A reusable spacecraft is a class of spacecraft that have been designed with repeated launch, orbit, deorbit and atmospheric reentry in mind. This contrasts with conventional spacecraft which are designed to be expended (thrown away, allowed to burn during reentry) after use. Examples of reusable spacecraft are spaceplanes (such as the Space Shuttle orbiters and the Dream Chaser) and space capsules like the SpaceX Dragon. Such spacecraft need mechanisms to prevent the disintegration of the spacecraft and its occupants/cargo during reentry. Failure of such systems may be catastrophic, as what happened in the Space Shuttle Columbia disaster.
Reusable spacecraft include mechanisms to deorbit and reenter the atmosphere in a controlled fashion. For this purpose, the Space Shuttle included OMS pods, and the SpaceX Dragon included its own engines, used for deorbiting. Deorbiting slows the spacecraft down, lowering its perigee to inside the atmosphere where the vehicle descends to Earth. [1] [2]
As a rough rule of thumb, 15% of the landed weight of an atmospheric reentry vehicle needs to be heat shielding. [3]
Thermal Protection Systems (TPS) can be made of a variety of materials, including reinforced carbon-carbon and ablative materials. [4] Historically these materials were first developed on ICBM MIRVs. However, the requirements of reusable space systems differ from those of single use reentry vehicles, especially with regards to heat shield requirements. In particular the need for durable high emissivity coatings that can withstand multiple thermal cycles constitutes a key requirement in the development of new reusable spacecraft. Current materials for such high emissivity coatings include transition metal disilicides. [5]
Ablative heat shields are reliable, but they can only be used once, and are heavy. Reinforced carbon-carbon heat tiles like those used on the Space Shuttle are fragile, and this was proved on the Space Shuttle Columbia disaster. Making a resistant yet lightweight and effective heat tile poses a challenge. The LI-900 material was used on the Space Shuttle.
Spacecraft that land horizontally on a runway require wings and undercarriage. These typically consume about 9-12% of the spacecraft mass,[ citation needed ] which either reduces the payload or increases the size of the spacecraft. Concepts such as lifting bodies offer some reduction in wing mass,[ citation needed ] as does the delta wing shape of the Space Shuttle orbiter.
Vertical landings can be accomplished either with parachutes or propulsively. SpaceX Dragon was an example of space capsule with parachute reusability. Its derivative, Dragon 2, was originally intended to propusively land on land. However, such concept of reusability was canceled in 2017 and now Dragon 2 uses parachutes to land in the ocean.
After the spacecraft lands, it may need to be refurbished to prepare it for its next flight. This process may be lengthy and expensive, taking up to a year. And the spacecraft may not be able to be recertified as human-rated after refurbishment. There is eventually a limit on how many times a spacecraft can be refurbished before it has to be retired, but how often a spacecraft can be reused differs significantly between the various spacecraft designs. [6] [7]
The Space Shuttle is a retired, partially reusable low Earth orbital spacecraft system operated from 1981 to 2011 by the U.S. National Aeronautics and Space Administration (NASA) as part of the Space Shuttle program. Its official program name was Space Transportation System (STS), taken from a 1969 plan for a system of reusable spacecraft where it was the only item funded for development.
A spacecraft is a vehicle that is designed to fly in outer space and operate there. Spacecraft are used for a variety of purposes, including communications, Earth observation, meteorology, navigation, space colonization, planetary exploration, and transportation of humans and cargo. All spacecraft except single-stage-to-orbit vehicles cannot get into space on their own, and require a launch vehicle.
Atmospheric entry is the movement of an object from outer space into and through the gases of an atmosphere of a planet, dwarf planet, or natural satellite. There are two main types of atmospheric entry: uncontrolled entry, such as the entry of astronomical objects, space debris, or bolides; and controlled entry of a spacecraft capable of being navigated or following a predetermined course. Technologies and procedures allowing the controlled atmospheric entry, descent, and landing of spacecraft are collectively termed as EDL.
Soyuz is a series of spacecraft which has been in service since the 1960s, having made more than 140 flights. It was designed for the Soviet space program by the Korolev Design Bureau. The Soyuz succeeded the Voskhod spacecraft and was originally built as part of the Soviet crewed lunar programs. It is launched on a Soyuz rocket from the Baikonur Cosmodrome in Kazakhstan. Between the 2011 retirement of the Space Shuttle and the 2020 demo flight of SpaceX Crew Dragon, the Soyuz served as the only means to ferry crew to or from the International Space Station, for which it remains heavily used. Although China did launch crewed Shenzhou flights during this time, none of them docked with the ISS.
In engineering, a heat shield is a component designed to protect an object or a human operator from being burnt or overheated by dissipating, reflecting, and/or absorbing heat. The term is most often used in reference to exhaust heat management and to systems for dissipating frictional heat. Heat shields are used most commonly in automotive and aerospace.
Hermes was a proposed spaceplane designed by the French Centre National d'Études Spatiales (CNES) in 1975, and later by the European Space Agency (ESA). It was superficially similar to the American Boeing X-20 Dyna-Soar and the larger Space Shuttle.
