Mars: For anyone interested in the Perseverance touch down

[3point14]

Way... way.. waaaay less science

The Apollo 17 astronauts explored a few square kilometres of the lunar surface, driving the LRV a cumulative distance of approximately 36 km in a total drive time of about four hours and twenty-six minutes; They walked up to 7.6 km from the LRV. . They did all that during three surface EVA's totaling 22h 3m 57s.

Curiosity Rover has driven 24 km in.... 8 years!

A human can see something interesting, make an immediate decision to walk over and pick it up, and make a decision on the spot as to whether it is worth further examination or not... can turn over things, look behind things, and make decisions based on what it sees. We haven't even begun to design a space-faring robot that can do anything like this.

Brilliant as Spirit, Opportunity and Curiosity have been, they are/were extremely limited in what they could do. A couple of humans on the surface of Mars could have achieved everything they have done over the last 17 years... in less than a couple of weeks

Isn't the compromise, at that point, humans in orbit and rovers on the surface? None of the mission difficulty of getting up and down to the surface, all the advantages of (all but) instantaneous communication and control with the surface rover.

 

[Mike!]

I was thinking more in terms of mission budget for weight.

If you've got spare weight on the disposable sky crane bit, perhaps you'd be better served by adding functionality to the long term rover rather than the soon to be crash landed skycrane.

I was thinking along the lines of, with the proper preparation, the crash itself could provide some useful information back at the newly landed rover.
We crash and shoot things into other things all the time in order to gather information. Since the sky crane is crashing anyway, get some data from it.

 

[MRC_Hans]

I was thinking along the lines of, with the proper preparation, the crash itself could provide some useful information back at the newly landed rover.
We crash and shoot things into other things all the time in order to gather information. Since the sky crane is crashing anyway, get some data from it.

Considered the level pf planning that goes into a mission like this, I would assume that any use of the sky crane after deployment of the rover was contemplated and found impractical.

Considerations would at minimum include weight, cost, development time, and reliability.

Also, there may actually be plans to let the rover seek out the crash site to gain any useful observations.

Hans

 

[cjameshuff]

I was thinking along the lines of, with the proper preparation, the crash itself could provide some useful information back at the newly landed rover.
We crash and shoot things into other things all the time in order to gather information. Since the sky crane is crashing anyway, get some data from it.

It might churn up something interesting, but the site would be covered with residual propellants, tangle hazards like the tethers, potentially unsafe pressure vessels and batteries, etc. Probably better off trying to track down the heat shield impact location.

 

[Trebuchet]

While the sky crane did have a camera or three, it had no means of storing or transmitting the data. That's what the downlink cable to the rover was for. It was designed to one job, one time, extremely well. And did.

 

[smartcooky]

Isn't the compromise, at that point, humans in orbit and rovers on the surface? None of the mission difficulty of getting up and down to the surface, all the advantages of (all but) instantaneous communication and control with the surface rover.

There are a couple of problems with that

1. It is almost as difficult in terms of weight budget to put a spacecraft into Low Mars Orbit (LMO) as it is to land it. A spacecraft has to get from 40,000 kph down to about 12,000 kph for a 400km LMO. Mars landers use the atmosphere (heat shields & parachutes) to do this. Using the atmosphere to get into orbit would require some very sophisticated manoeuvring, perhaps involving aerobraking and retro-firing to shed that excess 28,000 kph. This will involve carrying extra fuel and bigger fuel tanks (therefore a payload penalty).

2. Having the rover drivers in LMO won't be a lot of use as their spacecraft would only be able to remain in contact with the rover for a few minutes at a time. What would be needed is a spacecraft in areosynchronous equatorial orbit (AEO) about 17,000 km above Mars' equator within direct line of sight to the rover. To date, no attempt has ever been made to put a satellite into areosynchronous orbit. This will be even harder than getting into LMO... my quick, back of the envelope calculation shows that areosynchronous orbital velocity is about 5,200 kph, much lower than LMO, and no chance for aerobraking, so it would all have to be achieved with retro-firing... so even more fuel and bigger fuel tanks, so even more payload penalty at launch.

