Sub-orbital spaceflight

Sub-orbital spaceflight

Discussion
Ask a question about 'Sub-orbital spaceflight'
Start a new discussion about 'Sub-orbital spaceflight'
Answer questions from other users
Full Discussion Forum
 
Encyclopedia
Suborbital human spaceflight
Name Debut Flights
Mercury
Project Mercury
In January 1960 NASA awarded Western Electric Company a contract for the Mercury tracking network. The value of the contract was over $33 million. Also in January, McDonnell delivered the first production-type Mercury spacecraft, less than a year after award of the formal contract. On February 12,...

 
1961 2
X-15  1962 13 or 2
(Soyuz 18a
Soyuz 18a
Soyuz 18a was a manned Soyuz spacecraft launched by the Soviet Union in 1975, intended to dock with the orbiting Salyut 4 space station, but which failed to achieve orbit due to a serious malfunction during launch...

)
1975 1
SpaceShipOne  2004 3


A sub-orbital space flight is a spaceflight
Spaceflight
Spaceflight is the act of travelling into or through outer space. Spaceflight can occur with spacecraft which may, or may not, have humans on board. Examples of human spaceflight include the Russian Soyuz program, the U.S. Space shuttle program, as well as the ongoing International Space Station...

 in which the spacecraft
Spacecraft
A spacecraft or spaceship is a craft or machine designed for spaceflight. Spacecraft are used for a variety of purposes, including communications, earth observation, meteorology, navigation, planetary exploration and transportation of humans and cargo....

 reaches space
Outer space
Outer space is the void that exists between celestial bodies, including the Earth. It is not completely empty, but consists of a hard vacuum containing a low density of particles: predominantly a plasma of hydrogen and helium, as well as electromagnetic radiation, magnetic fields, and neutrinos....

, but its trajectory
Trajectory
A trajectory is the path that a moving object follows through space as a function of time. The object might be a projectile or a satellite, for example. It thus includes the meaning of orbit—the path of a planet, an asteroid or a comet as it travels around a central mass...

 intersects the atmosphere
Atmosphere
An atmosphere is a layer of gases that may surround a material body of sufficient mass, and that is held in place by the gravity of the body. An atmosphere may be retained for a longer duration, if the gravity is high and the atmosphere's temperature is low...

 or surface of the gravitating body from which it was launched, so that it does not complete one orbit
Orbit
In physics, an orbit is the gravitationally curved path of an object around a point in space, for example the orbit of a planet around the center of a star system, such as the Solar System...

al revolution.

For example, the path of an object launched from Earth
Earth
Earth is the third planet from the Sun, and the densest and fifth-largest of the eight planets in the Solar System. It is also the largest of the Solar System's four terrestrial planets...

 that reaches 100 km (62 mi) above sea level
Sea level
Mean sea level is a measure of the average height of the ocean's surface ; used as a standard in reckoning land elevation...

, and then falls back to Earth, is considered a sub-orbital spaceflight. Some sub-orbital flights have been undertaken to test spacecraft and launch vehicle
Launch vehicle
In spaceflight, a launch vehicle or carrier rocket is a rocket used to carry a payload from the Earth's surface into outer space. A launch system includes the launch vehicle, the launch pad and other infrastructure....

s later intended for orbital spaceflight
Orbital spaceflight
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...

. Other vehicles are specifically designed only for sub-orbital flight; examples include manned vehicles such as the X-15
North American X-15
The North American X-15 rocket-powered aircraft/spaceplane was part of the X-series of experimental aircraft, initiated with the Bell X-1, that were made for the USAAF/USAF, NACA/NASA, and the USN. The X-15 set speed and altitude records in the early 1960s, reaching the edge of outer space and...

 and SpaceShipOne, and unmanned ones such as ICBMs
Intercontinental ballistic missile
An intercontinental ballistic missile is a ballistic missile with a long range typically designed for nuclear weapons delivery...

 and sounding rocket
Sounding rocket
A sounding rocket, sometimes called a research rocket, is an instrument-carrying rocket designed to take measurements and perform scientific experiments during its sub-orbital flight. The origin of the term comes from nautical vocabulary, where to sound is to throw a weighted line from a ship into...

s.

Sub-orbital spaceflights are distinct from flights that attain orbit but use retro-rockets to deorbit after less than one full orbital period. Thus the flights of the Fractional Orbital Bombardment System
Fractional Orbital Bombardment System
The Fractional Orbital Bombardment System was a Soviet ICBM program in the 1960s that after launch would go into a low Earth orbit and would then de-orbit for an attack. It had no range limit and the orbital flight path would not reveal the target location...

 would not be considered sub-orbital; instead these are simply considered flights to low Earth orbit
Low Earth orbit
A low Earth orbit is generally defined as an orbit within the locus extending from the Earth’s surface up to an altitude of 2,000 km...

