Echoes of Sputnik in Modern Rocket Race for Space?

[TLAM Strike]

Originally Posted by UnderseaLcpl

There is nothing within reasonable range of our solar system worth visiting for any purpose other than data collection, and probes can manage that.

That is why we send in probes first, to find the interesting stuff that humans would like to go out and see. But major analysis needs to be done by humans since there is only so many tests that can be packed in to a probe.

And they are all very far away and very expensive to exploit, no matter how you approach it. Without some way of reliably and safely conveying spacecraft to and from other planets, and then transitioning any cargo form Earth orbit to the ground, the idea is pointless. For the moment, we're better off just focussing on this planet. There are only 6-something billion humans here. Most of them don't even manage to use non-renewable resources before they die or beget impoverished children who also die. Earth is inceredibly goddamn huge, and we've only explored a tiny fraction of the crust that we regularly draw energy and resources from. We'll be fine.

Sometimes more distant objects are easier to get to. Less mass means less fuel needed to slow down to land on and less fuel to leave. Also some asteroids are closer to earth and the moon at some points in their orbits.

In a perfect world, I'd have to agree with you. In this world, there is the need to maintain the satellite and replenish its fuel reserves so its orbit doesn't decay.

That is why many birds now have Ion thrusters. As long at its solar panels are drawing power it can generate thrust to maintain station.

That's true, but it hasn't been done yet. Why do you suppose that is?

Treaty with those godless commies.

[Gerald]

Sex in Space? Beware the Radiation, Scientists Say.

Astronauts sent to colonize Mars would be well advised to avoid getting pregnant en route to the Red Planet, according to a review of radiation hazards by three scientists.

High-energy particles bombarding the ship would almost certainly sterilize any female fetus conceived in deep space, making it that much more difficult to establish a successful Mars colony once the crew lands.

"The present shielding capabilities would probably preclude having a pregnancy transited to Mars," said radiation biophysicist Tore Straume of NASA Ames Research Center, lead author of the review published in the Journal of Cosmology.

Note: http://www.foxnews.com/scitech/2011/...y-proposition/

[UnderseaLcpl]

Originally Posted by TLAM Strike

That is why we send in probes first, to find the interesting stuff that humans would like to go out and see. But major analysis needs to be done by humans since there is only so many tests that can be packed in to a probe.

Good point but how many probes could we send for the cost of one manned spaceship?

Sometimes more distant objects are easier to get to. Less mass means less fuel needed to slow down to land on and less fuel to leave. Also some asteroids are closer to earth and the moon at some points in their orbits.

Agreed, but I remain certain that there is not one damn thing in this whole solar system worth leaving this planet's gravity well for in the first place.

That is why many birds now have Ion thrusters. As long at its solar panels are drawing power it can generate thrust to maintain station.

I don't know anything about that so I'm not qualified to comment at the moment. The idea sounds expensive, but if it is cost-effective I'm all for it.

As long as we're discussing the subject, it should be noted that it would be desireable for ion engines to be installed in tandem on spacecraft, provided they can be made to emit a really cool sound.

[TLAM Strike]

Originally Posted by UnderseaLcpl

Good point but how many probes could we send for the cost of one manned spaceship?

Its somewhere around 30/1.

For that price yea do it! Find us a place to go with a manned mission with those 30 probes!

But think of it this way as well... one manned mission can do the work of 30 unmanned missions.

Agreed, but I remain certain that there is not one damn thing in this whole solar system worth leaving this planet's gravity well for in the first place.

What about 20,000 Billion Dollars

I don't know anything about that so I'm not qualified to comment at the moment. The idea sounds expensive, but if it is cost-effective I'm all for it.

Its very cheap, I was mistaken when I said they don't need fueling just energy; they do need fuel (a gas). Xenon is a common propellant but they are doing experiments using Argon as a propellant. If you remember chemistry Argon is the 3rd most common gas found on Earth after Nitrogen and Oxygen.

