A reusable launch system is a space launch system that includes the recovery of some or all of the component stages. To date, several fully reusable sub-orbital systems and partially reusable orbital systems have been flown. No fully reusable orbital launch system has yet been demonstrated.
An orbital spaceflight is a spaceflight in which a spacecraft is placed on a trajectory where it could remain in space for at least one orbit. To do this around the Earth, it must be on a free trajectory which has an altitude at perigee above 100 kilometers (62 mi); this is, by at least one convention, the boundary of space. To remain in orbit at this altitude requires an orbital speed of ~7.8 km/s. Orbital speed is slower for higher orbits, but attaining them requires greater delta-v.
The first reusable launch vehicle to reach orbit was the Space Shuttle, which was not able to accomplish the intended goal of reducing launch costs to below those of expendable launch systems.
The Space Shuttle was a partially reusable low Earth orbital spacecraft system operated 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 of which it was the only item funded for development. The first of four orbital test flights occurred in 1981, leading to operational flights beginning in 1982. In addition to the prototype whose completion was cancelled, five complete Shuttle systems were built and used on a total of 135 missions from 1981 to 2011, launched from the Kennedy Space Center (KSC) in Florida. Operational missions launched numerous satellites, interplanetary probes, and the Hubble Space Telescope (HST); conducted science experiments in orbit; and participated in construction and servicing of the International Space Station. The Shuttle fleet's total mission time was 1322 days, 19 hours, 21 minutes and 23 seconds.
An expendable launch system is a launch vehicle that uses disposable components to carry a payload into space. Vehicles typically consist of several rocket stages that are discarded sequentially as their fuel is exhausted and the vehicle gains altitude and speed. Currently, satellites and human spacecraft are mainly launched on expendable launchers. ELV advantages include the possibility of cost savings through mass production and a greater payload fraction.
During the 21st century, commercial interest in reusable launch systems has grown, with several active launchers. The SpaceX Falcon 9 rocket has a reusable first stage and expendable second stage, The Spaceship Company has flown reusable suborbital spaceplanes, and the suborbital Blue Origin New Shepard rocket has recoverable first stages and crew capsules.
Space Exploration Technologies Corp., doing business as SpaceX, is a private US aerospace manufacturer and space transportation services company headquartered in Hawthorne, California. It was founded in 2002 by Elon Musk with the goal of reducing space transportation costs to enable the colonization of Mars. SpaceX has developed the Falcon launch vehicle family and the Dragon spacecraft family.
Falcon 9 is a two-stage-to-orbit medium lift launch vehicle designed and manufactured by SpaceX in the United States. It is powered by Merlin engines, also developed by SpaceX, burning liquid oxygen (LOX) and rocket-grade kerosene (RP-1) propellants. Its name is from the Millennium Falcon and the nine engines of the rocket's first stage. The rocket evolved with versions v1.0 (2010–2013), v1.1 (2013–2016), v1.2 "Full Thrust" (2015–2018), and its Block 5 variant, flying since May 2018. Unlike most rockets, which are expendable launch systems, Falcon 9 is partially reusable, with the first stage capable of re-entering the atmosphere and landing back vertically after separating from the second stage. This feat was achieved for the first time on flight 20 with the v1.2 version in December 2015.
The Spaceship Company (TSC) is a British/American spacecraft manufacturing company that was founded by Burt Rutan and Richard Branson in mid-2005 and was jointly owned by Virgin Group (70%) and Scaled Composites (30%) until 2012 when Virgin Galactic became the sole owner. TSC was formed to own the technology created by Scaled for Virgin Galactic's Virgin SpaceShip program. This includes developments on the care-free reentry system and cantilevered-hybrid rocket motor, licensed from Paul Allen and Burt Rutan's Mojave Aerospace. The company is manufacturing Virgin Galactic's spacecraft and will sell spacecraft to other buyers. The suborbital launch system offered will include the SpaceShipTwo spacecraft and the White Knight Two carrier aircraft.
The single stage to orbit (SSTO) approach has yet to be proven viable, while several partially reusable two stage to orbit vehicles are active or in an advanced stage of development.
