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

[Nibb31]

You are assuming that a breakdown or getting stuck would strand the rover. It would be designed get out of such situations.

Well, so would an unmanned rover. I'm also betting that part of thy "design to get out of such situations" will involve not driving too fast

You should look at the speed part as getting things done now instead of 30 years down the road. Give me one example, besides robotic space exploration, where such an approach is acceptable.

Well, most research takes time. Large fusion projects like ITER or things like LHC take decades to accomplish. We accept that.

And what's wrong with getting things done in 30 years? Is there a race on? Is Mars going to vanish in 30 years? Are the geological processes that take millions of years going to suddenly stop any time soon?

The reason why we don't have fast driving robotic rovers on Mars is safety, you don't want it to tip over, run in a ditch, break something, etc. Time delay is an important factor here as you can't intervene in something which happened 14 minutes ago.

Not only safety. It's mainly about power consumption (the faster you go, the more power you need, and that is an exponential curve). The power available to Curiosity or the MERs is tiny. Solar power is limited on Mars, and RTGs are designed to produce a low output over a long time. It's also because speed is simply not needed. It would actually be detrimental, because you would miss a lot of details if you were going faster.

What are you envisioning what a Robonaut would look like? Would it be able to walk? Would it be a halve rover halve robonaut setup? What can a robonaut do what a human can't? You also have to consider that it would take a lot of extra money to development cost and time to create something with those capabilities.

Off the top of my head, I would envision some sort of robotic lab with a sample return stage and a small fleet of semi-autonomous rovers, designed to be serviceable with packed spares and maybe to tow each other back to the base to provide some sort of rescue redundancy. It could have an RMS similar to the ISS Canadarm or DEXTRE, and a variety of tools (maybe a high pressure blower or a brush, fluid valves for refilling whatever needs refilling, and a manipulator for retreiving samples from the rovers or fixing things). You could have some instruments on the rovers, and other heavier ones on the lab module. You could even have the robotic equivalent of a pressurized multi-purpose manned lab with test tubes, bunsen burners, and microscopes if you really wanted to...

As for the Robonaut, you could stick it on the end of the Canadarm for the equivalent of teleoperated EVA activities. That is similar to what NASA is planning for the Robonaut that's on the ISS. Those are just possibilities of course, that I pulled out of my backside. There are plenty of robotic missions that you could fit on a 20 or 30-ton Mars lander if you had one, and by the time we have such a lander, robotics and AI will be much more advanced than they are now.

It would definitely be cheaper and faster to develop than a manned mission. You could even deploy several of these for the cost of a single manned expedition.

Their also slow because they need to assess each cm they travel, one false move and it's mission failed.

Yeah, which is good, so it can study the area more thoroughly at the same time.

A larger, and thus more complex robotic mission, has a bigger chance of failing without the option to fix it.

Sure, which is why my proposal above is probably not 100% realistic and also why the MER program sent two separate rovers. It's just to demonstrate that there is nothing that humans can do that robots can't do for cheaper, as long as you design them to. The best way to do robotic missions is to multiply you chances and instead of doing a single large robotic mission, you do hundreds of them. Zerging the damned planet with small MERs will provide a much more thorough exploration than sending a manned mission to a single location for a short period.

Sure if it could travel faster, throwing caution in the win, then yes it could go back and visit previous sites. It couldn't do experiments it wasn't designed for.

Neither can a manned mission. If you didn't bring a certain instrument with you, then tough luck. You could jury-rig a makeshift replacement, but there is no reason why a dexterious teleoperated robot couldn't do the same.

They also don't send the next mission to the same place.

But they could. And that is not necessarily the best option for a manned mission either. You would probably also want to land further missions in different places, like Apollo.

Is a repair robotic rover really feasible? I could see it fixing a wheel. But what if electronic components break down or if it gets stuck in a ditch?

What if the sample transfer part breaks? What if the rover position of it hinders the repair rover?

