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Offline Orionid

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Odp: Viking Orbiter
« Odpowiedź #15 dnia: Sierpień 31, 2020, 23:12 »
45 Years Ago: Viking 1 and 2 off to Mars
Aug. 20, 2020


Launches of the Viking spacecraft: Viking 1, left, and Viking 2.

(...) At the time the landers were the most sophisticated planetary spacecraft launched. Each carried two cameras as part of its imaging system, a seismometer, an x-ray fluorescence spectrometer, a weather instrument package to monitor temperature, pressure, and wind velocity, and a biological laboratory. (...)

The Viking spacecraft, at 7,776 pounds fully fueled the heaviest planetary spacecraft up to that time launched by the United States, required the most powerful rocket in America’s fleet, the Titan IIIE with a Centaur upper stage. Viking 1 took off from Launch Complex 41 at Cape Canaveral Air Force Station on Aug. 20, 1975, to begin its 304-day cruise to the Red Planet, followed by Viking 2 on Sept. 9 to begin its 320-day voyage. On June 19, 1976, Viking 1 entered an elliptical orbit around Mars. On July 20, by coincidence the seventh anniversary of the Apollo 11 Moon landing, the Viking 1 lander separated from the orbiter and began its descent to the surface, making a soft landing in the Chryse Planitia region of Mars. Within five minutes it began sending back its first photograph of the landing site. Viking 2 entered orbit around Mars on July 25 and the lander made its touchdown in Utopia Planitia on Sept. 3. (...)
https://www.nasa.gov/feature/45-years-ago-viking-1-and-2-off-to-mars

A Titan 3/Centaur rocket launched NASA's Viking 1 spacecraft on a 505-million-mile journey to Mars on Aug. 20, 1975. Viking 2 followed three weeks later.


Viking 40th Anniversary
16 289 wyświetleń•19 lip 2016


https://mars.nasa.gov/mars-exploration/missions/viking-1-2/

http://lk.astronautilus.pl/sondy/viking1.htm
http://lk.astronautilus.pl/sondy/viking2.htm

Offline Orionid

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Odp: Viking Orbiter
« Odpowiedź #16 dnia: Czerwiec 20, 2023, 19:12 »
19 czerwca minęła 40 rocznica wejścia na orbitę Marsa sondy Viking Orbiter 1 z przyczepionym do niej lądownikiem
https://pl.wikipedia.org/wiki/Viking_1
{...}
47 lat temu...
Masa orbitera wynosiła 2339 kg, a lądownika 978 kg,
Dla porównania masa lądowników Phoenix i InSight  wynosiła 350 kg.
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19.06.1976 kompletna sonda (wraz z lądownikiem) weszła na orbitę wokół Marsa stając się jego piątym sztucznym satelitą.
Początkowe parametry orbity wynosiły 1513 x 33 000 km, i = 37,8°,  T = 24,66 h.
http://lk.astronautilus.pl/sondy/viking1.htm
https://www.nytimes.com/1976/06/20/archives/viking-1-begins-orbiting-mars-stage-set-for-july-4-landing-flight.html
WP https://www.forum.kosmonauta.net/index.php?topic=5004.msg184692#msg184692
https://airandspace.si.edu/collection-objects/lander-mars-viking-proof-test-article/nasm_A19790215000
https://twitter.com/airandspace/status/1670957911000903685https://en.wikipedia.org/wiki/Viking_1
https://www.planetary.org/space-missions/viking

VIKING 1 BEGINS ORBITING MARS
By Boyce Rensberger Special to The New York Times June 20, 1976

PASADENA, Calif., June 19 —The Viking 1 spacecraft, designed to conduct man's first search for life on another planet, flew into orbit around Mars tonight, completing a 420‐million‐mile, 10‐month journey from earth.

The successful orbital insertion maneuver, involving a 38minute firing of the craft's braking rocket, set the stage for a landing to he attempted on July 4.

Flight controllers at the Nalinnet Aeronautics and Space Administration's Jet Propulsion Laboratory here pronounced the critical maneuver a complete success.

“It's been a great experience,” said James Martin, Viking project manager. “After eight years we're finally in orbit. Everything worked perfectly.”

Flight controllers said the maneuver placed Viking 1 in virtually perfect alignment for a landing in a region of Mars called Chryse. Earlier photographs in this area revealed erosional features suggesting that water had once flowed over the ground.