.

Usually a rocket is used, but experimentally a sub-orbital spaceflight has also been achieved with a space gun
Space gun
A space gun is a method of launching an object into outer space using a large gun, or cannon. It provides a method of non-rocket spacelaunch‎.In the HARP Project a U.S...

.


Altitude requirement



By one definition a sub-orbital spaceflight reaches an altitude
Altitude
Altitude or height is defined based on the context in which it is used . As a general definition, altitude is a distance measurement, usually in the vertical or "up" direction, between a reference datum and a point or object. The reference datum also often varies according to the context...

 higher than 100 km above sea level
Sea level
Mean sea level is a measure of the average height of the ocean's surface ; used as a standard in reckoning land elevation...

. This altitude, known as the Kármán line
Karman line
The Kármán line lies at an altitude of above the Earth's sea level, and is commonly used to define the boundary between the Earth's atmosphere and outer space...

, was chosen by the Fédération Aéronautique Internationale
Fédération Aéronautique Internationale
The Fédération Aéronautique Internationale is the world governing body for air sports and aeronautics and astronautics world records. Its head office is in Lausanne, Switzerland. This includes man-carrying aerospace vehicles from balloons to spacecraft, and unmanned aerial vehicles...

 because it is roughly the point where a vehicle
Vehicle
A vehicle is a device that is designed or used to transport people or cargo. Most often vehicles are manufactured, such as bicycles, cars, motorcycles, trains, ships, boats, and aircraft....

 flying fast enough to support itself with aerodynamic lift from the Earth's atmosphere
Earth's atmosphere
The atmosphere of Earth is a layer of gases surrounding the planet Earth that is retained by Earth's gravity. The atmosphere protects life on Earth by absorbing ultraviolet solar radiation, warming the surface through heat retention , and reducing temperature extremes between day and night...

 would be flying faster than orbital speed
Orbital speed
The orbital speed of a body, generally a planet, a natural satellite, an artificial satellite, or a multiple star, is the speed at which it orbits around the barycenter of a system, usually around a more massive body...

.
The US military and NASA award astronaut wings
Astronaut Badge
The Astronaut Badge is a badge of the United States, awarded to military and civilian pilots who have completed training and performed a successful spaceflight...

 to those flying above 50 miles (80.47 km), although the US State Department appears to not support a distinct boundary between atmospheric flight and space flight.

Orbit


During freefall the trajectory is part of an elliptic orbit
Elliptic orbit
In astrodynamics or celestial mechanics an elliptic orbit is a Kepler orbit with the eccentricity less than 1; this includes the special case of a circular orbit, with eccentricity equal to zero. In a stricter sense, it is a Kepler orbit with the eccentricity greater than 0 and less than 1 . In a...

 as given by the orbit equation
Orbit equation
In astrodynamics an orbit equation defines the path of orbiting body m_2\,\! around central body m_1\,\! relative to m_1\,\!, without specifying position as a function of time...

. The perigee
Perigee
Perigee is the point at which an object makes its closest approach to the Earth.. Often the term is used in a broader sense to define the point in an orbit where the orbiting body is closest to the body it orbits. The opposite is the apogee, the farthest or highest point.The Greek prefix "peri"...

 distance is less than the radius of the Earth R including atmosphere, hence the ellipse
Ellipse
In geometry, an ellipse is a plane curve that results from the intersection of a cone by a plane in a way that produces a closed curve. Circles are special cases of ellipses, obtained when the cutting plane is orthogonal to the cone's axis...

 intersects the Earth, and hence the spacecraft will fail to complete an orbit. The major axis is vertical, the semi-major axis
Semi-major axis
The major axis of an ellipse is its longest diameter, a line that runs through the centre and both foci, its ends being at the widest points of the shape...

 a is more than R/2. The specific orbital energy
Specific orbital energy
In the gravitational two-body problem, the specific orbital energy \epsilon\,\! of two orbiting bodies is the constant sum of their mutual potential energy and their total kinetic energy , divided by the reduced mass...

  is given by:



where is the standard gravitational parameter
Standard gravitational parameter
In astrodynamics, the standard gravitational parameter μ of a celestial body is the product of the gravitational constant G and the mass M of the body.\mu=GM \ The SI units of the standard gravitational parameter are m3s−2....

.