Well, same is true for a manned rover, yet you said that it would be designed so that it couldn't get stuck. So design your unmanned rover in the same way. Serviceability needs to be built in. Astronauts could only fix hubble because it was designed to be serviced by EVA. You can't repair something that isn't designed to be repaired. Of course, there are tradeoffs here. Sometimes, you need to just write it off. If it's a robot, well, it's a shame but we can send another one. If it's 2 astronauts suffocating in a stranded rover, then it's a tragedy.

Again, why is it taking "ages" OK? Al those other things you mentioned don't require humans on site, but they require a certain amount of speed. You don't want status on a nuclear reactor core 2 years later. Collapsed building, underwater pipelines, they all require it to be done in time frame of days, maybe weeks, but not years.

Yes, but if we decided to send people to Mars today, it would still take 15 years before they launched. You seem to imagine that we could do it next week if we wanted to, but large aerospace projects don't work that way. It would take more than a decade, and billions of dollars, to simply design a man-rated Mars lander and ascent vehicle. This is why Mars has always been 20 years away since the 1900's. I'm pretty confident that in 2030, we will still be aiming for a manned Mars landing in 2050.

Ultimately, what does it matter if it happens in 2025, 2050 or 2070 ? Humanity is over 200000 years old and billions of people have lived and died on this planet without seeing people land on Mars. Have they been better or worse from it? I'd like to see a Mars landing in my lifetime as much as anyone here, but I doubt I will. Well, I'll get over it. Other than satisfying my selfish entertainment needs, it's no big deal if I'm alive when it happens or not.

Edited March 9, 2015 by Nibb31

[Albert VDS]

Well, so would an unmanned rover. I'm also betting that part of they "design to get out of such situations" will involve not driving too fast

Just like how the Apollo astronauts drove at a snails pace, right? Maybe those speed aren't desirable for safety. But it wont be 90 meters per hour or 3.8 cm per second.

Well, most research takes time. Large fusion projects like ITER or things like LHC take decades to accomplish. We accept that.

ITER is new grounds of technology, that takes time, also funding problems is slowing it down. If we knew how to make it work, then it wouldn't take decades.

LHC is the worlds biggest testing facility, it's actually amazing how fast it got build considering all the countries and people involved in building it, not to mention the cost overruns.

They started building it in 1998, 10 years later is was build. However that has nothing to do with the actual experiment time.

Those things are getting done, while Mars exploration is stuck with rover which take ages to reach their destination.

And what's wrong with getting things done in 30 years? Is there are race on? Is Mars going to vanish in 30 years? Are the geological processes that take millions of years going to suddenly stop any time soon?

Because the future benefits of all the advances we make now, for example in science. Or take a look at it from a business stand point, would a company pursue something if it would take them 30 years? A company would choose

something which would get them to their goal in the fastest and most cost effective way possible. Cheap and safe does not equal cost effective to your goal. It costs SpaceX more money in the short term to develop a reusable

rocket, but in the long term it could save them a lot of money. I know NASA isn't a company, but it still has a budget and a goal. Both should be looked at in that way, because your only throwing away money in the long run.

Not only safety. It's mainly about power consumption (the faster you go, the more power you need, and that is an exponential curve). The power available to Curiosity or the MERs is tiny. Solar power is limited on Mars, and RTGs are designed to produce a low output over a long time. It's also because speed is simply not needed. It would actually be detrimental, because you would miss a lot of details if you were going faster.

You don't want the rover to fall over, so you use a Rocker-bogie system. This system only works by going slow. If the system would have called for a faster speeds then they would have used that.

The nav cams also have to be able to take coherent shots of it surroundings, no reason to go 10 km/h if you can't make heads or tails of the surrounds.

