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The "energy flash" of a hypervelocity impact during a laboratory simulation of what happens when a piece of orbital debris hits a spacecraft in orbit Hypervelocity Impact Demonstration.jpg
The "energy flash" of a hypervelocity impact during a laboratory simulation of what happens when a piece of orbital debris hits a spacecraft in orbit
Hypervelocity impact Hypervelocity Impact.png
Hypervelocity impact

Hypervelocity is very high velocity, approximately over 3,000 meters per second (6,700 mph, 11,000 km/h, 10,000 ft/s, or Mach 8.8). In particular, hypervelocity is velocity so high that the strength of materials upon impact is very small compared to inertial stresses. [1] Thus, metals and fluids behave alike under hypervelocity impact. Extreme hypervelocity results in vaporization of the impactor and target. For structural metals, hypervelocity is generally considered to be over 2,500 m/s (5,600 mph, 9,000 km/h, 8,200 ft/s, or Mach 7.3). Meteorite craters are also examples of hypervelocity impacts.



"Hypervelocity" refers to velocities in the range from a few kilometers per second to some tens of kilometers per second. This is especially relevant in the field of space exploration and military use of space, where hypervelocity impacts (e.g. by space debris or an attacking projectile) can result in anything from minor component degradation to the complete destruction of a spacecraft or missile. The impactor, as well as the surface it hits, can undergo temporary liquefaction. The impact process can generate plasma discharges, which can interfere with spacecraft electronics.

Hypervelocity usually occurs during meteor showers and deep space reentries, as carried out during the Zond, Apollo and Luna programs. Given the intrinsic unpredictability of the timing and trajectories of meteors, space capsules are prime data gathering opportunities for the study of thermal protection materials at hypervelocity (in this context, hypervelocity is defined as greater than escape velocity). Given the rarity of such observation opportunities since the 1970s, the Genesis and Stardust Sample Return Capsule (SRC) reentries as well as the recent Hayabusa SRC reentry have spawned observation campaigns, most notably at NASA Ames Research Center.

Hypervelocity collisions can be studied by examining the results of naturally occurring collisions (between micrometeorites and spacecraft, or between meteorites and planetary bodies), or they may be performed in laboratories. Currently the primary tool for laboratory experiments is a light-gas gun, but some experiments have used linear motors to accelerate projectiles to hypervelocity. The properties of metals under hypervelocity have been integrated with weapons, such as explosively formed penetrator. The vaporization upon impact and liquefaction of surfaces allow metal projectiles formed under hypervelocity forces to penetrate vehicle armor better than conventional bullets.

NASA studies the effects of simulated orbital debris at the White Sands Test Facility Remote Hypervelocity Test Laboratory (RHTL). [2] Objects smaller than a softball cannot be detected on radar. This has prompted spacecraft designers to develop shields to protect spacecraft from unavoidable collisions. At RHTL, micrometeoroid and orbital debris (MMOD) impacts are simulated on spacecraft components and shields allowing designers to test threats posed by the growing orbital debris environment and evolve shield technology to stay one step ahead. At RHTL, four two-stage light-gas guns propel 0.05 mm to 22.2 mm diameter projectiles to velocities as fast as 8.5 km/s.

Hypervelocity reentry events

DateEventSpeed (km/s)Notes
8 September 2004 Genesis SRC 11.04Crashed (drogue chute failure)
15 January 2006 Stardust SRC12.79Fastest man-made reentry on record (successful landing)
13 June 2010 Hayabusa SRC12.2Leading main Hayabusa spacecraft by 6,500 feet (2 000 m) (destructive reentry) [3]

Other definitions of hypervelocity

According to the United States Army, hypervelocity can also refer to the muzzle velocity of a weapon system, with the exact definition dependent upon the weapon in question. When discussing small arms a muzzle velocity of 5,000 ft/s (1524 m/s) or greater is considered hypervelocity, while for tank cannons the muzzle velocity must meet or exceed 3,350 ft/s (1021.08 m/s) to be considered hypervelocity, and the threshold for artillery cannons is 3,500 ft/s (1066.8 m/s). [4]

See also

Related Research Articles

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Atmospheric entry is the movement of an object from outer space into and through the gases of an atmosphere of a planet, dwarf planet, or natural satellite. There are two main types of atmospheric entry: uncontrolled entry, such as the entry of astronomical objects, space debris, or bolides; and controlled entry of a spacecraft capable of being navigated or following a predetermined course. Technologies and procedures allowing the controlled atmospheric entry, descent, and landing of spacecraft are collectively termed as EDL.

Meteoroid Sand- to boulder-sized particle of debris in the Solar System

A meteoroid is a small rocky or metallic body in outer space.

