The future of space travel: SLS vs Skylon

[Vertigo_One [Ops Mod]]

I very much enjoyed Hank's video a while back about the SLS and the future of manned space travel with the Orion Multi-Purpose crew vechile, but now, after having heard about the Skylon project, I can't help but feel that its...kind of a waste.

For those of you not in the know, here's a couple of links for a detailed explanation of what Skylon is

http://www.buildtheenterprise.org/getting-to-the-enterprise-skylon-...

http://www.bbc.co.uk/news/science-environment-17864782

http://www.bbc.co.uk/news/science-environment-17851603

But the main basic reason I think Skylon ultimately looks like so much more of a viable alternative to the SLS is that none of it is wasted. You have use of one SLS per mission. That is it. On the other hand, a single Skylon craft could conduct multiple missions over many years, which would ultimately be much much cheaper. With this in mind, I can't really see why the SLS is being as seriously considered by Nasa. It's now looking, at least in my mind, rather obsolete.

[CD]

Why though?  There's more to bone density than gravity.

[Eystein,]

Maybe, maybe not... The hypothesis derives from the fact that astronauts who returns after months in space suffers from significant bone density loss. Our bodies are quite plasticine and will also directly respond to additional strain. Not only by building muscles, but also by fortifying and strengthening its bones. Similarly in space our bodies detects complete lack of strain and will therefor not waste any energy on maintaining its bone tissue, because as for  what it is concerned, you don't need it anymore.

It may seem as if near surface level gravity and the background strain it continuously exposes us to is some kind of reference point, 0 on a scale. If you add strain, your bones will grow stronger, but if you reduce it, by going a place with weaker gravity for example, it will get weaker, maybe even disappear completely if you stay there permanently... Of course bones are also there to protect the the organs from external blows, so it might not disappear completely everywhere. Never the less after years in space or on Mars, your bones and muscles will be so severely weakened that a return to Earth would be life threatening.

Also if children raised on Mars indeed grows lankier than normal earthlings, then the capsule houses we've provided will become a bit cramped. Not to mention the space suits.

[CD]

Hmm.   I imagine pressure suits would help as well as strengthening exercises?

[Eystein,]

Yes I think they plan have small centrifuges and exercise equipment onboard (can't remember if they already have one onboard the ISS or not) that astronauts will have to spend a certain amount of time in every so often to either slow it down or stall it completely. It should be possible to overcome these issues for grown-ups, but for children it's still too much unknown. Must probably conduct animal experiments to se whether they grow frail and out of proportion.

[Eystein,]

But isn't SLS developed more for re-enabling further deep space explorations? Like launching new research satellites and probes, maybe even manned missions to the moon again, and later mars? Skylon can't reach outer space in order to escape Earth's gravitational pull, can it? Although it look mighty awesome!

[Vertigo_One [Ops Mod]]

Both the SLS and Skylon can reach outer space. Except unlike Skylon, the SLS cannot come back. The SLS will basically break apart and fall back down to Earth, and if you want to put more stuff up in orbit, you'll need more SLSs. The SLS can only re-enable further deep space missions in that it can carry that which will explore space up on it's back. Skylon could very eaisily do that too, the only difference is that Skylon could come back.

[Eystein,]

I mean outer space as in breaking away from Earth gravitational pull. Not to get things into orbit, but to send them off to other worlds... in a sense? I agree though that for all other use and purposes the Skylon seems a more sensible option.

[Vertigo_One [Ops Mod]]

Skylon couldn't do that, but nor could the SLS. The SLS could only carry up that which would be able to go interplanetary. The vast majority of it would be thrown away on the way up, as the fuel tanks empty. The difference for Skylon is that it does not throw away it's tanks, because it isn't using that kind of rocket engine. The only reason that the SLS is being talked about with reference to interplanetary travel is that it is designed to take up the Orion Multi-purpose crew vehicle, which would be able to go interplanetary. Although Skylon isn't specifically designed to take Orion, it could also transport interplanetary vehicles.

[Eystein,]

I'm sorry I'm explaining myself badly, I'm tired and should go to bed. By worlds I meant objects in our solar system. I'm not completely detached from reality ;)

Okey, so you can actually deploy interplanetary vehicles such as satellites and exploration robots from the Skylon too while it's in orbit? If so that is excellent and makes sense actually.

[Vertigo_One [Ops Mod]]

Indeed, and the cool thing is that Skylon can land and be reused. An altogether much better plan than the SLS, which just seems to chuck itself to pieces on the way up.

[CD]

*hands over all my monies*

[Latch33570]

Vertigo by SLS do you mean rockets?

Did ya'll know that with the shuttle the largest tank was brought up nearly to orbital level and purposefully detached and inserted back to orbit. What a waste. There was several groups wanting to go ahead and use the tanks to build and add on to a new space station or put additions to the ISS.