Spaceplane is a winged vehicle that acts as an aircraft while in the atmosphere and as a spacecraft while in space. To do so, spaceplanes must incorporate features of both aircraft and spacecraft. Space Shuttle is a spaceplane, takes off vertically using rockets, but when it comes back to the ground it uses its wings for lift and lands like a plane. Another, Dream Chaser, is under development.
Spaceplanes operate at either a sub-orbital or an orbital level: a sub-orbital flight is one that reaches space but does not complete a full ‘orbit’ of the Earth. 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 but then landed as unpowered gliders.
One of the reason Spaceplanes are being developed is also because of increasing interest of people in space tourism, people who want to visit space. Spaceplanes can enable intercontinental travel at very high speeds, travelling on a sub-orbital trajectory, journey times from the UK to Australia could be cut from the current duration of around 20 hours to as little as two hours.
Another reason Spaceplanes are being also planned is to reduce the access to space for launching payloads. Current satellite launch systems, require scheduling years in advance for an extremely limited inventory of available slots. Moreover, launches often cost hundreds of millions of dollars each, due in large part to the massive amounts of dedicated infrastructure and large number of personnel required.
Sub-orbital spaceplanes will be able to insert small satellites into Low Earth Orbit (LEO) or into geostationary orbit. Spaceplanes could also launch constellations of small satellites which do not require the weight capability, or large expense, associated with traditional payload launches sold by United Launch Alliance, the Boeing-Lockheed Martin Corp. joint venture, Arianespace, or Elon Musk’s SpaceX. The solar-powered space planes were built by Boeing and feature a miniature payload bay to host experiments or smaller satellites.
They shall also provide revolutionary military capability like prompt global strike, launch on demand, satellite servicing and antisatellite missions. The U.S. Air Force has at least two reusable X-37B spacecraft in its fleet, and both have flown multiple flights.
Spaceplanes must operate in space, like traditional spacecraft, but also must be capable of atmospheric flight, like an aircraft. These requirements drive up the complexity, risk, dry mass, and cost of spaceplane designs. The flight trajectory required to reach orbit results in significant aerodynamic loads, vibrations, and accelerations, all of which have to be withstood by the vehicle structure.
Perhaps even more of a technical challenge is that the aerodynamics of horizontal take off to orbit are brutal. Rockets fly vertically, and get out of the atmosphere by a relatively short line. Horizontal take-off craft have to fly very fast through the atmosphere for a much longer time. This causes temperatures and stresses that are significant. The craft also has to remain stable, through supersonic speeds while it’s weight might be shifting due to burning fuel.
Even more challenging is how to handle the air at that speed. At supersonic speeds the air being taken in to provide the oxygen for the engines will be heated to over 1000C. The biggest challenge has been to design an engine that can cool that air down to sub zero temperatures in a fraction of a second. Some designs have a precooling component, but again that adds weight.
Once on-orbit, a spaceplane must be supplied with power by solar panels and batteries or fuel cells, maneuvered in space, kept in thermal equilibrium, oriented, and communicated with. On-orbit thermal and radiological environments impose additional stresses. This is in addition to accomplishing the task the spaceplane was launched to complete, such as satellite deployment or science experiments.
Orbital spacecraft reentering the Earth’s atmosphere must shed significant velocity, resulting in extreme heating. For example, the Space Shuttle thermal protection system (TPS) protects the orbiter’s interior structure from surface temperatures that reach as high as 1,650 °C (3,000 °F), well above the melting point of steel. Suborbital spaceplanes fly lower energy trajectories that do not put as much stress on the spacecraft thermal protection system. The Space Shuttle Columbia disaster was the direct result of a TPS failure.
Aerodynamic control surfaces must be actuated. Landing gear must be included at the cost of additional mass.
Current spaceplane engine designs are significantly heavier than conventional jet engines or rocket engines, even if you add the weight of the empty oxygen tanks. The weight of fuel is shed as the fuel is burned and expelled as propellant. The extra weight of a heavier engine, however, stays with the craft all the way into orbit. So far the heavy weight of such engines more than offsets the savings in fuel weight. So any future design would have to put a premium on reducing that weight, otherwise most of the potential advantage is gone.
An air-breathing orbital spaceplane would have to fly what is known as a ‘depressed trajectory,’ which places the vehicle in the high-altitude hypersonic flight regime of the atmosphere for an extended period of time. This environment induces high dynamic pressure, high temperature, and high heat flow loads particularly upon the leading edge surfaces of the spaceplane, requiring exterior surfaces to be constructed from advanced materials and/or use active cooling.
Despite many plans, prototypes, and experimental flights since, only two spaceplanes have ever entered service, the Space Shuttle and the top-secret Boeing X-37B. Only the small, unmanned Boeing remains in service.
Space Plane progress
Considering their commercial and military potential many countries have launched spaceplane programs. Three types of spaceplane have successfully launched to orbit, reentered Earth’s atmosphere, and landed: the Space Shuttle, Buran, and the X-37. Another, Dream Chaser, is under development.Virgin Orbit says it will debut LauncherOne with its modified Boeing 747 carrier aircraft early this year, and Huntsville, Alabama, startup Aevum plans a first launch using a drone in 2021.