 

[alfaniner]

(Pick your own name and post before viewing the spoiler.)

I know that NASA has a penchant for giving whimsical names to physical features they find. As far as I know, this one hasn't been named yet but I'd call it

Pieta

 

[arthwollipot]

Looks like a dead shark with arms.

 

[3point14]

There are a couple of problems with that

1. It is almost as difficult in terms of weight budget to put a spacecraft into Low Mars Orbit (LMO) as it is to land it. A spacecraft has to get from 40,000 kph down to about 12,000 kph for a 400km LMO. Mars landers use the atmosphere (heat shields & parachutes) to do this. Using the atmosphere to get into orbit would require some very sophisticated manoeuvring, perhaps involving aerobraking and retro-firing to shed that excess 28,000 kph. This will involve carrying extra fuel and bigger fuel tanks (therefore a payload penalty).

2. Having the rover drivers in LMO won't be a lot of use as their spacecraft would only be able to remain in contact with the rover for a few minutes at a time. What would be needed is a spacecraft in areosynchronous equatorial orbit (AEO) about 17,000 km above Mars' equator within direct line of sight to the rover. To date, no attempt has ever been made to put a satellite into areosynchronous orbit. This will be even harder than getting into LMO... my quick, back of the envelope calculation shows that areosynchronous orbital velocity is about 5,200 kph, much lower than LMO, and no chance for aerobraking, so it would all have to be achieved with retro-firing... so even more fuel and bigger fuel tanks, so even more payload penalty at launch.

Well, if you're going to bring awkward things like reality into the equation, I just don't know what to tell you.


Aerobraking isn't entirely out of the question, you just need to do less of it to leave apogee at the height of areosynchronous orbit rather than LMO then burn prograde at apogee to circularise.

I am utterly certain about this, because it works in KSP...*


The other issue would be gravity, or lack of it. Something spinning would be required in Mars orbit to simulate gravity which just adds to the complexity, this wouldn't be required with boots on the ground.


A further issue which occurs to me is that with a station rather than a ground intallation it's much less easy for any stranded botanists to jury rig a potato farm.



(*Of course I realise this approach probably comes with a whole heap of issues of which I am not aware that would probably make it impractical.)

 

[smartcooky]

...it works in KSP...

The four words you should never say to an Aerospace engineer!!

 

[cjameshuff]

The other issue would be gravity, or lack of it. Something spinning would be required in Mars orbit to simulate gravity which just adds to the complexity, this wouldn't be required with boots on the ground.

You also have much higher radiation exposure...on the surface you have the planet blocking half the sky, and the atmosphere actually provides significant shielding on the other half. The atmosphere also shields you from micrometeorites. In addition to requiring less propulsive delta-v to reach, the surface is a much healthier and safer environment.

And the atmosphere and ice mean you can make use of local resources for return propellant and life support.

 

[Sideroxylon]

(Pick your own name and post before viewing the spoiler.)

I know that NASA has a penchant for giving whimsical names to physical features they find. As far as I know, this one hasn't been named yet but I'd call it

Pieta

More photos is more grist for the pareidolia mill.

 

[alfaniner]

This is what they went with.

The rock has been informally named the "harbour seal", for obvious reasons.

 

[theprestige]

Way... way.. waaaay less science

The Apollo 17 astronauts explored a few square kilometres of the lunar surface, driving the LRV a cumulative distance of approximately 36 km in a total drive time of about four hours and twenty-six minutes; They walked up to 7.6 km from the LRV. . They did all that during three surface EVA's totaling 22h 3m 57s.

Curiosity Rover has driven 24 km in.... 8 years!

A human can see something interesting, make an immediate decision to walk over and pick it up, and make a decision on the spot as to whether it is worth further examination or not... can turn over things, look behind things, and make decisions based on what it sees. We haven't even begun to design a space-faring robot that can do anything like this.

