Here’s why many in aerospace remain skeptical of the journey to Mars

Wouldn't it be easier to deploy a permanent base in the Moon, and then leverage it for a Mars mission?

 

[Chuckstar]

Dan Homerick[/url]":3h6ho7gp]

vrDrew99[/url]":3h6ho7gp]We can just about land a decent sized vehicle on the Martian surface - but until we solve the fundamental propellant problem - it is doomed to be a one-way trip.

I'm sure people will hold up the idea of generating the fuel for the return trip on Mars. If that's a key requirement for doing a large scale Mars expedition, we should be developing and testing the technology now. As far as I know, there hasn't even been a "Challenge" style program to get this idea started. I expect that resource extraction of any form is going to be ridiculously hard. It's energy intensive, requires move large masses of material, and isn't useful unless done on a pretty large scale.

There's been lots of work on in-situ fuel production, both at the theoretical level and in the form of demonstration apparatuses. Obviously, there's work that needs to be done to design an actual, flight-ready system robust enough to operate on Mars with low-probability of breakdown, but the basic science of the ilk you're describing has already been done.

You don't need to move lots of material, btw. You extract everything you need from the atmosphere, with the addition of hydrogen you bring from Earth.

 

[Chuckstar]

Bertie68[/url]":30xe1fhv]

MagicDot[/url]":30xe1fhv]Miss Newman, how much will the project cost?
Real Answer: 1.5 trillion dollars
Scripted Answer: Well, if you read our plan which plans the plan we have planned for extensive planning during the planning stage. Have you read it? If not I encourage you to do so.

Miss Newman, how long until people walk on Mars?
Real Answer: 100 years
Scripted Answer: Well, if you read our plan which plans the plan we have planned for extensive planning during the planning stage. Have you read it? If not I encourage you to do so.

This is not a technical challenge. It is one of logistics and politics and both are a staggering challenge right now. Take comfort in the fact that your great grandchildren just might live long enough to see it.

If we take into account that the Apollo program consumed 4-5% of the yearly US GDP during its development, we can easily make a guesstimate of how much would cost the ticket to Mars.

Huh? Apollo varied between 0.2% and 0.7% of GDP, with levels above 0.2% only lasting for 8 years. Basically, you're off by a factor of 10. At peak (for two years) it represented just over 4% of federal outlays, but it's a really steep peak leading up to and after those two years.

EDIT: The point of the steepness of the peak being that if you average over the 12 years (or something like that) that the program ran, Apollo represented well under 4% of federal outlays, and probably somewhere around 0.4% to 0.5% of GDP.

EDIT2: Putting Apollo in perspective in today's terms: 0.5% of GDP today would be $80 billion a year. This is about 4.5x NASA's current budget of $18 billion. A meaningful increase, but hardly rising to the level of "ridiculous", considering a total federal budget of just over $3 trillion and the annual defense budget is close to $700 billion. If you just inflation-adjust the cost of Apollo, you get a total (not annual) amount of somewhere around $150 billion.

 

[Chuckstar]

uhuznaa[/url]":212hlt0z]

SixDegrees[/url]":212hlt0z]

afidel[/url]":212hlt0z]

arcite[/url]":212hlt0z]What would be the scientific value of a manned trip to Mars anyway? Big picture...what could be learned by human exploration that could not with cutting edge robots and probes?

The total amount of surface exploration done by robot probes to date could be accomplished by a manned mission in an afternoon.

No, not even remotely close, unless you're only talking about covering ground - which is nothing more than a flag-planting exercise that is pretty much pointless. The amount of actual science done by probes has been utterly staggering, and even a large human team would be very hard pressed simply to duplicate it over the course of an extended visit, let alone expand on it.

This is a usual misunderstanding: People see rovers drive a few miles in years and think that driving around is exploration and science. It isn't. Humans do the science even with robots and being there is actually more of a disadvantage than anything else, since you need to breath and drink and eat all the time. And then the probes and robots are very little mass compared to what you'd need to bring for a crewed mission.

