boosters: The Shuttle SRB System

The Space Shuttle program marked a new era in spaceflight, one focused on reusability. The most prominent reusable components were the two massive Solid Rocket Boosters (SRBs) that provided the majority of the thrust at liftoff. After burning out and separating from the external tank about two minutes into the flight, each 1.3-million-pound booster followed a ballistic arc to an apogee of around 220,000 feet before falling back to Earth. Recovering these immense structures for refurbishment and reuse required the largest parachute system ever deployed in an operational space program.

The SRB recovery system was housed in the forward section of the booster. The sequence began with the jettison of the nose cap, which deployed a pilot parachute. This, in turn, pulled out a large drogue parachute, which was essential for stabilizing the long, heavy cylinder as it tumbled back through the atmosphere and for slowing it from high speeds. At an altitude of about 6,000 feet, the frustum (the cone-shaped section below the nose cap) separated, pulling out the three main parachutes.

These main parachutes were colossal, each measuring 136 feet in diameter. The cluster of three canopies slowed the enormous booster to a survivable splashdown velocity of about 50 miles per hour in the Atlantic Ocean. Like the crewed capsule systems that preceded it, the SRB recovery system was entirely unguided. The parachutes were designed for pure deceleration, not steering. NASA calculated a large impact area, a box approximately 6 by 9 nautical miles, located about 140 miles downrange from the launch site. Two dedicated recovery ships, the Liberty Star and Freedom Star, would be stationed just outside this box, ready to steam in, retrieve the boosters, their frustums, and all 12 parachutes, and tow them back to port. This system, flown on every Shuttle mission, represents the pinnacle of large-scale, unguided decelerator technology, a purely utilitarian design driven by the economic imperative of hardware reuse.

The Modern Era: Commercial Crew and Artemis

The 21st century has brought a renaissance in human spaceflight, with a new generation of crewed spacecraft developed through partnerships between NASA and commercial companies, alongside NASA’s own deep-space exploration vehicle. These modern capsules – SpaceX’s Crew Dragon, Boeing’s CST-100 Starliner, and NASA’s Orion – have inherited the lessons learned from fifty years of spaceflight. Their landing systems reflect a fascinating divergence in design philosophy, blending heritage concepts with cutting-edge materials, advanced analytical techniques, and a renewed focus on crew safety and operational efficiency. While one returns to the proven method of ocean splashdown, another finally achieves the long-held dream of a terrestrial touchdown, and the third uses sophisticated atmospheric guidance to achieve unprecedented landing accuracy.

Splashdown Revisited: SpaceX’s Crew Dragon

With its Crew Dragon spacecraft, SpaceX chose to return to the landing method proven by the Mercury, Gemini, and Apollo programs: a parachute-assisted splashdown at sea. While the concept is heritage, the execution represents a significant technological evolution. The Crew Dragon’s landing system is a model of robust redundancy. After reentry, the spacecraft deploys two drogue parachutes to provide initial stabilization and deceleration. These are followed by four large main parachutes, one more than the three used by Apollo and Orion, providing an extra layer of safety.

A key area of innovation for Dragon has been in its materials and manufacturing. While early development parachutes used traditional materials, the operational versions incorporate advanced, high-strength textiles. The suspension lines, for instance, have been upgraded from nylon to Zylon, a specialized polymer with a superior strength-to-weight ratio. This allows for stronger, lighter parachutes. In a strategic move to gain greater control over quality and the pace of innovation, SpaceX acquired Pioneer Aerospace, a long-time parachute manufacturer, and brought the entire design and production process in-house. This vertical integration allows for rapid iteration and a deep understanding of every component in the system.

