/sci/ - Science & Math

>>6083838
>>Government won't fund unmanned space exploration.
COUNTEREXAMPLE: Curiosity rover on Mars right now.

When was the last time we had a human mission beyond low Earth orbit?

And Curiosity actually got people excited about planetary science.

>>6083400
Yes actually. Just last year NASA and the CSA demonstrated that the satellites we have up there today could be remotely refueled and repaired with robots with the successful Robotic Refueling Mission.

But, both those space probes pictured can already be launched with current rockets in a single launch. Shame is that today the only things being launched by said rockets are military satellites.

>>6083412
If you haven't noticed, we are already exploiting space with communications satellites. These are quite expensive, so it makes sense to repair them.

Another way to exploit space is to build solar power satellite to beam power down to Earth, having remote robotic assembly and maintenance certainly makes it easy.

>>6079298
>>why nasa talking about Colonization of Mars
Currently, NASA is not talking about colonizing anything

>>shouldn't we Colonize the moon first ?
Yes, sorta.

Aside from scientific study of Mars, there is really no reason to colonize Mars. One would be better off colonizing other extreme environments on Earth than Mars.

Now there are good reasons for colonizing the Moon in a limited manner, the main being so we can mine it.

Now why would we ever want to mine the Moon? Pretty much everything we can find on the Moon, we can also find on Earth, the only difference is the cost of moving

stuff from the Moon to space is a lot less than the cost of moving stuff from the Earth to space.

By building a mass driver on the Moon, one can cheaply lift millions of tons of lunar regolith to L2, enabling the construction of very large space structures.

Now the main large space structure we care about is something called a powersat, a giant solar powered satellite for beaming gigawatts of microwave power to a receiver on Earth. Such a system is the ultimate clean power source, it produces no pollution, isn't subject to limitations like fossil fuels, and operates around the clock, night and day beaming down solar power to Earth.

Now to build such a satellite, it would help, but is not required, to have a human presence in space to assist in the construction of these solar power satellites. Now that we have cheap lunar regolith, we can build huge space colonies for maintaining this human presence.

Space colonies, unlike Mars, have 1G gravity, protection, access to microgravity, and an environment that people would actually want to live in as opposed to the cold irradiated desert that is Mars.

But, we'd need to colonize(with either robots or humans) the Moon first to make them.

>>6060025
They would not, mainly because Earth's magnetic field is weak.

However, if one has an object with a very strong magnetic field that is dynamically controlled one could potentially launch that object into space from either of earth's poles.

It is theoretically possible to this with something called a magnetic sail, but this requires much better superconductors than we have today

http://en.wikipedia.org/wiki/Magnetic_sail#Inside_a_planetary_magnetosphere

>>6056619
>>hold it's own weight
the problem with space elevators isn't building a cable that can hold it's own weight, it's building a cable strong enough to hold onto a counterweight above geostationary orbit. A space elevator is in tension, not compression.

>>6057369
>>6057436

Because in order for the counterweight to support any weight, it must be above geostationary orbit, so it is spinning faster than the earth and centrifugal force will attempt to pull it away from earth.

>>6056623
The problem with lofstrom loops is one needs gigawatts of power to keep the thing from falling down, all the time.

>>6056201
Surprisingly yes, material requirements are actually more for a 370 km space tower than a space elevator. 35800 km is about as long as all the cables in the golden gate bridge

>>6055987
Well it is going to get impossible here pretty, due to global warming.

One way to make a HUGE cannon cheaply, is melt a hole in the Antarctic ice sheet 1000 or so miles long and line that with a thin layer of steel so the ice does not melt.

Then fill the hole up with hydrogen and pop a ramjet carrying it's own oxygen down it.

Only problem with this, is that the ice sheets we'd need to use are melting...

See: http://www.nss.org/settlement/nasa/Nowicki/SPBI110.HTM

Of course, your gun only needs to be really long if you want to have low accelerations so one can send up people, if one's sending up robots, the gun can be much shorter.

>>5915289
Space colonization is cooler! We should destroy Mars and turn it into space colonies. We could get so much more living space!

>>5914589
Looks like that is indeed the case:
http://en.wikipedia.org/wiki/Nuclear_marine_propulsion

Though this did happen:
http://en.wikipedia.org/wiki/Soviet_submarine_K-431

It is sort of nice that the reactor is floating in a sea of nuclear poison, but if you ask me, I much prefer
>>the Russians actually experimented with liquid metal reactors in submarines.
lead cooled ones too, so if they ever stopped the reactor, all the pipes become clogged with solid lead alloy:

http://en.wikipedia.org/wiki/Lead-cooled_fast_reactor#Russia.2FUSSR

>>5913268
Been tried, there were funding issues:
http://en.wikipedia.org/wiki/Rocket_Racing_League

>>5914556
Fair enough. Seems like it would take a while to detect small objects with the system.

>>5913618
4000 mph is not how fast the hyperloop goes. However, Elon Musk is big on scaling and building a 500 mile long magnetic people mover certainly advances the prospects for HUGE SPACE GUNS.