Land 100 tons of rovers and THEN try to beat the science that these rovers can facilitate with what a handful of guys stumbling around in the dust can do. EVA's aren't easy anyway, don't think a few months on Mars would allow more than a handful of days covering ground. At least both Apollo and the ISS seem to indicate that this is not as easy as movies make it look like. Every man-hour on the Moon was about $1B, and there is little reason to think that things would be cheaper on Mars.

Apollo 17 did 22 hours of EVA on the surface over the course of 3 days, covering 22 miles of ground. The idea that a Mars mission could only do a handful of EVA-days over the course of months is nonsensical.

EDIT: To put that distance in perspective, Spirit travelled 7 miles, Opportunity traveled 42 and Curiosity has traveled 4.

 

[Chuckstar]

uhuznaa[/url]":1qwuqpxx]

Chuckstar[/url]":1qwuqpxx]

uhuznaa[/url]":1qwuqpxx]

SixDegrees[/url]":1qwuqpxx]

afidel[/url]":1qwuqpxx]

arcite[/url]":1qwuqpxx]What would be the scientific value of a manned trip to Mars anyway? Big picture...what could be learned by human exploration that could not with cutting edge robots and probes?

The total amount of surface exploration done by robot probes to date could be accomplished by a manned mission in an afternoon.

No, not even remotely close, unless you're only talking about covering ground - which is nothing more than a flag-planting exercise that is pretty much pointless. The amount of actual science done by probes has been utterly staggering, and even a large human team would be very hard pressed simply to duplicate it over the course of an extended visit, let alone expand on it.

This is a usual misunderstanding: People see rovers drive a few miles in years and think that driving around is exploration and science. It isn't. Humans do the science even with robots and being there is actually more of a disadvantage than anything else, since you need to breath and drink and eat all the time. And then the probes and robots are very little mass compared to what you'd need to bring for a crewed mission.

Land 100 tons of rovers and THEN try to beat the science that these rovers can facilitate with what a handful of guys stumbling around in the dust can do. EVA's aren't easy anyway, don't think a few months on Mars would allow more than a handful of days covering ground. At least both Apollo and the ISS seem to indicate that this is not as easy as movies make it look like. Every man-hour on the Moon was about $1B, and there is little reason to think that things would be cheaper on Mars.

Apollo 17 did 22 hours of EVA on the surface over the course of 3 days, covering 22 miles of ground. The idea that a Mars mission could only do a handful of EVA-days over the course of months is nonsensical.

EDIT: To put that distance in perspective, Spirit travelled 7 miles, Opportunity traveled 42 and Curiosity has traveled 4.

The Apollo crews had to hurry. And their spacesuits were worn out after a few EVA's. Keeping up that pace over months would have been impossible. And again, "covering ground" is in no way a useful metric here. Landing 15 tons of rovers instead and having these slowly doing science for months or years would have bought more science for less. Even back then and more so today.

I'm all for going to Mars but we will never get there without looking coldly at the facts. Science will never be the reason for a crewed Mars mission. Or for any manned spaceflight for that matter. The only reason to go there is to go there. Reason enough, but if you pretend the reason to be science you'll be disappointed over and over again because robotics are better and cheaper for that. If you want mankind to go to Mars stop using science as an excuse. Because even the most cursory mission analysis will show you that THIS isn't going to be the reason to go. It's no surprise that SpaceX talks very little of science as a reason to go to Mars.

They'd only have to keep that pace up for a week to reach a "handful" of days. And their suits weren't particularly designed for any longer. We have 50 years of materials science, space experience, miniaturization and production experience we can put behind designing better suits, not to mention the fact that the design spec will be different. Covering ground is an entirely useful metric. Just ask any geologist what the most important metric for doing field geology is. They'll tell you that you the most important thing is covering a lot of ground.

