Reusability


Parachutes for reusability

Even though SpaceX might be the most known mission to incorporate reusability, multiple missions used parachutes or other methods to recover rocket stages to reuse them.


Electron

Operator: Rocketlabs

Mission:  Small payloads to LEO and beyond

First flight:  May 2017

Status:  Active


During the development of Electron, it was stated that reusability would not be incorporated into the design. However, after about nine flights, it was announced that reusability would be included in future versions. Interesting is the choice of the recovery system for the electron first stage. 

Animation of the Electron first stage recovery

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. 


Starship

Operator: SpaceX

Mission:  Missions to LEO, the moon and Mars

First flight:  2023

Status:  Under development


The SpaceX Starship rocket is a fully reusable launch vehicle that aims to enable human exploration and settlement of the moon and Mars. The Starship consists of two stages: the Super Heavy booster and the Starship spacecraft. The mission of the Starship is to deliver up to 100 people or 100 tons of cargo to various destinations in the solar system. One of the key challenges of the Starship mission is the entry, descent and landing (EDL) system, which must safely bring the rocket back to Earth or other planetary surfaces after each flight. 

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 stabilize 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 successfully in 2024. After this flight the booster flew back to the launch pad where it landed on the "chopsticks".


Starship stacked before orbital test flight

Starship stacked before orbital test flight

Falcon 9

Operator: SpaceX

Mission:  Orbital missions

First flight: 

Status:  Operational


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. 

Falcon 9 stage with parachutes

Miura 5

Operator: PLD

Mission:  Small payloads to LEO

First flight:  Unflown

Status:  In development


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.


Drop test of the Miura 5 first stage demonstrator

Long March rocket boosters

Operator: CNSA

Mission:  Risk reducting for long March missions

First flight: ?

Status:  In development


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. 


Chineese booster2
Chineese booster

Vulcan SMART

Operator: United Launch Alliance

Mission:  Reusability of first-stage engines

First flight:  TBD

Status:  In development


The Vulcan rocket is the latest addition to the United Launch Alliance family. To reduce the cost of the rocket, ULA proposes to reuse the engine section of the first stage. By only reusing the first stage engines, ULA can reduce the mass and cost of the parachute system. The SMART (Sensible Modular Autonomous Return Technology) reuse system relies on an inflatable heat shield and a parafoil. The inflatable heat shield modifies the ballistic coefficient of the entry vehicle such that the main parachute can be deployed safely. The main parachute system of SMART a parafoil, which is grabbed in mid-air. This system is thus quite compatible to the Electron system. 


Boeing EELV recovery system

Operator: Boeing

Mission:  Partial reusability of first stage engines

First flight:  -

Status:  Cancelled

The EELV was a program of the United States Airforce to ensure access to space. The launchers Delta IV and Atlas V were developed for this program which are currently operated by ULA [102]. However, the development of these launcher families was done before ULA was ULA by two different companies. These were Boeing and Lockheed Martin. With Boeing developing the Delta IV.

But before the Delta IV had its final design and name, some ideas were tested to make Boeing’s EELV launcher at least partially reusable. In the initial stage of developing what would ultimately become the Delta IV as we know it now. The first stage would be propelled by the reusable space shuttle main engine (SSME) [100]. The SSME was an expensive and complex engine, and only using this as an expandable engine would probably be too expensive. So to reduce the cost, a system was developed where the engine would be de-coupled from the tank and recovered [100].

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].

K-1

Operator: NASA, Kistler

Mission:  Payloads to LEO

First flight:  Unflown

Status:  Cancelled


One of the first reusable launchers was the Kistler K-1. This launcher was developed to launch the Irridium communication network into orbit. To reduce costs, the launcher was to be fully reusable. This meant that both the first stage, called Launch Assist Platform (LAP), and the second stage called Orbital Vehicle (OV) would be recovered. Both stages would be recovered using a parachute deceleration system and airbag landing system. The system was developed by Airborn parachute systems.