Almost always a < R, corresponding to a lower than the minimum for a full orbit, which is

Thus the net extra specific energy needed compared to just raising the spacecraft into space is between 0 and .

Speed, range, altitude


To minimize the required delta-v
Delta-v
In astrodynamics a Δv or delta-v is a scalar which takes units of speed. It is a measure of the amount of "effort" that is needed to change from one trajectory to another by making an orbital maneuver....

 (an astrodynamical
Astrodynamics
Orbital mechanics or astrodynamics is the application of ballistics and celestial mechanics to the practical problems concerning the motion of rockets and other spacecraft. The motion of these objects is usually calculated from Newton's laws of motion and Newton's law of universal gravitation. It...

 measure which strongly determines the required fuel
Fuel
Fuel is any material that stores energy that can later be extracted to perform mechanical work in a controlled manner. Most fuels used by humans undergo combustion, a redox reaction in which a combustible substance releases energy after it ignites and reacts with the oxygen in the air...

), the high-altitude part of the flight is made with the rocket
Rocket
A rocket is a missile, spacecraft, aircraft or other vehicle which obtains thrust from a rocket engine. In all rockets, the exhaust is formed entirely from propellants carried within the rocket before use. Rocket engines work by action and reaction...

s off (this is technically called free-fall even for the upward part of the trajectory). The maximum speed
Speed
In kinematics, the speed of an object is the magnitude of its velocity ; it is thus a scalar quantity. The average speed of an object in an interval of time is the distance traveled by the object divided by the duration of the interval; the instantaneous speed is the limit of the average speed as...

 in a flight is attained at the lowest altitude of this free-fall trajectory, both at the start and at the end of it.

If one's goal is simply to "reach space", for example in competing for the Ansari X Prize
Ansari X Prize
The Ansari X Prize was a space competition in which the X Prize Foundation offered a US$10,000,000 prize for the first non-government organization to launch a reusable manned spacecraft into space twice within two weeks...

, horizontal motion is not needed. In this case the lowest required delta-v is about 1.4 km/s, for a sub-orbital flight with a maximum speed of about 1 km/s. Moving slower, with less free-fall, would require more delta-v.

Compare this with orbital spaceflights: a low Earth orbit (LEO), with an altitude of about 300 km), needs a speed around 7.7 km/s, requiring a delta-v of about 9.2 km/s.

For sub-orbital spaceflights covering a horizontal distance the maximum speed and required delta-v are in between those of a vertical flight and a LEO. The maximum speed at the lower ends of the trajectory are now composed of a horizontal and a vertical component. The higher the horizontal distance
Distance
Distance is a numerical description of how far apart objects are. In physics or everyday discussion, distance may refer to a physical length, or an estimation based on other criteria . In mathematics, a distance function or metric is a generalization of the concept of physical distance...

 covered, the more are both speeds, and the more is the maximum altitude. For the V-2 rocket
V-2 rocket
The V-2 rocket , technical name Aggregat-4 , was a ballistic missile that was developed at the beginning of the Second World War in Germany, specifically targeted at London and later Antwerp. The liquid-propellant rocket was the world's first long-range combat-ballistic missile and first known...

, just reaching space but with a range of about 330 km, the maximum speed was 1.6 km/s. Scaled Composites SpaceShipTwo
Scaled Composites SpaceShipTwo
The Scaled Composites Model 339 SpaceShipTwo is a suborbital, air-launched spaceplane, designed for space tourism. It is under development by The Spaceship Company, a California-based joint venture between Scaled Composites and the Virgin Group, as part of the Tier 1b program.SpaceShipTwo is...

 which is under development will have a similar free-fall orbit but the announced maximum speed is 1.1 km/s (perhaps because of engine shut-off at a higher altitude).

For larger ranges, due to the elliptic orbit the maximum altitude can even be considerably more than for a LEO. On an intercontinental flight, such as that of an intercontinental ballistic missile or possible future commercial spaceflight, the maximum speed is about 7 km/s, and the maximum altitude about 1200 km. Note that an intercontinental flight at an altitude of 300 km would require a larger delta-v, that of a LEO.
It should be noted that any spaceflight
Spaceflight
Spaceflight is the act of travelling into or through outer space. Spaceflight can occur with spacecraft which may, or may not, have humans on board. Examples of human spaceflight include the Russian Soyuz program, the U.S. Space shuttle program, as well as the ongoing International Space Station...

 that returns to the surface, including sub-orbital ones, will undergo atmospheric reentry
Atmospheric reentry
Atmospheric entry is the movement of human-made or natural objects as they enter the atmosphere of a celestial body from outer space—in the case of Earth from an altitude above the Kármán Line,...

