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Offline Orionid

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Mariner 10
« dnia: Sierpień 03, 2019, 15:36 »
45 lat temu w 1974 Mariner 10 dokonał przelotów w pobliżu Wenus i Merkurego. Była to pierwsza misja planetarna, która odwiedziła  więcej niż jedną planetę i jednocześnie ostatnia w ramach serii próbników Mariner.



<a href="http://www.youtube.com/watch?v=ILyO19Nm-Nc" target="_blank">http://www.youtube.com/watch?v=ILyO19Nm-Nc</a>
https://www.youtube.com/watch?v=ILyO19Nm-Nc

Kluczowe daty:

03.11.1973  Z wyrzutni LC-36B na Cape Canaveral  RN Atlas SLV-3D/Centaur-D1A  wyniosła na trajektorię skierowaną ku Wenus sondę międzyplanetarną  Mariner 10.

     01.1974 Obserwacje komety Kohoutek w ultrafiolecie.

05.02.1974 Mariner-10 zbliżył się do Wenus na odległość 5768 km. 

29.03.1974 Podczas pierwszego przelotu sonda zbliżyła się do powierzchni Merkurego na odległość 704 km.

21.09.1974 Podczas drugiego przelotu sonda zbliżyła się do powierzchni Merkurego na odległość  48 069 km.

16.03.1975 Podczas trzeciego przelotu sonda zbliżyła się do powierzchni Merkurego na odległość 327 km.

24.03.1975 Zapasy gazu kontrolującego położenie zostały wyczerpane, powodując  zakończenie misji.

https://history.nasa.gov/SP-423/mariner.htm
https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=1973-085A
https://space.skyrocket.de/doc_sdat/mariner-10.htm
https://en.wikipedia.org/wiki/Mariner_10

Publikacja wydana przez NASA nt wyprawy:

The Voyage of Mariner 10: Mission to Venus and Mercury (NASA History Series Book 114)
by Eric Burgess (Author), Dunne , James A. (Author) Kindle Edition

File Size: 4708 KB
Print Length: 336 pages
Publisher: National Aeronautics and Space Administration (June 7, 2012)
Publication Date: June 7, 2012
https://www.amazon.com/Voyage-Mariner-10-Mission-Mercury-ebook/dp/B008A1ESEK

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Odp: Mariner 10
« Odpowiedź #1 dnia: Sierpień 03, 2019, 15:41 »
45 Years Ago, Mariner 10 Off to Venus and Mercury
Nov. 5, 2018

A unique opportunity presented itself in 1973 to send a spacecraft to visit both Venus and Mercury in a single mission. Using gravity assist, a technique theorized for decades but never used before, under favorable conditions a spacecraft sent to one planet can use that planet’s gravitational force to essentially slingshot on to its next target. The method saved the cost of additional fuel and a larger rocket that would be necessary to launch the heavier spacecraft as well as time to get to the ultimate destination. In 1969, NASA approved a plan to send a spacecraft to Mercury, using Venus for a gravity assist. The mission, first known as Mariner Venus Mercury, was later renamed Mariner 10 and managed by the Jet Propulsion Laboratory in Pasadena, California. It was the last in the Mariner series of very successful spacecraft that revealed many secrets about the inner solar system.


Left: Planned trajectory of Mariner 10 to explore Venus and Mercury.
Right: Image of Mariner 10 showing its scientific instruments.


Planetary scientists had learned a great deal about Venus from both Earth-based observations and spacecraft encounters. Two American spacecraft, Mariner 2 in 1962 and Mariner 5 in 1967, studied Venus during their fly-bys and revealed much about the planet’s atmosphere, showing it to be much hotter (527o C) and denser (75-100 atmospheres) than previously expected, and found only a very weak magnetic field. The Soviet Union dispatched several spacecraft to Venus as part of the Venera program and two, Venera 7 in 1970 and Venera 8 in 1972, managed to soft-land on the planet’s hellish surface and return data for less than an hour. Their scientific instruments confirmed the high temperatures and pressures, to which the spacecraft rapidly succumbed.

