The Hellenic Navy (HN) (Greek: Πολεμικό Ναυτικό, Polemikó Naftikó, abbreviated ΠΝ) is the naval force of Greece, part of the Greek Armed Forces. The modern Greek navy has its roots in the naval forces of various Aegean Islands, which fought in the Greek War of Independence. During the periods of monarchy (1833–1924 and 1936–1973) it was known as the Royal Navy (Βασιλικόν Ναυτικόν, Vasilikón Naftikón, abbreviated ΒΝ).The total displacement of all the navy's vessels is approximately 150,000 tons.The motto of the Hellenic Navy is "Μέγα το της Θαλάσσης Κράτος" from Thucydides' account of Pericles' oration on the eve of the Peloponnesian War. This has been roughly translated as "Great is the country that controls the sea". The Hellenic Navy's emblem consists of an anchor in front of a crossed Christian cross and trident, with the cross symbolizing Greek Orthodoxy, and the trident symbolizing Poseidon, the god of the sea in Greek mythology. Pericles' words are written across the top of the emblem. "The navy, as it represents a necessary weapon for Greece, should only be created for war and aim to victory."...............The Hellenic Merchant Marine refers to the Merchant Marine of Greece, engaged in commerce and transportation of goods and services universally. It consists of the merchant vessels owned by Greek civilians, flying either the Greek flag or a flag of convenience. Greece is a maritime nation by tradition, as shipping is arguably the oldest form of occupation of the Greeks and a key element of Greek economic activity since the ancient times. Nowadays, Greece has the largest merchant fleet in the world, which is the second largest contributor to the national economy after tourism and forms the backbone of world shipping. The Greek fleet flies a variety of flags, however some Greek shipowners gradually return to Greece following the changes to the legislative framework governing their operations and the improvement of infrastructure.Blogger Tips and Tricks
This is a bilingual blog in English and / or Greek and you can translate any post to any language by pressing on the appropriate flag....Note that there is provided below a scrolling text with the 30 recent posts...Αυτό είναι ένα δίγλωσσο blog στα Αγγλικά η/και στα Ελληνικά και μπορείτε να μεταφράσετε οποιοδήποτε ποστ σε οποιαδήποτε γλώσσα κάνοντας κλικ στη σχετική σημαία. Σημειωτέον ότι παρακάτω παρέχεται και ένα κινούμενο κείμενο με τα 30 πρόσφατα ποστς....This is a bilingual blog in English and / or Greek and you can translate any post to any language by pressing on the appropriate flag....Note that there is provided below a scrolling text with the 30 recent posts...Αυτό είναι ένα δίγλωσσο blog στα Αγγλικά η/και στα Ελληνικά και μπορείτε να μεταφράσετε οποιοδήποτε ποστ σε οποιαδήποτε γλώσσα κάνοντας κλικ στη σχετική σημαία. Σημειωτέον ότι παρακάτω παρέχεται και ένα κινούμενο κείμενο με τα 30 πρόσφατα ποστς.........

Monday, September 22, 2014

NASA's Maven spacecraft in orbit around Mars, ..[ 4681 ]

NASA says Maven spacecraft enters orbit around Mars

Mars Maven_Cham640.jpg
In this artist concept provided by NASA, the MAVEN spacecraft approaches Mars on a mission to study its upper atmosphere. (AP Photo/NASA)
NASA's Maven spacecraft has entered orbit around Mars, completing a journey that lasted nearly a year and covered 442 million miles. 
NASA said late Sunday that the robotic explorer had fired its brakes and slipped into orbit, successfully completing the first part of its $671 million mission. 
"This is such an incredible night," John Grunsfeld, NASA's chief for science missions, told The Associated Press. 
Flight controllers will spend the next six weeks adjusting Maven's altitude and checking its science instruments. Then Maven will start probing the planet's upper atmosphere. The spacecraft will conduct its observations from orbit; it's not meant to land.
Scientists believe the Martian atmosphere holds clues as to how Earth's neighbor went from being warm and wet billions of years ago to cold and dry. That early moist world may have harbored microbial life, a tantalizing question yet to be answered.
The spacecraft was launched from Cape Canaveral this past November, making it the 10th U.S. mission sent to orbit the red planet. Three earlier ones failed, and until the official word came of success late Sunday night, the entire team was on edge.
"I don't have any fingernails any more, but we've made it," said Colleen Hartman, deputy director for science at Goddard Space Flight Center in Greenbelt, Maryland. "It's incredible."
The spacecraft was clocking more than 10,000 mph when it hit the brakes for the so-called orbital insertion, a half-hour process. The world had to wait 12 minutes to learn the outcome, once it occurred, because of the lag in spacecraft signals given the 138 million miles between the two planets on Sunday.
"Based on observed navigation data, congratulations, Maven is now in Mars orbit," came the official announcement. Flight controllers applauded the news and shook hands; laughter filled the previously tense-filled room.
Maven joins three spacecraft already circling Mars, two American and one European. And the traffic jam isn't over: India's first interplanetary probe, Mangalyaan, will reach Mars in two days and also aim for orbit.
Maven's chief investigator, Bruce Jakosky of the University of Colorado's Laboratory for Atmospheric and Space Physics in Boulder, hopes to learn where all the water on Mars went, along with the carbon dioxide that once comprised an atmosphere thick enough to hold moist clouds.
The gases may have been stripped away by the sun early in Mars' existence, escaping into the upper atmosphere and out into space. Maven's observations should be able to extrapolate back in time, Jakosky said.
Maven -- short for Mars Atmosphere and Volatile Evolution Mission -- will spend at least a year collecting data. That's a full Earth year, half a Martian one. Its orbit will dip as low as 78 miles above the Martian surface as its eight instruments make measurements. The craft is as long as a school bus, from solar wingtip to tip, and as hefty as an SUV.
Maven will have a rare brush with a comet next month.
The nucleus of newly discovered Comet Siding Spring will pass 82,000 miles from Mars on Oct. 19. The risk of comet dust damaging Maven is low, officials said, and the spacecraft should be able to observe Siding Spring as a science bonus.
Lockheed Martin Corp., Maven's maker, is operating the mission from its control center at Littleton, Colorado.
This is NASA's 21st shot at Mars and the first since the Curiosity rover landed on the red planet in 2012. Just this month, Curiosity arrived at its prime science target, a mountain named Sharp, ripe for drilling. The Opportunity rover is also still active a decade after landing.
All these robotic scouts are paving the way for the human explorers that NASA hopes to send in the 2030s.
The Associated Press contributed to this report.

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