{"id":679,"date":"2012-08-06T15:23:56","date_gmt":"2012-08-06T15:23:56","guid":{"rendered":"http:\/\/megalextoria.wordpress.com\/?p=679"},"modified":"2012-08-06T15:23:56","modified_gmt":"2012-08-06T15:23:56","slug":"nasas-curiosity-rover-lands-on-mars","status":"publish","type":"post","link":"https:\/\/www.megalextoria.com\/wordpress\/index.php\/2012\/08\/06\/nasas-curiosity-rover-lands-on-mars\/","title":{"rendered":"NASA’s Curiosity rover lands on Mars"},"content":{"rendered":"
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In an unparalleled technological triumph, a one-ton nuclear-powered rover the size of a small car was lowered to the surface of Mars on the end of a 25-foot-long bridle suspended from the belly of a rocket-powered flying crane late Sunday to kick off an unprecedented $2.5 billion mission.<\/p>\n

With flight controllers at NASA\u2019s Jet Propulsion Laboratory anxiously watching telemetry flowing in from Mars, 154 million miles away and 13.8 minutes after the fact, the Mars Science Laboratory rover \u2014 Curiosity \u2014 radioed confirmation of touchdown at 10:32 p.m. PDT (GMT-7).<\/p>\n

\u201cTouchdown confirmed. We\u2019re safe on Mars!\u201d said mission control commentator Allen Chen as the flight control team erupted in cheers and applause.<\/p>\n

\u201cIt\u2019s just absolutely incredible, it doesn\u2019t get any better than this,\u201d said NASA Administrator Charles Bolden. \u201cI was a basket case in there, I was really on pins and needles.<\/p>\n

\u201cIt\u2019s a huge day for the nation, it\u2019s a huge day for all of our partners and it\u2019s a huge day for the American people,\u201d he said. \u201cEverybody in the morning should be sticking their chests out, saying \u2018that\u2019s my rover on Mars.\u2019 Because it belongs to all of us.\u201d<\/p>\n

The target landing zone was Gale Crater near the base of a three-mile-high mound of layered rock that represents hundreds of thousands to tens of millions of years of martian history, a frozen record of the planet\u2019s changing environment and evolution.<\/p>\n

While the rover\u2019s exact position was not immediately known, there were no obvious problems during the dramatic entry, descent and landing and Curiosity presumably made it down inside a predicted footprint measuring four miles wide and 12 miles long \u2014 a pinpoint landing compared to previous missions.<\/p>\n

The seven-minute descent to the surface provided high drama as flight controllers monitored telemetry from the spacecrat, relayed through NASA\u2019s aging Mars Odyssey spacecraft. As each major milestone ticked off, engineers clapped and cheered.<\/p>\n

\u201cWe have acquired the ground with the radar,\u201d Chen reported. \u201cHeat shield has separated, we have found the ground. We\u2019re standing by to prime the engines in preparation for powered flight. Six-point-nine kilometers and descending\u2026\u201d<\/p>\n

A few minutes later, the rover and its descent stage fell away from the vehicle\u2019s braking parachute and eight rocket engines ignited to stabilize the craft and slow the fall to touchdown velocity.<\/p>\n

\u201cWe are in powered flight,\u201d Chen reported. \u201cWe\u2019re at an altitude of one kilometer and descending about 70 meters per second\u2026 500 meters in altitude\u2026 standing by for sky crane. We found a nice flat place, we\u2019re coming in ready for sky crane. Down to 10 meters per second, 40 meters altitude.\u201d<\/p>\n

A few moments later, just above the surface, the rocket-powered sky crane lowered Curiosity to the surface on the end of a 25-foot-long bridle, a landing technique never before attempted and one that added tension to an already anxious atmosphere.<\/p>\n

While engineers did not expect pictures right away, blurry low-resolution thumbnails from the rover\u2019s rear hazard avoidance cameras were transmitted within minutes of touchdown showing a wheel on the surface of Mars.<\/p>\n

\u201cOdysesey data is still strong,\u201d Chen reported. \u201cOdyseey is nice and high in the sky. At this time we\u2019re standing by for images\u2026\u201d<\/p>\n

\u201cWe\u2019ve got thumbnails,\u201d someone said.<\/p>\n

\u201cWe are wheels down on Mars!\u201d Chen reported.<\/p>\n

\u201cOh my God,\u201d someone said in the background.<\/p>\n

Exploring the crater floor and climbing Mount Sharp over the next two years, Curiosity will look for signs of past or present habitability and search for carbon compounds, the building blocks of life as it is known on Earth.<\/p>\n