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!

Drop test of the Kistler K1 first stage showing the six Ringsail parachutes

Space Shuttle boosters

Operator: NASA

Mission: Crewed flights to LEO

First flight:  April 1981

Status:  Retired (last flight July 2011)


A famous reusable spacecraft was the US Space shuttle. The orbiter of the space shuttle was reusable by launching vertically and landing horizontally. Besides the vehicle itself, the solid boosters were recovered, refurbished and reused. The boosters were 45.46 meters high and had a diameter of 3.71. The empty mass of 91tons resulted in some of the largest and heaviest parachutes ever made. 

Space Shuttle booster Entry Descent and Landing

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. 

Ares 1

Operator: NASA

Mission: Crewed flights to LEO

First flight:  2009

Status:  Retired after one flight


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].



Ares 1x booster flight

Energia boosters

Operator:  Roscosmos

Mission:  Reusability of the booster

First flight:  

Status: 


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.  


Energia booster recovery [1]

Sea dragon

Operator:  -

Mission:  Reusability of rocket stages

First flight:  -

Status:  Cancelled


A rocket even larger then the NASA Saturn V, the Sea Dragon would be able to lift 550 tons to low earth orbit. The rocket was to launch from the ocean as no launch pad was big enough the accommodate the rocket. Interesting is that both stages of the rocket were to be reusable. The first stage would land using an inflatable heat shield allowing the stage to safely land in the ocean. No parachutes were to be used on the stage. The heat shield would be stowed around the engine leading to a nose-down re-entry. This was due to the fact that Sea Dragon could withstand higher impact velocities. The accelerator, called the flare, would provide sufficient deceleration and stability. The second stage would first do a de-orbit manoeuvre, and would then also deploy the nozzle flare. It is unclear if the second stage would have had a parachute system.


NEXUS

Operator:  -

Mission:  Reusability of first stage

First flight:  -

Status:  Cancelled


The nexus rocket was a proposed reusable heavy lift rocket proposed by General Dynamics as the successor to the Saturn V rocket. It was intended to be able to carry 8 times the payload with a payload capacity of over 900 tonnes. The booster is intended to decelerate initially using parachutes before using retro rockets mounted at the top of the first stage to decelerate it to touch down velocity. The vehicle would ultimately make a soft touchdown in the ocean before being recovered, refurbished and reused. It was ultimately never built with the US instead opting for the Space Shuttle


Ariane 1

Operator:  Arianespace, ESA

Mission:  Reusing the first stage

First flight:  -

Status:  Retired, never recovered


Ariane is Europe's expendable workhorse launching from French Guiana. The launches have never been reused, but a variety of concepts has been proposed to reuse Ariane. The first concept was proposed for Ariane 1. In 1981 ESA approved a budget to allow Fokker Aerospace to place a cluster of parachutes in the interstage of Ariane 1. The first flight with the upgraded interstage was planned for Ariane Flight L05 and was about 850kg heavier. The first live test of the Ariane 1 parachute system was planned for flight V-14. The rocket lifted off on the second of July 1985 with a recovery boat ready in the ocean. Unfortunately, the parachutes did not deploy, and the rocket crashed. A next flight was planned but later cancelled in favour of the higher reliability of Ariane 4.


Ariane 5 boosters 

Operator:  Arianespace, ESA

Mission:  Post-flight inspection

First flight:  2003

Status:  Active?


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. 


Drop test of the Ariane 5 booster parachute system

Redstone rocket

Operator:  NASA

Mission:  Reusability

First flight:  

Status: cancelled


During the early work on the Redstone rocket, it was proposed to make the first stage reusable. It was proposed to have a two-stage parachute system where the first stage would have a single 5.2m  parachute and the second stage would have had three 20m parachutes for a safe water landing. Once in the water, the stage would have been retrieved by a ship.