Brilliant as Spirit, Opportunity and Curiosity have been, they are/were extremely limited in what they could do. A couple of humans on the surface of Mars could have achieved everything they have done over the last 17 years... in less than a couple of weeks

Nothing they could have done would have been worth risking human lives to do.

On top of which, nothing they could have done would have justified the cost of sending humans to Mars and guaranteeing their survival for up to two years, and their subsequent return to Earth.

Seriously. Stop to think about this for just a minute.

How much would it cost, to have humans assemble a man rated launch facility and launch vehicle on Mars, without stopping to do any science at all?

How much science would they have to do, to justify that cost, in your opinion? Let alone the risk to their lives in the process?

You'd have to spend fifty years just building the infrastructure to free up humans to do real science in relative safety, with an relatively reliable guarantee of safe return. Fifty years that could be spent sending better and better science robots at a fraction of the cost and zero risk to human life.

Please, for the love of science, for the love of reason, give up this romantic obsession with using public funds to put humans on Mars. If you really love science.

 

[theprestige]

There are a couple of problems with that

1. It is almost as difficult in terms of weight budget to put a spacecraft into Low Mars Orbit (LMO) as it is to land it. A spacecraft has to get from 40,000 kph down to about 12,000 kph for a 400km LMO. Mars landers use the atmosphere (heat shields & parachutes) to do this. Using the atmosphere to get into orbit would require some very sophisticated manoeuvring, perhaps involving aerobraking and retro-firing to shed that excess 28,000 kph. This will involve carrying extra fuel and bigger fuel tanks (therefore a payload penalty).

2. Having the rover drivers in LMO won't be a lot of use as their spacecraft would only be able to remain in contact with the rover for a few minutes at a time. What would be needed is a spacecraft in areosynchronous equatorial orbit (AEO) about 17,000 km above Mars' equator within direct line of sight to the rover. To date, no attempt has ever been made to put a satellite into areosynchronous orbit. This will be even harder than getting into LMO... my quick, back of the envelope calculation shows that areosynchronous orbital velocity is about 5,200 kph, much lower than LMO, and no chance for aerobraking, so it would all have to be achieved with retro-firing... so even more fuel and bigger fuel tanks, so even more payload penalty at launch.

And this is why I say the ISS is a waste, and we'd be better served by an orbital shipyard where very large robotic missions could be assembled from Earth-launched payloads.

You want to take solar system science to the next level? Heed my words.

 

[theprestige]

Look, the bottom line is this: Humans, of all the animals, are tool users. We should be building better tools, not just doing without. Sending humans to do science on Mars is like sending humans to plow a field with their bare hands.

 

[Steve]

Look, the bottom line is this: Humans, of all the animals, are tool users. We should be building better tools, not just doing without. Sending humans to do science on Mars is like sending humans to plow a field with their bare hands.

Why is this the "bottom line"? You seem to be saying here that the choice is either to send humans or to send tools, but not to send both?

There are humans who are willing and even enthusiastic about actually setting foot on Mars. And there are people who are very interested in developing the science and technology to be able to safely send humans to Mars. This science and technology will ultimately result in tools that are not currently available - a good thing it seems. The efforts to send humans to the moon resulted in a science and technology boom that had profound and unforeseen effects on many aspects of people's daily lives well beyond sending humans into space. I would expect similar for humans-to-Mars efforts.

If we are going to be sending stuff there anyway it is not a big deal to send some humans along with the other stuff. Is your rather strenuous objection to human space travel primarily based on economics, or is there some other reason?

Edit to ask: What is your opinion of the current Space-X efforts? Is their program to put humans is space misguided and/or a waste of scientific and technological resources?

 

[Ziggurat]

Look, the bottom line is this: Humans, of all the animals, are tool users. We should be building better tools, not just doing without. Sending humans to do science on Mars is like sending humans to plow a field with their bare hands.

That depends on what you think the point of going to Mars is. If the point is only to gather data about Mars, then you're probably right that it's more efficient to just send robots.

