Vomit Comet is a nickname for any
fixed-wing aircraftA fixed-wing aircraft, usually called an airplane, aeroplane or plane, is an aircraft capable of flight using forward motion that causes air to pass over its wings to generate lift. Planes include jet engine and propeller driven vehicles propelled forward by thrust, as well as unpowered aircraft...
that briefly provides a nearly weightless environment in which to train
astronautAn astronaut or cosmonaut is a person trained by a human spaceflight program to command, pilot, or serve as a crew member of a spacecraft....
s, conduct research, and film motion pictures.
Versions of such airplanes have in the past been operated by NASA Reduced Gravity Research Program, where the unofficial nickname originated.
NASAThe National Aeronautics and Space Administration is an agency of the United States government, responsible for the nation's public space program. NASA was established by the National Aeronautics and Space Act on July 29, 1958, replacing its predecessor, the National Advisory Committee for...
has adopted the official nickname
Weightless Wonder for publication.
The aircraft achieves weightlessness by following an
ellipticIn mathematics, an ellipse is the bounded case of a conic section, the geometric shape that results from cutting a circular conical or cylindrical surface with an oblique plane...
flight path relative to the center of the Earth.
Vomit Comet is a nickname for any
fixed-wing aircraftA fixed-wing aircraft, usually called an airplane, aeroplane or plane, is an aircraft capable of flight using forward motion that causes air to pass over its wings to generate lift. Planes include jet engine and propeller driven vehicles propelled forward by thrust, as well as unpowered aircraft...
that briefly provides a nearly weightless environment in which to train
astronautAn astronaut or cosmonaut is a person trained by a human spaceflight program to command, pilot, or serve as a crew member of a spacecraft....
s, conduct research, and film motion pictures.
Versions of such airplanes have in the past been operated by NASA Reduced Gravity Research Program, where the unofficial nickname originated.
NASAThe National Aeronautics and Space Administration is an agency of the United States government, responsible for the nation's public space program. NASA was established by the National Aeronautics and Space Act on July 29, 1958, replacing its predecessor, the National Advisory Committee for...
has adopted the official nickname
Weightless Wonder for publication.
Operating principles
The aircraft achieves weightlessness by following an
ellipticIn mathematics, an ellipse is the bounded case of a conic section, the geometric shape that results from cutting a circular conical or cylindrical surface with an oblique plane...
flight path relative to the center of the Earth. While following this path, the aircraft and its payload are in free fall and are literally
orbitIn physics, an orbit is the gravitationally curved path of one object around a point or another body, for example the gravitational orbit of a planet around a star....
ing the earth. During this time the aircraft does not exert any g-forces on its contents.
The trajectory of this flight path is almost always ambiguously described as "parabolic" without providing a frame of reference. To an observer on the non-inertial surface of the Earth the exact shape of the flight path would be complex due the
centrifugal forceIn classical mechanics, centrifugal force is an outward force associated with curved motion, that is, rotation about some center...
,
Coriolis effectIn physics, the Coriolis effect is an apparent deflection of moving objects when they are viewed from a rotating reference frame.Newton's laws of motion govern the motion of an object in an inertial frame of reference. When transforming Newton's laws to a rotating frame of reference, the Coriolis...
, and
Eötvös effectIn the early 1900s a German team from the Institute of Geodesy in Potsdam carried out gravity measurements on moving ships in the Atlantic, Indian and Pacific Oceans. While studying their results the Hungarian nobleman and physicist Baron Roland von Eötvös noticed that the readings were lower...
. However, if the aircraft were capable of reaching escape velocity, the path would be a parabola, and the experience of weightlessness would last forever.
The graph of the aircraft's altitude as a function of time is a
cycloidA cycloid is the curve defined by the path of a point on the edge of circular wheel as the wheel rolls along a straight line.It is an example of a roulette, a curve generated by a curve rolling on another curve....
.
Initially the aircraft climbs with a pitch angle of 45 degrees. Weightlessness is achieved by reducing thrust and lowering the nose to maintain a zero
angle of attackAngle of attack is a term used in fluid dynamics to describe the angle between a reference line on a body and the vector representing the relative motion between the body and the fluid through which it is moving. In general, the reference line could be any line on any arbitrarily shaped body in...
. Weightlessness begins while ascending and lasts all the way "up-and-over the hump", until the craft reaches a declined angle of 30 degrees. At this point, the craft has lost a significant amount of altitude, and must begin to pull into a climb. The forces are then roughly twice that of gravity on the way down, at the bottom, and up again. This lasts all the way until the aircraft is again halfway up its upward trajectory, and the pilot again initiates the zero-g flight path.