The U.S. Air Force’s unpiloted X-37B space plane landed back on Earth Sunday (Oct. 2019) after a record 780 days in orbit , racking up the fifth ultra-long mission for the military’s mini-shuttle fleet. The secretive spacecraft — also called the Orbital Test Vehicle (OTV), which looks like a miniature Space Shuttle — launched atop a SpaceX Falcon 9 rocket on Sept. 7, 2017, from Launch Complex 39A at NASA‘s Kennedy Space Center, and marked the first time the USAF launched the OTV with a provider other than United Launch Alliance (ULA). The U.S. Air Force’s unmanned X-37B space plane has flown four clandestine missions to date, carrying secret payloads on long-duration flights in Earth orbit. They were originally designed to spend up to 240 days in orbit.
Dawn Aerospace is developing a drone-launched rocket system. Rea said the uncrewed spaceplane would fly above 100 kilometers, reaching a speed of 4-kilometers per second. An expendable two-stage rocket would then vault “several hundred kilograms” into low Earth orbit, Wink said. Dawn Aerospace hasn’t finalized how much mass its future launch system will be able to carry, Wink said. The company plans to conduct a suborbital flight in 2020, in hopes of maturing launcher technology and creating an additional revenue stream by carrying payloads to microgravity, he and Rea said.
The company’s orbital launch system is at least four years away from flying, Wink said. “What we’re really after is applying the model of aviation to space transportation,” he said. “Part of that is not requiring a whole lot of ground infrastructure. We want to be as flexible as possible, taking off from any place in the world.”
Boeing and DARPA are partnering on a reusable suborbital spaceplane , the size of a business jet could be launching and landing at Cape Canaveral in 2020. XS-1 Spaceplane project that aims to create an aerospace platform that’s capable of providing hypersonic, airplane-like access to space to bolster U.S. national security. The craft would be capable of launching on short notice, cost little to get into low-Earth orbit and presumably be capable of re-entering the atmosphere to deliver munitions. In Jan 2020 Boeing withdrew from Experimental Spaceplane (XSP). “This effectively ends the XSP program; however, the objectives of the program remain of interest, and may be explored in separate, competitively selected efforts,” DARPA communications chief Jared Adams said.
China appears to have launched an experimental space plane, which may be the precursor to a vehicle that can carry humans to and from space. Early on 4 September 2020 , China launched a Long March 2F rocket from its Jiuquan Satellite Launch Center in the Gobi Desert. While there was no official announcement prior to the launch, several observers noticed air traffic restrictions that indicated a launch was taking place. The state-run Xinhua News Agency later confirmed the launch, saying that a “reusable experimental spacecraft” was on board that would “test reusable technologies during its flight, providing technological support for the peaceful use of space”. On 6 September, it reported that the craft had landed after a two-day mission. Orbital data confirmed that the vehicle had been placed in an orbit up to 350 kilometres in altitude, a similar height to China’s previous crewed flights.
Such a vehicle could take Chinese astronauts to and from orbit, possibly to a planned future Chinese space station. Jean Deville, a space analyst who tracks China’s activities, says a reusable crewed space plane could be part of China’s ambitious crewed space programme, which includes its operational Shenzhou spacecraft and a new deep space vehicle. “A space plane is an ideal technology for atmospheric re-entry due to less brutal accelerations for the human body,” she says. Another possibility is that the vehicle is more similar to the secretive American X-37B space plane, a small uncrewed reusable craft built by Boeing, which has flown to space multiple times on missions lasting more than a year, performing unknown activities in orbit.
China may have as many as seven crewed and non-crewed spaceplane projects in development. The European Space Agency’s similar autonomous Space Rider flying laboratory is expected to blast off in 2023 and India’s own mini spaceplane later this decade.
Virgin Galactic World’s largest all-carbon composite Spaceplane for commercial human spaceflight
According to the company’s Twitter, SpaceShipTwo reached an altitude of 82.68 kilometers (51.4 miles) in its testflight in DEc 18, just high enough to pass the definition the US military and NASAhave set for the edge of space (and high enough for both pilots to get FAA commercial astronaut wings). But it didn’t reach the Karman Line, the common line used to represent the border between Earth’s atmosphere and space, 100 kilometers above Earth’s surface. NASA also flew payloads on the flight, making it the first revenue-generating flight for the company.
Virgin Galactic’s space flight experience features an air launch followed by a rocket-powered ascent at three and a half times the speed of sound, the silence of space, several minutes of out-of-seat weightlessness and multiple windowed views of our home planet. It’s also the first vehicle built for commercial use and piloted by humans to reach space, according to Branson.
Virgin Galactic’s human spaceflight system consists of two vehicle types: SpaceShipTwo and WhiteKnightTwo. SpaceShipTwo is a reusable, winged spacecraft designed to repeatedly carry as many as eight people (including two pilots) into space. WhiteKnightTwo is a custom-built, four-engine, dual-fuselage jet carrier aircraft. It is designed to carry SpaceShipTwo up to an altitude of ~50,000 feet for safe and efficient air launch and dropped. At that point, SpaceShipTwo’s onboard rocket motor fires up, blasting the vehicle up to a minimum of 62 miles above Earth’s surface—the internationally accepted boundary where outer space begins. After lingering at the edge of space for a few minutes — where “space tourists” will be able to experience weightlessness — SpaceShipTwo shifts the positions of its wings to safely reenter Earth’s atmosphere and glide back down to a runway.