In comparison, very little was known about Mercury, the innermost planet in the solar system. No spacecraft had ever visited the planet, and its small size, distance from Earth, and proximity to the Sun made terrestrial observations difficult. A direct flight to Mercury would require a large expensive rocket due to the extra fuel required to reach the planet. The gravity-assist technique provided an opportunity for the first spacecraft-based observations of the little-known world.

Mariner 10’s goals at Venus were to add to existing information, such as closeup photography revealing the structure of the upper atmosphere, while at Mercury it was to conduct a more global survey of the planet. To accomplish these goals, Mariner 10 carried six scientific instruments – the Television Photography System consisting of two telescopes to image the planets; an infrared radiometer to calculate the temperature of Venus’ atmosphere and Mercury’s surface; an ultraviolet spectrometer primarily to detect any atmosphere around Mercury; plasma detectors to study the solar wind inside the orbit of Venus for the first time; a charged particle telescope to study cosmic radiation; and magnetometers to detect any magnetic field around Mercury. In addition, as the spacecraft passed behind the planet, its radio signals were used to probe Mercury’s atmosphere and precisely measure its radius. By precisely tracking the spacecraft’s trajectory as it passed Mercury, its mass and gravitational characteristics could be determined.

Shortly after midnight on November 3, 1973, the 500-kg Mariner 10 lifted off aboard its Atlas-Centaur rocket from Launch Pad 36B at Cape Canaveral, Florida. After a short time in a parking orbit around the Earth, the Centaur stage reignited, sending Mariner 10 toward Venus. During its first week in space, the spacecraft calibrated its camera system by taking photographs of the Earth and Moon, including of the Moon’s north polar region that was poorly imaged by earlier spacecraft. The three-month cruise to Venus included several spacecraft malfunctions, overcome by the dedicated ground control team. In January 1974, Mariner 10 made ultraviolet observations of Comet Kohoutek, adding to observations by ground-based observatories as well as the astronauts aboard the Skylab space station in Earth orbit.



Left: Launch of Mariner 10 on its Atlas-Centaur rocket.
Right: The flight spare of Mariner 10 on display at the National Air and Space Museum (NASM). Credits: NASM


The spacecraft passed within 5,768 kilometers (km) of Venus on February 5, 1974. During the fly-by, Mariner 10 sent back information about the Venus’ atmosphere and beaming back the first close-up images of the cloud-shrouded planet. Photographs taken in visible light revealed a featureless planet, but cloud detail was readily visible using ultraviolet filters. Mariner 10 returned 4,165 pictures of Venus. The gravity assist was successful, placing the spacecraft on a trajectory toward Mercury which it encountered on March 29 at a distance of 703 km. During this first spacecraft fly-by of the innermost planet, Mariner 10’s more than 2,000 photographs revealed Mercury’s surface to be heavily-cratered, reminiscent of the Moon. The spacecraft’s other instruments detected a weak magnetic field and a very thin atmosphere composed primarily of helium. Italian scientist and mathematician Giuseppe Colombo (1920-1984) from the University of Padua calculated that Mariner 10’s trajectory would make it possible to revisit Mercury every six months, with the spacecraft making one revolution around the Sun and Mercury making two during the interim. On September 21, during its second fly-by of Mercury, Mariner 10 passed at a more distant range of 48,069 km from the small planet’s southern hemisphere. The spacecraft returned 500 more images of Mercury. And on March 16, 1975, Mariner 10, nearly out of attitude control gas, made its final visit to Mercury, this time at a close range of 327 km, passing over the planet’s north pole. The spacecraft returned some of the most detailed images and additional data on the planet’s magnetic field.  Just eight days after this last encounter, Mariner 10 exhausted its supply of attitude control gas and ground controllers turned off its transmitter. The silent spacecraft sailed on in solar orbit.