Off the top of my head, I would envision some sort of robotic lab with a sample return stage and a small fleet of semi-autonomous rovers, designed to be serviceable with packed spares and maybe to tow each other back to the base to provide some sort of rescue redundancy. It could have an RMS similar to the ISS Canadarm or DEXTRE, and a variety of tools (maybe a high pressure blower or a brush, fluid valves for refilling whatever needs refilling, and a manipulator for retreiving samples from the rovers or fixing things). You could have some instruments on the rovers, and other heavier ones on the lab module. You could even have the robotic equivalent of a pressurized multi-purpose manned lab with test tubes, bunsen burners, and microscopes if you really wanted to...

Do we already have the capability to create robots which have fine motor systems and are small enough(compared to assembling machines) to be sent to Mars?

As for the Robonaut, you could stick it on the end of the Canadarm for the equivalent of teleoperated EVA activities. That is similar to what NASA is planning for the Robonaut that's on the ISS. Those are just possibilities of course that I pulled out of my backside. There are plenty of robotic missions that you could fit on a 20 or 30-ton Mars lander if you had one, and by the time we have such a lander, robotics and AI will be much more advanced than they are now.

It would definitely be cheaper and faster to develop than a manned mission. You could even deploy several of these for the cost of a manned expedition.

Are you guessing this whole cheaper part, because in your plan there is a lot of systems which needs to be developed.

Yeah, which is good, so it can study the area more thoroughly at the same time.

With most of the time spend on choosing a safe route. Have you followed Curiosity's mission, there's not a whole lot of drilling, sampling or analyzing compared to the days of driving.

Sure, which is why my proposal above is probably not 100% realistic. It's just to demonstrate that there is nothing that humans can do that robots can't do for cheaper, as long as you design them to. The best way to do robotic missions is to multiply you chances and instead of doing a single large robotic mission, you do hundreds of them. Zerging the damn planet with small MERs will provide a much more thorough exploration than sending a manned mission to a single location for a short period.

Which brings us to cost effective again. How many people do you think you'll need to have hundreds of rovers being looked after?

I wouldn't call 500 days a short period, considering they would be send to a differs terrain on each mission, if not exploring the outside then experimenting in the hab.

Neither can a manned mission. If you didn't bring a certain instrument with you, then tough luck. You could jury-rig a makeshift replacement, but there is no reason why a dexterious teleoperated robot couldn't do the same.

I highly doubt geologist equipment would be forgotten on a manned mission. If you didn't bring a certain instrument then you just take a small sample.

A rover team wants to find new places and do the experiments it's designed for, going back to a area which it's not designed for and if it takes weeks of driving is just not efficient.

But they could. And that is not necessarily the best option for a manned mission either. You would probably also want to land further missions in different places, like Apollo.

A manned mission wouldn't need to be revisited because it's more versatile than any rover, you can pretty much explore any where you want in that area for 500 days.

To get a mission approved, it needs to go up against other missions. Which one would you give funding to, a rover to the same place or a new place?

Well, same is true for a manned rover, yet you said that it would be designed so that it couldn't get stuck. So design your unmanned rover in the same way. Serviceability needs to be built in. Astronauts could only fix hubble because it was designed to be serviced by EVA. You can't repair something that isn't designed to be repaired. Of course, there are tradeoffs here. Sometimes, you need to just write it off. If it's a robot, well, it's a shame but we can send another one. If it's 2 astronauts suffocating in a stranded rover, then it's a tragedy.

You can design a manned rover to be serviced from the inside. And again are their real world machines which can fix other machine and are mobile?

I don't see why it needs to be doom and gloom for astronauts. Can't you think up backup plans for them if their rover is stranded? There are many ways to get out of a ditch. A broken wheel shouldn't hinder getting back to base.

And what if the manned rover sprung a leak? How about emergency LS pack which could extend their travel capability.

Yes, but if we decided to send people to Mars today, it would still take 15 years before they launched. You seem to imagine that we could do it next week if we wanted to, but large aerospace projects don't work that way. It would take more than a decade, and billions of dollars, to simply design a man-rated Mars lander and ascent vehicle. This is why Mars has always been 20 years away, since the 1900's. I'm pretty confident that in 2030, we will still be aiming for a manned Mars landing in 2050.