. The speed at the start of that is basically the maximum speed of the flight. The aerodynamic heating
Aerodynamic heating
Aerodynamic heating is the heating of a solid body produced by the passage of fluid over a body such as a meteor, missile, or airplane. It is a form of forced convection in that the flow field is created by forces beyond those associated with the thermal processes...

 caused will vary accordingly: it is much less for a flight with a maximum speed of only 1 km/s than for one with a maximum speed of 7 or 8 km/s.

Flight duration


In a vertical flight of not too high altitudes, the time of the free-fall is both for the upward and for the downward part the maximum speed divided by the acceleration of gravity, so with a maximum speed of 1 km/s together 3 minutes and 20 seconds. The duration of the flight
Flight
Flight is the process by which an object moves either through an atmosphere or beyond it by generating lift or propulsive thrust, or aerostatically using buoyancy, or by simple ballistic movement....

 phases before and after the free-fall can vary.

For an intercontinental flight the boost phase
Boost phase
The boost phase is the portion of the flight of a ballistic missile or space vehicle during which the booster and sustainer engines operate until it reaches peak velocity. This phase can take 3 to 4 minutes , the altitude at the end of this phase is 150–200 km, and the typical burn-out speed...

 takes 3 to 5 minutes, the free-fall (midcourse phase) about 25 minutes. For an ICBM the atmospheric reentry
Atmospheric reentry
Atmospheric entry is the movement of human-made or natural objects as they enter the atmosphere of a celestial body from outer space—in the case of Earth from an altitude above the Kármán Line,...

 phase takes about 2 minutes; this will be longer for any soft landing, such as for a possible future commercial flight.

Suborbital flights can last many hours. Pioneer 1
Pioneer 1
On October 11, 1958, Pioneer 1 became the first spacecraft launched by NASA, the newly formed space agency of the United States. The flight was the second and most successful of the three Thor-Able space probes.- Spacecraft design :...

 was NASA
NASA
The National Aeronautics and Space Administration is the agency of the United States government that is responsible for the nation's civilian space program and for aeronautics and aerospace research...

's first space probe
Space probe
A robotic spacecraft is a spacecraft with no humans on board, that is usually under telerobotic control. A robotic spacecraft designed to make scientific research measurements is often called a space probe. Many space missions are more suited to telerobotic rather than crewed operation, due to...

, intended to reach the Moon
Moon
The Moon is Earth's only known natural satellite,There are a number of near-Earth asteroids including 3753 Cruithne that are co-orbital with Earth: their orbits bring them close to Earth for periods of time but then alter in the long term . These are quasi-satellites and not true moons. For more...

. A partial failure caused it to instead follow a suborbital trajectory, reentering the Earth's atmosphere 43 hours after launch.

Flight profiles


While there are a great many possible sub-orbital flight profiles, it is expected that some will be more common than others.

Ballistic missiles


The first suborbital vehicles which reached space were ballistic missiles. The very first ballistic missile to reach space was the German V-2
V-2 rocket
The V-2 rocket , technical name Aggregat-4 , was a ballistic missile that was developed at the beginning of the Second World War in Germany, specifically targeted at London and later Antwerp. The liquid-propellant rocket was the world's first long-range combat-ballistic missile and first known...

 on October 3, 1942 which reached an altitude of 60 miles (96.6 km). That in fact was the first man-made object of any kind to reach space. Then in the 1950s the USA and USSR concurrently developed much longer range Intercontinental Ballistic Missiles (ICBM)s all of which were based on the V-2 Rocket and the work of the scientists at Peenemunde
Peenemünde
The Peenemünde Army Research Center was founded in 1937 as one of five military proving grounds under the Army Weapons Office ....

. There are now many countries who possess ICBMs and even more with shorter range IRBMs (Intermediate Range Ballistic Missiles).

Tourist flights


Sub-orbital tourist flights
Space tourism
Space Tourism is space travel for recreational, leisure or business purposes. A number of startup companies have sprung up in recent years, hoping to create a space tourism industry...

 will initially focus on attaining the altitude required to qualify as reaching space. The flight path will probably be either vertical or very steep, with the spacecraft landing back at its take-off site.

The spacecraft will probably shut off its engine
Engine
An engine or motor is a machine designed to convert energy into useful mechanical motion. Heat engines, including internal combustion engines and external combustion engines burn a fuel to create heat which is then used to create motion...

s well before reaching maximum altitude, and then coast up to its highest point. During a few minutes, from the point when the engines are shut off to the point where the atmosphere begins to slow down the downward acceleration, the passengers will experience weightlessness
Weightlessness
Weightlessness is the condition that exists for an object or person when they experience little or no acceleration except the acceleration that defines their inertial trajectory, or the trajectory of pure free-fall...