[UnderseaLcpl]

Originally Posted by TLAM Strike

Its somewhere around 30/1.

For that price yea do it! Find us a place to go with a manned mission with those 30 probes!

Oh, I think it will take more probes than that to find somewhere worth possibly maybe considering going any time in the forseeable future....

But think of it this way as well... one manned mission can do the work of 30 unmanned missions.

What makes you think so? Anything worth learning about any planet(oid) we can get to with a manned mission can be discerned via probe flybys for a fraction of the cost required to build a manned spacecraft.

What about 20,000 Billion Dollars

Sadly, even Eros is very far away (it will be around 70 times as far away as the moon at it's closest approach) and it is travelling very quickly. How, exactly, are we going to get to it and extract enough resources to recoup the cost of getting the damn ship into space in the first place, and then get the damn thing back on the ground with its payload? Methinks we are better off just waiting for a resource-rich asteroid to actually hit the planet for the time being if we want to extract resources.

I'm not saying that it can't or shouldn't be done, just that we're not even close to ready yet.

Its very cheap, I was mistaken when I said they don't need fueling just energy; they do need fuel (a gas). Xenon is a common propellant but they are doing experiments using Argon as a propellant. If you remember chemistry Argon is the 3rd most common gas found on Earth after Nitrogen and Oxygen.

I figured it would need some kind of reaction mass. I'm actually pleased to know that noble gases can be used; that's extremely convenient and practical for more reasons than availability.

Unfortunately, even with ion stabilization thrusters, there's still the small matter of getting the damn thing into orbit in the first place and maintaining/upgrading/replacing it, at the cost of millions of dollars per pound, so whatever it's doing up there had damn well better be worth it. Looming above our enemies with a payload of death does not fit that criteria, especially given the ease with which a satelite can be brought down by a developed nation.

Thus far, only the private sector has managed to recoup the investment on just getting stuff into orbit, though they have taken government help where it was available. It will be they who push space exploration and exploitation to the next level, and they'll do it profitably at exactly the right moment because they are governed by profit motive and highly replaceable.

[TLAM Strike]

Originally Posted by UnderseaLcpl

Oh, I think it will take more probes than that to find somewhere worth possibly maybe considering going any time in the forseeable future....

Well we don't need to send one to each planet or moon. The list of places to send probes is quite small, Mars, Europa (this should be the next major target for exploration IMHO), the other Galilean moons, Titian, and maybe Triton, Titania, and Iapetus.

What makes you think so? Anything worth learning about any planet(oid) we can get to with a manned mission can be discerned via probe flybys for a fraction of the cost required to build a manned spacecraft.

Flybys are one thing but landing on a planet or moon is another thing, especially if we are talking about the outer planets. The light speed lag is just too great to allow for ground (or in the case of Europa perhaps undersea) exploration by remote; an hour delay in 1 way signals and occasionally no signal at all when Jupiter is between Earth and the Moon with the probe.

Sadly, even Eros is very far away (it will be around 70 times as far away as the moon at it's closest approach) and it is travelling very quickly. How, exactly, are we going to get to it and extract enough resources to recoup the cost of getting the damn ship into space in the first place, and then get the damn thing back on the ground with its payload? Methinks we are better off just waiting for a resource-rich asteroid to actually hit the planet for the time being if we want to extract resources.

I'm not saying that it can't or shouldn't be done, just that we're not even close to ready yet.

Good things come to ye who waits...

Once we get there we can detonate a few H bombs on the surface and blast her in to a better orbit...

Unfortunately, even with ion stabilization thrusters, there's still the small matter of getting the damn thing into orbit in the first place and maintaining/upgrading/replacing it, at the cost of millions of dollars per pound, so whatever it's doing up there had damn well better be worth it. Looming above our enemies with a payload of death does not fit that criteria, especially given the ease with which a satelite can be brought down by a developed nation.

