Andy
  • Member for 6 years, 10 months
  • Last seen more than 5 years ago
What's the baseball bat for? (seen in CRS-8 berthing NASA TV broadcast)
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57 votes

The baseball bat is for "Attitude adjustment", apparently :) Source: Arstechnica photos of ISS control room (ADCO=Attitude Determination and Control officer) Here's a better pic of the bat from the ...

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How did astronauts navigate the Lunar Roving Vehicle (LRV) over the surface of the Moon?
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30 votes

The navigation system used a combination of magnetic pickups in the wheels (to count how many turns each one has taken) and a directional gyro. This allowed both turn angles and distances travelled to ...

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Do Astronauts lose finger nails in space?
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28 votes

They tended to suffer painful fingernails in the Apollo days, in the Lunar Surface Journal Schmitt and Cernan gave a good description of this on several pages. There were also references made in the ...

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Why did the Apollo Lunar Module have four landing legs?
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24 votes

There is some interesting information here. Three legs were probably not robust enough, they do not appear to have been considered seriously for any length of time. Five fixed legs was the main ...

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How was it possible for the Apollo 11 to film and take pictures with such radiation?
22 votes

Radiation can affect film - but bear in mind the radiation around Chernobyl was, truly, extremely high. The radiation in our region of space is not as extreme. Also bear in mind that the earlier ...

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Platinum Colloid in Liquid Hydrogen fuel to increase fuel efficiency
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20 votes

Short answer: no, it won't increase the performance of the rocket. Platinum (or other catalysts) can be used in fuel cells, where the purpose is to get a chemical reaction at (relatively) lower ...

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What are the top temperatures occurring during reentry?
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18 votes

The Stardust sample return probe had an interesting re-entry to Earth's atmosphere. Returning from a solar orbit the maximum deceleration has been reported as 34g. Maximum temperatures are estimated ...

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What would be the (most difficult) challenge to make a 10,000 year satellite?
15 votes

The biggest challenges are going to be what people have already mentioned - the funding (don't skirt over that comment, you did ask for the challenges), an energy source for 10,000 years, and how to ...

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How serious a problem can outgassing of satellites be?
14 votes

There are a few recorded incidents of spacecraft contamination caused by outgassing. On Cassini, some haze was noted in test photographs after launch; this was thought to be due to some outgassing ...

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Why are sections of Cassini photographs blurred?
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14 votes

Your guess is correct. To quote NASA's page, The mosaics each consist of multiple narrow-angle camera (NAC) images with data from the wide-angle camera used to fill in areas where NAC data was not ...

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Why were Space Shuttle astronauts able to walk off the orbiter?
12 votes

The shuttle post landing activities took a while to complete, and this would include the flight surgeon boarding to check the crew over before leaving. This would enable the crew to stretch their ...

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Who is the space artist? Patterns on the Spheres robots on the ISS
12 votes

These are some of the SPHERES satellites. They're little flying robots, driven by pressurised gas, intended to fly around inside the station. They were created for various indoor experiments, such as ...

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How precise are our Mars landings?
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12 votes

Curiosity was targeted at a small area later named Bradbury Landing and came down 2.4 km from the centre. See also: landing ellipse comparison (earlier probes were of much lower accuracy.) Of course,...

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By what methods can cubesats move from LEO to higher orbits?
12 votes

Engines are under development for CubeSats. For example there's the Electrospray (colloid) thruster which is effectively a low-thrust ion drive. An alternative is to launch from the ISS with a ...

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When can we (public) expect to see the first optical images of Jupiter from the Juno spacecraft?
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11 votes

There's an interesting Planetary Society article about this: What to expect from Junocam We won't be able to see spectacular views of Jupiter's belts and zones from Jupiter orbit until the very end ...

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What is the 'ET Disposal Problem'?
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10 votes

This was when planning safe disposal of the External Tank on certain types of launch abort. Source: Space Shuttle Abort Evolution page 9-10 A major design activity was conducted preparing for ...

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Dragon 2 Propellant Capacity
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9 votes

That's 1,388 kg of propellant for the whole vehicle, not per engine. Reading the original document referred to by Wikipedia, it says 3,060 pounds of propellant for the Crew Dragon capsule. (It's on ...

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Why did the Zond 5 tortoises lose body mass so quickly?
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9 votes

It's important to note that the tortoises carried on the Zond flight were probably not given any food or water, and I suspect they were selected because they could survive that for a long period. So ...

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What are these structures on the Lunar Ranging Retro Reflector (LRRR) arrays for?
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8 votes

The Apollo 11 EASEP handbook gives basic information on the first version. Of the LRRR, it has just two pages of text... There are some (poorly reproduced) images labelling the main parts. It's ...

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Detecting a Nuclear powered vehicle from outer space (at least 8 AU or further out) feasible?
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8 votes

I sometime see this quote in forum arguments against "Klingon/Romulan-style" cloaking in video games that tries to be close as possible to real-life I gather the "World Building" Stack exchange might ...

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Communion on the Moon
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7 votes

He was in the Lunar Excursion Module (LEM) at the time! :)

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How much harder is it to land on the Moon away from the equator and the poles?
7 votes

Equatorial (or near equatorial) sites would be preferred, because the flight from Earth to the Moon can be achieved on a free return trajectory. (Meaning, if the engine fails during the long coast ...

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Why does the ISS always point the same side towards the Earth?
7 votes

In a nutshell, to minimise drag caused by the trace of atmosphere up there. (The panels and radiators can be aligned as necessary in sun or shadow, but the best arrangement for the rest of the hull ...

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Drone Racing on moon
6 votes

Small automated flying probes have been considered for the exploration of lunar lava tubes. From Flying, Hopping Pit-Bots for Cave and Lava Tube Exploration on the Moon and Mars. by J. ...

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How is long-distance optical communications coming along in space?
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6 votes

The European Data Relay System has recently begun testing. It's for getting data from Earth orbiting satellites down to the ground quickly, without waiting for the satellite to pass over a base ...

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How will Yuri Milner and Stephen Hawking's nanobots decelerate and transmit data upon arrival at Alpha Centauri?
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6 votes

There seems to be very little published information at this stage. There is a main page that has been set up for the initiative (Yuri Milner's Breakthrough Foundation). The most interesting bits ...

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Why is comet deflection so hard (and how does a fusion rocket help)?
6 votes

Assuming that our vaporization is at least as effective as a rocket engine (ISP 500) that gives 2.5m/s delta v Unlikely - the rocket engine uses a shaped engine bell tuned to give the best thrust (...

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Could fuel be "hosed" (pumped) from the ground to a launcher?
6 votes

The simple solution is to launch from much higher up. Either an air launched rocket or launch from a raised platform. (Both have been described, and one has been used.) Or just begin the launch ...

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In what way is artificial gravity expected to avoid/reduce bone loss?
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5 votes

Just a partial answer, limited to this part of the question: Does each bone need to experience strain separately - is it localized, or is it more systemic. Bone growth is definitely controlled ...

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How long can a LEO Satellite maintain its orbit if it loses all power?
5 votes

It depends entirely on the orbit and the "aerodynamic" properties of the satellite. For example, the ISS is often quoted as descending between 70 to 100 metres per day and needs frequent boosts. (As ...

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