But if the point is in part to learn how to send humans to work off planet, then robots are no substitute. And if we are to ever become an interplanetary species, that's a prerequisite.

 

[erlando]

Obligatory Mark Rober* video



*Mark Rober was an engineer on Curiosity and worked among other things on the sky crane.

I absolutely love this stuff. A tear came to my eye when the announcer exclaimed "Touchdown! Perseverance is safely on the surface of Mars!" This is one of the greatest space engineering achievements ever.

"Rocket-powered sky crane". If that doesn't pique your interest nothing will. Come for the awesome engineering, stay for the mindblowing images and science to come.

 

[theprestige]

Why is this the "bottom line"? You seem to be saying here that the choice is either to send humans or to send tools, but not to send both?

The choice is whether or not to send humans to do science, with public funding. We can use tools to do science, at much lower cost and without putting human lives at risk. Therefore, I think it is a bad choice to use public funds to send humans.

There are humans who are willing and even enthusiastic about actually setting foot on Mars. And there are people who are very interested in developing the science and technology to be able to safely send humans to Mars.

Good for them. They should use their own funds for that purpose.

This science and technology will ultimately result in tools that are not currently available - a good thing it seems. The efforts to send humans to the moon resulted in a science and technology boom that had profound and unforeseen effects on many aspects of people's daily lives well beyond sending humans into space. I would expect similar for humans-to-Mars efforts.

I would expect similar for robots-to-Mars efforts. I would expect similar for a lot of efforts. Building really tall buildings. Designing more efficient nuclear weapons. Developing search and rescue robots. Exploring the deep ocean. Pursuing a cure for multiple sclerosis.

As a matter of public policy, throwing astronomical amounts of money at putting humans on Mars, just because someone might invent something really cool as an unforseen side effect, is a bad idea in my opinion. The mission has to be cost-justified on its own terms first, before we can start counting chickens from eggs that may or may not ever get laid. If the stated purpose of the funds is to do science on Mars, then we should insist that those funds be used wisely and efficiently to do science. Not to wastefully and foolishly do science because we like the idea of the accidental side effects of being wasteful and foolish about the mission.

If we are going to be sending stuff there anyway it is not a big deal to send some humans along with the other stuff. Is your rather strenuous objection to human space travel primarily based on economics, or is there some other reason?

It is absolutely a big deal to send some humans along with the other stuff. Several orders of magnitude bigger than just sending more robots. It's primarily an economic objection, because the economics simply don't justify it. It's also an ethical objection. Nothing we're doing on Mars is important enough to justify the cost of sending humans to do it. Certainly not important enough to put human lives at risk to do it.

Edit to ask: What is your opinion of the current Space-X efforts? Is their program to put humans is space misguided and/or a waste of scientific and technological resources?

As a private venture, I think it's fine.

I'm a space travel romantic. I want humans in space. I want humans on Mars. I want cities floating in the upper atmosphere of Venus. I want a generation ship on its way to Alpha Centauri. I want Elon Musk to direct his vast wealth towards his dream of human spaceflight. It's my dream too. I consider myself fortunate to live in a time where private ventures are actually able to take real steps in this direction.

But as a question of what governments should do with the funds they are given, I do not think romance is a justification for investing in human space travel. It's the difference between having a job and having a hobby. Elon Musk is indulging a hobby, and that's fine. But the government has a job to do, and that job isn't to enable Elon Musk's hobbies, or make my dreams of human space travel come true.

 

[theprestige]

That depends on what you think the point of going to Mars is. If the point is only to gather data about Mars, then you're probably right that it's more efficient to just send robots.

That's the stated point of the government-funded missions to Mars.

But if the point is in part to learn how to send humans to work off planet, then robots are no substitute. And if we are to ever become an interplanetary species, that's a prerequisite.

I'm pretty sure the government of the United States has no mandate to use public funds to transform humanity into an interplanetary species. I don't think there's any moral imperative to do so, and certainly no urgent need. If anything, I think we're getting way ahead of ourselves. Humans still have a lot of opportunity to get better at being a planetary species right here on Earth. Right here on Earth is where the governments of today should be focusing their resources.

