Mars Direct: How To Get To Mars With Existing Technology On A Budget We Can Afford!

[Bill Phil]

I didn't say it was a Titan orbiter. I said it was a Saturn orbiter that made multiple passes (as in, flyby passes) of Titan. But I'll concede this point in the interest of avoiding a debate about semantics.

But it's not dedicated to Titan.

The Titan lander would have been a lake-lander. Not quite a submarine, but closer. And there was talk of turning it into a boat.

There is a plan in the works for a full fledged submarine.

This doesn't actually mean anything. NASA employees don't decide what gets funded and what doesn't. Congress does. And Congress is not gong to authorize the use of SLS to launch a Europa mission, because SLS is so freaking expensive, and because Congress hates unmanned probes.

It means quite a lot. Especially since their information (especially this) was said as fact already, meaning it is already planned and perhaps funded.

True. But perhaps we should focus on getting more out of the mass we have, instead of spending billions of dollars to build a pointlessly powerful rocket to launch more massive things.

Having more mass means you can go to more places, assuming your mass ratio is better...

And going to more places means getting more science.

Not to mention that sometimes you just need to go big.

Tell me, what would you do with six Cassini's worth of probe available? Sure, it could carry more science instruments, but it would probably be easier to work on making those instruments smaller and more powerful, instead of trying to build a rocket big enough to launch them all together. (I will concede that there are some experiments and pieces of equipment that can't be miniaturized, and that having more payload available for them would be nice. But is it nice enough to justify a very expensive, brand new launch vehicle?)

You could have more reliable equipment. Many copies. It cold then last for many times longer than the prescribed time. (It kind of has, but hey).

You could use it as a communications relay, and release smaller probes throughout the Saturn system.

This is my entire point.

Didn't sound like it...

[cpast]

Really the production equipment needs to be on hand...

Not necessarily the rockets.

And by now, the equipment would have rusted, the building would be coming apart, and anything neither rusted nor falling apart would probably have been stolen and sold for scrap. When you try to reactivate it, you face the issue that manufacturing technology has come a long way, and so employees would have to go through significant amounts of training to learn how the old gear worked. There are maintenance costs associated with production gear. There are maintenance costs associated with factories. You can't operate it without trained workers, and all the trained workers from the Apollo days have retired (and even before then, they'd adjusted to more modern equipment, and not all would have been able to return).

If you want to keep a production line running, you have to produce stuff every now and then. Reactivating a long-closed production line is extremely expensive, and may well be more expensive than just building a new one.

[Bill Phil]

And by now, the equipment would have rusted, the building would be coming apart, and anything neither rusted nor falling apart would probably have been stolen and sold for scrap. When you try to reactivate it, you face the issue that manufacturing technology has come a long way, and so employees would have to go through significant amounts of training to learn how the old gear worked. There are maintenance costs associated with production gear. There are maintenance costs associated with factories. You can't operate it without trained workers, and all the trained workers from the Apollo days have retired (and even before then, they'd adjusted to more modern equipment, and not all would have been able to return).

If you want to keep a production line running, you have to produce stuff every now and then. Reactivating a long-closed production line is extremely expensive, and may well be more expensive than just building a new one.

It needs to be on hand and kept in well condition with people on hand who know how to use it. Or basically, on hand.

[GreenWolf]

There is a plan in the works for a full fledged submarine.

Okay, that actually sounds pretty cool. But there's nothing stopping it from being launch on an EELV (unless it's exorbitantly massive, but I doubt an unmanned sub needs to be that large.)

It means quite a lot. Especially since their information (especially this) was said as fact already, meaning it is already planned and perhaps funded.

If it was already funded, there would be legislation addressing it. Large amounts of government money don't move without congressional say so, and this sounds like a lot of money.

Having more mass means you can go to more places, assuming your mass ratio is better...

And going to more places means getting more science.

Not to mention that sometimes you just need to go big.

If you want to go more places, go ion. That nets you a far greater delta-v increase than increasing your mass ratio. And science isn't some nebulous, all important goal. Space probes have specific missions that they are designed for. And while increasing the mass of the probe can allow it to do more things on its mission, there comes a point where one probe can't accomplish any more mission goals on its own.

You could have more reliable equipment. Many copies. It cold then last for many times longer than the prescribed time. (It kind of has, but hey).

Space hardware is already pretty reliable. I mean, it's not like they just go to Radio Shack or Best Buy and grab some stuff off a shelf. Lots of money is spent designing and testing equipment that can stand up to the rigors of space.

Also, if you're going to send two of everything, why not just send a second probe (à la the Mars Exploration Rovers). Two probes can accomplish more things than one probe, and they give you redundancy.

You could use it as a communications relay, and release smaller probes throughout the Saturn system.

I like this idea. Mostly because I like the idea of using lots of tiny probes in place of one bigger probe.

[cpast]

It needs to be on hand and kept in well condition with people on hand who know how to use it. Or basically, on hand.