A single-stage-to-orbit vehicle reaches orbit from the surface of a body without jettisoning hardware, expending only propellants and fluids. The term usually, but not exclusively, refers to reusable vehicles. No Earth-launched SSTO launch vehicles have ever been constructed. To date, orbital launches have been performed by multi-stage rockets, either fully or partially expendable, the Space Shuttle having both attributes.
Expendable rockets air launched from aircraft can be considered partially reusable if the aircraft is thought of as the first stage of the launch vehicle. An example of this configuration is the Orbital Sciences Pegasus.
Air launching is the practice of releasing a rocket, missile, parasite aircraft or other aircraft payload from a mother ship or launch aircraft. The payload craft or missile is often tucked under the wing of the larger mother ship and then "dropped" while in flight. It may also be stored within a bomb bay, beneath the main fuselage or even on the back of the carrier aircraft, as in the case of the D-21 drone. Air launching provides several advantages over ground launching, giving the smaller craft an altitude and range boost, while saving it the weight of the fuel and equipment needed to take off on its own.
The Pegasus is an air-launched rocket developed by Orbital Sciences Corporation. Capable of carrying small payloads of up to 443 kilograms (977 lb) into low Earth orbit, Pegasus first flew in 1990 and remains active as of 2019. The vehicle consists of three solid propellant stages and an optional monopropellant fourth stage. Pegasus is released from its carrier aircraft at approximately 40,000 ft (12,000 m), and its first stage has a wing and a tail to provide lift and attitude control while in the atmosphere.
The Spaceship Company combination of SpaceShipTwo and White Knight Two is a fully reusable suborbital vehicle with wings on both the launch aircraft and the rocket-propelled second stage.
The Scaled Composites Model 339 SpaceShipTwo (SS2) is an air-launched suborbital spaceplane type designed for space tourism. It is manufactured by The Spaceship Company, a California-based company owned by Virgin Galactic.
Non-rocket spacelaunch systems provide a theoretical increase in efficiency.
Vehicles that land horizontally on a runway require wings and undercarriage. These typically consume about 9-12% of the landing vehicle mass, which either reduces the payload or increases the size of the vehicle. Concepts such as lifting bodies offer some reduction in wing mass, as does the delta wing shape of the Space Shuttle.
Vertical landings can be accomplished either with parachutes (as with Soyuz) or propusively. The DC-X is an example of a propulsive lander,and the Falcon 9 rocket is the first orbital rocket to vertically land its first stage on the ground. This typically requires about 10% of the total first stage propellant, disproportionately reducing the payload that can be carried due to the rocket equation.
Reusable stages mass more than equivalent expendable stages. This is unavoidable due to the supplementary systems and/or surplus propellant needed to land a stage. The actual mass penalty depends on the vehicle and the return mode chosen.
As a rough rule of thumb, 15% of the landed weight of an atmospheric reentry vehicle needs to be heat shielding.
Thermal Protection Systems (TPS) can be made of a variety of materials, including reinforced carbon-carbon and ablative materials.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.
With the invention of rocket propulsion in the first half of the twentieth century, space travel became a technical possibility.
Early ideas of a single-stage reusable spaceplane proved unrealistic and although even the first practical rocket vehicles could reach the fringes of space, re-usable technology was too heavy. The problem of mass efficiency was overcome by using multiple expendable stages in a vertical-launch multistage rocket. The first re-usable stages did not appear until the advent of the US Space Shuttle in 1981.
Modern reusable orbital vehicles include the X-37 and the Dream Chaser.
The late 1960s saw the start of the Space Shuttle design process, resulting in a reusable orbiter spacecraft and solid rocket boosters with an expendable external tank.The Shuttle was much more expensive to operate than an expendable launch system.
The Soviet Union followed suit with Buran, with the cost becoming untenable in the early 1990s. Russia's satellites and spacecraft have launched on expendable vehicles ever since.
In 1986 President Ronald Reagan called for an air-breathing scramjet NASP/X-30. The project failed due to severe technical issues and was canceled in 1993.