SpaceShipTwo is powered by a hybrid rocket motor — one that combines elements of solid rockets and liquid rocket engines by using a solid fuel source and a liquid oxidizer. WhiteKnightTwo with 140-foot-long wing spar is touted as the world’s largest all carbon composite aircraft. This dual-fuselage jet aircraft is powered by four Pratt & Whitney engines which “are amongst the most powerful, economic and efficient available.
During the last test flight in the Mojave Desert on 31 October 2014 SpaceShipTwo rocket plane disintegrated within seconds killing one pilot and injuring the other, after a premature repositioning of the vehicle’s twin tail wings. The violent crash of Virgin Galactic’s SpaceShipTwo was caused by a combination of human error and inadequate safety procedures, a nine-month investigation by the National Transportation Safety Board found.
Virgin Galactic’s small satellite launch system
Virgin Galactic small satellite launch system consists of two systems, one is modified Boeing 747 jet, nicknamed Cosmic Girl that shall carry the second system, a satellite-launching rocket called LauncherOne, beneath the plane’s left wing. Cosmic Girl will carry LauncherOne to at an altitude of approximately 35,000 feet before releasing the launch vehicle to begin its rocket-powered flight to orbit.
Virgin had already announced in September that it would offer launches of 200kg to a sun-synchronous orbit for less than $10 million, with options to launch as much as 400kg. The aim is to undercut traditional rocket launches and provide reliable access to space, even in bad weather — which the 747 can often fly above, since it can fly above the troposphere. Once released from the carrier aircraft, the LauncherOne rocket fires up its single main stage engine, a 73,500 lbf, LOX/RP-1 rocket engine called the “NewtonThree.” Typically, this engine will fire for approximately three minutes.
After stage separation, the single upper stage engine, a 5,000 lbf LOX/RP-1 rocket engine called the “NewtonFour” will carry the satellite(s) into orbit. Typically, the second stage will execute multiple burns totaling nearly six minutes. Both the NewtonThree and the NewtonFour are highly reliable liquid rocket engines designed, tested, and built by Virgin Galactic. At the end of this sequence, LauncherOne will deploy our customers’ satellite (or satellites) into their desired orbit. Both stages of LauncherOne will be safely deorbited, while the carrier aircraft will return to a predetermined airport, where it can be quickly prepared for its next flight.
The recent rise of cubesats and microsatellites depend heavily on development of low cost small satellite launch vehicles for commercial satellite start-ups, universities, schools, and even crowdfunding campaigns. These can then be used cost effectively to conduct a staggering array of missions from exploration of space to improving life here on Earth.
Europe’s IXV Space plane
The European Space Agency expects to carry out the qualification flight of the Space Rider spaceplane in 2021 followed by multiple demonstration missions before handing over the program to industry, according to Lucia Linares, head of ESA space transportation strategy and policy. By 2025, ESA officials said, Space Rider could be operating commercially, flying science payloads and bringing them back to Earth for roughly $40,000 per kilogram. Space Rider, at an expected 4-5 meters in length, will be about half the size of the U.S. Air Force’s X-37B unmanned orbital spaceplane. Linares also said that ESA and its partner Arianespace are readying for a proof-of-concept flight of the Small Spacecraft Mission Service, which is set to take place in early 2019. The mission will test a new smallsat dispenser aboard the Vega rocket, Arianespace’s smallest launcher.
Space Rider is based on ESA’s successful suborbital re-entry test vehicle, the Intermediate Experimental Vehicle (IXV). In 2015, the IXV flew more than halfway around the world in 100 minutes before parachuting into the Pacific Ocean for recovery. A 2020 test flight would see Space Rider launch atop Arianespace’s Vega-C rocket (which makes its own debut in 2019) and land on a runway on one of the Atlantic’s Azores islands, Santa Maria. During operational flights, Space Rider will orbit 400 kilometers above the Earth for a few months at the time, opening its payload bay doors to expose experiments to the space environment.
After Space Riders’s first mission in 2020, it would fly five more missions spaced six to 12 months apart, according to Tumino. During this first few years of operations, a decision would be made about how many Space Riders to build for commercial operations; Arianespace, he said, might decide to operate a fleet of them. During development, a full-scale Space Rider model will be dropped in 2019 from an atmospheric balloon or helicopter to test the vehicle’s parafoil landing system.
At the center of IXV’s technology demonstration goals is the ambition to build affordable reusable vehicles capable of operating modular payloads for multiple applications in various orbits – with missions concluding with a touchdown on a conventional runway. IXV is a wingless spacecraft with a lifting body design, which means the vehicle’s aerodynamic shape gives it the lift it needs to stay aloft. Two aft-mounted flaps will steer the spacecraft during its descent.
The spacecraft’s belly is covered in protective heat-resistant panels made of carbon fibers that have been woven into a ceramic matrix. An infrared camera and 300 sensors on the heat shield will map the heat flow on IXV’s belly during re-entry. ESA’s IXV project is developing and flight-testing critical reentry technologies like Aerothermodynamics, Guidance Navigation and Control (GNC) and Thermal Protection and Hot Structures
This new vehicle will be a step up from IXV and serve as an orbital platform to test in orbit technologies not only for future European Space Transportation, but also for multiple applications such as future reusable launchers stages (lower and upper), robotic exploration (for example, sample return from mars or asteroid), servicing of orbital infrastructures (for example, international space station), servicing of future generation satellites (for example, in-orbit refuelling or disposal), microgravity experiments (for example, optimum time/cost ratio), earth sciences (for example, high-altitude atmospheric research), earth observation (for example, crisis monitoring).