If we simply cannot abide without having humans in space for some reason, I would much prefer an orbital shipyard. Such a program would satisfy both my romantic and pragmatic urges. An orbital shipyard would enable much larger and more productive robotic probes to the other planets. It would also give us lots of practical experience of humans working in space. It would also advance the development of long-term space habitation, which is a practical requirement for humanity as an interplanetary species.

You want a control station in Mars orbit? Build one in Earth orbit, and put it to work doing useful stuff in Earth orbit. Then we'll talk about taking it on the road.

Honestly, I'm surprised more people aren't pissed off about this: Right now, the upper limit to the science we can do on Mars is the amount of payload we can lift from the Earth's surface in a single launch. This is a stupid limit. If doing more science is a valid goal - and I think it is - then we should be focused a lot more on making payloads from LEO our limit. But nobody is talking seriously about this. Not NASA. Not Musk. Not even the Chinese. It baffles me.

 

[theprestige]

Obligatory Mark Rober* video



*Mark Rober was an engineer on Curiosity and worked among other things on the sky crane.

I absolutely love this stuff. A tear came to my eye when the announcer exclaimed "Touchdown! Perseverance is safely on the surface of Mars!" This is one of the greatest space engineering achievements ever.

"Rocket-powered sky crane". If that doesn't pique your interest nothing will. Come for the awesome engineering, stay for the mindblowing images and science to come.

I too love this stuff. Rocket-powered sky crane on Mars is mind-blowingly awesome, and I'm lucky to be alive to see it happen.

 

[Ziggurat]

I'm pretty sure the government of the United States has no mandate to use public funds to transform humanity into an interplanetary species.

It's got a mandate to send men to Mars.

I don't think there's any moral imperative to do so, and certainly no urgent need.

Urgency is relative, but it's going to be a long process.

If anything, I think we're getting way ahead of ourselves. Humans still have a lot of opportunity to get better at being a planetary species right here on Earth. Right here on Earth is where the governments of today should be focusing their resources.

The budgetary allocation towards manned extraplanetary missions is a fairly small portion of our government budget.

If we simply cannot abide without having humans in space for some reason, I would much prefer an orbital shipyard.

For what, though? For staying in orbit? That's useless. The only real use for an orbital shipyard is as a launching pad to go farther.

You want a control station in Mars orbit? Build one in Earth orbit, and put it to work doing useful stuff in Earth orbit. Then we'll talk about taking it on the road.

Now we're down to quibbling about the exact optimal strategy. Without real expertise in the field, our speculations are of limited value.

Honestly, I'm surprised more people aren't pissed off about this: Right now, the upper limit to the science we can do on Mars is the amount of payload we can lift from the Earth's surface in a single launch.

I don't think that's true at all. There's no real technological hurdle to multiple launch missions. I think it's more that we're not ready to put that much resources into a single mission yet.

If doing more science is a valid goal - and I think it is - then we should be focused a lot more on making payloads from LEO our limit. But nobody is talking seriously about this. Not NASA. Not Musk. Not even the Chinese. It baffles me.

I'm not sure what you mean by this. It seems like SpaceX has done quite a lot to lower the cost of heavy lift capabilities. NASA is a mess, but that would likely be true no matter what their priorities were.

 

[Steve]

The choice is whether or not to send humans to do science, with public funding. We can use tools to do science, at much lower cost and without putting human lives at risk. Therefore, I think it is a bad choice to use public funds to send humans.


Good for them. They should use their own funds for that purpose.


I would expect similar for robots-to-Mars efforts. I would expect similar for a lot of efforts. Building really tall buildings. Designing more efficient nuclear weapons. Developing search and rescue robots. Exploring the deep ocean. Pursuing a cure for multiple sclerosis.