The system is designed to be highly fault-tolerant, capable of landing the crew safely even if one of the four main parachutes fails to deploy. Interestingly, SpaceX’s original vision for Crew Dragon was far more ambitious. The spacecraft was designed from the ground up to perform propulsive landings on land, using its powerful SuperDraco thruster pods to touch down with pinpoint accuracy, much like the company’s Falcon 9 boosters. certifying this novel landing method for human flight with NASA proved to be a complex and lengthy challenge. To expedite the operational readiness of the spacecraft, SpaceX and NASA agreed to revert to the more easily certifiable and well-understood parachute and splashdown system for all crewed missions. The propulsive landing capability has been retained, but it now serves as a last-resort contingency; in the unlikely event of a catastrophic failure of all parachutes, the spacecraft’s software is designed to automatically fire the SuperDracos to attempt a survivable landing.

Touching Down on Land: Boeing’s Starliner

In stark contrast to SpaceX’s approach, Boeing’s CST-100 Starliner was designed to fulfill the original dream of the Gemini program: a land-based recovery of a capsule in the United States. It is the first American crewed capsule designed to touch down on solid ground, targeting several pre-selected sites in the western U.S. To achieve this, Boeing developed a unique hybrid landing system that combines parachutes with a novel airbag attenuation system.

The Starliner’s descent sequence begins similarly to other capsules, with the deployment of two drogue parachutes followed by three main parachutes to slow the vehicle. The final, critical phase of landing is what sets it apart. Just moments before touchdown, a set of six large airbags, stowed at the base of the capsule, rapidly inflate. These bags act as a giant cushion, absorbing the energy of the impact and providing a gentle landing for the crew inside. This system eliminates the need for complex and expensive ocean recovery operations, allowing ground crews to access the capsule and its crew almost immediately after landing.

The development of this complex, first-of-its-kind system has not been without challenges. During testing, engineers identified potential weaknesses in the “soft links” – the textile loops connecting the parachute’s suspension lines to the risers attached to the spacecraft. This discovery, along with concerns about the overall strength of the canopies under certain failure scenarios, prompted a significant redesign and a rigorous new campaign of drop tests at the U.S. Army’s Yuma Proving Ground. Like its counterparts, the Starliner’s parachute system is designed to be fault-tolerant, capable of a safe landing even if one of its three main parachutes fails to open. The journey of the Starliner’s landing system illustrates the significant engineering hurdles involved in turning the decades-old dream of a land landing into a safe, reliable reality.

To the Moon and Back: NASA’s Orion

NASA’s Orion spacecraft, the cornerstone of the Artemis program to return humans to the Moon, is the direct technological descendant of the Apollo Command Module. Its landing system is a testament to fifty years of progress in materials science, computer modeling, and system engineering. Orion’s parachute system is the most complex ever designed for a crewed capsule, involving a total of 11 parachutes. The sequence begins with the jettison of the forward bay cover, which is pulled away by three dedicated parachutes. This is followed by the deployment of two drogue parachutes for stabilization, then three pilot chutes that extract the three massive main parachutes.

Like Apollo, Orion is designed for a water landing and can land safely on just two of its three 116-foot-diameter main parachutes. The real advancements are in the details. The canopies are a hybrid of nylon and high-strength Kevlar. The suspension lines and risers that connect the parachutes to the spacecraft are made entirely of braided Kevlar, replacing the heavy steel cables used on Apollo. This use of advanced materials makes the system stronger, lighter, and more compact. The design also incorporates innovations like a solid Kevlar “vent hoop” at the apex of each main parachute. This ring structure secures the canopy’s radial lines, eliminating the risk of the lines tangling during deployment, a known concern with older designs.

Perhaps the most significant advancement for Orion is not in the parachutes themselves, but in how the spacecraft gets to the point of deployment. Orion achieves its high landing accuracy through a sophisticated guidance technique used during atmospheric entry, long before any parachutes are deployed. This “skip-entry” maneuver involves the spacecraft using its aerodynamic lift to briefly dip into the upper atmosphere and then “skip” back out, much like a stone skipped across water. This maneuver allows Orion to bleed off energy while extending its downrange travel by thousands of miles. This capability gives the flight controllers immense flexibility to correct for trajectory errors and precisely target a small landing zone off the coast of California. By placing the capsule exactly where it needs to be before the parachutes open, the skip-entry provides the precision that eluded early designers, ensuring a faster, safer recovery for crews returning from the Moon and, one day, from Mars.