No, this doesn't mean the argument for going to Mars is that it's a cheaper way to get science done. But your counterarguments don't need to be nonsensical to make the point. And claiming that you'd only get a few days of EVA time over the course of months and that covering ground isn't an important metric are both nonsensical arguments.

 

[Chuckstar]

Bertie68[/url]":3h0plsyu]

Chuckstar[/url]":3h0plsyu]

Bertie68[/url]":3h0plsyu]

MagicDot[/url]":3h0plsyu]Miss Newman, how much will the project cost?
Real Answer: 1.5 trillion dollars
Scripted Answer: Well, if you read our plan which plans the plan we have planned for extensive planning during the planning stage. Have you read it? If not I encourage you to do so.

Miss Newman, how long until people walk on Mars?
Real Answer: 100 years
Scripted Answer: Well, if you read our plan which plans the plan we have planned for extensive planning during the planning stage. Have you read it? If not I encourage you to do so.

This is not a technical challenge. It is one of logistics and politics and both are a staggering challenge right now. Take comfort in the fact that your great grandchildren just might live long enough to see it.

If we take into account that the Apollo program consumed 4-5% of the yearly US GDP during its development, we can easily make a guesstimate of how much would cost the ticket to Mars.

Huh? Apollo varied between 0.2% and 0.7% of GDP, with levels above 0.2% only lasting for 8 years. Basically, you're off by a factor of 10. At peak (for two years) it represented just over 4% of federal outlays, but it's a really steep peak leading up to and after those two years.

EDIT: The point of the steepness of the peak being that if you average over the 12 years (or something like that) that the program ran, Apollo represented well under 4% of federal outlays, and probably somewhere around 0.4% to 0.5% of GDP.

EDIT2: Putting Apollo in perspective in today's terms: 0.5% of GDP today would be $80 billion a year. This is about 4.5x NASA's current budget of $18 billion. A meaningful increase, but hardly rising to the level of "ridiculous", considering a total federal budget of just over $3 trillion and the annual defense budget is close to $700 billion. If you just inflation-adjust the cost of Apollo, you get a total (not annual) amount of somewhere around $150 billion.

OK, I admit I had not contrasted the info just before writing. I had read the figures some time ago and what I posted was a ballpark estimate. But also did not fall too far away: https://en.wikipedia.org/wiki/Budget_of_NASA

As you can see, the total NASA budget peaked in 1966 at 4,41% of Fed Budget (er, not GDP). I think we can safely assume most of it was devoted to the Apollo program.

At peak, only 70% of NASA's budget went to Apollo. But even that 4.4% number is misleading, as it's peak funding and not averaged over the course of any program.
Apollo cost $25.4 billion from 1960 to 1973. Federal spending for those 13 years was roughly $2.2 trillion. The result is an average of 1.1% of federal outlays. NASA is currently about 0.5% of federal outlays. NASA as a whole was about $55 billion over those 13 years, so closer to 2.5% for all of NASA. It's interesting to note that throughout the Apollo era, NASA was spending huge sums of money on non-Apollo programs. Lots of these would have been programs with military applications -- for example, NASA ran the X-plane program -- but also included things like the NERVA nuclear-powered rocket engine suitable for missions to Mars as well as the early R&D spending on the Space Shuttle. I'm not sure whether NERVA was considered to have military applications, but the Space Shuttle certainly was. The point of the military applications being that in many politicians' eyes, at the time, a large percentage of NASA's budget was really part of military spending, even if it wasn't itemized that way.

I'm not making the military-related comments to be judgmental, just to be realistic about congress's appetite for "military" vs "exploration". In other words, in order to expect congress to fund a similar level today as they did for NASA as whole back in the 60s, one would have to give congress a similar military justification as they had in the 60s. Otherwise, it's not really apples-to-apples. The same is not quite as true when looking at Apollo in particular, as the direct military applicability was known to be rather limited, with Apollo being more driven by general concepts surrounding national prestige, rather than specific military applicability. That's a long-winded way of saying that it's hard to analyze non-Apollo spending by NASA in the 60s vs today's NASA budget without considering how/whether military applicability has changed, considering congress's differing appetite for military spending vs pure science spending in both time periods.