Reaction Engines fully reusable, single-stage to orbit, unmanned spaceplane
UK-based company Reaction Engines is developing a fully reusable, single-stage to orbit, unmanned spaceplane called SKYLON. Its SABRE (Synergetic Air-Breathing Rocket Engine) will enable it to take off from a runway and transition from air-breathing to rocket propulsion at an altitude of 80,000 feet (26 kilometres). The Synergetic Air Breathing Rocket Engine (Sabre) is a hydrogen-powered engine that can propel a spaceplane like Skylon from zero to hypersonic speeds by using the oxygen in the Earth’s atmosphere, and then when travelling fast enough, blast the vehicle into space using an on-board supply of oxygen like a conventional rocket.
Proposed uses for SKYLON are to launch satellites and carry cargo astronauts to the International Space Station (ISS). According to the company, Skylon can haul 12,000 kilos to low Earth orbit every few days. SABREs can be modified for purely atmospheric operation. The resulting hypersonic passenger aircraft could travel 20,000 km at Mach 5. However there are several challenges in building engines that could provide effective thrust from liftoff to altitudes as high as 25 kilometers including extremely high temperature of compressed air.
Since January 2014, the Air Force Research Laboratory (AFRL) has been developing hypersonic vehicle concepts that use the Synergetic Air-Breathing Rocket Engine (SABRE). In April 2015, Reaction Engines announced that an AFRL study had concluded that SABRE is feasible. One of the key SABRE technologies that AFRL, based in Ohio, will start work on later this year, is related to the engine’s precooler. SABRE’s precooler will cool such air from more than 1,832 degrees Fahrenheit (1,000 degrees Celsius) down to minus 238 F (minus 150 C) in one one-hundredth of a second. The oxygen in the chilled air will become liquid in the process.
It reportedly uses liquid helium cooling for this. The superheated air is blasted through a light-weight, ring-like device made up of thousands of thin-walled tubes through which coolant is passed. The aim of this precooler is to remove the extreme heat very quickly. When used in the Sabre engine, it’s hoped it will prevent its internal components melting in the high temperatures and ensure the engine runs efficiently. Early in 2019, the precooler had worked at 420C (788F) in conditions that replicated flight speeds of Mach 3.3, or more than three times the speed of sound. But the engineers wanted to reach the magic number of Mach 5. That is more than 6,200 km per hour (3,800 mph).
At Mach 5 and an altitude of 20km (12 miles) Sabre stops breathing the air, closes it inlets and starts to burn liquid oxygen mixed with its hydrogen fuel to reach speeds of Mach 25 which allow it to go into Earth orbit. In October 2019, the record was smashed, and Mach 5 was reached. The precooler successfully “quenched” air flowing into the machine at more than 1,000C (1,800F) in less than 1/20th of a second.
The success of the test earned team leader Helen Webber the Royal Aeronautical Society’s prestigious Sir Ralph Robins medal for engineering leadership, and the wider team a haul of awards. Now Webber is working on the core of the Sabre engine itself. While we may have to wait 10 years for flight trials of the engine to begin, their innovative heat-management technology looks set to be applied to other areas. In electric cars, for example, new efficient light-weight heat exchangers will make lithium batteries charge faster and last longer.
“Reaction Engines are doing a nice job of saying we are going to develop this technology first, and then this one,” says Christopher Combs, University of Texas at San Antonio. “It is easier to pitch heat exchangers to investors which can be used in a jet fighter in five years than pitching the Skylon and saying it will take 30 years to build.”
BAE has brought up 20-percent stake in the company for £20.6 million, and with £60 million in grants coming from the UK government, the company thinks it should have the resources it needs to stage a full-scale ground test of SABRE by 2020, and unmanned test flights around 2025.
China developing hybrid usable space plane
In July 2021, China successfully tested an experimental spacecraft that state media has hailed “an important symbol of China’s rise from a space power to a space superpower”. The vessel was described by the China Aerospace Science and Technology Corporation (CASC) as laying “a solid foundation for the development of China’s reusable space transport technology between Earth and space” – in other words, laying a foundation for the development of a reusable hypersonic space plane.
China unveiled its plans to launch its reusable spacecraft in 2020, according to a statement from China Aerospace Science and Technology Corporation. Unlike traditional one-off spacecraft, the new spacecraft will fly into the sky like an aircraft, said Chen Hongbo, a researcher from the corporation. The spacecraft can transport people or payload into the orbit and return to Earth. Chen said that the spacecraft will be easier to maintain and can improve the frequency of launches at lower cost, bringing new opportunities for more people to travel into space.