The different approaches taken by SpaceX and Boeing reflect distinct philosophies in managing risk and complexity. SpaceX opted for a method with deep historical roots – the ocean splashdown – which minimized the development risk associated with the landing event itself. Their innovation focused on refining the system through advanced materials, increased redundancy with four main parachutes, and bringing manufacturing in-house for greater control. This strategy shifted complexity to the post-landing phase, requiring a well-orchestrated maritime recovery operation. Conversely, Boeing pursued the long-sought-after goal of a land landing, which promised to simplify post-flight logistics and provide immediate access to the crew. This choice necessitated a more complex and novel landing system, combining parachutes with a large airbag array. This path accepted a higher upfront development risk, as evidenced by the extensive testing and redesigns required to certify the system, in exchange for a more streamlined and efficient recovery process on the ground. This divergence shows that in modern spacecraft engineering, the path to safety and reliability is not singular; it involves a careful trade-off between developmental challenges and operational simplicity.

Beyond Earth: Decelerators for Other Worlds

The challenge of safely landing a spacecraft is magnified enormously when the destination is not Earth, but another planet. Each world with an atmosphere presents a unique set of problems, demanding specialized decelerator technologies far removed from those used for returning to our home planet. The thin, cold atmosphere of Mars, in particular, has driven the development of a unique class of parachutes designed to function in an environment where Earth-based systems would fail, and it is pushing engineers toward entirely new concepts for landing the heavy payloads of the future.

Landing on Mars: A Supersonic Challenge

Landing on Mars is a notoriously difficult engineering problem, often referred to as the “seven minutes of terror.” The planet’s atmosphere creates a paradox for landing systems. It is substantial enough to generate immense frictional heating on a vehicle entering at high speed, requiring a robust heat shield. At the same time, it is more than 100 times thinner than Earth’s at the surface, making it almost useless for slowing a heavy spacecraft to a safe landing speed using only aerodynamic drag. A heat shield can slow a lander, but not enough. A spacecraft will still be traveling at supersonic speeds – faster than the speed of sound – when it is relatively low in the atmosphere.

This environment makes conventional parachutes unusable. A standard parachute deployed at supersonic speeds would be instantly shredded by the aerodynamic forces. To solve this problem, NASA engineers developed a specialized design known as the “Disk-Gap-Band” (DGB) parachute. First used for the Viking landers in 1976, some variant of the DGB has been used on every successful Mars landing since, including Pathfinder, the Spirit and Opportunity rovers, Phoenix, and the Curiosity and Perseverance rovers.

The DGB design is visually distinct. It consists of a solid circular disk of fabric at the top, followed by an open ring or “gap,” and then a lower, wider “band” of fabric to which the suspension lines are attached. This specific geometry has proven to be exceptionally stable during the violent process of inflation at supersonic speeds. The gap allows some air to pass through, which helps to prevent the wild oscillations that can plague other parachute designs in a supersonic flow.

These Martian parachutes are not steerable. Their one and only job is to survive the brutal deployment and generate as much drag as possible in the thin atmosphere. As the rovers have grown larger and heavier, the parachutes have become immense. The one used for the one-ton Perseverance rover was 70.5 feet in diameter and had to withstand over 65,000 pounds of force upon inflation. To handle these loads, they are constructed from a combination of high-strength, lightweight materials, including specialized nylon for the canopy and Technora and Kevlar for the suspension lines and structural reinforcements. Even with this massive parachute, the lander is still moving at over 200 miles per hour when it gets close to the ground. The final landing must be accomplished by other means, such as the airbag system used for Pathfinder or the rocket-powered “sky crane” that lowered Curiosity and Perseverance to the surface.

