Parachutes for reusability

A ballute stabiliser was used to mitigate SpaceX's problems with aerothermal heating. The ballute can also be seen in the Copenhagen Suborbitals recovery system. Not too many details are known regarding the exact dimensions and deployment altitudes. 

As the main parachute, a lift-generating parafoil was chosen that will be captured in mid-air. This recovery means no seawater can enter the rocket engine, leading to easier refurbishment operations. After several test flights with a fully instrumented Electron rocket, Rocketlab completed several parachute tests. During these tests, the first stage landed in the water using a traditional round canopy.  

As of today, Rocket Labs has performed four launches in which the first stage was recovered. During two additional flights the booster was intended to be caught in mid-air, this however failed. 

The EDL system of the Starship relies on a combination of aerodynamics, propulsive maneuvers and landing legs to achieve a precise and soft touchdown. The EDL system of the Starship is designed to handle different atmospheric conditions and gravity levels depending on the destination. For example, on Earth, the Starship will perform a "belly flop" manoeuvre, where it uses its large surface area and four flaps to slow down and stabilise during re-entry. Then, it will fire its Raptor engines, flip itself upright and extend its six landing legs before landing on a designated pad.

On Mars, where the atmosphere is thinner and gravity is lower, the Starship will use less propellant to land. The EDL system of the Starship has undergone several tests and improvements over the past few years, with several prototypes reaching high altitudes and demonstrating various aspects of the EDL system. The most recent test, SN15, successfully launched and landed without exploding for the first time in May 2021. 

The full stack has been launched twice, both not reaching orbit. The first test flight ended in a catastrophic explosion during the first stage burn where the second flight made it all the way to stage separation. 

The Falcon 9 is a rocket developed by SpaceX and was part of the commercial cargo contracts set up by NASA to re-supply the International Space Station. The vehicle original variants of the vehicle were used solely for this purpose but the rocket has found itself to be a low-cost alternative for many missions. The rocket has always been designed with reusability in mind. The two flights were done using parachutes for the first stage landing. This was removed after two flights and as of the V1.1 variant, a propulsive landing was envisioned. During the first several attempts this failed until the landing of B1019, the first of the "full thrust" variants.  It was not until the Block 5 variant that the boosters would be reused more than once. 

Ever since the landings have been routine SpaceX has lost several boosters due to various reasons. This included the lost of B1058 after falling over in rough seas. 

PLD is a start-up founded in 2011 with the objective to build European rockets. The company aims to build Miura 1, a sounding rocket, and Miura 5, an orbital rocket. To reduce the cost of Miura 5, the first stage is to be reusable. To make this possible a parachute system, developed by Airborne Systems North America, is used. The system was tested during a drop test at El Arenosillo Experimentation Center of INTA. The vehicle was dropped from an army chinook after which all parachutes performed as expected. The vehicle splashed down with 10 m/s and was recovered by divers. It is unclear how PLD sees the refurbishment operations of the launcher at this moment. 

Miura 5 is expected to launch from the Guiana Space Centre. To reduce cost the Miura 5 rocket shares about 70% of the technology with the Miura 1 sounding rocket.

Although not primarily developed for reusability, the Chinese Long March 2 and 3 rockets have been seen with parachutes recently. These parachutes are primarily attached to (one of the) four liquid strap-on boosters. The goal of these parachutes is not to reuse, but to reduce the risk of impact. The Chinese launch sites are situated such that the boosters might impact on populated areas. By including a parachute this area can be reduced by about 70-80% [176]. 

The exact design is somewhat unknown. In 2021 images were published showing a 300 m2 parafoil-like parachute, but other images show a more conventional round parachute. 

For this system, only drop-test were performed, but the system used for this consisted of three 41.5 m diameter Ringsails, which were deployed with two reefed stages to limit the loading. During the parachute deployment, a spray shield would be deployed that would inflate around the engine nozzle using Helium and protect the engine from the salt water after splashdown [100,101].

Although the drop tests successfully met all goals, this concept was not used on the Delta IV[100]. It is unclear why, but in the end, the Delta IV launcher chose to instead modify the SSME into a cheaper and simpler single-use engine, the RS-68. The idea was not lost with the transfer from Boeing to ULA as for the current Vulcan launcher. A similar concept is currently under development, the SMART system, which aims to recover the engine of the Vulcan[103].