China is developing a perspective hybrid reusable space vehicle that will combine three different kinds of engine technologies, reported CCTV. Namely, the new ship that is being developed as a “combination powered aircraft” will rely on an indigenous turbine, ramjet and rocket engines to power the spaceship in different phases of the flight into space. Scientists believe that they are capable of producing an aircraft that will take off at low speed using a high-performance aviation turbine engine or air-breathing rocket engine. After reaching a certain speed, supersonic combustion ramjet engine will kick allowing the vehicle to reach the upper atmosphere where the rocket engine will be used to break through Earth’s gravity.
The idea envisions that the combination of engines will allow the aircraft to take off like an airplane and land at an airport facility, saving costs by getting rid of the expenses associated with the space launch facility. “We have made a long-term plan of taking about three to five years to master the key technologies, and significantly improve the capability of the spacecraft during the application,” said Zhang Yong, China Aerospace Science & Technology Corp, as quoted by Xinhua. “We aim to implement the technology in suborbital flight and orbital insertion by 2030.”
China launched a scaled-down model of a multipurpose, reusable space plane from a test site in the Gobi Desert in Feb 2018, part of its race to develop space travel technology. The hypersonic space drone lifted off from the Jiuquan Satellite Launch Centre in Inner Mongolia, accelerated to more than five times the speed of sound and reached orbital altitude before returning safely to ground, according to a researcher with knowledge of the experiment. China’s goal was to develop a space plane for both military and civilian missions, capable of travelling fast enough to penetrate missile defence systems and with the heft to help rebuild satellite networks or lift tourists to space, the researcher said.
China’s Shenlong space plane
A Jan. 8 report in Hong Kong’s Tung Fang Jih Pao quotes official military commentator Song Zhongping as saying the Strategic Support Force will be made up of an Internet Army, an Aerospace Army and Electronic Warfare Troops. Song went on to say that the new force would be equipped in the future with the Shenlong space plane that is capable of traveling in both space and air.
The Shenlong – Divine Dragon – employs high speed with maneuverability and radar-evading stealth features. It will be capable of long-range flight. In late 2010 or early 2011, China is believed to have conducted a sub orbital test of its Shenlong small space plane, a technology test bed which could also be developed into a multi-mission dual use platform similar to the U.S. Boeing X-37B small space plane.
According to official military commentator Song Zhongping , the unmanned Shenlong is being developed as space weapons launch platform, as well as for surveillance, intelligence and early-warning missions. The Shenlong – Divine Dragon – employs high speed with maneuverability and radar-evading stealth features.
Military analysts said the disclosure that the PLA plans to use the Shenlong for its Strategic Support Force highlights the buildup of PLA space warfare capabilities. The PLA also is working on rapid global strike weapons, including hypersonic glide vehicles to deliver nuclear or conventional weapons, anti-satellite missiles and other weapons, and missile defenses.China also conducted the sixth successful test of a new hypersonic strike vehicle capable of traveling up to 10 times the speed of sound.
China’s space plane program is controlled by China’s People’s Liberation Army (PLA), will likely be “dual use,” designed to fulfill military and non-military missions. China’s space planes may also be intended to fulfill new strategies (doctrines) outlined by the People’s Liberation Army Air Force (PLAAF) Commander General Xu Qiliang in 2009, as “effecting air and space integration, possessing capabilities for both offensive and defensive operations.”
“Space planes are attractive militarily because they are reusable, can be configured to perform passive or active military missions, such as capturing and returning an enemy satellite,” Rick Fisher, a China military affairs analyst with the International Assessment and Strategy Center said.
China Sets Sights On Building The Largest Spaceplane In The World
China Academy of Launch Vehicle Technology is working on an enormous spaceplane, which when ready will be capable of transporting up to 20 people to space. This number is the highest recorded of passengers accommodated by a commercial spaceflight company.
The team has already proposed two prototype designs of the commercial rocket plane. The first has 10 tons, and will be followed by a more complex prototype of 100 tons. The first rocket is designed to fly up to 62 miles high — at the official line that marks the beginning of space travel — while the second prototype will go 19 miles farther. “The vehicle will take off vertically like a rocket and land on the runway automatically without any ground or on-board intervention,” according to Han Pengxin, the academy team leader. The rocket plane will burn liquid oxygen and liquid methane.
The Chinese rocket is to be finished in no more than two years, since “almost all of the ground tests have been finished and all the subsystems of the test vehicle worked very well,” said Han. Some members of the scientific community, however, are skeptical about how realistic these plans are. Roger Launius, spaceflight expert and former NASA cheif historian, says “The most unusual part is the belief that they can send up to 20 people to 100 kilometers and more on a rocket without a mother ship and no staging, reusing it some 50 times. It’s not explained how that will be accomplished. And the fact that they think they can test fly in the next 2 years is remarkable.”
The Chinese company is not the only one to invest in commercial space travel. SpaceShip Two of Virgin Galactic will also transport passengers into space, but no more than six at a time.
On November 15, 1988, the Soviet Union’s Buran spaceplane lifted skyward, joining NASA’s space shuttle as a new breed of reusable spacecraft. But with the USSR on the brink of collapse, that hopeful first launch would be the orbiter’s last.