In the 1990s the McDonnell Douglas Delta Clipper VTOL SSTO proposal progressed to the testing phase. The DC-X prototype demonstrated rapid turnaround time and automatic computer control.
In mid-1990, British research evolved an earlier HOTOL design into the far more promising Skylon design, which remains in development.
From the commercial side, Rocketplane Kistler and Rotary Rocket attempted to build reusable privately developed rockets before going bankrupt.
NASA proposed risky reusable concepts to replace the Shuttle technology, to be demonstrated under the X-33 and X-34 programs, which were both cancelled in the early 2000s due to rising costs and technical issues. The Space Shuttle retired in 2011.
The Ansari X Prize contest was intended to develop private suborbital reusable vehicles. Many private companies competed, with the winner, Scaled Composites, reaching the Kármán line twice in a two-week period with their reusable SpaceShipOne.
In 2012, SpaceX started a flight test program with experimental vehicles. These subsequently led to the development of the Falcon 9 re-usable rocket launcher.
On 23 November 2015 the Blue Origin New Shepard rocket became the first Vertical Take-Off/Landing (VTOL) rocket to reach space by passing the Kármán line (100 kilometres), reaching 329,839 feet (100.5 kilometers) before returning to a parachute landing.
SpaceX achieved the first vertical soft landing of a re-usable orbital rocket stage on December 21, 2015, after helping send 11 Orbcomm OG-2 commercial satellites into low Earth orbit.
The first Falcon 9 second flight occurred on 30 March 2017.SpaceX now routinely recovers and reuses their first stages, with the intent of reusing fairings as well.
As of March 2019 [update] , the only reusable operational orbital booster was Falcon 9. SpaceX is also developing the BFR.
|Blue Origin||New Shepard||US||Prototype|
|ISRO||RLV-TD||India||Project||Successful flight test|
|The Spaceship Company||SpaceShipTwo||US||Prototype|
|SpaceX||Falcon 9||US||Operational||First stage reusable.|
|SpaceX||Falcon Heavy||US||Operational||Core and side boosters reusable.|
A spacecraft is a vehicle or machine designed to fly in outer space. 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.
Spaceflight is ballistic flight into or through outer space. Spaceflight can occur with spacecraft with or without humans on board. Yuri Gagarin of the Soviet Union was the first human to conduct a spaceflight. Examples of human spaceflight include the U.S. Apollo Moon landing and Space Shuttle programs and the Russian Soyuz program, as well as the ongoing International Space Station. Examples of unmanned spaceflight include space probes that leave Earth orbit, as well as satellites in orbit around Earth, such as communications satellites. These operate either by telerobotic control or are fully autonomous.
A booster rocket is either the first stage of a multistage launch vehicle, or else a shorter-burning rocket used in parallel with longer-burning sustainer rockets to augment the space vehicle's takeoff thrust and payload capability. Boosters are traditionally necessary to launch spacecraft into low Earth orbit, and are especially important for a space vehicle to go beyond Earth orbit. The booster is dropped to fall back to Earth once its fuel is expended, a point known as booster engine cut-off (BECO). The rest of the launch vehicle continues flight with its core or upper-stage engines. The booster may be recovered and reused, as was the case of the Space Shuttle.
A spaceplane is an aerospace vehicle that can fly like an aircraft in Earth's atmosphere and maneuver like a spacecraft in the vacuum of space. To do so, spaceplanes must incorporate features of both aircraft and spacecraft, and occupy an intermediate space between the two types. Orbital spaceplanes are mostly spacecraft, sub-orbital spaceplanes are mostly aircraft.
A two-stage-to-orbit (TSTO) or two-stage rocket launch vehicle is a spacecraft in which two distinct stages provide propulsion consecutively in order to achieve orbital velocity. It is intermediate between a three-stage-to-orbit launcher and a hypothetical single-stage-to-orbit (SSTO) launcher.
