A single-stage-to-orbit (SSTO) vehicle reaches orbit from the surface of a body using only propellants and fluids and without expending tanks, engines, or other major hardware. The term usually, but not exclusively, refers to reusable vehicles. To date, no Earth-launched SSTO launch vehicles have ever been flown; orbital launches from Earth have been performed by either fully or partially expendable multi-stage rockets.
A scramjet is a variant of a ramjet airbreathing jet engine in which combustion takes place in supersonic airflow. As in ramjets, a scramjet relies on high vehicle speed to compress the incoming air forcefully before combustion, but where as a ramjet decelerates the air to subsonic velocities before combustion using shock cones, a scramjet has no shock cone and slows the airflow using shockwaves produced by its ignition source in place of a shock cone. This allows the scramjet to operate efficiently at extremely high speeds.
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.
Skylon is a series of concept designs for a reusable single-stage-to-orbit spaceplane by the British company Reaction Engines Limited (Reaction), using SABRE, a combined-cycle, air-breathing rocket propulsion system.
The NASA X-43 was an experimental unmanned hypersonic aircraft with multiple planned scale variations meant to test various aspects of hypersonic flight. It was part of the X-plane series and specifically of NASA's Hyper-X program developed in the late 1990s. It set several airspeed records for jet aircraft. The X-43 is the fastest jet-powered aircraft on record at approximately Mach 9.6.
The Lockheed Martin X-33 was a proposed uncrewed, sub-scale technology demonstrator suborbital spaceplane that was developed for a period in the 1990s. 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 (uncrewed) flight control, rapid flight turn-around times through streamlined operations, and its lifting body aerodynamics.
SABRE is a concept under development by Reaction Engines Limited for a hypersonic precooled hybrid air-breathing rocket engine. The engine is being designed to achieve single-stage-to-orbit capability, propelling the proposed Skylon spaceplane to low Earth orbit. SABRE is an evolution of Alan Bond's series of LACE-like designs that started in the early/mid-1980s for the HOTOL project.
The Australian Space Research Institute (ASRI) was formed 1991 with the merger of the AUSROC Launch Vehicle Development Group at Monash University, Melbourne and the Australian Space Engineering Research Association (ASERA).
The DARPA FALCON Project was a two-part joint project between the Defense Advanced Research Projects Agency (DARPA) and the United States Air Force (USAF) and is part of Prompt Global Strike. The first part of the project aimed to develop a Small Launch System (SLS) capable of accelerating hypersonic gliding weapons as well as launching small satellites into Earth orbit. The second part of the project aimed to develop Hypersonic Weapon Systems (HWS): a short term high performance hypersonic gliding weapon previously named the X-41 Common Aero Vehicle (CAV) that could be launched from Expendable Launch Vehicles (ELV), Reusable Launch Vehicles (RLVs), Hypersonic Cruise Vehicles (HCV), or Space Maneuvering Vehicles (SMP), and a long term hypersonic cruise aircraft named the Hypersonic Cruise Vehicle (HCV). This two-part program was announced in 2003 and continued into 2006.
The Boeing X-51 Waverider is an unmanned research scramjet experimental aircraft for hypersonic flight at Mach 5 and an altitude of 70,000 feet (21,000 m). The aircraft was designated X-51 in 2005. It completed its first powered hypersonic flight on 26 May 2010. After two unsuccessful test flights, the X-51 completed a flight of over six minutes and reached speeds of over Mach 5 for 210 seconds on 1 May 2013 for the longest duration powered hypersonic flight.
Scramjet programs refers to research and testing programs for the development of supersonic combustion ramjets, known as scramjets. This list provides a short overview of national and international collaborations, and civilian and military programs. The USA, Russia, India, and China (2014), have succeeded at developing scramjet technologies.
Lockheed L-301 was an experimental air-breathing hypersonic aircraft project. It was developed by the NASA and United States Air Force (USAF) organization National Hypersonic Flight Research Facility, with Skunk Works as the prime contractor. In January 1977, the program was "tentatively scheduled to operate two vehicles for eight years and to conduct 100 flights per vehicle." NASA discontinued work on L-301 and NHRF in September 1977 due to budget constraints and lack of need.
The Tupolev Tu-2000 was a planned hypersonic flight experimental aircraft designed by the Tupolev design bureau. It was intended to test technologies for a single-stage-to-orbit aerospaceplane and also the Tupolev Tu-360 intercontinental bomber.
Hypersonic flight is flight through the atmosphere below altitudes of about 90 km at speeds greater than Mach 5, a speed where dissociation of air begins to become significant and high heat loads exist. Speeds over Mach 25 have been achieved below the thermosphere as of 2020.
Non-rocket spacelaunch refers to theoretical concepts for launch into space where much of the speed and altitude needed to achieve orbit is provided by a propulsion technique that is not subject to the limits of the rocket equation. Although all space launches to date have been rockets, a number of alternatives to rockets have been proposed. In some systems, such as a combination launch system, skyhook, rocket sled launch, rockoon, or air launch, a portion of the total delta-v may be provided, either directly or indirectly, by using rocket propulsion.
Reusable Launch Vehicle–Technology Demonstration Programme is a series of technology demonstration missions that has been conceived by the Indian Space Research Organisation (ISRO) as a first step towards realising a Two Stage To Orbit (TSTO) re-usable launch vehicle, in which the second stage is a spaceplane.
HyShot is a research project of The University of Queensland, Australia Centre for Hypersonics, to demonstrate the possibility of supersonic combustion under flight conditions using two scramjet engines, one designed by The University of Queensland and one designed by QinetiQ.
The HSTDV is an unmanned scramjet demonstration aircraft for hypersonic flight. It is being developed as a carrier vehicle for hypersonic and long-range cruise missiles, and will have multiple civilian applications including the launching of small satellites at low cost. The HSTDV program is being run by the Defence Research and Development Organisation (DRDO).
Hypersonic Technology Vehicle 2 (HTV-2) is an experimental hypersonic glide vehicle developed as part of the DARPA Falcon Project designed to fly in the Mach 20 range. It is a test bed for technologies to provide the United States with the capability to reach any target in the world within one hour using an unmanned hypersonic bomber aircraft.
The Lockheed Martin SR-72, colloquially referred to as "Son of Blackbird", is an American hypersonic UAV concept intended for intelligence, surveillance and reconnaissance (ISR) proposed privately in 2013 by Lockheed Martin as a successor to the retired Lockheed SR-71 Blackbird. In 2018, company executives said an SR-72 test vehicle could fly by 2025 and enter service in the 2030s.