Russia is now developing an unmanned spaceplanes. The development of a “space yacht” capable of taking off from ordinary airfields to deliver tourists to near-earth orbit, is conducted in Russia with the support of the National Technology Initiative’s (NTI) AeroNet and SpaceNet working groups, chief designer of NPO Aviation and Space Technologies Alexander Begak told Sputnik. “We have an opportunity to land on any airfield, the device lands like an airplane… We now calculate the optimal time for space travel, a comfortable flight path, because experience shows that people do not need to be in zero-gravity condition for as long as 10 minutes”, Begak said. The development of a suborbital unmanned spacecraft dubbed Selena Space Yacht began two years ago, he noted. According to the designer’s idea, the vehicle will enter space at a maximum speed of 3.5 mach (2.685 miles per hour) to a height of 120-140 kilometers and will return back into the atmosphere at a speed of 0.85 mach.
A total of three “space yachts” will be created, with six passenger seats and one pilot seat each. Despite the fact that the spacecraft will be unmanned, the pilot will still be present for convenience of passengers. “There will be a pilot inside, but he will not control the spacecraft. This is due to the fact that people should feel comfortable, knowing that there is a pilot on board, and after entering the atmosphere, he will congratulate the passangers on this event”, Begak said. The cost of the flight will be about $200,000-$300,000 per person, the first flights could start in 5 years, he added. Earlier, the designer had already built unique devices, which, in particular, were exhibited at MAKS and Army aerospace shows. In just one month last year, Begak created Begalet HYPE, a device capable of flying, travelling by road and by water.
Russia is developing PAK-DA is the first Russian hypersonic stealth bomber. PAK-DA will serve as a launch platform for long-range nuclear and conventional cruise missiles and a host of precision-guided munitions. The PAK-DA will be equipped with a special hybrid Turbofan engine, making it capable of low-level space flight. When flying inside the earth’s atmosphere, the bomber will burn traditional kerosene fuel. Once in space, the engine switches to methane and oxygen, allowing the PAK-DA to fly without air. General Sergei Karakayev, commander of Russian Strategic Missile Forces, said that a model for the engine had already been built and tested at Russia’s Military Academy in Serpukhovo.
Dawn Aerospace aims to launch New Zealand’s 1st space plane
In Jan 2021, Dawn Aerospace got the nod from the New Zealand Civil Aviation Authority (CAA) to fly the company’s Mk-II Aurora space plane, which is designed to send satellites into space on multiple flights a day, at a conventional airport whose name and location has not been disclosed yet. Usually such vehicles need to be launched at isolated facilities, because otherwise regulators need to shut down the local commercial air space to allow the space planes to fly out of the atmosphere.
“The challenge of getting to space is equal parts the vehicle, the launch infrastructure and the regulation,” Dawn chief technical officer Stefan Powell said in a statement. “We have made great strides in revolutionizing the hardware. Today is a significant step towards the rest; showing we can fly from one of the thousands of civilian airports around the world, and do so without kicking other aircraft out of their airspace. This is the key to rapid, reusable and sustainable spaceflight.”
Putting Dawn Aerospace’s vehicle at an airport may, in the long run, reduce costs and other complications, the company added in the statement. The company and CAA spent 18 months designing flight procedures and systems to let Dawn’s planes fly safely along with commercial flights at the airport.
US Military Spaceplanes
The US’s 2006 QDR stressed on need for prompt global strike capabilities, noting that they would provide the United States with the ability “to attack fixed, hard and deeply buried, mobile and re-locatable targets with improved accuracy anywhere in the world promptly upon the President’s order.”
US Air Force X-37B Space Plane
The robotic vehicle resembles NASA’s famous space shuttle but is much smaller. The X-37B is about 29 feet (8.8 meters) long and 9.5 feet (2.9 m) tall, with a wingspan just less than 15 feet (4.6 m). At launch, it weighs 11,000 lbs. (4,990 kilograms). Since its maiden launch in April 2010, the X-37B has been launched vertically atop a United Launch Alliance’s Atlas V (501) rocket from Cape Canaveral Air Force Base in Florida and cruising back to Earth for an autonomous runway landing at California’s Vandenberg Air Force Base. “The primary objectives of the X-37B are twofold: reusable spacecraft technologies for America’s future in space and operating experiments which can be returned to, and examined, on Earth,” according to the Air Force.
One of the payloads carried aloft is the second version of the Advanced Structurally Embedded Thermal Spreader (ASETS-II). The hardware, designed to test a thermal management system optimized for the space environment, was developed under a program managed by the Air Force Research Laboratory (AFRL) Space Vehicles Directorate at Kirtland Air Force Base in Albuquerque, New Mexico. Among the experiments for the flight are deploying 10 CubeSats contained in eight P-Pods that are part of the National Reconnaissance Office’s (NRO’s) Ultra Lightweight Technology and Research Auxiliary Satellite (ULTRASat). The 10 CubeSats in ULTRASat are managed by the NRO and NASA.
Also aboard the X-37B is a NASA materials science experiment called METIS and an advanced Hall thruster experiment. Hall thruster is a type of electric propulsion device that uses an electric field to ionise and accelerate a noble gas like xenon, propelling it outwards to produce thrust for the vehicle. These generate lower thrust when compared to that of conventional rocket engines and have to operate for longer periods of time to achieve the desired result. They are however more efficient for small velocity changes and also provide better fuel economy.
The X-37Bs “could be used to rendezvous and inspect satellites, either friendly or adversarial, and potentially grab and de-orbit satellites,” the Secure World Foundation, a space advocacy group, pointed out.