The Next Frontier: Inflatable Decelerators

As NASA plans for future missions, including eventually sending humans to Mars, the limitations of even the largest DGB parachutes are becoming apparent. Landing a human habitat, ascent vehicle, and the associated supplies will require payloads many times heavier than the Perseverance rover. A parachute system for such a mission would need to be impractically large and heavy. To overcome this barrier, NASA is developing a revolutionary new technology: the Hypersonic Inflatable Aerodynamic Decelerator, or HIAD.

A HIAD is not a parachute in the traditional sense. It is a large, inflatable structure that functions as a deployable heat shield. Made of flexible, heat-resistant materials, the HIAD can be packed into a relatively small volume within a launch vehicle’s fairing. Before the spacecraft enters the atmosphere, the HIAD inflates, expanding into a large, blunt-nosed cone, many times the diameter of a conventional rigid aeroshell.

This massive increase in surface area provides two key advantages. First, it allows the vehicle to begin decelerating much higher in the thin upper atmosphere, where the air is less dense. This spreads the deceleration over a longer period, reducing the peak heating experienced by the spacecraft. Second, the enormous drag it creates is far more effective at slowing the vehicle than a rigid heat shield of the same mass. This allows for the landing of significantly heavier payloads and provides access to higher-elevation landing sites on Mars, which are currently off-limits because the atmosphere is too thin for current systems to work.

The viability of this technology was spectacularly proven in November 2022 with the Low-Earth Orbit Flight Test of an Inflatable Decelerator (LOFTID) mission. Launched as a secondary payload, the 6-meter (20-foot) diameter LOFTID vehicle was placed on a reentry trajectory from Earth orbit. It successfully inflated, survived the searing heat of reentry at hypersonic speeds, and splashed down under a conventional parachute. The successful test demonstrated the fundamental principles of the HIAD and moved the technology from a theoretical concept to a proven capability. HIADs represent a new class of decelerator, one that blurs the line between a heat shield and a parachute, and they may be the essential technology that finally enables humans to set foot on Mars.

The Future of Recovery: Guided Reusability

The decades-long journey of steerable decelerators is now coming full circle. The mature, reliable parafoil technology, honed through years of military and research applications, is now being scaled up and adapted to tackle one of the biggest challenges in modern spaceflight: the recovery and reuse of large rocket stages. This effort aims to finally realize the original dream that inspired the Gemini program – a controlled, gliding return from the edge of space – but on a scale that early pioneers could have scarcely imagined. This new application promises to enhance the economic viability of space launch by enabling the routine recovery of the most expensive and complex parts of a rocket.

Bringing Back the First Stage

The advent of reusable rockets, pioneered by SpaceX with the propulsive landing of its Falcon 9 first stage, has fundamentally changed the economics of space launch. While propulsive landing is a proven and effective method, it comes with a performance penalty, as the booster must reserve a significant amount of propellant for its landing burns. This reduces the total payload mass it can lift to orbit.

As an alternative, several companies are developing systems that use large, steerable parafoils to recover rocket components. United Launch Alliance (ULA) is actively developing its SMART (Sensible, Modular, Autonomous Return Technology) concept for its next-generation Vulcan rocket. The plan is not to recover the entire first stage, but only the most valuable part: the engine section. After the first stage completes its burn, the engine module would separate, deploy an inflatable heat shield (HIAD) to protect it during reentry, and then unfurl a large parafoil. The parafoil’s GNC system would then guide the engine module to a designated point in the sky where it would be captured in mid-air by a helicopter equipped with a retrieval system.

This approach offers several advantages. It avoids the performance penalty of carrying landing fuel, allowing the rocket to fly with its maximum payload capacity. It also completely avoids contact with corrosive saltwater, which significantly simplifies the refurbishment process compared to the ocean splashdowns of the Space Shuttle’s SRBs. The mid-air retrieval concept, while complex, builds on techniques that have been used for decades to recover film canisters from spy satellites and other sensitive payloads.