But before the rover\u2019s geological fieldwork can begin, engineers will devote several weeks to carefully checking out Curiosity\u2019s complex systems and testing its state-of-the-art instruments and cameras.<\/p>\n

Curiosity\u2019s landing represented the most challenging robotic descent to the surface of another world ever attempted, a tightly choreographed sequence of autonomously executed events with little margin for error.<\/p>\n

NASA managers went out of their way to brace reporters for the possibility of failure.<\/p>\n

\u201cNo matter what happens, I just want the team to know I am really proud and privileged to have worked with these guys and gals,\u201d Doug McCuistion, director of Mars exploration at NASA Headquarters, said earlier Sunday. \u201cThey\u2019re amazing. They\u2019ve done everything humanly possible to make this happen.\u201d<\/p>\n

Adam Steltzner, the leader of the EDL team at the Jet Propulsion Laboratory in Pasadena, Calif., said earlier Sunday he was \u201crationally confident, emotionally terrified.\u201d<\/p>\n

\u201cThis team \u2026 has worked really hard for the better part of a decade, and the fruits of that labor get put to the test tonight,\u201d he said. \u201cIt\u2019s a little anxiety provoking. But I will say I slept better last night than I have slept in a couple of years, because she\u2019s kind of on her own now. When I look back on the hard work that we\u2019ve done, I believe the team has done everything that we can to deserve success tonight.\u201d<\/p>\n

And that\u2019s exactly what they got. While precise numbers were not expected until the telemetry could be analyzed, the entry, descent and landing appeared to follow the script as planned, which is reflected in the following description.<\/p>\n

The Mars Science Laboratory spacecraft consisted of an interplanetary cruise stage, providing power and communications during the long-flight out from Earth, and the Curiosity rover, cocooned inside a heat shield and aeroshell to protect it from the extreme temperatures of atmospheric entry.<\/p>\n

After covering 352 million miles since launch from Cape Canaveral, Fla., last November, the cruise stage separated from the lander around 10 p.m. But because of the distance between Earth and Mars \u2014 154 million miles \u2014 it took radio signals confirming critical events 13.8 minutes to reach the flight control team at JPL. That translated into 10:14 p.m. \u201cEarth-received time.\u201d<\/p>\n

One minute later, thrusters fired to stop the entry vehicle\u2019s 2-rpm rotation and the spacecraft re-oriented itself heat shield forward and slammed into the discernible atmosphere at 10:24 p.m. at an altitude of about 78 miles and a velocity of 13,200 mph. At that point, it was about 390 miles \u2014 seven minutes \u2014 from touchdown in Gale Crater.<\/p>\n

The Mars Science Laboratory was the first spacecraft to attempt a so-called guided entry on another planet.<\/p>\n

To control its lift, which allowed Curiosity\u2019s flight computer to make a pinpoint landing, two 165-pound tungsten weights were ejected just before entry to change the spacecraft\u2019s center of mass. During hypersonic flight, thruster firings controlled the orientation of the vehicle\u2019s \u201clift vector\u201d to compensate for actual atmospheric conditions as it precisely controlled its path toward Gale Crater.<\/p>\n

About one minute and 15 seconds after entry, the spacecraft\u2019s heat shield was expected to experience peak temperatures of up to 3,800 degrees Fahrenheit as atmospheric friction provided 90 percent of the spacecraft\u2019s deceleration. Ten seconds after peak heating, that deceleration was expected to peak at 10 to 15 times the force of Earth\u2019s gravity at sea level.<\/p>\n

Plummeting toward Mars, the rover\u2019s flight computer continued steering the spacecraft, firing thrusters to make subtle changes in the flight path as required by atmospheric density and other variables.<\/p>\n

The guided entry phase of flight was programmed to an end about four minutes after entry began. Six 55-pound weights then had to be ejected to move the center of mass back to the central axis of the spacecraft to help ensure stability when its braking parachute deployed.<\/p>\n

Seconds later, at an altitude of about seven miles and a velocity of some 900 miles per hour, the huge chute unfurled and inflated to a diameter of 70 feet, delivering a 65,000-pound jolt to the still-supersonic spacecraft.<\/p>\n

The heat shield was expected to be jettisoned about 24 seconds later, at an altitude of about five miles and a descent rate of 280 mph, exposing the rover\u2019s undercarriage to view.<\/p>\n

A sophisticated radar altimeter then began measuring altitude and velocity, feeding those data to the rover\u2019s flight computer while a high-definition camera began recording video of the remaining few minutes of the descent.<\/p>\n

