The aerospike engine is a type of rocket engine that maintains its aerodynamic efficiency across a wide range of altitudes. It belongs to the class of altitude compensating nozzle engines. Aerospike engines were proposed for many single-stage-to-orbit (SSTO) designs. They were a contender for the Space Shuttle main engine. However, as of 2023 no such engine was in commercial production, although some large-scale aerospikes were in testing phases.
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 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.
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 around 80 kilometers (50 mi); this is the boundary of space as defined by NASA, the US Air Force and the FAA. 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 Fédération Aéronautique Internationale has established the Kármán line at an altitude of 100 km (62 mi) as a working definition for the boundary between aeronautics and astronautics. This is used because at an altitude of about 100 km (62 mi), as Theodore von Kármán calculated, a vehicle would have to travel faster than orbital velocity to derive sufficient aerodynamic lift from the atmosphere to support itself.
Pegasus is an air-launched launch vehicle developed by Orbital Sciences Corporation (OSC) and now built and launched by Northrop Grumman. Pegasus is the world's first privately developed orbital launch vehicle. Capable of carrying small payloads of up to 443 kg (977 lb) into low Earth orbit, Pegasus first flew in 1990 and remains active as of 2021. The vehicle consists of three solid propellant stages and an optional monopropellant fourth stage. Pegasus is released from its carrier aircraft at approximately 12,000 m (39,000 ft), and its first stage has a wing and a tail to provide lift and altitude control while in the atmosphere. Notably, the first stage does not have a thrust vector control (TVC) system.
Orbital Sciences Corporation was an American company specializing in the design, manufacture, and launch of small- and medium- class space and launch vehicle systems for commercial, military and other government customers. In 2014, Orbital merged with Alliant Techsystems to create a new company called Orbital ATK, Inc., which in turn was purchased by Northrop Grumman in 2018. The remnants of the former Orbital Sciences Corporation became a subsidiary of Northrop Grumman, known as Northrop Grumman Space Systems.
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 ASM-135 ASAT is an air-launched anti-satellite multistage missile that was developed by Ling-Temco-Vought's LTV Aerospace division. The ASM-135 was carried exclusively by United States Air Force (USAF) F-15 Eagle fighter aircraft.
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.
Stargazer is a Lockheed L-1011 TriStar built in 1974, that was modified in 1994 for use by Orbital Sciences as a mother ship launch pad for the Pegasus launch vehicle. As of October 2022, 45 rockets have been launched from it, using the Pegasus-H and Pegasus-XL configurations. As of 2019, Stargazer is the only L-1011 airframe still airworthy.
The NOTS-EV-2 Caleb, also known as NOTS-500, Hi-Hoe and SIP was an expendable launch system, which was later used as a sounding rocket and prototype anti-satellite weapon. It was developed by the United States Navy's Naval Ordnance Test Station (NOTS) as a follow-up to the NOTS-EV-1 Pilot, which had been abandoned following ten launches officially classified as failed missions. Two were launched in July and October 1960, before the cancellation of the project. Following cancellation, two leftover Calebs were used in the Satellite Interceptor Program (SIP), while three more were used as sounding rockets, under the designation Hi-Hoe. These derivatives flew until July 1962, when the Hi-Hoe made its final flight.
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.
SpaceX manufactures launch vehicles to operate its launch provider services and to execute its various exploration goals. SpaceX currently manufactures and operates the Falcon 9 Full Thrust family of medium-lift launch vehicles and the Falcon Heavy family of heavy-lift launch vehicles – both of which powered by SpaceX Merlin engines and employing VTVL technologies to reuse the first stage. As of 2023, the company is also developing the fully reusable Starship launch system, which will replace the Falcon 9 and Falcon Heavy.
Stratolaunch LLC is an American aerospace company providing high-speed flight test services. It was originally formed in 2011 to develop a new air-launched space transportation system, with its corporate headquarters located in Seattle, Washington. The company and development project were officially announced in December 2011 by Microsoft co-founder Paul Allen and Scaled Composites founder Burt Rutan, who had previously collaborated on the creation of SpaceShipOne. After 10 years of previous private investment, the company was acquired in 2019 by Cerberus Capital Management and has since been 100% privately funded and operated as a non-traditional defense contractor.
The Scaled Composites Model 351 Stratolaunch or Roc is an aircraft built by Scaled Composites for Stratolaunch Systems to carry air-launch-to-orbit (ALTO) rockets, and subsequently repurposed to offer air launch hypersonic flight testing after a change of ownership. It was announced in December 2011, rolled out in May 2017, and flew for the first time on April 13, 2019, shortly after the death of founder Paul Allen. The aircraft features a twin-fuselage design and the longest wingspan ever flown, at 385 feet (117 m), surpassing the Hughes H-4 Hercules "Spruce Goose" flying boat of 321 feet (98 m). The Stratolaunch is intended to carry a 550,000-pound (250 t) payload and has a 1,300,000-pound (590 t) maximum takeoff weight.
LauncherOne was a two-stage orbital launch vehicle developed and flown by Virgin Orbit that had operational flights from 2021 to 2023, after being in development from 2007 to 2020. It was an air-launched rocket, designed to carry smallsat payloads of up to 300 kg (660 lb) into Sun-synchronous orbit (SSO), following air launch from a carrier aircraft at high altitude. The rocket was carried to the upper atmosphere on a modified Boeing 747-400, named Cosmic Girl, and released over ocean. Initial work on the program was done by Virgin Galactic, another Virgin Group subsidiary, before a separate entity — Virgin Orbit — was formed in 2017 to complete development and operate the launch service provider business separately from the passenger-carrying Virgin Galactic business.
Pegasus II, also known as Thunderbolt, was an air-launched orbital rocket under development in 2012–2015 by Orbital Sciences Corporation for use by Stratolaunch Systems.
Northrop Grumman Innovation Systems (NGIS) was a sector of Northrop Grumman from 2018 through 2019. It was formed from Orbital ATK Inc. a company which resulted from the merger of Orbital Sciences Corporation and parts of Alliant Techsystems in 2015. Orbital ATK was purchased by Northrop Grumman in 2018. Northrop Grumman Innovation Systems designed, built, and delivered space, defense, and aviation-related systems to customers around the world both as a prime contractor and as a merchant supplier. It had a workforce of approximately 12,000 employees dedicated to aerospace and defense including about 4,000 engineers and scientists; 7,000 manufacturing and operations specialists; and 1,000 management and administration personnel. With Northrop Grumman's reorganization of its divisions effective January 1, 2020, NGIS was split, with most of the sector merging with other Northrop Grumman businesses into a new Space Systems sector.
Spirit of Mojave, previously Cosmic Girl is a Boeing 747-400 aircraft. A former passenger airliner operated by Virgin Atlantic, it was purchased by Virgin Galactic in 2015 to be used as the first stage launch platform for the air launch stage of the smallsat orbital launch vehicle, the LauncherOne. In 2017, the aircraft was transferred to the orbital launch subsidiary, Virgin Orbit, and its livery updated to Virgin Orbit. LauncherOne attempted its first launch on 25 May 2020; the launch was a failure. The first successful launch took place on 17 January 2021.
The Antonov An-325 was a proposed evolution of the Antonov An-225 "Mriya", designed to launch spacecraft of various purposes into circular, elliptical and high-circle orbits, including geostationary orbit. It was planned to be an enlarged and improved version of the An-225, but was never built.
