NASA Waits For Answers As Russia Investigates "Razor's Edge" Soyuz Landing

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surferastra

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<p>(From The Spacearium, http://www.spacearium.com and repritned with permission because I'm the author)</p><p>JOHNSON SPACE CENTER, TX - It will take one to three months before NASA knows what caused a series of problems during the re-entry of Soyuz TMA-11 that put the three astronauts on board in significantly more danger than had been reported at the time.. The Interfax news agency reported one Russian official as likening the situation to being on a "razor's edge."&nbsp;&nbsp; Russia has formed a state commission to study the bone-rattling landing and determine what may need to be done to ensure such a hard landing doesn't occur again. </p><p>On board the Soyuz was the Expedition 16 crew of the space station, commander Peggy Whitson and flight engineer Yuri Malenchenko. With them was the first South Korean astronaut, spaceflight participant So-yeon Yi.</p><p>Several problems occurred during the spacecraft's descent to Earth, which may or may not be related.</p><p>For some reason, the Soyuz hit the atmosphere at the wrong angle, with its hatch facing forward rather than its heat shield. Apparently, the re-entry capsule failed to separate from the rest of the craft correctly, which left it in the wrong orientation. Soyuz was already entering the upper atmosphere before its attitude control system was able to re-orient the vehicle.</p><p>As a result, the hatch was severely damaged, although, fortunately, not breached. In addition to the damaged hatch, the communications antenna on the outside of the capsule burned off completely, leaving the crew unable to communicate with ground controllers until they were on the ground and able to use a satellite phone kept on board.</p><p>During&nbsp; the descent, smoke started to fill the crew cabin. Indicative of a potential electrical fire, the smoke cleared once Malenchenko turned off display lights.</p><p>During re-entry, perhaps because of the improper orientation of the spacecraft, the Soyuz' onboard guidance computer experienced some anomaly that caused the spacecraft to switch to a "ballistic entry".</p><p>In a normal landing, the guidance computer uses the Soyuz' reaction control system to keep the vehicle from entering too steeply and guide the spacecraft to a precise landing target.</p><p>If the guidance system fails, the capsule reverts to a mode called ballistic entry, essentially an uncontrolled plunge through the atmosphere that's much steeper than a guided entry. </p><p>The re-entry trajectory of the Soyuz is designed to limit the forces of deceleration to about 5 G's, or five times the force of Earth's gravity. During Expedition 16's re-entry, the crew experienced forces nearly 10 times that of normal Earth gravity for several minutes coupled with bone-rattling vibrations. For astronauts returning from six months in weightlessness, a ballistic re-entry is extremely uncomfortable at best, and poses some level of risk for injury to the crew.</p><p>This was the second ballistic re-entry in a row and the third since 2005. The problem during the previous Soyuz landing was traced to a short-circuit in a hand controller cable on the spacecraft. Smoke in the cabin of Soyuz TMA-11 may be an important clue if TMA-11 experienced a repeat of the wiring problem.</p><p>Malenchenko emphasized the crew took no pro-active action that led to the ballistic entry. "There was no action of the crew that led to this," said Malenchenko.</p><p>The Soyuz landed 295 miles off target due to the ballistic entry. In the days after the crew returned to the cosmonaut training center in Star City, Russia, details of the hair-raising landing began to emerge. </p><p>"During descent, I saw some kind of fire outside," said So-yeon Yi. "At first I was really scared because it looked really, really hot and I thought we could burn." </p><p>Had the crew hatch on the capsule been breached or if the Soyuz failed to right itself early in re-entry, the spacecraft would have burned up and killed all three space travelers. Damage to the landing parachutes could have led to the capsule slamming into the Kazakh Steppes at 200 mph, with a similar outcome.</p><p>However, NASA and Russian officials as well as the Expedition 16 crew stressed the need to not overreact and let the state commission figure out what happened, why it happened and what corrective action to take.</p><p>"They are doing everything we would do. We'll get good result from this (investigation)," said NASA Associate Administrator for space Operations Bill Gerstenmaier. "We just need to get through this investigation."</p><p>So far, there's been no suggestion of grounding the Soyuz. Indeed, such an option doesn't seem possible. Soyuz is critical to maintain the 6-month rotation of crews on the space station. In fact, beginning next year the rate of Soyuz flights will have to double in order to support the increase in the size of the station crew from three to six members.</p><p>Also, the current Expedition 17 crew will return home on board the same Soyuz they rode to orbit. Landing of Soyuz TMA-12 is slated for late October. Russian and U.S. officials expect to have completed troubleshooting efforts on Soyuz TMA-11's hard landing by then. </p><p>(Source: The Spacearium, spacearium.com)</p>
 
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Swampcat

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Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>(From The Spacearium, http://www.spacearium.com and repritned with permission because I'm the author)JOHNSON SPACE CENTER, TX - It will take one to three months before NASA knows what caused a series of problems during the re-entry of Soyuz TMA-11 that put the three astronauts on board in significantly more danger than had been reported at the time.. The Interfax news agency reported one Russian official as likening the situation to being on a "razor's...blah, blah, blah...Posted by surferastra</DIV><br /><br />Thanks for the post, surferastra, but, IMO,&nbsp;it should've been posted in one of the existing threads. <div class="Discussion_UserSignature"> <font size="3" color="#ff9900"><p><font size="1" color="#993300"><strong><em>------------------------------------------------------------------- </em></strong></font></p><p><font size="1" color="#993300"><strong><em>"I hold it that a little rebellion now and then is a good thing, and as necessary in the political world as storms in the physical. Unsuccessful rebellions, indeed, generally establish the encroachments on the rights of the people which have produced them. An observation of this truth should render honest republican governors so mild in their punishment of rebellions as not to discourage them too much. It is a medicine necessary for the sound health of government."</em></strong></font></p><p><font size="1" color="#993300"><strong>Thomas Jefferson</strong></font></p></font> </div>
 
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drwayne

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<p>Please take a moment before posting news items to see if an existing thread is covering it.&nbsp; I know of several existing threads about this topic.&nbsp; For example, this thread was only a couple of threads from the top when you posted yours:</p><p>"Soyuz; abnormal reentry/landing."</p><p>We try to avoid starting a bunch of threads covering the same news item.&nbsp; This avoids the problems of multiple threads about a single topic crowding out other topics.</p><p>Thanks!,</p><p>Wayne</p> <div class="Discussion_UserSignature"> <p>"1) Give no quarter; 2) Take no prisoners; 3) Sink everything."  Admiral Jackie Fisher</p> </div>
 
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