The first stage of the K1 would use two drogue parachutes and six main parachutes. Each parachute was reefed upon inflation. The parachutes for the first and second stage were identical. This means that the overall design work was simplified. The drogue parachutes chosen were 23ft Variable Porosity Conical Ribbon parachutes with a 1.2 Do suspension line length. The main parachutes were massive 156 ft Ringsail parachutes. Now, even though these parachutes are already very impressive, the second stage was equipped with a stabilising drogue parachute to help the stage be in the right orientation. This 23ft Hemisflo drogue parachute was deployed at Mach 2.5 and experienced a supersonic flight time of 23 seconds. To date, this is one of the largest supersonic parachutes produced. 

The landing of both stages was done using airbags for a land landing. This ensured a landing close to the launch site and a quick turn around time. The land landing prevented seawater from entering the rocket itself, leading to lengthy and expensive refurbishment operations. 

Unfortunately, the Kistler K1 never flew, but drop tests have been done to demonstrate the parachute system. A photo of one of the drop tests can be seen on the right. Even though the rocket never flew the engineers have written several papers on the recovery system. These are definitely worth your time!

After an apogee of about 72 km, the boosters would tumble back to earth awaiting the deployment of the pilot chute at 4.8 km. This pilot chute was quickly followed by a drogue and later by the main parachute. To prevent enablement the drogue was ejected together with the frustum. This combination was also recovered by the ships. Earlier space shuttle missions would separate the main parachute at impact, however, this lead to extensive damage. For later flights the boosted used a salt-based release system that would release the main parachutes after landing.  

The boosters landed nozzle down, trapping air in the empty casing. This trapped air ensured the boosters remained afloat. The booster floated vertically with the top of the booster about 9.1m above the water. When the retrieval team neared the boosters, divers placed a plug and pumped the boosters such that the boosters floated horizontally allowing them to be towed back to land. 

Just as was done for the space shuttle solid rocket booster, the first stage of the Ares-I, roughly the same SRB but with one more segment, also has a recovery system onboard. Since the first stage of the Ares-I was significantly higher than the Space shuttle variant, a new system was needed to land the system safely.

The design ended up being an upgraded version of the space shuttle SRB system. After separation of the first stage, at 57.6 km, a tumbling motion of 12-16 degrees per second is introduced [17]. This resembles the motion of the space shuttle SRB after its separation from the tank. This tumbling motion is induced to increase the effective drag from the system and lower the terminal velocity of the stage. The stage travels to an apogee of 99.1 km before starting the descent.

At 4900 m, the nose cap is jettisoned, and a 3.5m pilot chute is deployed. This pilot chute pulls out a single 20.7m diameter drogue chute. This parachute does most of the work, reducing the velocity to 93.9 m/s [13]. After which the largest parachutes ever produced are deployed, these are a cluster of three 45.7m diameter parachutes, each weighing roughly 940 kg [13,14,15,16,17].

All the parachutes used for the Ares-I are quarter-spherical parachutes produced with continuous ribbons. This was designed to reduce possible tearing of the parachute. Also, the quarter-spherical produced shape would resemble the inflated shape of the parachute more.  With these improvements in construction, the 45.7m diameter quarter spherical main parachute of Ares provides the equivalent drag of a 47.9m diameter conical parachute as used on the Space Shuttle [17].

The Energia was a heavy lift vehicle at the end of the Soviet era. The launcher was designed, in part, to launch the Buran to orbit. Unlike the US Space Shuttle, the Energia was designed to fly without the Buran. Energia consisted of a core stage with four liquid boosters. These boosters would be recovered for reuse. The implemented concept consisted of a parachute to orient the booster in a nose-down orientation for re-entry. When re-entry has completed a cluster of four main parachutes would be deployed for a safe landing. The booster itself would be oriented in a horizontal position, and landing legs would be deployed. For final deceleration, a retrorocket pack would fire just before the ground. 

Other proposals included a winged return vehicle with deployable wings and a turbine engine. Other proposals included a parachute system for landing the core stage of the Energia as well.  

Ariane 5 uses two solid boosters to help lift off from the launch pad. These boosters separate after burn out, but just like the space shuttle, they can be safely landed and retrieved. This is done every now and then by Arianespace for post-flight inspection. The boosters are however not reused. The last known booster recovery was done in 2009 during the first Ariane 5 ECA mission. 

The Ariane 5's parachute system is somewhat unique in that it uses a smaller parachute in series with a larger one. This is done to reduce the vertical velocity during parachute inflation. The smaller parachute is identical to the drogue parachute. The system has three 90m² drogue parachutes that inflate in four reefing steps. The main parachute is 1800 m² and also inflates in four reefing steps. The supporting parachute is identical to the drogue parachute.  The main parachute is identical to the parachute used for the Energia boosters.