As a matter of public policy, throwing astronomical amounts of money at putting humans on Mars, just because someone might invent something really cool as an unforseen side effect, is a bad idea in my opinion. The mission has to be cost-justified on its own terms first, before we can start counting chickens from eggs that may or may not ever get laid. If the stated purpose of the funds is to do science on Mars, then we should insist that those funds be used wisely and efficiently to do science. Not to wastefully and foolishly do science because we like the idea of the accidental side effects of being wasteful and foolish about the mission.


It is absolutely a big deal to send some humans along with the other stuff. Several orders of magnitude bigger than just sending more robots. It's primarily an economic objection, because the economics simply don't justify it. It's also an ethical objection. Nothing we're doing on Mars is important enough to justify the cost of sending humans to do it. Certainly not important enough to put human lives at risk to do it.


As a private venture, I think it's fine.

I'm a space travel romantic. I want humans in space. I want humans on Mars. I want cities floating in the upper atmosphere of Venus. I want a generation ship on its way to Alpha Centauri. I want Elon Musk to direct his vast wealth towards his dream of human spaceflight. It's my dream too. I consider myself fortunate to live in a time where private ventures are actually able to take real steps in this direction.

But as a question of what governments should do with the funds they are given, I do not think romance is a justification for investing in human space travel. It's the difference between having a job and having a hobby. Elon Musk is indulging a hobby, and that's fine. But the government has a job to do, and that job isn't to enable Elon Musk's hobbies, or make my dreams of human space travel come true.

OK. A lot of words to say humans on Mars is ok as long as your money is not involved in sending them there. I have no problem with that. Let private enterprise take the risks and reap whatever benefits they find along the way. Just so long as governments who do not participate in the process do not interfere with the process and do not expect to gain by any of the benefits.

 

[theprestige]

OK. A lot of words to say humans on Mars is ok as long as your money is not involved in sending them there. I have no problem with that. Let private enterprise take the risks and reap whatever benefits they find along the way. Just so long as governments who do not participate in the process do not interfere with the process and do not expect to gain by any of the benefits.

You're taking this to a weird place I have no interest in going.

 

[Steve]

You're taking this to a weird place I have no interest in going.

I'm not following. You don't want government money spent to put humans on Mars but you are ok with private enterprise doing it. I am also ok with that. I would like to see humans on Mars by whatever means but I doubt that I will live so long. Nothing weird here.

I merely added the caveat that governments should not expect to benefit from the science and technology developed in the process if they do not contribute. If governments do not care to contribute they should just stay out of the way and let private enterprise do what they do best. Nothing weird here either.

I have no idea about the weird place you think this is going and I don't think I want to know.

 

[theprestige]

It's got a mandate to send men to Mars.

Which I think is a stupid mandate. But perhaps mandate is the wrong word. I mean something more like a moral imperative.

Urgency is relative, but it's going to be a long process.

My take is that it's going to be a long enough process that no meaningful amount of time will be lost by present-day governments focusing their resources on terrestrial concerns, and leaving it to the future to pursue interplanetary goals.

The budgetary allocation towards manned extraplanetary missions is a fairly small portion of our government budget.

I'd happy if it were smaller still. Infinitesimal, even.

For what, though? For staying in orbit? That's useless. The only real use for an orbital shipyard is as a launching pad to go farther.

Or go bigger. Which is exactly the use I proposed. It's super weird that I said exactly what I would use it for, and yet you still asked what I'd use it for.

Now we're down to quibbling about the exact optimal strategy. Without real expertise in the field, our speculations are of limited value.

I'm okay with that.

I don't think that's true at all. There's no real technological hurdle to multiple launch missions. I think it's more that we're not ready to put that much resources into a single mission yet.

Larger upper stages can push larger payloads. Larger payloads can include larger probes, and larger reentry apparatuses that can in turn deliver larger payloads to the Martian surface.

Sure, we could launch all the components from Earth, and have them assemble and integrate themselves when they reach Mars, but I suspect it'll be much easier to succeed if we put it all together at this end.

I'm not sure what you mean by this. It seems like SpaceX has done quite a lot to lower the cost of heavy lift capabilities. NASA is a mess, but that would likely be true no matter what their priorities were.