The Lockheed Martin X-33 was an unmanned, sub-scale technology demonstrator suborbital spaceplane developed in the 1990s under the U.S. government-funded Space Launch Initiative program. The X-33 was a technology demonstrator for the VentureStar orbital spaceplane, which was planned to be a next-generation, commercially operated reusable launch vehicle. The X-33 would flight-test a range of technologies that NASA believed it needed for single-stage-to-orbit reusable launch vehicles, such as metallic thermal protection systems, composite cryogenic fuel tanks for liquid hydrogen, the aerospike engine, autonomous (unmanned) flight control, rapid flight turn-around times through streamlined operations, and its lifting body aerodynamics.
The DC-X, short for Delta Clipper or Delta Clipper Experimental, was an unmanned prototype of a reusable single-stage-to-orbit launch vehicle built by McDonnell Douglas in conjunction with the United States Department of Defense's Strategic Defense Initiative Organization (SDIO) from 1991 to 1993. Starting 1994 until 1995, testing continued through funding of the US civil space agency NASA. In 1996, the DC-X technology was completely transferred to NASA, which upgraded the design for improved performance to create the DC-XA.
A space vehicle or spaceship is a rocket-powered vehicle used to transport unmanned satellites or humans between the Earth's surface and outer space. The earliest space vehicles were expendable launch systems, consisting of rocket launch vehicles carrying spacecraft payloads which were relatively small portions of the total vehicle size and mass. The single or multistage rocket without the payload is referred to as a launch vehicle. Most space vehicles in production use are expendable systems, although reusable launch systems have been envisioned since the late 1960s.
The Boeing X-37, also known as the Orbital Test Vehicle (OTV), is a reusable uncrewed 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 United States Air Force for orbital spaceflight missions intended to demonstrate reusable space technologies. It is a 120%-scaled derivative of the earlier Boeing X-40.
Vertical takeoff, vertical landing (VTVL) is a form of takeoff and landing for rockets. Multiple VTVL craft have flown.
USA-212 was the first flight of the Boeing X-37B Orbital Test Vehicle 1, an American unmanned robotic vertical-takeoff, horizontal-landing (VTHL) spaceplane. It was launched aboard an Atlas V rocket from Cape Canaveral on 22 April 2010, and operated in low Earth orbit. Its designation is part of the USA series.
A heavy-lift launch vehicle, HLV or HLLV, is an orbital launch vehicle capable of lifting between 20,000 to 50,000 kg to low Earth orbit (LEO). As of 2017, operational heavy-lift launch vehicles include the Ariane 5, the Proton-M and the Delta IV Heavy. In addition, the Angara A5, the Falcon 9 Full Thrust, the Falcon Heavy and the Long March 5 are designed to provide heavy-lift capabilities but have not yet been proven to carry a 20-tonne payload into LEO. Several other heavy-lift rockets are in development.
Aircraft can have different ways to take off and land. Conventional airplanes accelerate along the ground until sufficient lift is generated for takeoff, and reverse the process to land. Some airplanes can take off at low speed, this being a short takeoff. Some aircraft such as helicopters and Harrier Jump Jets can take off and land vertically. Rockets also usually take off vertically, but some designs can land horizontally.
The DARPA XS-1 is an experimental spaceplane/booster with the planned capability to deliver small satellites into orbit for the U.S. Military. It is reported to be designed to be reusable as frequently as once a day, with a stated goal of doing so for 10 days straight. The XS-1 is intended to directly replace the "first stage" of a multistage rocket that will be capable of hypersonic flight at suborbital altitude, enabling one or more expendable upper stages to separate and deploy a payload into low Earth orbit. The XS-1 would then return to Earth, where it could ostensibly be serviced fast enough to repeat the process at least once every 24 hours.
Falcon 9 v1.1 was the second version of SpaceX's Falcon 9 orbital launch vehicle. The rocket was developed in 2011–2013, made its maiden launch in September 2013, and its final flight in January 2016. The Falcon 9 rocket was fully designed, manufactured, and operated by SpaceX. Following the second Commercial Resupply Services (CRS) launch, the initial version Falcon 9 v1.0 was retired from use and replaced by the v1.1 version.
A super heavy-lift launch vehicle (SHLLV) is a launch vehicle capable of lifting more than 50 tonnes (110,000 lb) of payload into low Earth orbit (LEO).
|Wikimedia Commons has media related to Reusable manned spacecraft .|