DARPA’s Experimental Spaceplane (XS-1) program
DARPA announced the XS-1 program in 2013 as a way of supporting the development of responsive, reusable launch vehicles. One major goal of the program was to perform 10 flights of the vehicle in 10 days, with at least one of those flights going to Mach 10, to demonstrate its rapid turnaround. DARPA launched Experimental Spaceplane (XS-1) program with aim to develop an unmanned military space plane to carry small satellites into space and serve as a test bed for a futuristic fleet of hypersonic vehicles. XS-1 could ‘create a new paradigm for more routine, responsive and affordable space operations,’ according to DARPA, the military research arm heading the project.
DARPA selected The Boeing Company to complete advanced design work for the Agency’s Experimental Spaceplane (XS-1) program, which aims to build and fly the first of an entirely new class of hypersonic aircraft that would bolster national security by providing short-notice, low-cost access to space. The program aims to achieve a capability well out of reach today—launches to low Earth orbit in days, as compared to the months or years of preparation currently needed to get a single satellite on orbit. Success will depend upon significant advances in both technical capabilities and ground operations, but would revolutionize the Nation’s ability to recover from a catastrophic loss of military or commercial satellites, upon which the Nation today is critically dependent.
The XS-1 is designed to quickly lift satellites as heavy as 3,000 pounds into orbit for $5 million or less, launching from the ground, deploying a small upper-stage module, and then landing like a traditional airplane—the key to reuse and lower operating expense. Darpa also has a separate program aimed at launching 100-pound satellites for less than $1 million per launch, using conventional aircraft.
XS-1 shall be also be capable of releasing an expendable upper stage in low-Earth orbit able to deploy a 3,000-pound satellite to polar orbit. “The XS-1 would be neither a traditional airplane nor a conventional launch vehicle but rather a combination of the two, with the goal of lowering launch costs by a factor of ten and replacing today’s frustratingly long wait time with launch on demand,” said Jess Sponable, DARPA program manager. “Phantom Express is designed to disrupt and transform the satellite launch process as we know it today, creating a new, on-demand space-launch capability that can be achieved more affordably and with less risk,” said Darryl Davis, president of Boeing Phantom Works.
The Phantom Express will be powered with an Aerojet Rocketdyne Holdings Inc. AR-22 engine, a newer version of the main engine trio that served on NASA’s Space Shuttle. Boeing will design and build the aircraft through 2019, including 10 engine ground firings over 10 days, followed by 12-15 flight tests in 2020. A Boeing spokeswoman declined to comment on the project’s cost.
The Phantom Express booster stage will have advanced, lightweight composite cryogenic tanks to hold the super-cold propellants feeding the AR-22 engine. Hybrid metallic-composite wings and control surfaces on the spaceplane will be fitted with “third-generation thermal protection” to withstand the rigors of hypersonic flight and re-entry temperatures of more than 2,000 degrees Fahrenheit (1,100 degrees Celsius), according to DARPA and Boeing.
Other technologies in the XS-1 design include:
- Advanced, lightweight composite cryogenic propellant tanks to hold liquid oxygen and liquid hydrogen propellants
- Hybrid composite-metallic wings and control surfaces able to withstand the physical stresses of suborbital hypersonic flight and temperatures of more than 2,000o F
- Automated flight-termination and other technologies for autonomous flight and operations, including some developed by DARPA’s Airborne Launch Assist Space Access (ALASA) program
DARPA’s XS-1 space plane is functionally similar to launch vehicle. XS-1 envisions that a fully reusable unmanned booster vehicle would fly to high speeds at a suborbital altitude. At that point, one or more expendable upper stages would separate, boost and deploy a satellite into low Earth orbit (LEO). The reusable first stage would then return to earth, land and be prepared for the next flight.
“In an era of declining budgets and adversaries’ evolving capabilities, quick, affordable and routine access to space is increasingly critical for both national and economic security”, says DARPA.
The second stage of the initiative will have four primary technical goals.
- Fly 10 times in a 10-day period (not including weather, range and emergency delays) to demonstrate aircraft-like access to space and eliminate concerns about the cost-effectiveness and reliability of reusable launch.
- Achieve flight velocity sufficiently high to enable use of a small (and therefore low-cost) expendable upper stage.
- Launch a 900 to 1,500-lb (408 to 680-kg) representative payload to demonstrate an immediate responsive launch capability able to support both DoD and commercial missions. The same XS-1 vehicle could eventually also launch future 3,000+-lb (1,361-kg) payloads by using a larger expendable upper stage.
- Reduce the cost of access to space for 3,000+-lb payloads, with a goal of approximately $5 million per flight for the operational system, which would include a reusable booster and expendable upper stage(s).
Successful design would require integrating state-of-the-art technologies, processes and system approaches to deliver routine aircraft-like operability, reliability and cost efficiency. In particular, incorporation of autonomous technology and operations promises to significantly decrease the logistical footprint and enable rapid turnaround between flights.
Structures made of advanced materials, cryogenic tanks, durable thermal protection, and modular subsystems would make possible a vehicle able to launch, fly to high speeds and then land in a condition amenable to rapid turnaround and launch with the next payload. Reusable, reliable propulsion would also be essential for a low-cost and recurring flight capability.