.

In 2004, a number of companies worked on vehicles in this class as entrants to the Ansari X Prize competition. The Scaled Composites
Scaled Composites
Scaled Composites is an aerospace company founded by Burt Rutan and currently owned by Northrop Grumman that is located at the Mojave Spaceport, Mojave, California, United States...

 SpaceShipOne was officially declared by Rick Searfoss
Richard A. Searfoss
Richard Alan Searfoss is a retired United States Air Force colonel, NASA Astronaut and test pilot.-Early life:Searfoss was born on June 5, 1956, in Mount Clemens, Michigan, but considers Portsmouth, New Hampshire, to be his hometown...

 to have won the competition on October 4, 2004 after completing two flights within a two week period.

In 2005, Sir Richard Branson
Richard Branson
Sir Richard Charles Nicholas Branson is an English business magnate, best known for his Virgin Group of more than 400 companies....

 of the Virgin Group
Virgin Group
Virgin Group Limited is a British branded venture capital conglomerate organisation founded by business tycoon Richard Branson. The core business areas are travel, entertainment and lifestyle. Virgin Group's date of incorporation is listed as 1989 by Companies House, who class it as a holding...

 announced the creation of Virgin Galactic
Virgin Galactic
Virgin Galactic is a company within Richard Branson's Virgin Group which plans to provide sub-orbital spaceflights to the paying public, along with suborbital space science missions and orbital launches of small satellites...

 and his plans for a 9 seat capacity SpaceShipTwo named VSS Enterprise
VSS Enterprise
The VSS Enterprise is the first of five commercial suborbital spacecraft being constructed for Virgin Galactic by Scaled Composites....

. It has since been completed with eight seats (one pilot, one co-pilot and six passengers) and has taken part in captive-carry tests and with the first mother-ship WhiteKnightTwo, or VMS Eve
VMS Eve
VMS Eve is a carrier mothership for Virgin Galactic and launch platform for Scaled Composites SpaceShipTwo-based Virgin SpaceShips....

. It has also completed solitary glides, although the hybrid rocket
Hybrid rocket
A hybrid rocket is a rocket with a rocket motor which uses propellants in two different states of matter - one solid and the other either gas or liquid. The Hybrid rocket concept can be traced back at least 75 years....

 motor has not yet been fired. Four more of each have been ordered and will operate from the new Spaceport America
Spaceport America
Spaceport America is a spaceport located in the Jornada del Muerto desert basin in New Mexico, United States. It lies north of El Paso, north of Las Cruces, east of Truth or Consequences...

. Flights have been scheduled for 2011 driven by a "safety-driven schedule".

Scientific experiments


A major use of suborbital vehicles today are as scientific sounding rockets. Scientific suborbital flights began in the 1920s when Robert H. Goddard
Robert H. Goddard
Robert Hutchings Goddard was an American professor, physicist and inventor who is credited with creating and building the world's first liquid-fueled rocket, which he successfully launched on March 16, 1926...

 launched the first liquid fueled rockets, however they did not reach space
Space
Space is the boundless, three-dimensional extent in which objects and events occur and have relative position and direction. Physical space is often conceived in three linear dimensions, although modern physicists usually consider it, with time, to be part of a boundless four-dimensional continuum...

 altitude. Modern sounding rocket flights began in the late 1940s using vehicles derived from German V-2 ballistic missiles. Today there are dozens of different sounding rockets on the market, from a variety of suppliers in various countries. Typically, researchers wish to conduct experiments in microgravity or above the atmosphere. There have reportedly been several offers from researchers to launch experiments on SpaceShipOne, which have been turned down until the next version of the vehicle http://news.bbc.co.uk/1/hi/sci/tech/3722596.stm.

Suborbital transportation


Research, such as that done for the X-20 Dyna-Soar
X-20 Dyna-Soar
The X-20 Dyna-Soar was a United States Air Force program to develop a spaceplane that could be used for a variety of military missions, including reconnaissance, bombing, space rescue, satellite maintenance, and sabotage of enemy satellites...

 project suggests that a semi-ballistic sub-orbital flight could travel from Europe to North America in less than an hour.

However, the size of rocket, relative to the payload, necessary to achieve this, is similar to an ICBM. ICBMs have delta-v's somewhat less than orbital; and therefore would be somewhat cheaper than the costs for reaching orbit, but the difference is not large.