Ultimately, what does it matter if it happens in 2025, 2050 or 2070 ? Humanity is over 200000 years old and billions of people have lived and died on this planet without seeing people land on Mars. Have they been better or worse from it? I'd like to see a Mars landing in my lifetime, but I doubt I will. Well, I'll get over it. Other than satisfying my selfish entertainment needs, It's no big deal.

Where did I say we can go next week? It would at least take 10 years if you get a capable booster, and that might even be optimistic. But this discussion is more about rover vs manned.

It all boils down to cost and goal effective. You want to know if Mars harbored life, has liquid water, what kind of effect low G has on the human body, if we can ever live beyond Eart, etc. etc. then you'll have to send humans.

So it's safer to send robots. Would that still be of a concern if space travel would be cheap and people would be lining up to go to Mars, know well that they are at risk?

Do we really need to send people to the ISS? They are at risk every second they are on board of it. Why do we do it? Because we advance our knowledge. When we try to make working in space safer, we also invent safer work and living applications for use on Earth. Maybe we could discover a way to cure certain diseases concerning bone and muscle when we try to stay longer and longer in space. But the greatest thing is that we don't know what we'll achieve if we pursue such goals as landing people on Mars.

[Kryten]

Using ground covered as a proxy for science is only useful if you're actually doing science observations every step, as MER and MSL have been doing.

[Nibb31]

ITER is new grounds of technology, that takes time, also funding problems is slowing it down. If we knew how to make it work, then it wouldn't take decades.

LHC is the worlds biggest testing facility, it's actually amazing how fast it got build considering all the countries and people involved in building it, not to mention the cost overruns.

They started building it in 1998, 10 years later is was build. However that has nothing to do with the actual experiment time.

If we decided to send people to Mars, it would also take decades, because we also don't know how to make it work. We have some of the theory, and a few DRM ideas, but as with the above projects, it's development engineering that takes time. Large aerospace projects work in the same way. It took nearly 20 years for the F35 to fly. Orion has been in development for 15 years. Even a turboprop cargo plane like the A400M has taken over a decade of development.

Those things are getting done, while Mars exploration is stuck with rover which take ages to reach their destination.

Because the future benefits of all the advances we make now, for example in science. Or take a look at it from a business stand point, would a company pursue something if it would take them 30 years? A company would choose

something which would get them to their goal in the fastest and most cost effective way possible. Cheap and safe does not equal cost effective to your goal. It costs SpaceX more money in the short term to develop a reusable

rocket, but in the long term it could save them a lot of money. I know NASA isn't a company, but it still has a budget and a goal. Both should be looked at in that way, because your only throwing away money in the long run.

You're confusing commercial R&D with fundamental research. There isn't much ROI in extraplanetary research so there isn't much private money invested in it. It's not going to change any time soon. Nobody foresees any direct applications of Martian geological science that are going to change our lives over the next 30 years.

Do we already have the capability to create robots which have fine motor systems and are small enough(compared to assembling machines) to be sent to Mars?

Curiosity has a pretty fine motor system in its robotic arm. There are impressive advances in robotics and AI all the time. There is no reason to believe robots are not going to get even better and smarter.

Are you guessing this whole cheaper part, because in your plan there is a lot of systems which needs to be developed.

Yes, but that vision is more of an extrapolation of existing technology. You're going to need much more development and even more robustness and reliability for a manned mission. It will always be cheaper to send people than to send robots.

Which brings us to cost effective again. How many people do you think you'll need to have hundreds of rovers being looked after?

No idea. As I said, I'm not designing an actual mission. I was merely speculating over what might exist. I would imagine that advances in AI and factorisation of resources would reduce the number of people required to monitor each individual rover compared to today.

I wouldn't call 500 days a short period, considering they would be send to a differs terrain on each mission, if not exploring the outside then experimenting in the hab.

But in your previous post, you claimed that they would revisit the same site for some reason. You need to make up your mind.