Left: Venus as imaged by Mariner 10 using an ultraviolet filter to highlight the clouds that are invisible in the visible spectrum.
Right: Mercury as imaged by Mariner 10 during its first flyby.


The mission of Mariner 10 was a great success and unique in many ways. It was the first spacecraft to use gravity assist to visit more than one planet, a technique now used regularly to visit multiple bodies in the solar system. It was the first spacecraft to take close-up photographs of Venus and the first to explore Mercury. In just over 500 days, on a journey of more than a billion kilometers, Mariner 10 visited Venus once and Mercury three times, returning 7,000 photographs and greatly expanding our understanding of both planets. It also photographed the Earth and Moon and studied Comet Kohoutek.

After Mariner 10, many spacecraft returned to explore Venus. Some flew by the planet, others entered orbit, while still others dropped off probes, balloons, and soft landers to thoroughly study the planet and its atmosphere. No spacecraft would visit Mercury again for 36 years, until NASA’s MESSENGER spacecraft arrived to study the planet from orbit between 2011 and 2015. The joint European-Japanese BepiColombo spacecraft, named after the same Giuseppe Colombo who calculated Mariner 10’s resonant trajectory, is currently on its way to Mercury. Composed of two separate spacecraft, it will spend one year in orbit around Mercury after arriving in 2025.


https://www.nasa.gov/feature/45-years-ago-mariner-10-off-to-venus-and-mercury

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Odp: Mariner 10
« Odpowiedź #2 dnia: Sierpień 03, 2019, 15:41 »
45 Years Ago: Mariner 10 flies by Venus
Feb. 5, 2019


Left: Composite view of Earth and Moon, taken by Mariner 10 shortly after launch.
Right: Comet Kohoutek. Credits: Table Mountain Observatory.


Planetary scientists had learned a great deal about Venus from both Earth-based observations and previous American and Soviet spacecraft encounters. Mariner 10’s goals at Venus were to add to existing knowledge, and beam back the first ever close-up photographs of the planet to reveal the structure of the upper atmosphere. To accomplish these and other goals, Mariner 10 carried out seven scientific experiments – the Television Photography System consisting of two telescopes to image the planet; an infrared radiometer to calculate the temperature of Venus’ atmosphere; an ultraviolet spectrometer primarily to detect any atmosphere around Mercury; plasma detectors to study the solar wind inside the orbit of Venus for the first time; a charged particle telescope to study cosmic radiation; magnetometers to detect any magnetic field around Venus and Mercury; and a celestial mechanics and radio science experiment to investigate Venus and Mercury’s mass and gravitational characteristics.

On Nov. 3, 1973, Mariner 10 lifted off from Cape Canaveral, Florida, to begin its journey to Venus and Mercury. Shortly after leaving Earth orbit, the spacecraft calibrated its camera system by taking photographs of the Earth and Moon. The first photos of Earth were taken just 16 hours after launch at a distance of 120,000 miles. The spacecraft photographed the Moon’s north polar region, an area that was poorly imaged by earlier spacecraft. Planned course corrections 10 days after launch and on Jan. 21, 1974, adjusted the fly-by distance to within 8 miles of the target. The three-month cruise to Venus included several spacecraft malfunctions, overcome by the dedicated ground control team at JPL. In late January, Mariner 10 made ultraviolet measurements of Comet Kohoutek, adding to observations by ground-based facilities as well as the astronauts aboard the Skylab space station in Earth orbit.

The spacecraft approached Venus from its night side, and passed within 3,584 miles of the planet on Feb. 5, 1974. During the fly-by, Mariner 10 performed flawlessly and sent back information about Venus’ atmosphere and environment and beamed back the first close-up images of the cloud-shrouded planet. Photographs taken in visible light revealed a featureless orb, but using ultraviolet filters revealed extensive cloud details. A series of images confirmed terrestrial observations that Venus’ cloud tops rotate with a period of four days. In all, Mariner 10 returned 4,165 pictures of Venus.