DARPA have funded the second stage of the program in August 2015, three teams, one from Boeing and Jeff Bezos’s Blue Origin, one of Northrup Grumman that also features Scaled Composites and Virgin Galactic, and one from Masten Space Science Systems together with XCOR Aerospace, were each awarded $6.5 million to continue development of their (eventually) cheap, reusable space planes.
‘Our design would allow the autonomous booster to carry the second stage and payload to high altitude and deploy them into space. ‘The booster would then return to Earth, where it could be quickly prepared for the next flight by applying operation and maintenance principles similar to modern aircraft.’ said Will Hampton, Boeing XS-1 program manager.
Phase 3 objectives include 12 to 15 flight tests, currently scheduled for 2020. After multiple shakedown flights to reduce risk, the XS-1 would aim to fly 10 times over 10 consecutive days, at first without payloads and at speeds as fast as Mach 5. Subsequent flights are planned to fly as fast as Mach 10, and deliver a demonstration payload between 900 pounds and 3,000 pounds into low Earth orbit.
In July 2018, Aerojet Rocketdyne showed that its AR-22 engine was capable of such a high flight rate when the company performed 10 static-fire tests of the same engine in a 240-hour period. At the time, DARPA called that test series “a significant go/no-go milestone for us” to continue with the program. Neither DARPA nor Boeing, though, provided many updates on the status of the program after that series of tests.
Boeing has decided to no longer continue development of an experimental suborbital spaceplane for the Defense Advanced Research Projects Agency, the latest setback for DARPA’s long-running efforts in space access. DARPA cited that series of AR-22 engine tests as one of the major achievements of the program. “The detailed engineering activities conducted under the Experimental Spaceplane Program affirmed that no technical showstoppers stand in the way of achieving DARPA’s objectives, and that a system such as XSP would bolster national security,” Adams said. “Through XSP, DARPA identified evidence that present-day liquid rocket propulsion systems are capable of supporting XSP objectives, remain of interest, and may be explored in separate efforts.” “We will make it a priority to harvest the significant learnings from this effort and apply them as Boeing continues to seek ways to provide future responsive, reusable access to space,” Drelling said.
Boeing’s decision, which effectively ends the XSP program, adds another chapter to DARPA’s history of unsuccessful launch vehicle development efforts. In the early 2000s, DARPA’s Responsive Access, Small Cargo, Affordable Launch (RASCAL) program supported initial development of an air-launch system using a high-speed aircraft by a small California startup, Space Launch Corp. DARPA terminated the RASCAL program in 2005 while that concept was still in its early design phases.
DARPA then embarked on Force Application and Launch from Continental U.S. (FALCON) program to develop both a hypersonic testbed vehicle and a small launch system. FALCON included study contracts to several companies, such as Lockheed Martin, Orbital Sciences and SpaceX. Another startup, AirLaunch LLC, proposed development of a small launch vehicle that would be deployed from a C-17 cargo aircraft, conducting a drop test to demonstrate the feasibility of their concept. DARPA, though, elected to focus the FALCON program on a hypersonic testbed.
Coincident with the XS-1 program was DARPA’s Airborne Launch Assist Space Access (ALASA), which sought to develop a small rocket that could be launched from a fighter with just 24 hours’ notice and for no more than $1 million. Boeing won a contract in 2014 to develop a rocket using an unusual “mixed monopropellant” of nitrous oxide and acetylene, called NA-7, that could be launched from an F-15. However, DARPA ended plans to perform a flight demonstration with ALASA in November 2015 after discovering that NA-7 was too volatile to be safely handled. The agency did continue ground tests of some technologies related to the program.
DARPA Falcon HTV-2 Experimental Hypersonic Test Vehicle
In 2003, the Air Force and DARPA (the Defense Advanced Research Projects Agency) initiated a program, known as FALCON (force application and launch from continental United States) to research a delivery vehicle with goal to deliver non-nuclear ordnance anywhere in the world in under an hour. HTV-2 would be rocket launch system, unmanned and controlled from ground.
The system comprises two parts: a launch vehicle similar to a ballistic missile, and a hypersonic reentry vehicle, known as the Common Aero Vehicle (CAV) that, together, would provide the United States with the ability to meet the requirements of the prompt global strike mission. Delivery of CAVs may be conducted from a future military space plane (MSP) that could carry several CAVs, each containing multiple submunitions.
The FALCON glider is constructed from an array of exotic materials like carbon-carbon, which is used for both the body and aeroshell which provides protection against the extreme temperatures that moving at Mach 20 produces. These parts are built (or rather molded and cured) from piles of polymer composite using a recently unveiled “tape-wrap” process. This fabrication technique drastically cuts the cost of producing these vehicles. This technique requires 10 times fewer parts, 50 percent less human labor, and reduces the production cost by 40 percent per pound of carbon-carbon.
DARPA has already attempted two test flights—in 2010 and 2011—aimed at collecting detailed flight and telemetry data, though both missions failed after about nine minutes into their planned 30-minute flights. A seven-month study by the military’s Defense Advanced Research Projects Agency, or DARPA, has found that HTV-2 amazingly recovered from shockwaves that forced it to roll while traveling at Mach 20 in an August 2011 test. But the unmanned aircraft was unable to cope with damage to its exterior caused by its extreme speed, DARPA officials said