I highly doubt geologist equipment would be forgotten on a manned mission. If you didn't bring a certain instrument then you just take a small sample.

Which is inherently true for a rover too. The reason you don't bring an instrument is due to payload margins, but if a robot is working with the same payload margins as a manned expedition, it can obviously bring more instruments. Manned missions will have their payload constraints too you know.

A rover team wants to find new places and do the experiments it's designed for, going back to a area which it's not designed for and if it takes weeks of driving is just not efficient.

A manned mission wouldn't need to be revisited because it's more versatile than any rover, you can pretty much explore any where you want in that area for 500 days.

To get a mission approved, it needs to go up against other missions. Which one would you give funding to, a rover to the same place or a new place?

There is no inherent difference in those points between a manned or a robotic mission.

You can design a manned rover to be serviced from the inside. And again are their real world machines which can fix other machine and are mobile?

We send robots to fix pipelines or nuclear reactors. We have drones and teleoperated robots that can do microsurgery. There is no inherent barrier to imagining a robot that can do routine maintenance and easy swaps of equipment to prolong the life of another robot, especially if that other robot is designed to be serviced in that manner. Or you could design that robot from the start so that it is robust enough to survive 20 years on the surface without maintenance. It's just a matter of developing the hardware to fit the requirements. Current requirements are dictated by power production and weight, but if you increase those parameters to the same level as a manned mission would require, then none of that is inherently impossible.

I don't see why it needs to be doom and gloom for astronauts. Can't you think up backup plans for them if their rover is stranded? There are many ways to get out of a ditch. A broken wheel shouldn't hinder getting back to base.

And what if the manned rover sprung a leak? How about emergency LS pack which could extend their travel capability.

An unmanned rover wouldn't spring a leak it in the first place And it can also be designed to get back to base with a broken wheel. Again, there is no inherent advantage to a manned rover here.

You want to know if Mars harbored life, has liquid water, what kind of effect low G has on the human body, if we can ever live beyond Eart, etc. etc. then you'll have to send humans.

This is pretty much the only valid argument for sending humans to Mars: biological effects on the human body. However, it is a bit circular if the only reason for sending people to Mars is to study how to send people to Mars.

Edited March 9, 2015 by Nibb31

[Albert VDS]

Tell me on thing Nibb, do you even believe that humans should leave Earth?

[Nibb31]

I don't know if we should or shouldn't. I believe that we will do it when there is a strong enough push to do it. I don't see any political, economical or social forces that are pushing right now, which is why there is no strong resolve to send humans to Mars.

I certainly don't believe that colonization is anywhere in our future. As a species, the only hospitable environment for us is the one that we evolved into. Our survival as a species lies here, not in some sci-fi dreamworld. To live anywhere else is always going to be dangerous and expensive with excessive reliance on technology to stay alive. I don't see Mars or the Moon as ever being a better place for people to want to raise kids than Earth.

Edited March 9, 2015 by Nibb31

[Albert VDS]

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.

[-Velocity-]

Politics are what killed space exploration...

Apathy, ignorance, and human stupidity are what killed space exploration. If the public had more of a hunger for it, the politicians would follow.

[Kryten]

Human stupidity killed awareness of space exploration in a segment of the population, naming no names. Pretending that it's not real 'exploration' if it doesn't have humans is a big part of why so much money is wasted on monsters like Orion instead of something potentially useful.

[Bill Phil]

Apathy, ignorance, and human stupidity are what killed space exploration. If the public had more of a hunger for it, the politicians would follow.

Well, what you just said is politics in a nutshell...

Except for a few good souls.

[billbobjebkirk]

Human stupidity killed awareness of space exploration in a segment of the population, naming no names. Pretending that it's not real 'exploration' if it doesn't have humans is a big part of why so much money is wasted on monsters like Orion instead of something potentially useful.

The public does seem to be understanding that automated missions have value, given the publicity surrounding Curiosity, Rosetta, Dawn, and New Horizons.