In general, this aircraft is used to train astronauts in zero-g maneuvers, giving them about 25 seconds of weightlessness out of 65 seconds of flight. This often produces
nauseaNausea is the sensation of unease and discomfort in the stomach with an urge to vomit.-Causes:...
due to
airsicknessAirsickness is a sensation which is induced by air travel. It is a specific form of motion sickness, and is considered a normal response in healthy individuals...
, especially in novices, giving the plane its nickname.
Usage by NASA
NASA has flown zero-g flights on various aircraft for many years. In 1959,
Project MercuryProject Mercury was the first human spaceflight program of the United States. It ran from 1959 through 1963 with the goal of putting a human in orbit around the Earth...
astronauts trained in a
C-131 SamaritanThe Convair C-131 Samaritan was an American military transport produced from 1954 to 1956.-Design and development:The design began life in a production requirement by American Airlines for a pressurized airliner to replace the classic Douglas DC-3. Convair's original design had two engines and 40...
aircraft, which was dubbed the "Vomit Comet".
Twin
KC-135 StratotankerThe Boeing KC-135 Stratotanker was the first jet powered aerial refueling tanker of the US Air Force, replacing the KC-97 Stratotanker. Similar in design to the later and enlarged Boeing 707 airliner, it was initially tasked to refuel strategic bombers, but was used extensively in the Vietnam war...
s were used until December 2004 and have since been retired. One, a KC-135A known as NASA 930, was also used by
Universal PicturesThis is a partial listing of films produced and/or distributed by Universal Pictures, the main motion picture production/distribution arm of Universal Studios, a subsidiary of NBC Universal.-1920:* White Youth* The Flaming Disc...
and
Imagine EntertainmentImagine Entertainment is a film and television production company founded in 1986 by director Ron Howard and producer Brian Grazer. Their productions include the television series 24 and Arrested Development and the films A Beautiful Mind, Apollo 13, and The Da Vinci Code.Karen Kehela Sherwood is...
for filming scenes involving weightlessness in the movie
Apollo 13Apollo 13 is a 1995 film that dramatized the ill-fated lunar mission of the same name in 1970. The movie was adapted by William Broyles, Jr. and Al Reinert from the book Lost Moon by Jim Lovell and Jeffrey Kluger, and was directed by Ron Howard...
; that aircraft was retired in 2000 and is now on display at
Ellington FieldEllington Airport is a joint civil-military airport located within the City of Houston in the U.S. state of Texas, southeast of Downtown Houston. The airport was established in 1917 during the height of World War I when aviation was in its infancy...
, near the Johnson Space Center. It is estimated to have flown over 58,000 parabolas. The other (N931NA or NASA 931) made its final flight on October 29, 2004, and is permanently stored in the
Pima Air & Space MuseumThe Pima Air & Space Museum is located at 6000 East Valencia Road in Tucson, Arizona. It is the world's largest, non-government funded aerospace museum. The museum was opened to the public in May 1976 with 75 aircraft on display. It now contains a collection of over 250 aircraft occupying 80 acres ...
in Tucson, Arizona.
In 2005, NASA replaced the aircraft with a
McDonnell DouglasMcDonnell Douglas was a major American aerospace manufacturer and defense contractor, producing a number of famous commercial and military aircraft. It formed from a merger of McDonnell Aircraft and Douglas Aircraft in 1967. McDonnell Douglas was based at St. Louis's Lambert International...
C-9B Skytrain II that was formerly owned by KLM Royal Dutch Airlines and the
United States NavyThe United States Navy is the sea branch of the U.S. Armed Forces. It is one of the seven uniformed services of the United States. As of 31 December 2008, the U.S. Navy had about 331,682 personnel on active duty and 124,000 in the Navy Reserve. It operates 283 ships in active service and more than...
.
Canada
The
Canadian Space AgencyThe Canadian Space Agency is the Canadian government space agency responsible for Canada's space program. It was established in March 1989 by the Canadian Space Agency Act and sanctioned in December 1990...
and the National Research Council have a Falcon 20 used for microgravity research. The small plane is normally not used for people to float freely and experience weightlessness, however comedian
Rick MercerRichard Vincent "Rick" Mercer is a Canadian comedian, television personality, political satirist, and a blogger.Mercer first came to national attention in 1990, when he premiered his one-man show Show Me the Button, I'll Push It, or Charles Lynch Must Die at the Great Canadian Theatre Company in...
did so for a segment on his
showRick Mercer Report is a Canadian television comedy series which airs on CBC Television...
.