Six minutes after entry, now one mile up and falling toward the surface at roughly 180 mph, the rover and its rocket pack were cut away from the parachute and backshell, falling like a rock through the thin martian atmosphere.<\/p>\n

An instant later, eight hydrazine-burning rocket engines, two at each corner of the descent stage, ignited to stabilize and quickly slow the craft\u2019s vertical velocity to less than 2 mph.<\/p>\n

About 16 seconds before touchdown, at an altitude of just under 70 feet, Curiosity was lowered on the end of a 25-foot-long bridle made up of three cables. As the support and data cables unreeled, the rover\u2019s six motorized wheels presumably snapped into position for touchdown.<\/p>\n

Finally, seven minutes after the entry began and descending at a gentle 1.7 mph, Curiosity\u2019s wheels touched the surface of Mars. Radio confirmation of landing came in at 10:32 p.m., about 3 p.m. local time on Mars.<\/p>\n

Curiosity\u2019s flight computer, sensing \u201cweight on wheels,\u201d then sent commands to fire small explosive devices that severed the cables connecting the rover to the still-firing propulsion system. Its work complete, the descent stage flew away to a crash landing a safe distance away.<\/p>\n

\u201cWe have three different signals we would use to confirm touchdown and we need all three of those things to look right before we say so,\u201d Steltzner said earlier Sunday. \u201cOne of those is a message from the spacecraft that says \u2018I touched down, and this is the velocity I touched down at and where I think I am.\u2019<\/p>\n

\u201cThe rover has an inertial measurement unit, a gyro and an accelerometer set, and we look at that stream to say the rover\u2019s not moving at all, that signal says \u2018I think I\u2019m on the ground and I\u2019m not moving.\u2019 And the third is, we wait a safe period of time and confirm we\u2019re getting continuous UHF (radio) transmission. And frankly, that\u2019s there to make sure the descent stage hasn\u2019t fallen back down on top of the rover. When all three of those signals are positive, we declare touchdown confirmation.\u201d<\/p>\n

And that\u2019s exactly what Chen reported at 10:32 p.m.<\/p>\n

Full article: http:\/\/www.spaceflig \u2026 s\/msl\/120806landing\/<\/a><\/p>\n<\/div>\n<\/div>\n","protected":false},"excerpt":{"rendered":"

In an unparalleled technological triumph, a one-ton nuclear-powered rover the size of a small car was lowered to the surface of Mars on the end of a 25-foot-long bridle suspended from the belly of a rocket-powered flying crane late Sunday to kick off an unprecedented $2.5 billion mission. With flight controllers at NASA\u2019s Jet Propulsion Laboratory anxiously watching telemetry flowing in from Mars, 154 million miles away and 13.8 minutes after the fact, the Mars Science Laboratory rover \u2014 Curiosity \u2014 radioed confirmation of touchdown at 10:32 p.m. PDT (GMT-7). \u201cTouchdown confirmed. We\u2019re safe on Mars!\u201d said mission control commentator Allen Chen as the flight control team erupted in cheers and applause. \u201cIt\u2019s just absolutely incredible, it doesn\u2019t get any better than this,\u201d said NASA Administrator Charles Bolden. \u201cI was a basket case in there, I was really on pins and needles. \u201cIt\u2019s a huge day for the nation, it\u2019s a huge day for all of our partners and it\u2019s a huge day for the American people,\u201d he said. \u201cEverybody in the morning should be sticking their chests out, saying \u2018that\u2019s my rover on Mars.\u2019 Because it belongs to all of us.\u201d The target landing zone was Gale Crater near […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[22],"tags":[517,1091,1205],"class_list":["post-679","post","type-post","status-publish","format-standard","hentry","category-space","tag-curiosity","tag-mars","tag-nasa"],"_links":{"self":[{"href":"https:\/\/www.megalextoria.com\/wordpress\/index.php\/wp-json\/wp\/v2\/posts\/679","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.megalextoria.com\/wordpress\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.megalextoria.com\/wordpress\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.megalextoria.com\/wordpress\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.megalextoria.com\/wordpress\/index.php\/wp-json\/wp\/v2\/comments?post=679"}],"version-history":[{"count":0,"href":"https:\/\/www.megalextoria.com\/wordpress\/index.php\/wp-json\/wp\/v2\/posts\/679\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.megalextoria.com\/wordpress\/index.php\/wp-json\/wp\/v2\/media?parent=679"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.megalextoria.com\/wordpress\/index.php\/wp-json\/wp\/v2\/categories?post=679"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.megalextoria.com\/wordpress\/index.php\/wp-json\/wp\/v2\/tags?post=679"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}