Left: True color image of Venus taken by Mariner 10.
Right: Venus as imaged by Mariner 10 using an ultraviolet filter to highlight the clouds that are invisible in the visible spectrum.


Mariner 10 contributed significantly to our understanding of Venus during its fly-by. It confirmed that Venus lacks an appreciable magnetic field to deflect the solar wind, but its considerable atmosphere and ionosphere act to modify the stream of particles emanating from the Sun. The ionosphere in particular creates a bowshock, preventing the particles of the solar wind from penetrating into the atmosphere. The celestial mechanics experiment found that Venus is 100 times closer to being a perfect sphere than the Earth. The spacecraft found that temperatures at Venus’ cloudtops are the same on both the day and night sides. Data from Mariner 10’s radio science instrument allowed scientist to build detailed pressure, density, and temperature profiles of the Venusian atmosphere. For the most part temperatures increased toward the surface, but Mariner 10 found four temperature inversions higher in the atmosphere likely caused by cloud formations.

The gravity assist at Venus was highly successful, and Mariner 10 continued on to Mercury to conduct the first ever encounter with that planet on Mar. 29, 1974. The spacecraft’s unique trajectory enabled it to return for two additional fly-bys of the innermost planet at six-month intervals.


https://www.nasa.gov/feature/45-years-ago-mariner-10-flies-by-venus

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Odp: Mariner 10
« Odpowiedź #3 dnia: Sierpień 03, 2019, 15:41 »
45 Years Ago: Mariner 10 First to Explore Mercury
March 29, 2019


Image of Mariner 10 highlighting its scientific instruments.


Mariner 10’s trajectory through the inner solar system.

(...) Planetary scientists had learned a great deal about Venus from both Earth-based observations and previous American and Soviet spacecraft encounters. In comparison, very little was known about Mercury, the innermost planet in the solar system. No spacecraft had ever visited the planet, and its small size, distance from Earth, and proximity to the Sun made terrestrial observations difficult. A direct flight to Mercury would have required a large and expensive rocket due to the extra fuel needed to reach the planet. The gravity-assist technique provided an opportunity for the first spacecraft-based observations of the little-known world.

Mariner 10’s goals at Venus were to add to existing information, such as closeup photography revealing the structure of the upper atmosphere, while at Mercury it was to conduct a more global survey of the planet. To accomplish these and other goals, Mariner 10 carried out seven scientific experiments – the television photography system consisting of two telescopes to image the planets; an infrared radiometer to calculate the temperature of Venus’ atmosphere and Mercury’s surface; an ultraviolet spectrometer primarily to detect any atmosphere around Mercury; plasma detectors to study the solar wind inside the orbit of Venus for the first time; a charged particle telescope to study cosmic radiation; magnetometers to detect any magnetic field around Venus and Mercury; and a celestial mechanics and radio science experiment to investigate Venus and Mercury’s mass and gravitational characteristics. As the spacecraft passed behind Mercury, its radio signals were used to determine if the planet had an atmosphere and precisely measure its radius. By precisely tracking the spacecraft’s trajectory as it passed Mercury, the planet’s mass and gravitational characteristics could be determined.



Image of Venus taken with an ultraviolet filter by Mariner 10 to show cloud features.

Mariner 10 lifted off from Cape Canaveral, Florida, on Nov. 3, 1973, to begin its journey to Venus and Mercury. The spacecraft passed within 3,584 miles of Venus on Feb. 5, 1974, returning more than 4,000 images and contributing significantly to our understanding of the cloud-shrouded planet during its flyby. But Venus’ most important contribution to the mission was the gravity assist it provided to alter Mariner 10’s trajectory and send it on its way to Mercury. Mission planners chose the trajectory in such a way that the encounter with Mercury would occur when the planet was at its furthest point from the Sun in its elliptical orbit so that Mariner 10 would not have to travel any closer to the Sun than necessary to reduce the risk of overheating. In another bit of trajectory planning, Professor Giuseppe “Bepi” Colombo at the University of Padua in Italy determined that Mariner 10 could be placed in such an orbit that it would re-encounter Mercury every 176 days, exactly twice the time it takes the planet to orbit around the Sun. The only downside to this timing was that Mercury’s rotation period is in a 3:2 resonance with its period of revolution around the Sun, meaning that every time Mariner 10 returned to the planet, Mercury presented the same sunlit hemisphere for observation. Thus only about 40-45% of the planet’s surface was imaged, but at high enough resolution to generate a detailed map.


