VOMIT COMET

'''Vomit Comet''' is a nickname for any airplane that briefly provides a nearly weightless environment in which to train astronauts, conduct research, and film motion pictures.
Versions of such airplanes have in the past been operated by NASA's Reduced Gravity Research Program since 1973, where the nickname originated. NASA prefers the nickname 'Weightless Wonder' for public relations reasons.

Contents

Operating principles

History

Commercial flights

Airsickness

Other uses of the term

See also

Notes

References

External links

Operating principles

Main articles: Weightlessness

The airplane produces weightlessness by following a parabolic vertical flight path. A parabolic flight path is the same path that would be taken by an object in free fall, such as a cannonball fired into the air. As a result, the aircraft does not exert any G force on its contents, so the contents have zero apparent weight relative to the aircraft. After a few seconds, the aircraft pulls into a climb, resulting in high G forces until the next parabola begins.^[1]
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 nausea due to airsickness, especially in novices, giving the plane its nickname. Astronauts training for the Moon missions practiced walking with 1/6 of their weight to simulate the level of gravity on the Moon.

History

NASA has flown parabolic flights on various aircraft for many years. In 1959, Project Mercury astronauts trained in a C-131 Samaritan aircraft, which was dubbed the "Vomit Comet".^[2]
Twin KC-135 Stratotankers were used until December 2004 and have since been retired. One, a KC-135A known as NASA 930 was also used by Universal Pictures and Imagine Entertainment for filming scenes involving weightlessness in the movie ''Apollo 13''; that airplane was retired in 2000 and is now on display at Ellington Field, near the Johnson Space Center. It's 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 Museum in Tucson, Arizona.
In 2005, NASA replaced the airplane with a McDonnell Douglas C-9B Skytrain II that was formerly owned by KLM Airlines and the United States Navy [1]. The same year, the Zero-Gravity Corporation, a commercial parabolic flight operator which offers parabolic flight to both researchers and adventure tourists, began flying parabolic flights for NASA with Boeing 727 jets.
Since 1984, the ESA and the CNES have flown similar reduced-gravity missions in a variety of airplanes, including NASA's KC-135, a Caravelle, an Ilyushin IL-76 MDK, and, most recently, an Airbus A300 known as the ''Zero-G'', which is flown out of the Bordeaux-Mérignac airport in France.^[3]

Commercial flights

In late 2004, Zero Gravity Corporation became the first and only company in the United States to offer parabolic weightlessness flights to the general public. Each flight consists of around 15 parabolas, including simulations of the gravity levels of the Moon and Mars, as well as complete weightlessness.^[4]

Airsickness

According to Reduced Gravity Research Program director John Yaniec, anxiety contributes most to passengers' airsickness. Yaniec gives a rough estimate that of passengers, "one third [become] violently ill, the next third moderately ill, and the final third not at all."
Commercial operator ZeroG Corp claims their tourist rides with up to 15 parabolas are much less traumatic compared to the typical research flight with from 40 up to 80 parabolas.^[5]

Other uses of the term

''Vomit comet'' may also refer to any other form of transportation on which riders are said to become nauseated or seasick, such as a bus that transports late-night revelers ^{[6] [7]} or fast boat such as a high speed catamaran. ^{[8] [9]}

See also

★ Microgravity

★ Space tourism

Notes

1. C-9B Flight Trajectory
2. Page hosts a NASA photograph dated 01.01.1959, which is also at .
3. ESA's A300 Zero-G Program
4. MSNBC article
5. Zero G corp FAQ on motion sickness
6. Double-Tongued Dictionary entry
7. All night TTC bus
8. Key West ferry
9. Isle of Wight Ferry

References

★ Haber, Fritz and Haber, Heinz: ''Possible Methods of Producing the Gravity-Free State for Medical Research'', Journal of Aviation Medecine XXI (1950)

★ Easton, Pam (Oct. 30, 2004). NASA's weightless aircraft is retired. Associated Press.

★ Glen Golightly (May. 15, 2000). Vomit Comet finds a home. Space.com Houston Bureau.

★ Dennis Overbye (March 1, 2007), ''Stephen Hawking plans prelude to the ride of his life'', New York Times

External links

★ Reduced Gravity Research Program

★ Interview with John Yaniec

★ About the NASA Reduced Gravity Research Program

★ "ATLAS aerospace" is a Russian company that offers reduced gravity flights in an "IL-76 MDK" wide-body airplane.

★ Virtual tour of the Airbus A-300 Zero-G

★ C-135 Variants Part 6 - includes scale drawing of NASA 930

★ Reduced Gravity Experiment in a Nasa´s KC-135A