 

[Chuckstar]

SpaceMonster![/url]":21o7bs10]

afidel[/url]":21o7bs10]

arcite[/url]":21o7bs10]What would be the scientific value of a manned trip to Mars anyway? Big picture...what could be learned by human exploration that could not with cutting edge robots and probes?

The total amount of surface exploration done by robot probes to date could be accomplished by a manned mission in an afternoon.

I'm surprised how much afidel's reply was downvoted. I'm a fan of space-exploration and therefore a fan of robotic probes since they do most of the exploration, but it's absurd to think they're a fast way of doing things. If NASA spots a good rock 20 yards away from Curiosity's they'll poke it with the laser, then plot a driving course, position the drill and take the sample. With a 40-minute communication delay this can take over a day to plan and execute. An astronaut would just walk over with a rock hammer and have an answer in under a minute.

Exploring the surface of Mars would be done more effectively by a human presence.

The counterpoint is that you could have dozens of rovers at various places on the surface all at the same time for the cost of sending humans to one location.

 

[Chuckstar]

SpaceMonster![/url]":2qyco20g]

Chuckstar[/url]":2qyco20g]

SpaceMonster![/url]":2qyco20g]

afidel[/url]":2qyco20g]

arcite[/url]":2qyco20g]What would be the scientific value of a manned trip to Mars anyway? Big picture...what could be learned by human exploration that could not with cutting edge robots and probes?

The total amount of surface exploration done by robot probes to date could be accomplished by a manned mission in an afternoon.

I'm surprised how much afidel's reply was downvoted. I'm a fan of space-exploration and therefore a fan of robotic probes since they do most of the exploration, but it's absurd to think they're a fast way of doing things. If NASA spots a good rock 20 yards away from Curiosity's they'll poke it with the laser, then plot a driving course, position the drill and take the sample. With a 40-minute communication delay this can take over a day to plan and execute. An astronaut would just walk over with a rock hammer and have an answer in under a minute.

Exploring the surface of Mars would be done more effectively by a human presence.

The counterpoint is that you could have dozens of rovers at various places on the surface all at the same time for the cost of sending humans to one location.

An excellent point but consider the end point of Mars exploration. Humans will have to go to Mars sooner or later for a variety of reasons and once they're there the development of Mars rovers will stagnate. If the dozens of rovers lack some necessary capability that's been identified then we won't spend 10 years designing a new robotic way of doing the task. We'll either send preexisting human tools to the humans or tell them to improvise the needed tool. Robots don't adapt, they have to replaced with new versions. It takes a lot of time.

We should stop messing around with taking photos of our destiny and get on with living it.

"Consider the end point of Mars exploration..."

Which is what?

Why will humans have to go to Mars eventually?

Even if humans will go to Mars eventually, what's the logic behind spending the money to go now?

And there will be a very limited ability to improvise tools, even if humans are there. If your laser chromatograph isn't up to the task, you're not going to build a new one on Mars. And getting a new one there will take just as long if not longer by sending it with the next humans than sending it with the next rover.

Your original point "humans are better explorers" has now devolved to a logic-less mess of "we may as well go now."

 

[Chuckstar]

SpaceMonster![/url]":2rcic4kh]

A better question than "why go now?" is "why wait?" and the Spirit rover didn't get stuck in the sand because it's laser chromatograph wasn't up to the task.

Wait because it's super-expensive, and it's much cheaper to send any number of rovers, instead. Now we're just going in circles... Like Spirit.

(And of course some things that can go wrong with rivers humans could fix. But again, you could have literally dozens of the things running around for the same cost as humans.)