>>5914297
Well, they'd have a hard time distinguishing bullets from lead solder in plumbing, fishing weights, and car batteries. The resolution of muon radiography is extremely low. Like feet or worse.

2nd, for cosmic ray muon radiography to work, you need to be UNDER the object you want to scan.

So, 100% bullshit.

>>5914441
Russians are working on it, more of a 'let's make a reactor portable.'

Also known as an aircraft carrier or nuclear submarine. Most portable nuclear reactors call for highly enriched fuel(~80-90%) to keep things compact, which can lead to new problems and nuclear proliferation concerns.

>>Tsunamis
If it's close to land then it's close to the worst part of a tsunami

>>5914452
Well, we're talking a superconducting magnet strong enough to give Mars a magnetic field, even weakly attracted materials will eventually accumulate.

Rust is also not a well defined material that include ferromagnetic iron oxides.

>>5914185
Mars will have a magnetic field. In addition, due to dust storms ferromagnetic soil particles will accumulate around the martian equator.

Perhaps we can call it the 'rust belt'

>>5914264
685 Mph at sea level is a Mach number of 0.9, that's far from hypersonic. Still, playing 'air-hockey' near the speed of sound is going to be pretty gnarly aerodynamically speaking.

Perhaps they intend to use some sort of supersonic Wing In Ground effect vehicle. Pic related, very roughly what a supersonic WIG could look like.

>>5910712
The Technological Readiness Level(TRL) of SABRE is pretty low. It's going to grinding to increase the TRL of SABRE.

The TRL of launching rockets is pretty high, the TRL of getting rockets to hover is also fairly high.

TL;DR, it may not be more economical, but it's what we have right now.

Honestly, I'd like to see someone test out a KITE space launch system, which uses a regular 747 to KITE things into orbit:

https://en.wikipedia.org/wiki/Non-rocket_spacelaunch#Endo-atmospheric_tethers

>>5875834
Bad idea. Better idea is to get your kite moving up to hypersonic speeds so you can skim the Karman line

Though there is another type of KITE that can get even higher, the Kinetics Interchange TEther.

Basically you get yourself a large slow moving aircraft like a Boeing 747 and put a nice high strength tether(such materials are strong enough today) attached to a hypersonic space plane you want to put into orbit.

You get your 747 up to cruisin' altitude and unreel the cable with the space plane on it so it's 90 miles long or so and use the lifting body on the space plane to go against the plane's direction of motion so it arcs around and release it at the end of the arc.

In the end you end up with a space plane going hypersonic on a ballistic trajectory that is trivially easy to circularize.

TL;DR Aside from a good understanding of hypersonic aerodynamics, we have all the technology we need to cheaply shoot stuff into space using commercially available jet liners.

lolwut

http://www.youtube.com/watch?feature=player_embedded&v=sGXTF6bs1IU

http://www.clavius.org/

>>5854956
a better question is why did you take a a picture of display and not screen shot?

As for your question, the space treaty. Militarizing space is a bad idea.

>>5823059
Yes actually, but you have to bring your own air with you.

One proposed of mining the Moon and other airless bodies is to push a bit of tubing under the regolith(dirt) and apply a puff of compressed air. This suddenly expands carrying regolith up the tubing and into the storage compartment.

A video here explains more:

http://spectrum.ieee.org/video/aerospace/robotic-exploration/lunar-vacuum-cleaner


Now if you want to make your local VACUUM CLEANER in orbit so you can grow expensive crystals, you take a big plate and grow whatever you want in it's ULTRA-HIGH-VACUUM wake

http://en.wikipedia.org/wiki/Wake_Shield_Facility

pick related

>>5744615
The only resources worth extracting from the moon we know of lie at about 0- 1 meter deep.

And most large mining operations will throw most of the dirt back just to get the volatiles out.

>>5744697
did you even read the article I linked? A large scale deoxygenation operation can effectively degrade the local lunar vacuum, making a variety of industrial processes impractical.

Now if start to deoxygenate enough rock you get an atmosphere that thick enough its hard for the solar wind to blow away easily and you end up with a 'transient atmosphere' that last thousands of years.

http://nextbigfuture.com/2011/12/friedlander-cold-crown-cold-trap-for.html

>>Add several "highways" for equipment and trucks going to-and-fro
find the highways in this post here:
>>5744438

Lunar travel probably won't be by road. With all that nice insulating frictionless vacuum and superconductors that can be made from lunar resources to work at lunar ambient temperatures:
http://en.wikipedia.org/wiki/Magnesium_diboride

You could make one hell of a vactrain.

Or you could avoid making a road entirely and just rocket from place to place

>>5744581
>>We could purposely dump massive amounts of pollutants and we would still be nowhere near anything remotely resembling an atmosphere
And pollute the lunar vacuum so we can't carry out industrial processes up there?

http://www.islandone.org/Settlements/DegradeLunarVacuum.html

You wouldn't want to vent pollutants, you'd want to recycle them. If you are venting anything containing carbon, nitrogen, or other volatile elements, you are throwing money down the drain.

>>preserved for historic reasons
we need to start the preservation as soon as possible, micrometeoroids, Moonquakes, and electrostatic effects must have done quite a number on all those astronaut footprints by now