It's not about how cheap it is to lift a payload to LEO. It's about the upper limit on payload weight that can be lifted to LEO in one go. The total payload that can be delivered to the Martian surface is limited by the total weight of payload the skycrane can support. That, in turn, is limited by the total weight of skycrane+rover+Mars transfer vehicle that can be lifted from the Earth's surface in one go.

My claim is that if you made three launches to LEO, each one at max payload weight, one being the rover, one being the skycrane, and one being the interplanetary transfer vehicle, and assembled them in LEO, you could do a LOT more at the far end.

Maybe now that SpaceX is lowering launch costs, we'll start to consider that option.

 

[Ziggurat]

My claim is that if you made three launches to LEO, each one at max payload weight, one being the rover, one being the skycrane, and one being the interplanetary transfer vehicle, and assembled them in LEO, you could do a LOT more at the far end.

I don't think that's actually true. Perseverance is very similar to earlier probes. Why are we replicating past capability instead of deploying something really new? Because it's mostly got the instruments we want already. The point of sending more of the same instruments is to sample more of Mars' surface. More different instruments with diminishing benefits sampling one place is less useful than spreading key instruments across more of Mars.

 

[Skeptic Ginger]

Obligatory Mark Rober* video



*Mark Rober was an engineer on Curiosity and worked among other things on the sky crane.

I absolutely love this stuff. A tear came to my eye when the announcer exclaimed "Touchdown! Perseverance is safely on the surface of Mars!" This is one of the greatest space engineering achievements ever.

"Rocket-powered sky crane". If that doesn't pique your interest nothing will. Come for the awesome engineering, stay for the mindblowing images and science to come.

Fantastic!

Thanks for that.

I love his other stuff too!

 

[alfaniner]

Here's a comic strip I just happened to come upon last night. It was made in 1906! I have to wonder if any of the lander team was inspired by this.

 

[Steve001]

Nothing they could have done would have been worth risking human lives to do.

On top of which, nothing they could have done would have justified the cost of sending humans to Mars and guaranteeing their survival for up to two years, and their subsequent return to Earth.

Seriously. Stop to think about this for just a minute.

How much would it cost, to have humans assemble a man rated launch facility and launch vehicle on Mars, without stopping to do any science at all?

How much science would they have to do, to justify that cost, in your opinion? Let alone the risk to their lives in the process?

You'd have to spend fifty years just building the infrastructure to free up humans to do real science in relative safety, with an relatively reliable guarantee of safe return. Fifty years that could be spent sending better and better science robots at a fraction of the cost and zero risk to human life.

Please, for the love of science, for the love of reason, give up this romantic obsession with using public funds to put humans on Mars. If you really love science.

Your perspective would have kept humanity in Africa to this day.

 

[smartcooky]

Your perspective would have kept humanity in Africa to this day.

THIS!

Polo, Columbus, Vespucci, Cabot, Magellan, Tasman, Cook, Scott, Speke, Shackleton, Peary, Ross..... 'Nah, better to stay in port and play it safe'

Hillary, Tensing, Mallory, Hunt, Bonington, Lowe..... 'Nah, "because it's there" is not a good enough reason'

Armstrong, Aldrin, Conrad, Bean, Shepard, Mitchell, Scott, Irwin, Young, Duke, Cernan, Schmitt..... 'Nah, Nothing to see or do there, its just grey dust and rock'

 

[smartcooky]

My claim is that if you made three launches to LEO, each one at max payload weight, one being the rover, one being the skycrane, and one being the interplanetary transfer vehicle, and assembled them in LEO, you could do a LOT more at the far end.

Do you have any idea what you are saying?

Have you seen what it takes to assemble and attach the rover to the skycrane, and if so, do you really think it would be possible to do that in space?

 

[Steve]

THIS!