A bird in low orbit is easy to down but one in a high orbit is much harder; the time on target for any ASAT is sufficiently great that any space based platform in a high orbit could out maneuver its attacker or shoot it down... unless of course the attacking platform was its self capable of large maneuvers and defending its self... at which point we start talking about space going warships.

Now I doubt that Ion thrusters would be used for SCM, any of the more conventional drives would be better served for that.

And of course upgrading becomes cheaper if those new parts don't need to be built on Earth. Its a lot cheaper to ship from Luna to Earth orbit than from Earth sea level to Earth orbit.

[UnderseaLcpl]

Originally Posted by TLAM Strike

Well we don't need to send one to each planet or moon. The list of places to send probes is quite small, Mars, Europa (this should be the next major target for exploration IMHO), the other Galilean moons, Titian, and maybe Triton, Titania, and Iapetus.

You are aware that all of those places are very distant, frozen, radiation-blasted, inhospitable hellholes, yes?

Flybys are one thing but landing on a planet or moon is another thing, especially if we are talking about the outer planets. The light speed lag is just too great to allow for ground (or in the case of Europa perhaps undersea) exploration by remote; an hour delay in 1 way signals and occasionally no signal at all when Jupiter is between Earth and the Moon with the probe.

I am aware of this and it is just one more reason to use probes. If you're aware of the light-speed lag, you must have at least some appreciation for the amount of resources needed to sustain a human crew for a journey of such length. More importantly, you must be aware of how much mass those resources comprise and the delta-v required to get them anywhere anytime soon.

Good things come to ye who waits...

I didn't take the time to evaluate this link very thoroughly. As far as I can tell, it's a suggestion for ho to move stuff from one planet to another with minimum delta-v. While I have no doubt that it's a good system, it doesn't solve the problem of getting large quantities of goods in or out of Earth's gravity well.

Once we get there we can detonate a few H bombs on the surface and blast her in to a better orbit...

It would take more than a "few" H-bombs to significantly alter the trajectory of a 15-trillion ton asteroid travelling at I-don't-know-but-pretty-goddamn-fast-velocity, especially given the reduced effectiveness of nuclear blasts in space. Then there's the matter of getting the H-bombs there in the first place, and we're still constrained by the fact that it costs millions of dollars to get a pound of any material into or out of Earth's gravity.

A bird in low orbit is easy to down but one in a high orbit is much harder; the time on target for any ASAT is sufficiently great that any space based platform in a high orbit could out maneuver its attacker or shoot it down...

Not really. You, yourself, pointed out that there is no stealth in space a while ago, and you were right. The extreme detectability of any power source or communications source, not to mention the radar signature, needed to make an orbital weapon platform viable and capable of doging attacks would make it a very easy target for missiles, even ground-based HARMs. Not that we'd need them, we could just as easily fry it with directed microwaves.

unless of course the attacking platform was its self capable of large maneuvers and defending its self... at which point we start talking about space going warships

.

That's not going to happen for quite a while yet. There is no reason to attempt to construct a space warship or even a OWP.

Now I doubt that Ion thrusters would be used for SCM, any of the more conventional drives would be better served for that.

I don't know what you mean by "SCM".

And of course upgrading becomes cheaper if those new parts don't need to be built on Earth. Its a lot cheaper to ship from Luna to Earth orbit than from Earth sea level to Earth orbit.

And that's the real trick, isn't it? How, exactly do we manage to get a manufacturing or mining facility onto the moon, and then transit the finished goods back to the surface at a price people are willing to pay? Again, I'm not saying it can't be done, just that the technology and demand aren't there yet.

[TLAM Strike]

Originally Posted by UnderseaLcpl

You are aware that all of those places are very distant, frozen, radiation-blasted, inhospitable hellholes, yes?

Sounds sort of like the Middle East... except for the frozen part...

Again send the probes and find something useful then invest in the manned mission if it finds something useful. Other than that the major reason to go out to the outer planets is harvesting resources, there are huge stocks of valuable fuels in those bloated gas bags...