A reusable launch vehicle has parts that can be recovered and reflown, while carrying payloads from the surface to outer space. Rocket stages are the most common launch vehicle parts aimed for reuse. Smaller parts such as rocket engines and boosters can also be reused, though reusable spacecraft may be launched on top of an expendable launch vehicle. Reusable launch vehicles do not need to make these parts for each launch, therefore reducing its launch cost significantly. However, these benefits are diminished by the cost of recovery and refurbishment.
A spaceplane is a vehicle that can fly and glide like an aircraft in Earth's atmosphere and maneuver like a spacecraft in outer space. To do so, spaceplanes must incorporate features of both aircraft and spacecraft. Orbital spaceplanes tend to be more similar to conventional spacecraft, while sub-orbital spaceplanes tend to be more similar to fixed-wing aircraft. All spaceplanes to date have been rocket-powered for takeoff and climb, but have then landed as unpowered gliders.
The TKS spacecraft was a Soviet spacecraft conceived in the late 1960s for resupply flights to the military Almaz space station.
The Boeing X-37, also known as the Orbital Test Vehicle (OTV), is a reusable robotic spacecraft. It is boosted into space by a launch vehicle, then re-enters Earth's atmosphere and lands as a spaceplane. The X-37 is operated by the Department of the Air Force Rapid Capabilities Office, in collaboration with United States Space Force, for orbital spaceflight missions intended to demonstrate reusable space technologies. It is a 120-percent-scaled derivative of the earlier Boeing X-40. The X-37 began as a NASA project in 1999, before being transferred to the United States Department of Defense in 2004. Until 2019, the program was managed by Air Force Space Command.
A space capsule is a spacecraft designed to transport cargo, scientific experiments, and/or astronauts to and from space. Capsules are distinguished from other spacecraft by the ability to survive reentry and return a payload to the Earth's surface from orbit or sub-orbit, and are distinguished from other types of recoverable spacecraft by their blunt shape, not having wings and often containing little fuel other than what is necessary for a safe return. Capsule-based crewed spacecraft such as Soyuz or Orion are often supported by a service or adapter module, and sometimes augmented with an extra module for extended space operations. Capsules make up the majority of crewed spacecraft designs, although one crewed spaceplane, the Space Shuttle, has flown in orbit.
The Space Shuttle thermal protection system (TPS) is the barrier that protected the Space Shuttle Orbiter during the searing 1,650 °C (3,000 °F) heat of atmospheric reentry. A secondary goal was to protect from the heat and cold of space while in orbit.
A reentry capsule is the portion of a space capsule which returns to Earth following a spaceflight. The shape is determined partly by aerodynamics; a capsule is aerodynamically stable falling blunt end first, which allows only the blunt end to require a heat shield for atmospheric entry. A crewed capsule contains the spacecraft's instrument panel, limited storage space, and seats for crew members. Because a capsule shape has little aerodynamic lift, the final descent is via parachute, either coming to rest on land, at sea, or by active capture by an aircraft. In contrast, the development of spaceplane reentry vehicles attempts to provide a more flexible reentry profile.
The Intermediate eXperimental Vehicle (IXV) is a European Space Agency (ESA) experimental suborbital re-entry vehicle. It was developed to serve as a prototype lifting body orbital return vehicle to validate the ESA's work in the field of reusable orbital return vehicles.
Fuji (ふじ) was a crewed spacecraft of the space capsule kind, proposed by Japan's National Space Development Agency (NASDA) Advanced mission Research center in December 2001. The Fuji design was ultimately not adopted.
Buran was the first spaceplane to be produced as part of the Soviet/Russian Buran program. Buran completed one uncrewed spaceflight in 1988, and was destroyed in 2002 due to the collapse of its storage hangar. The Buran-class orbiters used the expendable Energia rocket, a class of super heavy-lift launch vehicle. Besides describing the first operational Soviet/Russian shuttle orbiter, "Buran" was also the designation for the entire Soviet/Russian spaceplane project and its flight articles, which were known as "Buran-class orbiters".
The Space Capsule Recovery Experiment is an Indian experimental spacecraft which was launched at 03:53 UTC on January 10, 2007, from Sriharikota by the Indian Space Research Organisation (ISRO). The launch was conducted using the C7 launch of the PSLV rocket, along with three other satellites. It remained in orbit for 12 days before re-entering the Earth's atmosphere and splashing down into the Bay of Bengal at 04:16 UTC on January 22.
Kosmos 1686, also known as TKS-4, was a heavily modified TKS spacecraft which docked unmanned to the Soviet space station Salyut 7 as part of tests to attach scientific expansion modules to stations in Earth orbit. The module which docked to the station was the FGB component of a TKS vehicle launched on September 27, 1985, and was designed to test systems planned for use on the Mir Core Module. The spacecraft docked with Salyut 7 on October 2, 1985, during the long-duration stay of the cosmonauts of its fifth principal expedition, which arrived on Soyuz T-14. It was the last flown TKS spacecraft.
The Crew Module Atmospheric Re-entry Experiment (CARE) is an experimental test vehicle for the Indian Space Research Organisation's future ISRO orbital vehicle called Gaganyaan. It was launched successfully on 18 December 2014 from the Second Launch Pad of the Satish Dhawan Space Centre, by a LVM3 designated by ISRO as the LVM 3X CARE mission. Total cost of mission was ₹155 crore. Cost of launch vehicle and CARE module was ₹140 crore and ₹15 crore.