Autor Wątek: Mariner 6, Mariner 7  (Przeczytany 220 razy)

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Offline ekoplaneta

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Mariner 6, Mariner 7
« dnia: Lipiec 31, 2019, 21:27 »
50 lat temu 31 lipca 1969 r., druga po Marinerze 4 z 1965 r., sonda - Mariner 6 przeleciała koło Czerwonej Planety:



Najmniejsza odległość Marinera 6 od Marsa podczas przelotu wynosiła 3428 km.



Filmik pokazujący Marsa wraz z zbliżaniem się do niej sondy:

https://planetary.s3.amazonaws.com/assets/images/4-mars/2013/20130903_mariner6_approach.gif

Zdjęcia wykonane Czerwonej Planecie z bliska:



Meridiani Planum (zwana wówczas Meridiani Sinus, następnie Meridiani Terra) widziana przez Marinera 6 oraz lecącego kolejno Marinera 7. Na zdjęciu widać krater Endeavour badany niedawno przez łazik Opportunity  :)




Książka o zdjęciach wykonanych przez Marinera 6 i 7
https://www.scribd.com/document/45904461/The-Mariner-6-and-7-Pictures-of-Mars
« Ostatnia zmiana: Lipiec 31, 2019, 21:31 wysłana przez ekoplaneta »

Offline Orionid

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Odp: Mariner 6, Mariner 7
« Odpowiedź #1 dnia: Sierpień 01, 2019, 02:18 »
Najmniejsza odległość Marinera 6 od Marsa podczas przelotu wynosiła 3428 km.
Inne źródła nie potwierdzają podanego wyżej dystansu.
Ciekawe, że tylko różnica 1 km w czasie najbliższych zbliżeń do Marsa dzieliła obie sondy.

(...) At 05:03 UT on 31 July the near-encounter phase began, including collection of 26 close-up images. Due to a cooling system failure, channel 1 of the IR spectrometer did not cool sufficiently to allow measurements from 6 to 14 micrometers so no infrared data were obtained over this range. Closest approach occurred at 05:19:07 UT at a distance of 3431 km from the martian surface. (...)
https://space.skyrocket.de/doc_sdat/mariner-6.htm
https://en.wikipedia.org/wiki/Mariner_6_and_7

Mariner-6 http://lk.astronautilus.pl/sondy/mariner6.htm
Mariner-7 http://lk.astronautilus.pl/sondy/mariner7.htm

Offline Orionid

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Odp: Mariner 6, Mariner 7
« Odpowiedź #2 dnia: Sierpień 01, 2019, 02:19 »
Nieco szczegółów technicznych:

Mariner 6-7, launched 2/2469 and 3/27/69,
Mars flybys 7/31/69 and 8/5/69;
mass 413 kg (908 lb) each;
wide- and narrow-angle cameras with digital tape recorder,
infrared spectrometer and radiometer,
ultraviolet spectrometer,
radio occultation and celestial mechanics.
https://www.jpl.nasa.gov/news/fact_sheets/mariner.pdf

Scientific Instrument(s)
- Imaging system
- Infrared spectrometer
- Infrared radiometer
- Ultraviolet spectrometer
- Conical radiometer
https://www.jpl.nasa.gov/missions/mariner-7/
http://www.astronautix.com/m/mariner6-7.html

Informacje z trasy dolotu do Marsa sprzed 50 lat:
https://www.jpl.nasa.gov/news/news.php?feature=6103

Historyczne materiały o misjach:

<a href="http://www.youtube.com/watch?v=AIRdzcPyDeE" target="_blank">http://www.youtube.com/watch?v=AIRdzcPyDeE</a>
https://www.youtube.com/watch?v=AIRdzcPyDeE

<a href="http://www.youtube.com/watch?v=ghD1OA_puiE" target="_blank">http://www.youtube.com/watch?v=ghD1OA_puiE</a>
https://www.youtube.com/watch?v=ghD1OA_puiE

Offline Orionid

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Odp: Mariner 6, Mariner 7
« Odpowiedź #3 dnia: Sierpień 01, 2019, 02:19 »
50 Years Ago: Mariner 6 and 7 off to Mars
Feb. 25, 2019


Left and middle: Launch of Mariner 6 and 7. Right: Mariner 6 and 7 spacecraft.