And that actually requires using it from time to time. And hiring new people and running them through using it. And this requires paying trained staff, and having them show up for refreshers every so often. That's a good part of the cost of actually building the rockets; it is extremely expensive. Really, keeping a production line ready to reactivate requires reactivating it every so often; you can't keep it fully mothballed, or it will just not work.

[Bill Phil]

Okay, that actually sounds pretty cool. But there's nothing stopping it from being launch on an EELV (unless it's exorbitantly massive, but I doubt an unmanned sub needs to be that large.)

I don't know... It depends on the final probe. Which is why having a heavy-lift launcher is useful.

If it was already funded, there would be legislation addressing it. Large amounts of government money don't move without congressional say so, and this sounds like a lot of money.

I assume it's an early stage program, or basically only enough money to plan it.

If you want to go more places, go ion. That nets you a far greater delta-v increase than increasing your mass ratio. And science isn't some nebulous, all important goal. Space probes have specific missions that they are designed for. And while increasing the mass of the probe can allow it to do more things on its mission, there comes a point where one probe can't accomplish any more mission goals on its own.

Going Ion has many drawbacks, with the one advantage of having a lot of Isp.

It's time or Dv. That's the trade off.

Space hardware is already pretty reliable. I mean, it's not like they just go to Radio Shack or Best Buy and grab some stuff off a shelf. Lots of money is spent designing and testing equipment that can stand up to the rigors of space.

Also, if you're going to send two of everything, why not just send a second probe (à la the Mars Exploration Rovers). Two probes can accomplish more things than one probe, and they give you redundancy.

I know it's reliable. But you never quite know...

Sending a second probe would mean getting another launch vehicle. Unless they launch on the same vehicle, hence a larger heavy-lift vehicle.

I like this idea. Mostly because I like the idea of using lots of tiny probes in place of one bigger probe.

So, data from a bunch of places at once or something?

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And that actually requires using it from time to time. And hiring new people and running them through using it. And this requires paying trained staff, and having them show up for refreshers every so often. That's a good part of the cost of actually building the rockets; it is extremely expensive. Really, keeping a production line ready to reactivate requires reactivating it every so often; you can't keep it fully mothballed, or it will just not work.

By using it, do you mean build a full fledged rocket? Because that's not what I mean...

[GreenWolf]

I don't know... It depends on the final probe. Which is why having a heavy-lift launcher is useful.

I guess. But really, a heavy-lift launcher could be useful for lots of things, if it was cheap enough. The problem is that the cost of SLS makes it prohibitive for really launching anything.

I assume it's an early stage program, or basically only enough money to plan it.

Then we'll have to wait until it's more fully developed until we can really make anything other than guesses about it. But I highly doubt that SLS would ever be authorized for an unmanned probe. As Winchell Chung (of Atomic Rockets) says, "No Buck Rogers = No Bucks".

Going Ion has many drawbacks, with the one advantage of having a lot of Isp.

It's time or Dv. That's the trade off.

True, but probes don't care how long it takes to get somewhere. Time is really only a constraint for manned spaceflight. Everything else can afford to slow boat its way wherever it's going.

I know it's reliable. But you never quite know...

Sending a second probe would mean getting another launch vehicle. Unless they launch on the same vehicle, hence a larger heavy-lift vehicle.

Launching them on the same vehicle would undermine the redundancy of having two probes. What happens if your launcher fails?

Also, going off of the costs of EELV launches (around 400 million) and expected SLS launch costs (planned to be 500 million, but will probably end up being over to 1 billion), it would actually be cheaper to launch two EELVs instead of one SLS. And if you go with a Falcon 9 instead (60 million for civilian launches, 100 million for government), you could send ten small probes. You might not be able to send them all at once, but you could still send them.

So, data from a bunch of places at once or something?

Basically, yeah. I mean, the MER rovers, landed on opposite sides of the planet. If we sent ten little probes to Titan, they could land all over. In lakes, on mountains, near the poles, at the equator. Sounds a lot better than sending one big probe to explore a tiny part of the moon.

[Bill Phil]

True, but probes don't care how long it takes to get somewhere. Time is really only a constraint for manned spaceflight. Everything else can afford to slow boat its way wherever it's going.

However, the people manning the equipment and waiting for data care about time. Which is why Daedalus Study was done...

[Rondon]

There are many environments in the world that were are not suited to live, in fact most would kill us if we didn't have technology.

But still we live in places which only sees snow, or were desert sand is the main feature on the landscape.

Do we need to move people away from those places, because it's not what we evolved into?

I could see it being the same way for Mars, we already depends on technology to keep us alive then why not on an other planet.

I would say in most places on earth you need food and water, not technology to survive, but even taking the statement at face value, the less suitable the environment is the more technology you need to survive. This would be especially true for Mars and the more technology you require the greater the cost of said technology and the greater the risk that this technology will fail.

It's not that we need to move people who live in inhospitable climates, it's that majority live where it is the most comfortable, there are plenty of places on earth where you genuinely do need technology to keep you alive, e.g. the ocean and Antarctica, but though people work there, there is no great rush to live there.