Ecuador
The first zero G plane in Latin America is a T-39 Sabreliner nicknamed
CONDOR, operated by the Ecuadorian space agency and the
Ecuadorian Air ForceThe Ecuadorian Air Force is the Air arm of the Military of Ecuador.- History :The FAE was officially created on October 27th 1920. However, like in many other countries, military flying activity started before the formal date of birth of the Air Force. The history of Ecuador is marked by many...
. It has operated since May, 2008. On June 19 2008, this plane carried 7 year old Jules Nader as he set the Guinness world record for the youngest human being to fly in microgravity. Nader worked on a hydrodynamics experiment designed by his brother.
Europe
Since 1984, the
ESA|owner = |headquarters = Paris|spaceport = Guiana Space Centre|image = ESA LOGO.svg|size = 240px|acronym = ESA|established = 1975|administrator = Jean-Jacques Dordain...
and the
CNESThe is the French government space agency . Its headquarters are located in central Paris and it's placed under the supervision of the french Ministries of Defense and Research...
flew similar reduced-gravity missions in a variety of aircraft, including NASA's KC-135, a
CaravelleThe Sud Aviation SE 210 Caravelle was the first short/medium-range jet airliner, produced by the French Sud Aviation firm starting in 1955 . The Caravelle would go on to be one of the more successful European first generation jetliners, selling throughout Europe and even penetrating the United...
, an
Ilyushin IL-76 MDKThe Ilyushin Il-76 is a multi-purpose 4-engined strategic airlifter that was first planned as a commercial freighter in 1967. Intended as a replacement for the An-12, the Il-76 was designed for delivering heavy machinery to remote, poorly-serviced areas of Russia...
, and, most recently, an
Airbus A300The Airbus A300 is a short- to medium-range widebody aircraft. Launched in 1972 as the world's first twin-engined widebody, it was the first product of the Airbus consortium of European aerospace companies, wholly owned today by EADS. The A300 ceased production in July 2007, along with the smaller...
known as the
Zero-G, which is flown out of the
Bordeaux-Mérignac airportBordeaux - Mérignac Airport is an airport serving the French city of Bordeaux. It is located in the town of Mérignac, 6 miles west of Bordeaux, within the département of Gironde. In 2008, the airport served more than 3 519 000 travellers...
in
FranceFrance , officially the French Republic , is a country located in Western Europe, with several overseas islands and territories located on other continents. Metropolitan France extends from the Mediterranean Sea to the English Channel and the North Sea, and from the Rhine to the Atlantic Ocean...
. Since 1997, CNES subsidiary Novespace has handled the management of these flights.
Russia
In
RussiaRussia , officially known as both Russia and the Russian Federation , is a country in northern Eurasia . It is a semi-presidential republic, comprising 83 federal subjects...
, commercial flights are offered on the
Ilyushin Il-76The Ilyushin Il-76 is a multi-purpose 4-engined strategic airlifter that was first planned as a commercial freighter in 1967. Intended as a replacement for the An-12, the Il-76 was designed for delivering heavy machinery to remote, poorly-serviced areas of Russia...
jet; several U.S. companies book flights on these jets. The 1999 pornographic film
The Uranus Experiment 1 had scenes filmed on such an aircraft; it is notable for containing the first instance of zero-gravity sex caught on film.
United States
In late 2004,
Zero Gravity CorporationZero Gravity Corporation is a privately held space entertainment and tourism company, based in Virginia. Its mission is to bring the excitement and adventure of weightlessness to the public through a safe, fun and cost-effective experience. ZERO-G operates weightless flights from major airports...
became the first and only company in the United States to offer zero-g flights to the general public, using
Boeing 727The Boeing 727 is a mid-size, narrow-body, three-engine, T-tailed commercial jet airliner. The first Boeing 727 flew in 1963 and for over a decade it was the most produced commercial jet airliner in the world. When production ended in 1984, a total of 1,831 aircraft had been produced...
jets. Each flight consists of around 15 parabolas, including simulations of the gravity levels of the Moon and Mars, as well as complete weightlessness.
Airsickness
According to former Reduced Gravity Research Program director John Yaniec, anxiety contributes most to passengers' airsickness. Yaniec gives a rough estimate of passengers, that "one third
[become] violently ill, the next third moderately ill, and the final third not at all." Vomiting is referred to as a "kill".
Further reading
- Haber, Fritz and Haber, Heinz: "Possible Methods of Producing the Gravity-Free State for Medical Research", Journal of Aviation Medicine XXI (1950)
- Easton, Pam (October 30, 2004). NASA's weightless aircraft is retired. Associated Press.
- Golightly, Glen (May 15, 2000). Vomit Comet finds a home. Space.com Houston Bureau.
- Overbye, Dennis (March 1, 2007), "Stephen Hawking plans prelude to the ride of his life", New York Times
External links