While much of NASA’s focus in 1969 centered on accomplishing President John F. Kennedy’s goal of landing a man on the Moon before the end of the decade, the Agency was also exploring further out in the solar system using robotic spacecraft. Managed by the Jet Propulsion Laboratory in Pasadena, California, Mariner 6 and 7 were NASA’s next steps in the exploration of Mars. Previously, only one spacecraft, Mariner 4, had made a successful reconnaissance of the Red Planet. It beamed back to Earth 22 black and white images of Mars during its fly-by in July 1965, showing a Moon-like heavily cratered surface. Shortly after that pioneering encounter, NASA authorized the Mariner Mars 1969 project, consisting of two identical spacecraft to make closer fly-bys of the Red Planet and take more detailed photographs and other measurements. Each 908-pound spacecraft carried eight experiments to study the atmosphere and surface of Mars during their fly-bys of the planet. The experiments were:  an infrared spectrometer; an infrared radiometer to measure the surface temperature of Mars; an ultraviolet spectrometer; an S-band occultation experiment; a thermal control flux monitor; a television camera system with wide- and narrow-angle telescopes; a celestial mechanics experiment; and a general relativity experiment.


Trajectories of Mariner 6 and 7 from Earth to Mars.

During a countdown test on Feb. 14, 1969, a malfunction in Mariner 6’s unfueled Atlas rocket caused helium pressure gas, used to keep the booster rigid, to escape. The rocket began to crumple, but two technicians, Bill McClure and Jack Beverlin quickly activated a manual override and repressurized the rocket. Although the booster was damaged, the technicians’ action saved the spacecraft and its Centaur upper stage. For their quick thinking in a dangerous situation, they each received an Exceptional Bravery Medal and in 2014 an escarpment on Mars was posthumously named the McClure-Beverlin Ridge in their honor.

Engineers quickly placed Mariner 6 and its Centaur on top of the rocket planned for Mariner 7, and launched it on schedule and without incident on Feb. 25, 1969. Mariner 7, on top of a new Atlas-Centaur, followed on Mar. 27. Their respective Centaur upper stages sent them on their way to Mars. Course corrections on Mar. 1 for Mariner 6 and Apr. 8 for Mariner 7 refined their trajectories. Because of their different paths, the two spacecraft arrived at Mars just five days apart despite the month separating their launches. After a flight of 156 days from Earth, Mariner 6 flew within 2,132 miles of Mars on July 31, roughly twice as close as Mariner 4’s flyby in 1965. During the encounter, the spacecraft returned 75 photographs and science data. Contact was temporarily lost with Mariner 7 just five days before its planned encounter, but by Aug. 2 the spacecraft was restored to full capability as it began its encounter with Mars. Three days later, it passed within 2,130 miles of Mars’ southern hemisphere, returning 126 photographs and science data.

https://www.nasa.gov/feature/50-years-ago-mariner-6-and-7-off-to-mars

Offline Orionid

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Odp: Mariner 6, Mariner 7
« Odpowiedź #4 dnia: Sierpień 01, 2019, 02:19 »
50 Years Ago: Mariner 6 and 7 Explore Mars
July 31, 2019

Lost in the publicity glare following the Apollo 11 Moon landing, two intrepid robotic spacecraft flew by Mars in the summer of 1969 and returned photographs and much useful scientific information about the Red Planet. Managed by the Jet Propulsion Laboratory in Pasadena, California, Mariner 6 and 7 were NASA’s next steps in the exploration of Mars following the pioneering flyby completed by Mariner 4 in July 1965. Each 908-pound spacecraft carried eight experiments to study the atmosphere and surface of Mars during their fly-bys of the planet. The experiments were:  an infrared spectrometer; an infrared radiometer to measure the surface temperature of Mars; an ultraviolet spectrometer; an S-band occultation experiment; a thermal control flux monitor; a television camera system with wide- and narrow-angle telescopes; a celestial mechanics experiment; and a general relativity experiment.