Polo, Columbus, Vespucci, Cabot, Magellan, Tasman, Cook, Scott, Speke, Shackleton, Peary, Ross..... 'Nah, better to stay in port and play it safe'

Hillary, Tensing, Mallory, Hunt, Bonington, Lowe..... 'Nah, "because it's there" is not a good enough reason'

Armstrong, Aldrin, Conrad, Bean, Shepard, Mitchell, Scott, Irwin, Young, Duke, Cernan, Schmitt..... 'Nah, Nothing to see or do there, its just grey dust and rock'

Somehow in the past several decades it seems that risk taking has become something to be avoided at all costs, and even legislated against. Adventure is no longer allowed. Wrap the kids (and even adults) in bubble wrap to keep them safe from all harm.

I am glad I grew up in the 50's/60's when kids were still allowed to learn from their cuts, bruises, scrapes, and the occasional break. We had good neighbors in those days too. That's where I learned to chase the kids off my lawn!

 

[Skeptical Greg]

Nothing they could have done would have been worth risking human lives to do.

What makes human life so valuable other than the ability to imagine that is?

Any humans involved have the right to decide whether or not they want to risk their life.

 

[Steve]

What makes human life so valuable other than the ability to imagine that is?

Any humans involved have the right to decide whether or not they want to risk their life.

I am fairly sure that theprestige's issue is not the value of human life but:

Please, for the love of science, for the love of reason, give up this romantic obsession with using public funds to put humans on Mars. If you really love science.

 

[Roboramma]

Honestly, I'm surprised more people aren't pissed off about this: Right now, the upper limit to the science we can do on Mars is the amount of payload we can lift from the Earth's surface in a single launch. This is a stupid limit. If doing more science is a valid goal - and I think it is - then we should be focused a lot more on making payloads from LEO our limit. But nobody is talking seriously about this. Not NASA. Not Musk. Not even the Chinese. It baffles me.

SpaceX plans to get Starship to Mars.

Starship can't just launch from the earth to Mars. It would need to refuel in orbit six times.

That seems to be exactly what you're talking about. There's not much difference between launching six different small payloads and assembling them in orbit and launching a ship and refueling it six times in orbit: the payload you send to Mars is still much larger than a single launch from the Earth's surface can allow.

So it seems like SpaceX trying to develop exactly the capability that you say they aren't developing.

I like your idea of an orbital shipyard, and mostly agree about robotic vs. manned spaceflight (mostly, not entirely), but at least to an extent SpaceX is working on what you think they should be working on.

 

[smartcooky]

SpaceX plans to get Starship to Mars.

Starship can't just launch from the earth to Mars. It would need to refuel in orbit six times.

That seems to be exactly what you're talking about. There's not much difference between launching six different small payloads and assembling them in orbit and launching a ship and refueling it six times in orbit: the payload you send to Mars is still much larger than a single launch from the Earth's surface can allow.

So it seems like SpaceX trying to develop exactly the capability that you say they aren't developing.

I like your idea of an orbital shipyard, and mostly agree about robotic vs. manned spaceflight (mostly, not entirely), but at least to an extent SpaceX is working on what you think they should be working on.

The prestige is talking about building a bigger, better rover by making them all bigger on the earth, launching each of them separately (the rover, the skycrane and the cruise stage) then assembling them in orbit - and he accuses me of having unrealistic, romantic ideas.

This is just pure fantasy. It would require an on-orbit assembly facility, probably including a colossal clean room, a crapload of specialist tools, equipment and test gear, and probably a lot of specialist people as well, who would now need astronaut training. All of this would need to be launched into orbit and would require several launches.

I don't have the expertise to accurately speak to how much more difficult this would be that what they have done so far, but my guess would be at least two or three orders of magnitude - perhaps STS60 would like to comment IIRC, he is our resident payload integration guy.

 

[Lukraak_Sisser]

Hmmm lets see, use my public funds to do something that will inspire generations of people to strive to see new things, or use my public funds to keep an arsenal of weapons capable of destroying humanity forever.

Choices choices.

 

[smartcooky]

Hmmm lets see, use my public funds to do something that will inspire generations of people to strive to see new things, or use my public funds to keep an arsenal of weapons capable of destroying humanity forever.

Choices choices.