Other launch providers are exploring similar concepts. The Chinese space program has conducted tests using parafoils to guide the spent strap-on boosters from its Long March rockets. While the primary goal of these tests has been to reduce the size of the impact zone for safety reasons – preventing debris from falling on populated areas – the technology is clearly applicable to full recovery and reuse. These efforts signal a broader industry trend toward using guided parafoils as a key enabling technology for the next generation of reusable launch vehicles.

Closing the Loop

The development of large-scale, autonomously guided parafoil systems for booster recovery represents the culmination and convergence of the two historical threads that have defined the quest for steerable decelerators. The dream of a controlled, gliding landing, first attempted with Francis Rogallo’s flexible wing for the Gemini capsule, is now on the verge of being realized, not for a small crew capsule, but for multi-ton rocket engine modules returning from the edge of space.

The aerodynamic superiority of Domina Jalbert’s ram-air parafoil, once made practical by the invention of the slider, has been scaled up to immense proportions. Decades of steady development, driven by the needs of military precision airdrop and NASA’s own research programs like the X-38, have matured the technology to an extraordinary level of reliability and capability. When combined with modern advances in GPS navigation, miniaturized flight computers, and robust actuation systems, these giant fabric wings can now safely and precisely guide the most valuable components of a launch system back from incredible speeds and altitudes.

This closes the loop on a journey that began with a simple kite made from kitchen curtains. It fulfills the vision of turning a ballistic descent into a controlled flight. While the application has shifted from crew capsules to rocket hardware, the fundamental goal remains the same: to bring valuable assets back from space with precision and reliability, paving the way for a future where access to space is more routine, more sustainable, and more economical than ever before.

Summary

The history of steerable parachutes in space applications is a story of ambition, innovation, and the persistent effort to master the final moments of a mission. It began with the elegant vision of Francis Rogallo, whose flexible “Parawing” promised to turn the first American space capsules into steerable gliders. This concept, born from a simple kite, led to the Paresev program, where legendary astronauts learned to fly this new type of wing. the technological hurdles of creating a reliable, full-scale inflatable system under the immense pressures of the Space Race proved insurmountable for the Gemini program, leading NASA to embrace the dependable, albeit unguided, round parachutes that would define the Apollo and early Shuttle eras.

In parallel, a more aerodynamically advanced concept was emerging from the work of Domina Jalbert. His ram-air “parafoil” was a true inflatable wing, offering superior glide performance and control. The invention of the slider, which tamed the parafoil’s violent opening shock, unlocked its potential, making it the foundation for modern guided decelerators. This technology was proven in military precision airdrop systems and reached its zenith in NASA’s X-38 program, which demonstrated that a massive 7,500-square-foot parafoil could safely land a 25,000-pound space station lifeboat.

Today, these historical threads are woven into the fabric of modern spaceflight. The new generation of crew capsules showcases a diversity of approaches. SpaceX’s Crew Dragon has refined the Apollo-era splashdown with advanced materials and greater redundancy, while Boeing’s Starliner finally achieves the original Gemini dream of a cushioned land landing using a hybrid parachute-airbag system. NASA’s Orion, built for lunar missions, achieves unprecedented landing accuracy not through a steerable parachute, but through a sophisticated “skip-entry” guidance maneuver performed before the parachutes even deploy.

Beyond Earth, the unique challenges of the Martian atmosphere led to the development of specialized, non-steerable Disk-Gap-Band parachutes, capable of surviving supersonic deployment. The need to land even heavier payloads is now driving the development of Hypersonic Inflatable Aerodynamic Decelerators (HIADs), a new class of technology that blurs the line between heat shield and parachute. Finally, the journey comes full circle as large-scale, autonomously guided parafoils are now being developed to recover reusable rocket boosters, promising to make spaceflight more economical. From a simple kite to a guided wing landing a rocket engine from the edge of space, the quest for a controlled landing continues to shape the future of exploration.

Last update on 2025-12-19 / Affiliate links / Images from Amazon Product Advertising API