Close-up of science instrument platform aboard Mariner 6 and 7 – a) infrared radiometer, b) wide-angle TV camera, c) ultraviolet spectrometer, d) narrow-angle TV camera, e) infrared spectrometer.

Launched on Feb. 25 and March 27, respectively, Mariner 6 and 7 arrived at Mars just five days apart despite being launched a month apart. After a flight of 156 days from Earth, Mariner 6 flew within 2,132 miles of Mars on July 31, roughly twice as close as Mariner 4’s flyby in 1965. Controllers lost contact with Mariner 7 for seven hours just five days before its planned flyby, but by Aug. 2, after quick replanning, they restored the spacecraft to full capability as it began its encounter with Mars. Three days later, it passed within 2,130 miles of Mars’ southern hemisphere. Both spacecraft flew behind the planet and a radio occultation experiment measured the surface pressure of the Martian atmosphere to be between 6 and 7 mb, or less than 10% of Earth’s atmosphere at sea level. After their successfully flybys, Mariner 6 and 7 sailed on into solar orbit.


Globe of Mars to show the areas photographed by Mariner 6 (top row of photos) and Mariner 7 (bottom row).


Three black-and-white photographs taken through different color filters were combined to create this color image of Mars taken by Mariner 7.

Earth-based telescopes in the 1960s could not reveal Martian surface features smaller than 62 miles. The Mariner 4 photographs in 1965 showed details as small as about two miles but the total area imaged covered less than 1% of the planet’s surface. This made relating the views seen in the Mariner 4 images to global features difficult. Mariner 6 and 7 took a sequence of far-encounter images that covered the entire planet at resolutions far greater than possible with Earth-based telescopes. The near-encounter close-up images covered about 20% of the planet’s surface, with resolution down to 900 feet using the narrow-angle camera.

By combining three black-and-white images taken by Mariner 7 through different color filters, scientists were able to reconstruct a color image of the planet that showed greater detail than any Earth-based photograph. In three of its photographs, Mariner 7 managed to capture an image of Mars’ larger moon Phobos as it passed below the spacecraft. Although the moon was close to the camera’s resolving power, it clearly appeared to be elongated in shape. This was the first photograph of a planetary satellite taken by a spacecraft.

During its encounter, Mariner 6 returned a total of 75 photographs, 50 during the far encounter phase and 25 during the near encounter. Mariner 7 added 93 far-encounter and 33 near-encounter photos. The infrared radiometers on both spacecraft indicated that the thin Martian atmosphere was composed almost entirely of carbon dioxide, as was the south polar cap.



Phobos (left black dot in inset) photgraphed by Mariner 7.

The photographs and science data returned by Mariner 6 and 7 significantly increased our understanding of Mars but also posed new questions. Missions that orbited and landed on the Red Planet followed in the 1970s.

John Uri
NASA Johnson Space Center
https://www.nasa.gov/feature/50-years-ago-mariner-6-and-7-explore-mars

Offline Orionid

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Odp: Mariner 6, Mariner 7
« Odpowiedź #5 dnia: Sierpień 04, 2019, 23:55 »
5 sierpnia mija 50 lat od uzyskania pierwszego zdjęcia Phobosa wykonanego przez sondę Mariner 7.
Poniżej prezentacja danych uzyskanych na podstawie przelotu.


Phobos: Preliminary Results from Mariner 7
Bradford A. Smith Science  15 May 1970

Analysis of an image of Phobos on Mariner 7 frame 7F91 indicates that the martian satellite is larger and has a darker surface than had previously been thought. The limb profile measures 18 by 22 kilometers and is elongated along the orbital plane. Phobos has an average visual geometric albedo of 0.065 lower than that known for any other body in the solar system. It seems probable that Phobos did not form by accretion around primordial Mars, but was captured at some later time.
https://science.sciencemag.org/content/168/3933/828
« Ostatnia zmiana: Sierpień 05, 2019, 05:07 wysłana przez Orionid »

Offline ekoplaneta

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Odp: Mariner 6, Mariner 7
« Odpowiedź #6 dnia: Sierpień 05, 2019, 06:27 »
5 sierpnia mija też 50 lat od przelotu Marinera 7 koło Marsa  :)