[Bill Phil]

Human stupidity killed awareness of space exploration in a segment of the population, naming no names. Pretending that it's not real 'exploration' if it doesn't have humans is a big part of why so much money is wasted on monsters like Orion instead of something potentially useful.

SLS would allow for a Europa or Titan probe. Finally a landing... Or at least a dedicated orbiter. Submarine in titan's case.

Plus, heavy launchers are useful, but only with decent launch rates.

[Kryten]

The limiting factor for almost all planetary mission concepts is not throw weight, it's funding.

[Bill Phil]

The limiting factor for almost all planetary mission concepts is not throw weight, it's funding.

True. But a heavy launch vehicle is useful.

We should not have stopped building Saturn Vs.

Edited March 9, 2015 by Bill Phil

[billbobjebkirk]

True. But a heavy launch vehicle is useful.

We should not have stopped building Saturn Vs.

The problem is, in 1968, nobody outside NASA was thinking that we would need the Saturn Vs ever again; Apollo was over.

[GreenWolf]

SLS would allow for a Europa or Titan probe. Finally a landing... Or at least a dedicated orbiter. Submarine in titan's case.

(Emphasis mine.)

You mean like Cassini–Huygens?

It sure is a shame that we can't send a probe to Titan without SLS.

Edit: Just realized that putting quoted text in italics doesn't actually work. Changed it to bold.

Edited March 11, 2015 by GreenWolf

[Bill Phil]

(Emphasis mine.)

You mean like Cassini–Huygens?

It sure is a shame that we can't send a probe to Titan without SLS.

A dedicated orbiter that has a lot of mass. It's kind of implied...

The sarcasm is not welcome.

- - - Updated - - -

The problem is, in 1968, nobody outside NASA was thinking that we would need the Saturn Vs ever again; Apollo was over.

Yeah....

But people should know that having then on hand is a good thing.

[Kibble]

But people should know that having then on hand is a good thing.

Exactly! Nothing compares to the value of in-production operational space vehicle hardware. Space Launch System won't have liquid boosters because the kerosene pipes at Launch Complex 39 weren't kept operational and ended up rusted-out and useless. We'll never* build any Apollo hardware again just because we shut down the production lines for it </3

*except AJ-10 rocket engine used on Delta-K upper stage and Orion, and R-4D thrusters used on ATV, Orion, and Kounotori

[cpast]

And how much would said hardware have been used over the years? Keeping production lines open is incredibly expensive, as is maintaining hardware that's sitting in a warehouse (you can't just stash some Saturn Vs around and expect them to work years later; unless you're actively maintaining them, they won't). NASA has a finite budget; it's not worth spending a large fraction of it on hardware that you aren't going to use, just so you can continue spending money on it to keep the parts you've built from rusting away, unless there's likely to be an urgent need to have hardware or production capacity on hand *right now*.

[Bill Phil]

And how much would said hardware have been used over the years? Keeping production lines open is incredibly expensive, as is maintaining hardware that's sitting in a warehouse (you can't just stash some Saturn Vs around and expect them to work years later; unless you're actively maintaining them, they won't). NASA has a finite budget; it's not worth spending a large fraction of it on hardware that you aren't going to use, just so you can continue spending money on it to keep the parts you've built from rusting away, unless there's likely to be an urgent need to have hardware or production capacity on hand *right now*.

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

Not necessarily the rockets.

[GreenWolf]

A dedicated orbiter that has a lot of mass. It's kind of implied...

The sarcasm is not welcome.

Cassini was a dedicated orbiter with a lot of mass. Albeit, it was a Saturn orbiter, but it still made multiple passes of Titan.

SLS is overkill for sending unmanned probes anywhere. Existing EELV hardware can send probes wherever we need. The real difficulty is getting enough funding for the probe itself. (Which is why I'm peeved that EJSM/Laplace was given priority over TSSM [although it looks like it won't matter now, since ESA is saying EJSM is unlikely with NASA's current budget. Go figure.])

