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How did they solve Saturn V pogo oscillation problems?
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20 votes

Apparently the issue could not be addressed in time for the Apollo 13 mission as is evidenced by this note in the NASA archives available online. During the Apollo 13 flight the pogo effect had ...

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What is the vapour/smoke that comes from a rocket before launch?
16 votes

Typical spacecraft fuels/oxidizers are super-cooled. The vapour visible is formed due to the extreme temperature difference. The Apollo 11 flight journal has this to say Filling these tanks with ...

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What is the purpose of having a countdown during a rocket launch?
14 votes

Countdown is more than the "60", "30 seconds", 10,9...1 we see on TV, or hear on the PA adjacent to the launch site. Countdown commences well before the launch date with regular checkpoints for ...

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Has water ever been confirmed on comets?
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14 votes

Indeed the presence of water has been confirmed. The late 1980s mission Giotto confirmed the existence of water on a comet well-known to mankind - Halley's Comet. Wikipedia states: Measured volume of ...

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What procedures are there to perform emergency surgery on the space station or space shuttle?
11 votes

The Med.Ops section of the ISS User's Guide is apparently available online. It is generally split into the following sections Crew Health Procedures Routine Non-emergency procedures Emergency ...

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is it possible to use mechanical pencil instead of space pen in ISS?
11 votes

Not only is it possible, it was so done. Mechanical pencils were used earlier. They were phased out because of the danger they posed. Wikipedia says NASA programs previously used pencils (for ...

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How would it be possible to kick start Mars's magnetic field?
10 votes

Yes, this is purely speculation (+: (apart from the content available from web-references) Wikipedia writes to say Mars is the fourth planet from the Sun and the second smallest planet in the ...

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Why does the Dawn spacecraft have three ion engines at different angles?
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9 votes

Each of Dawn's three 30-centimeter-diameter (12- inch) ion thrust units is movable in two axes to allow for migration of the spacecraft's center of mass during the mission. This also allows the ...

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How is gyroless operation possible?
8 votes

The issue, and it's resolution are listed in detail on the NASA web-site. The web-site links to the exact maneuver appear to be broken. However this paper sums up the gyro-less operation as follows ...

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Why did Apollo mission numbering skip 2,3,4,5 and 6?
8 votes

This site writes to say Apollo 2 and 3: There were no craft named Apollo 2 or 3. Apparently after the Apollo-1 craft was destroyed during a pre-flight test at Cape Canaveral, the first few mission ...

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How far do you have to be from Earth to be "in space"?
8 votes

Concurrent with TildalWave's reply I too say 'Karman line'(100 kilometres (62 mi) above the Earth's sea level). Apart from the fact the K-line is legally so recognized an alternative definition of 'in ...

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Are all rocket launch sites surrounded by water bodies?
5 votes

The question may be re-phrased to read - Where should a space launch site be located? Just like a car with an IC engine, a spacecraft is really riding a controlled explosion. Therefore it makes ...

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Can a rocket motor be shut off after ignition?
5 votes

A qualified 'Yes'. Wikipedia on Solid fuel rockets states More advanced solid rocket motors can not only be throttled but also be extinguished and then re-ignited by controlling the nozzle ...

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Were there significant instances of cooperation during the Space Race?
4 votes

There were several instances of cooperation during the space-race; Russia was not entirely isolated. Russia (USSR, to be precise) was an active participant in the IAF, and UN programmes such as COSPAR....

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Does the radiation danger in interplanetary space decrease the further you get from the sun?
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4 votes

Let's start with a few unspoken assumptions Radiation refers to emissions from any body in space. To name a few possible sources Star Nebula Gas giant Danger means danger to humans Sun refers to ...

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What is the rationale behind the allocation of micro-wave bands for space communication?
3 votes

As yet I am unable to reply to the former two queries raised i.e. Whether communication frequencies are allocated on a per-agency, or a per-mission basis. Whether allocated frequencies are re-cycled ...

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How can I figure out the distance to Juno at any point in time?
3 votes

The event web-site you posted shows theground-track, and a list of cities to orient a directional antenna . This site also writes to say See Juno’s current position, speed and more via NASA’s ...

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Why do ISS astronauts use lower quality microphones for official radio communication than for PR events?
2 votes

Pure speculation on my part. To anybody not habituated to listening to radio communication, static/radio-interference may necessitate multiple 'takes'. This may be the case with the majority of ...

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Why not land booster stages in a cone or net?
2 votes

I'll second the earlier answers by @Hobbes, and @HDE226868. Aiming for a hole in the ground would be a trickier task, to say naught of the potential damage to the fuselage. The idea of a net could ...

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Quite some lateral wobble immediately following Antares Orb-2 liftoff. Is that normal?
2 votes

This is speculation - not a complete answer. The smoke blowing off the pad made me take a gander at http://www.wunderground.com/weather-forecast/US/VA/Wallops_Island.html for today July 13th, 2014 ...

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Will Juno be visible during its flyby?
1 votes

You may visit Heavens Above to configure your current location. The next step is to visit this page on the same site. It renders a map showing your configured location against the Juno Ground-track. ...

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What is a feeder uplink/downlink?
0 votes

Feeder link is from the Gateway to the satellite Check the image on Slide#3 of the link

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Why are spacecraft assembled in cleanrooms?
-1 votes

No specialist I, but I would argue the cleanliness becomes essential for at-least two reasons as follows - Contamination: Even the air we breathe is filled with bacteria, and what-not. Spacecraft ...

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