The Gas Giants just might be the Persian Gulf of the 22nd century.

I am aware of this and it is just one more reason to use probes. If you're aware of the light-speed lag, you must have at least some appreciation for the amount of resources needed to sustain a human crew for a journey of such length. More importantly, you must be aware of how much mass those resources comprise and the delta-v required to get them anywhere anytime soon.

Well the Dv to get from earth orbit to the outer planets is a lot less than to get from earth surface to the outer planets. Which is the major reason to build factories in space. Build and assemble spacecraft in space and avoid the hassle of hauling them up from the gravity well. But if we could build an Orion or Mini-Mag Orion in orbit and avoid the whole "nukes going off on the planet" issue the time to travel between planets diminishes a lot.

I didn't take the time to evaluate this link very thoroughly. As far as I can tell, it's a suggestion for ho to move stuff from one planet to another with minimum delta-v. While I have no doubt that it's a good system, it doesn't solve the problem of getting large quantities of goods in or out of Earth's gravity well.

See above....

It would take more than a "few" H-bombs to significantly alter the trajectory of a 15-trillion ton asteroid travelling at I-don't-know-but-pretty-goddamn-fast-velocity, especially given the reduced effectiveness of nuclear blasts in space. Then there's the matter of getting the H-bombs there in the first place, and we're still constrained by the fact that it costs millions of dollars to get a pound of any material into or out of Earth's gravity.

Again see above.

But there are nuclear shape charges that have been designed that would work great to impart momentum on another object in space.

Not really. You, yourself, pointed out that there is no stealth in space a while ago, and you were right. The extreme detectability of any power source or communications source, not to mention the radar signature, needed to make an orbital weapon platform viable and capable of doging attacks would make it a very easy target for missiles, even ground-based HARMs. Not that we'd need them, we could just as easily fry it with directed microwaves.

stealth works both ways. The OWP has the advantage of being able to spot incoming attacks launched from planet side (perhaps by a early warning network of birds in even higher orbits). Early warning means the OWP can maneuver out of the attacker's threat or employ defense measures. The attacking weapon would need sufficient CCMs to ensure it reaches it target and/or sufficient fuel to course correct to compensate for the OWP evasive maneuvers. Very quickly the ASAT's size becomes closer to the OWP's.

Also since its in space I assume the OWP would be shielded from Microwaves since the sun produces them in high quantities. Also I assume that ground based microwave "guns" would be target #1 (along with space launch centers) for an OWP. Also remember that in space the OWP doesn't have to deal with the atmosphere degrading microwave performance meaning that a microwave weapon would work even better in space (it can be smaller or more powerful for the same size) < another reason to build an OWP.

That's not going to happen for quite a while yet. There is no reason to attempt to construct a space warship or even a OWP.

Well the building of one becomes the reason to build more. The threat of what one could do becomes the reason for everyone else to build ones to fight it.

I don't know what you mean by "SCM".

Thats like ACM but... [dramatic]in space[/dramatic]

And that's the real trick, isn't it? How, exactly do we manage to get a manufacturing or mining facility onto the moon, and then transit the finished goods back to the surface at a price people are willing to pay? Again, I'm not saying it can't be done, just that the technology and demand aren't there yet.

Well it will take new tech no doubt but the thing is send a small factory that builds something simple there first... say mirrors... big mirrors, like kilometer sized. the moon has lots of silica to make them and send them in to Earth orbit to focus light on to specific spots on the surface like say power generating stations... or hostile countries Power is one thing we all need, what could cheap (once the initial investment has been recouped) power mean? Especially to those who own it? No more big oil (big solar?)

And while they are at it they can use some of those mirrors to keep the planet's temperature stable (reflect sunlight away from Earth), beam power to spacecrafts for propulsion, and maybe use that to send more mirrors to Venus and Mars (to cool one and heat the other). Who would not want to own a share of the next energy monopoly, space travel monopoly and terraforming monopoly all with one investment?