Seriously though, space probes are easy to launch. They don't have life support requirements, nor do they have to come back (unless it's a sample return mission, obviously). And, since robots don't really care how long it takes to get somewhere, you can use ion drives (like Dawn) and lots of gravity assists (like every deep space probe ever).

Edit: For reference, Titan Saturn System Mission, which is/was a long term Titan orbiter + lander + hot air balloon planned for launch on a Delta or an Atlas. Exactly what you wanted, with no need for the Senate Launch System.

Edited March 11, 2015 by GreenWolf

[billbobjebkirk]

SLS is overkill for sending unmanned probes anywhere. Existing EELV hardware can send probes wherever we need. The real difficulty is getting enough funding for the probe itself. (Which is why I'm peeved that EJSM/Laplace was given priority over TSSM [although it looks like it won't matter now, since ESA is saying EJSM is unlikely with NASA's current budget. Go figure.])

There are several missions that can seriously benefit from Heavy-Lift capacity, such as Mars Sample Return, Ice Giants Orbiters, and solar orbiters.

[GreenWolf]

There are several missions that can seriously benefit from Heavy-Lift capacity, such as Mars Sample Return, Ice Giants Orbiters, and solar orbiters.

The only one of those that I can see that would really require heavy lift is the Mars sample return. Everything else can be done with gravity assists (as is already the case) or ion drives (which I fully expect to become more prolific now that Dawn has demonstrated just how freaking useful they are). And the Mars sample return mission doesn't really require a heavy lifter. You could go with a multiple launch, Mars Orbital Rendezvous mission. But yes, I will concede that sample return from anything larger than an asteroid would be greatly helped by a heavy lifter.

[Bill Phil]

Cassini was a dedicated orbiter with a lot of mass. Albeit, it was a Saturn orbiter, but it still made multiple passes of Titan.

SLS is overkill for sending unmanned probes anywhere. Existing EELV hardware can send probes wherever we need. The real difficulty is getting enough funding for the probe itself. (Which is why I'm peeved that EJSM/Laplace was given priority over TSSM [although it looks like it won't matter now, since ESA is saying EJSM is unlikely with NASA's current budget. Go figure.])

Seriously though, space probes are easy to launch. They don't have life support requirements, nor do they have to come back (unless it's a sample return mission, obviously). And, since robots don't really care how long it takes to get somewhere, you can use ion drives (like Dawn) and lots of gravity assists (like every deep space probe ever).

Edit: For reference, Titan Saturn System Mission, which is/was a long term Titan orbiter + lander + hot air balloon planned for launch on a Delta or an Atlas. Exactly what you wanted, with no need for the Senate Launch System.

Cassini was strictly an orbiter of Saturn. While flybys are types of orbits, they weren't closed orbits.

I guess you missed the Titan Submarine part, huh?

Anyways, I've talked with NASA employees who say that SLS might be used for a Europa mission.

And, anything with more mass can simply do more stuff.

Btw, Cassini is 2 mTs dry, so it's not all that massive. Compare it to a launcher with a 70 mT launcher you could almost get 3 times the mass! With a 100 mT launcher you could get almost 6 times Cassini's mass to Saturn. Assuming a similar trajectory. That's quite a lot of payload.

I know probes are small. It's surprising how much you can do with a 500 kg probe...

[GreenWolf]

Cassini was strictly an orbiter of Saturn. While flybys are types of orbits, they weren't closed orbits.

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.

I guess you missed the Titan Submarine part, huh?

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.

Anyways, I've talked with NASA employees who say that SLS might be used for a Europa mission.

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.

And, anything with more mass can simply do more stuff.

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.

Btw, Cassini is 2 mTs dry, so it's not all that massive. Compare it to a launcher with a 70 mT launcher you could almost get 3 times the mass! With a 100 mT launcher you could get almost 6 times Cassini's mass to Saturn. Assuming a similar trajectory. That's quite a lot of payload.

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?)

I know probes are small. It's surprising how much you can do with a 500 kg probe...

This is my entire point.