Left: Mariner 10 image of Mercury taken during the first flyby.
Right: Image of Mercury from the second flyby showing the planet’s southern hemisphere, with the South Pole near the bottom of the picture at the terminator.


A mid-course correction on March 16 refined the spacecraft’s trajectory for optimum science measurements during the first Mercury encounter. The first instruments were activated the next day and the first images of the planet were returned one week later. These initial pictures displayed about the same amount of detail as photographs taken from Earth, but as the spacecraft approached the planet, the pictures began to reveal surface features. On March 29, Mariner 10 passed only 438 miles above Mercury’s surface and continued to photograph the planet until April 3, by which time it had returned more than 2,000 images as well as a wealth of data from its other scientific instruments. At first glance, Mercury appeared very Moon-like with a heavily cratered surface, but overall the planet’s surface features showed less contrast than our satellite. Other features such as scarps or cliffs present on Mercury are absent on the Moon and hint at the planet’s formation. Mercury also has mare or flat plain like features like the Moon and Mars, possible clues to similar planetary ancestries in terms of bombardment by asteroids. Somewhat surprisingly, Mariner 10’s magnetometer detected a weak (about 1/60th the strength of Earth’s) magnetic field. Radio tracking of the spacecraft’s trajectory revealed Mercury to be much closer to being a perfect sphere than Earth.  The large temperature difference between Mercury’s day and night sides, more than 600oF, indicates that its surface is composed of similar material to the Moon’s, a blanket of dust pulverized by meteoric impacts.


Left: View of Mercury’s South Pole taken during the second flyby – the pole is near the right rim of the large crater (Chau Meng Fu crater) at the bottom of the photo.
Right: View of Hero Rupes scarp in the southern hemisphere taken during the second flyby.



Closeup view of Hero Rupes scarp in the southern hemisphere taken during the third flyby.

Mariner 10 went on to make two more successful fly-bys of Mercury. Five mid-course corrections were required to properly aim the spacecraft for its second encounter and also enable the third. On Sep. 21, 1974, it passed at a more distant 29,875 miles of Mercury’s sunlit side and this trajectory allowed the planet’s south polar region to be observed. Some 500 new images of the planet were returned during the three-day encounter, and the greater distance of the flyby allowed scientists to create a series of hemisphere-wide mosaics of amazing detail. The spacecraft’s ultraviolet spectrometer confirmed that Mercury has a very thin atmosphere composed mainly of helium.

The third encounter took place on March 16, 1975, but not without some drama in the days leading up to it. Mariner 10, already running low on attitude control fuel, rolled out of communication with Earth. Controllers scrambled to get time on tracking antennas to regain control of the spacecraft and succeeded just in time for the encounter. This time the fly-by distance was only 203 miles above the surface, with the main goals to study the planet’s magnetic field and to take more detailed imagery of sites of interest identified from the first two encounters. About 450 useful narrow strips of photographs were taken, some with a surface resolution down to about 450 feet. Eight days later, Mariner 10 depleted its attitude control fuel and mission controllers sent a signal to turn the spacecraft off. This brought to an end to the flight operations of a highly successful mission that essentially explored two planets for the price of one, and completed four encounters for the price of two. Scientists continued to analyze the data returned by Mariner 10 for many years. The discoveries at Venus and especially at Mercury added a great deal to our knowledge of the inner solar system. (...)


John Uri NASA Johnson Space Center
https://www.nasa.gov/feature/45-years-ago-mariner-10-first-to-explore-mercury