Possible Organisms

Biologists believe that if there is still water in the area, the chances of the soil harboring living organisms is greatly enhanced. If the water is gone, the landing site may still contain organic compounds indicating that life once existed there.

The maneuver that put Viking I into orbit was controlled automatically by computers aboard the spacecraft. The specific command; were radioed to Viking at 2 A.M. Eastern daylight time and stored in its computer.

—Al: 4:33 this afternoon the 7,700‐pound spacecraft rolled and yawed itself into a position so that its rocket exhaust would point straight ahead. At 6:21 P.M., when Viking was 7,500 miles from Mars, its engine began firing to slow down the craft. Thirty‐eight minutes later the engine stopped, leaving the spacecraft moving slowly enough to be captured by Mars's gravity but fast enough not to fall to the surface.

After each step, flight controllers had to wait about 17 minutes before learning wheth er it had been successful. That is how long it takes radio signals, traveling at the speed of light to reach the earth from Mars, which is now 236 million miles away. By comparison, signals from the moon during the Apollo flights took less than two seconds to reach earth.

Moving Target

The reason Viking had to travel farther than the present distance between earth and Mars is that it was being aimed at a moving target. Engineers at‐ the let Propulsion Laboratory faced the same problem as a hunter who must aim ahead of a flying duck to be sure that the shot hits the duck

If the craft had been aimed directly at Mars at the time of its launching last August, Mars would have moved several million miles in its orbit around the sun by the time Viking reached Mars's orbital path. Mars is the next planet beyond the earth, reckoning from the sun.

During the 10 months Viking has been chasing Mars, the planet has moved halfway around the sun.

Although Viking is now safely in orbit around Mars, it must fire its engine once and possibly twice more during the next, week to change the time it takes to make an orbit. At present, the spacecraft is in an elliptical path that will take About 42.6 hours to complete. The lowest point of the orbit is 930 miles above the surface of Mars. The highest point is 31.440 miles above the surface.

On Monday afternoon, just a3 the craft is completing its first such orbit, its engine will fire again to reduce the size of the orbit and, hence, the time it takes to go around.

On Site Each Orbit

The goal is to put Viking into a path that takes 24.6 hours to complete. Because this is exactly the time it takes Mars to revolve once on its axis, Viking will pass over the landing site once every orbit. An orbit of any other duration would make the spacecraft's ground track different with each pass.

This will give its cameras and other instruments a numher of chances to survey the landing site for any problems” it, may present during a landing attempt.

If the twin cameras, which can take stereo pairs of pictures, reveal that the site is too rocky or steeply sloped for a safe landing, an alternate site will be chosen.

When the spacecraft is ready to land; it will separate into two modules, an orbiter that will remain aloft and a threelegged lender that will drop through the thin Martian atmosphere on a parachute and then make a soft landing braked by small rockets.

Aboard the Lander is an automated biological laboratory, that can analyze soil samples, gathered by a mechanical arm.’

https://www.nytimes.com/1976/06/20/archives/viking-1-begins-orbiting-mars-stage-set-for-july-4-landing-flight.html
« Ostatnia zmiana: Czerwiec 26, 2023, 21:24 wysłana przez Orionid »

Offline Orionid

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Odp: Viking Orbiter
« Odpowiedź #17 dnia: Lipiec 25, 2023, 21:54 »
X lat temu, czyli o tym, że nawet z błędem można kopiować.
Drugie zdjęcie marsjańskiej twarzy zostało wykonane przez HIRISE (MRO).
5:03 PM · Jul 25, 2022
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On this day in 1976 the Viking 1 orbiter took this image of mesa-like landforms, one resembling a human face. More about unmasking the face on Mars via @NASA: https://s.si.edu/2L73q08
https://twitter.com/airandspace/status/15515839237166366724:57 PM · Jul 25, 2023
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On #TDIH in 1977, the Viking 1 orbiter took this image of mesa-like landforms, one resembling a human face. More about unmasking the face on Mars via @NASA: https://science.nasa.gov/science-news/science-at-nasa/2001/ast24may_1/
https://twitter.com/airandspace/status/1683853905740922888
« Ostatnia zmiana: Lipiec 25, 2023, 21:56 wysłana przez Orionid »

Polskie Forum Astronautyczne

Odp: Viking Orbiter
« Odpowiedź #17 dnia: Lipiec 25, 2023, 21:54 »