Thus due to the high cost, this is likely to be initially limited to high value, very high urgency cargo such as courier
Courier
A courier is a person or a company who delivers messages, packages, and mail. Couriers are distinguished from ordinary mail services by features such as speed, security, tracking, signature, specialization and individualization of express services, and swift delivery times, which are optional for...

 flights, or as the ultimate business jet
Business jet
Business jet, private jet or, colloquially, bizjet is a term describing a jet aircraft, usually of smaller size, designed for transporting groups of up to 19 business people or wealthy individuals...

; or possibly as an extreme sport
Extreme sport
An extreme sport is a popular term for certain activities perceived as having a high level of inherent danger...

, or for military
Military
A military is an organization authorized by its greater society to use lethal force, usually including use of weapons, in defending its country by combating actual or perceived threats. The military may have additional functions of use to its greater society, such as advancing a political agenda e.g...

 fast-response.

Tether launch assist



There have been proposals to use tethers (commonly referred to as skyhooks
Skyhook (structure)
Skyhooks are a theoretical class of cable based techniques intended to lift payloads to high altitudes and speeds. The name skyhook is a reference to an imaginary hook that hangs from the sky....

) to put suborbital payloads into orbit. For example, an orbiting space station
Space station
A space station is a spacecraft capable of supporting a crew which is designed to remain in space for an extended period of time, and to which other spacecraft can dock. A space station is distinguished from other spacecraft used for human spaceflight by its lack of major propulsion or landing...

 could extend a tether
Tether
A tether is a cord, fixture, or signal that anchors something movable to a reference point which may be fixed or moving. There are a number of applications for tethers: balloons, kites, tethered wind-energy conversion systems, anchors, tethered water-flow energy conversion systems, towing, animal...

, and a suborbital vehicle rendezvous with the end of the tether and dock to it. If practical, this would be considerably less expensive than launching payloads directly into orbit on rockets on a per flight basis.

Notable unmanned sub-orbital spaceflights

  • The first sub-orbital space flight was in early 1944, when a V-2 test rocket launched from Peenemünde
    Peenemünde
    The Peenemünde Army Research Center was founded in 1937 as one of five military proving grounds under the Army Weapons Office ....

     in Germany reached 189 kilometres altitude.
  • 8 September 1944, the world's first successful ballistic missile (V-2, launched by Germany) hits its target for the first time, Chiswick
    Chiswick
    Chiswick is a large suburb of west London, England and part of the London Borough of Hounslow. It is located on a meander of the River Thames, west of Charing Cross and is one of 35 major centres identified in the London Plan. It was historically an ancient parish in the county of Middlesex, with...

     in London, England. Three civilian
    Civilian
    A civilian under international humanitarian law is a person who is not a member of his or her country's armed forces or other militia. Civilians are distinct from combatants. They are afforded a degree of legal protection from the effects of war and military occupation...

    s were killed and seventeen injured, a massive crater was left. By September 1944, the V-2s routinely achieved Mach
    Mach number
    Mach number is the speed of an object moving through air, or any other fluid substance, divided by the speed of sound as it is in that substance for its particular physical conditions, including those of temperature and pressure...

    -4 during terminal descent.
  • Bumper
    Bumper (rocket)
    After a July 1946 suggestion by to combine the V-2 rocket and WAC Corporal, the US Bumper missile program was inaugurated on June 20, 1947:* to investigate launching techniques for a two-stage missile and separation of the two stages at high velocity,...

     5, a two stage rocket launched from the White Sands Proving Grounds. On 24 February 1949 the upper stage reached an altitude of 248 miles (399.1 km) and a speed of 7,553 feet per second
    Feet per second
    The foot per second is a unit of both speed and velocity . It expresses the distance in feet traveled or displaced, divided by the time in seconds...

     (2300 meters per second approx.) which is nearly Mach-7.
  • USSR — Energia
    Energia
    Energia was a Soviet rocket that was designed by NPO Energia to serve as a heavy-lift expendable launch system as well as a booster for the Buran spacecraft. Control system main developer enterprise was the NPO "Electropribor"...

    , 1986, Polyus payload failed to reach orbit; this was the most massive object launched into suborbital spaceflight to date
  • USA USAF/NASA/DARPA's X-37 B, intended to demonstrate reusable space technologies, The X-37 began as a NASA project in 1999, then was transferred to the US Department of Defense in 2004. It had its first flight as a drop test on April 7, 2006, at Edwards AFB. The spaceplane's first orbital mission, USA-212 was launched on April 22, 2010 using an Atlas V rocket and landed on Dec. 3rd 2010.