A projectile is any object thrown by the exertion of a force. Although any object in motion through space may be called a projectile, the term more commonly refers to a ranged weapon. Mathematical equations of motion are used to analyze projectile trajectories.

Micrometeoroid small particle of rock in space, usually weighing less than a gram

A micrometeoroid is a tiny meteoroid; a small particle of rock in space, usually weighing less than a gram. A micrometeorite is such a particle that survives passage through the Earth's atmosphere and reaches the Earth's surface.

<i>Stardust</i> (spacecraft) Fourth mission of the Discovery program; sample return from the periodic comet Wild 2

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Space debris The pollution of orbit around Earth by defunct human-made objects

Space debris is a term for defunct human-made objects in space—principally in Earth orbit—which no longer serve a useful function. This can include nonfunctional spacecraft, abandoned launch vehicle stages, mission-related debris and fragmentation debris. Examples of space debris include derelict satellites and spent rocket stages as well as the fragments from their disintegration, erosion and collisions, such as paint flecks, solidified liquids from spacecraft breakups, unburned particles from solid rocket motors, etc. Space debris represents a risk to spacecraft.

Muzzle velocity is the speed of a projectile with respect to the muzzle at the moment it leaves the end of a gun's barrel. Firearm muzzle velocities range from approximately 120 m/s (390 ft/s) to 370 m/s (1,200 ft/s) in black powder muskets, to more than 1,200 m/s (3,900 ft/s) in modern rifles with high-velocity cartridges such as the .220 Swift and .204 Ruger, all the way to 1,700 m/s (5,600 ft/s) for tank guns firing kinetic energy penetrator ammunition. To simulate orbital debris impacts on spacecraft, NASA launches projectiles through light-gas guns at speeds up to 8,500 m/s (28,000 ft/s).

Laser broom Ground-based laser beam-powered system to clear space debris

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Whipple shield type of hypervelocity impact shield used on spacecraft

The Whipple shield or Whipple bumper, invented by Fred Whipple, is a type of hypervelocity impact shield used to protect crewed and uncrewed spacecraft from collisions with micrometeoroids and orbital debris whose velocities generally range between 3 and 18 kilometres per second.

Light-gas gun highly specialized gun designed to generate very high velocities

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Reentry capsule

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NASA Orbital Debris Program Office

The NASA Orbital Debris Program Office is located at the Johnson Space Center and is the lead NASA center for orbital debris research. It is recognized world-wide for its leadership in addressing orbital debris issues. The NASA Orbital Debris Program Office has taken the international lead in conducting measurements of the environment and in developing the technical consensus for adopting mitigation measures to protect users of the orbital environment. Work at the center continues with developing an improved understanding of the orbital debris environment and measures that can be taken to control its growth.

Explosively formed penetrator peoples

An explosively formed penetrator (EFP), also known as an explosively formed projectile, a self-forging warhead, or a self-forging fragment, is a special type of shaped charge designed to penetrate armor effectively. As the name suggests, the effect of the explosive charge is to deform a metal plate into a slug or rod shape and accelerate it toward a target. They were first developed as oil well perforators by American oil companies in the 1930s, and were deployed as weapons in World War II.

The physicist Sir Isaac Newton first developed this idea to get rough approximations for the impact depth for projectiles traveling at high velocities.

ASM-135 ASAT Type of Anti-satellite missile

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.

Aeroshell Protects a spacescraft during atmospheric reentry

An aeroshell is a rigid heat-shielded shell that helps decelerate and protects a spacecraft vehicle from pressure, heat, and possible debris created by drag during atmospheric entry. Its main components consist of a heat shield and a back shell. The heat shield absorbs heat caused by air compression in front of the spacecraft during its atmospheric entry. The back shell carries the load being delivered, along with important components such as a parachute, rocket engines, and monitoring electronics like an inertial measurement unit that monitors the orientation of the shell during parachute-slowed descent.

2009 satellite collision 2009 collision between the Iridium 33 and Cosmos-2251 satellites

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Impact survival

Impact survival is a theory that life, usually in the form of microbial bacteria, can survive under the extreme conditions they are exposed to during a major impact event, such as a meteorite striking the surface of a planet. This step is a necessity for the possibility of panspermia, for the microbial life must be able to survive both the escape out of the initial planetary atmosphere, likely due to a major impact, as well the reentry and collision with a second planetary body.


  1. Air Force Institute of Technology (1991). Critical technologies for national defense. AIAA. p. 287. ISBN   1-56347-009-8.
  2. "Remote Hypervelocity Test Laboratory". Archived from the original on 2012-04-04.
  3. "Space.com".
  4. "Dictionary of United States Army Terms" (PDF). Federation of American Scientists.