SPACE

[gumboot]

Walked into my bedroom to find my radio debating the merits of local-orbit space stations. Apparently in the middle of this: http://www.bbc.co.uk/programmes/b06s0njq

[pogo]

[Dio]

Very cool.

[Darkflame]

Things going to the ISS in the next few months.

with the following list of payloads that are slated to fly to the International Space Station (ISS) on upcoming cargo missions.

o Bigelow Expandable Activity Module (BEAM) will be berthed to the ISS for a two-year demonstration and analysis of inflatable habitats. The primary goals include the deployment process, thermal, radiation, and general operations during this test period. Launch is planned aboard the next SpaceX space station cargo resupply mission, CRS-8, currently scheduled for no earlier than March 20.

o Spacecraft Fire Safety (SAFFIRE) includes a planned set of test flights to seek fundamental understanding of flame spread in large-scale microgravity fires, demonstrate the performance of combustion product monitor systems, and conduct test of post-fire cleanup technologies for Orion, the space station and future habitation systems. These tests will be conducted on three Cygnus cargo ships after the spacecraft has safely departed from ISS.

o Aerosol Sampler will perform a demonstration of a modified off-the-shelf aerosol sampler on the space station to gather quantitative data on ambient air quality on the station. The station has high concentration of airborne particles that cause allergies and irritate crew members’ eyes and noses.

o More efficient air and water systems: Systems under development that are planned for demonstration on the space station over the next five years will increase efficiency and reduce dependence on resupply from Earth. These systems will improve waste water recovery (currently at 74 percent), air filtration and monitoring, atmospheric carbon dioxide (CO2) removal, and oxygen recovery from CO2, advancing from the current 43 percent to more than 75 percent.

http://www.spaceflightinsider.com/missi ... pace-habs/

I notice they are playing it safe and not doing their fire safety experiments while attached.

[Portland]

[pogo]

Really belongs in the Stupid Physics Questions thread. And anyway it’s wrong, dark energy is the handwavy invisible undetectable stuff that physicists have dreamed up to explain the expansion of the universe. Dark matter is rather different. For one the evidence of it is much stronger.

[pogo]

http://www.planetary.org/blogs/emily-la ... hange.html
High resolution images from China’s moon lander, e.g.:

Spoiler: show

[gumboot]

How's that formed, then? It looks weathered.

[Absolute_Zero]

Linking back to the 18-months previous discussion of NASA Eagleworks' so-called EmDrive...

I missed it last night, but allegedly the plucky Brit /s entry in the field, Roger Shawyer, put in an appearance on Horizon.

See here for repeat details.
http://www.radiotimes.com/episode/d2zck ... ty-control

[Absolute_Zero]

oops, misunderstood the Radio Times page. the first showing is this coming Wednesday @ 8pm.

[Deckard]

Thought this was a pretty amazing maths space answer.

"Mathematicians have calculated pi out to more than 13 trillion decimal places, a calculation that took 208 days. NASA's Marc Rayman explains that in order to send out probes and slingshot them accurately throughout the solar system, NASA needs to use only 15 decimal places, or 3.141592653589793. How precise are calculations with that number? This precise:

The most distant spacecraft from Earth is Voyager 1. It is about 12.5 billion miles away. Let's say we have a circle with a radius of exactly that size (or 25 billion miles in diameter) and we want to calculate the circumference, which is pi times the radius times 2. Using pi rounded to the 15th decimal, as I gave above, that comes out to a little more than 78 billion miles. We don't need to be concerned here with exactly what the value is (you can multiply it out if you like) but rather what the error in the value is by not using more digits of pi. In other words, by cutting pi off at the 15th decimal point, we would calculate a circumference for that circle that is very slightly off. It turns out that our calculated circumference of the 25 billion mile diameter circle would be wrong by 1.5 inches. Think about that. We have a circle more than 78 billion miles around, and our calculation of that distance would be off by perhaps less than the length of your little finger." and just 40 places for the visible universe !!

[zip accident]

Thought this was a pretty amazing maths space answer.

"Mathematicians have calculated pi out to more than 13 trillion decimal places, a calculation that took 208 days. NASA's Marc Rayman explains that in order to send out probes and slingshot them accurately throughout the solar system, NASA needs to use only 15 decimal places, or 3.141592653589793. How precise are calculations with that number? This precise:

The most distant spacecraft from Earth is Voyager 1. It is about 12.5 billion miles away. Let's say we have a circle with a radius of exactly that size (or 25 billion miles in diameter) and we want to calculate the circumference, which is pi times the radius times 2. Using pi rounded to the 15th decimal, as I gave above, that comes out to a little more than 78 billion miles. We don't need to be concerned here with exactly what the value is (you can multiply it out if you like) but rather what the error in the value is by not using more digits of pi. In other words, by cutting pi off at the 15th decimal point, we would calculate a circumference for that circle that is very slightly off. It turns out that our calculated circumference of the 25 billion mile diameter circle would be wrong by 1.5 inches. Think about that. We have a circle more than 78 billion miles around, and our calculation of that distance would be off by perhaps less than the length of your little finger." and just 40 places for the visible universe !!

Yeah, that is nice, thanks for posting that.

[Darkflame]

Nice comparison of scales.
I would guess a few more digits might be needed if you need it in calculations concerning, say, gravitational wave distortions.

[Absolute_Zero]

Here's another: thirty-nine decimal places are sufficient to calculate the circumference of the observable universe to a precision equal to the diameter of a single atom.

But easily the most surprising thing I've learned about pi [and some other irrational mathematical constants] is that it's possible to directly compute the nth digit [base 2 or 16] without calculating the preceding n − 1 digits.

When announced in '95, the Bailey–Borwein–Plouffe formula caused a bit of a stir... nobody had even speculated that this might be possible.

http://www.experimentalmath.info/bbp-codes/

[Darkflame]

I heard of that. Still cant get my head around how thats possible in some bases but not others.
--
Anyway, thought this was neat