Manned sub-orbital spaceflights


Above at least 100 km in altitude.
Date (GMT) Mission Crew Country Remarks
1 1961-05-05 Mercury-Redstone 3
Mercury-Redstone 3
Mercury-Redstone 3 was the first manned space mission of the United States. Astronaut Alan Shepard piloted a 15-minute Project Mercury suborbital flight in the Freedom 7 spacecraft on May 5, 1961 to become the first American in space, three weeks after the Soviet cosmonaut Yuri Gagarin had carried...

Alan Shepard
Alan Shepard
Alan Bartlett Shepard, Jr. was an American naval aviator, test pilot, flag officer, and NASA astronaut who in 1961 became the second person, and the first American, in space. This Mercury flight was designed to enter space, but not to achieve orbit...

First manned sub-orbital spaceflight, first American in space
2 1961-07-21 Mercury-Redstone 4
Mercury-Redstone 4
Mercury-Redstone 4 was the second United States manned space mission, launched on July 21, 1961. The Mercury program suborbital flight used a Redstone rocket. The spacecraft was named Liberty Bell 7 piloted by astronaut Virgil I. "Gus" Grissom. It reached an altitude of more than 118.26 mi ...

Virgil Grissom
3 1963-07-19 X-15 Flight 90
X-15 Flight 90
-Crew:-Mission parameters:*Mass: 15,195 kg fueled; 6,577 kg burnout; 6,260 kg landed*Maximum Altitude: 106.01 km*Range: 534 km*Burn Time: 84.6 seconds*Mach: 5.50*Launch Vehicle: NB-52B Bomber #008...

Joseph A. Walker
Joseph A. Walker
Joseph Albert "Joe" Walker was an American NASA test pilot, and member of the U.S. Air Force Man In Space Soonest program. In 1963, he made two X-15 Experimental rocket aircraft flights beyond the altitude of 100 kilometers - at the edge of outer space...

First winged craft in space
4 1963-08-22 X-15 Flight 91
X-15 Flight 91
X-15 Flight 91 was a 1963 American human spaceflight mission, and the second and final flight in the program to achieve sub-orbital spaceflight: a flight over 100km in altitude. It was the first flight of a reused spacecraft, as plane number three flew the previous sub-orbital flight on July 19....

Joseph A. Walker First person and spacecraft to make two flights into space
5 1975-04-05 Soyuz 18a
Soyuz 18a
Soyuz 18a was a manned Soyuz spacecraft launched by the Soviet Union in 1975, intended to dock with the orbiting Salyut 4 space station, but which failed to achieve orbit due to a serious malfunction during launch...

Vasili Lazarev
Oleg Makarov
Failed orbital launch. Aborted after malfunction during stage separation
6 2004-06-21 SpaceShipOne flight 15P
SpaceShipOne flight 15P
-Flight profile:All times are in PDT, which is seven hours behind UTC. This was the local civil time at the spaceport on the day of the flight. All measurements are first stated in the U.S...

Mike Melvill
Mike Melvill
Michael Winston "Mike" Melvill is one of the test pilots for SpaceShipOne, the experimental spaceplane developed by Scaled Composites. Melvill piloted SpaceShipOne on its first flight past the edge of space, flight 15P on June 21, 2004, thus becoming the first commercial astronaut and the 434th...

First commercial spaceflight
7 2004-09-29 SpaceShipOne flight 16P
SpaceShipOne flight 16P
Flight 16P of SpaceShipOne was a spaceflight in the Tier One program that took place on September 29, 2004. It was the first competitive flight in the Ansari X PRIZE competition to demonstrate a non-governmental reusable manned spacecraft, and is hence also referred to as the X1 flight...

Mike Melvill First of two flights to win Ansari X-Prize
8 2004-10-04 SpaceShipOne flight 17P
SpaceShipOne flight 17P
Flight 17P of SpaceShipOne was a spaceflight in the Tier One program that took place on October 4, 2004. It was the second competitive flight in the Ansari X Prize competition to demonstrate a non-governmental reusable manned spacecraft, and is hence also referred to as the X2 flight...

Brian Binnie
Brian Binnie
William Brian Binnie is a former United States Navy officer and is one of the test pilots for SpaceShipOne, the experimental spaceplane developed by Scaled Composites.-History:...

Second X-Prize flight, clinching award

Future of manned sub-orbital spaceflight


Private companies such as Virgin Galactic
Virgin Galactic
Virgin Galactic is a company within Richard Branson's Virgin Group which plans to provide sub-orbital spaceflights to the paying public, along with suborbital space science missions and orbital launches of small satellites...

, XCOR, Armadillo Aerospace
Armadillo Aerospace
Armadillo Aerospace is an aerospace startup company based in Mesquite, Texas. Its initial goal is to build a manned suborbital spacecraft capable of space tourism, but it has stated long-term ambitions of orbital spaceflight. The company was founded by John Carmack.On October 24, 2008, Armadillo...

, Blue Origin
Blue Origin
Blue Origin is a privately funded aerospace company set up by Amazon.com founder Jeff Bezos. The company was awarded $3.7 million in funding in 2009 by NASA via a Space Act Agreement under the Commercial Crew Development program for development of concepts and technologies to support future human...

 and Masten Space Systems
Masten Space Systems
Masten Space Systems is an aerospace startup company in Mojave, California that is developing a line of vertical takeoff, vertical landing spacecraft, initially for unmanned suborbital research flights and eventually intended to support unmanned orbital launches.- Overview :Masten Space Systems...

 are taking an interest in sub-orbital spaceflight, due in part to ventures like the Ansari X Prize. NASA and others are experimenting with scramjet
Scramjet
A scramjet is a variant of a ramjet airbreathing jet engine in which combustion takes place in supersonic airflow...

 based hypersonic
Hypersonic
In aerodynamics, a hypersonic speed is one that is highly supersonic. Since the 1970s, the term has generally been assumed to refer to speeds of Mach 5 and above...

 aircraft which may well be used with flight profiles that qualify as sub-orbital spaceflight. In addition, the VSS Enterprise
VSS Enterprise
The VSS Enterprise is the first of five commercial suborbital spacecraft being constructed for Virgin Galactic by Scaled Composites....

 is expected to begin manned sub-orbital flights starting in 2011. Non-profit entities like ARCASPACE
ARCASPACE
Asociația Română pentru Cosmonautică și Aeronautică or Romanian Cosmonautics and Aeronautics Association is a non-governmental organization that promotes aerospace projects as well as other space-related activities...

 and Copenhagen Suborbitals
Copenhagen Suborbitals
Copenhagen Suborbitals is a non-profit organization working towards suborbital manned spaceflight. Founded in 2008 by Kristian von Bengtson and Peter Madsen the project has accomplished a successful sea launch of a test hybrid rocket, carrying a full scale human model...

 also attempt rocket
Rocket
A rocket is a missile, spacecraft, aircraft or other vehicle which obtains thrust from a rocket engine. In all rockets, the exhaust is formed entirely from propellants carried within the rocket before use. Rocket engines work by action and reaction...

-based launches.

See also


  • Point-to-point sub-orbital spaceflight
    Point-to-point sub-orbital spaceflight
    Point-to-point sub-orbital spaceflight is a category of spaceflight in which a spacecraft uses a sub-orbital flight for transportation. This can provide a two-hour trip from London to Sydney. Today, no company offers this type of spaceflight for transportation. However, Virgin Galactic is planning...

  • Orbital spaceflight
    Orbital spaceflight
    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...

  • Spaceflight
    Spaceflight
    Spaceflight is the act of travelling into or through outer space. Spaceflight can occur with spacecraft which may, or may not, have humans on board. Examples of human spaceflight include the Russian Soyuz program, the U.S. Space shuttle program, as well as the ongoing International Space Station...

  • Spaceport
    Spaceport
    A spaceport or cosmodrome is a site for launching spacecraft, by analogy with seaport for ships or airport for aircraft. The word spaceport, and even more so cosmodrome, has traditionally been used for sites capable of launching spacecraft into orbit around Earth or on interplanetary trajectories...

  • List of rocket launch sites
  • Office of Commercial Space Transportation
    Office of Commercial Space Transportation
    The Office of Commercial Space Transportation is the branch of the United States Federal Aviation Administration that approves any commercial rocket launch operations—that is, any launches that are not classified as model, amateur, or "by and for the government."-Overview:Under...

  • Canadian Arrow
    Canadian Arrow
    The Canadian Arrow is a privately funded rocket and space travel project founded by London, Ontario, Canada entrepreneurs Geoff Sheerin, Dan McKibbon and Chris Corke...

  • Supersonic Transport
    Supersonic transport
    A supersonic transport is a civilian supersonic aircraft designed to transport passengers at speeds greater than the speed of sound. The only SSTs to see regular service to date have been Concorde and the Tupolev Tu-144. The last passenger flight of the Tu-144 was in June 1978 with its last ever...