It's bigger than you think and closer too...

louis · 2018-05-13 17:06:35

I was struck by a discussion at the LENR Forum...

https://www.lenr-forum.com/forum/thread … #post85282

...seems like even many tech-savvy people misunderstand (a) how close we are to colonising Mars and (b) do not realise the huge economic potential of settlement there.

The game changers are:

1. Rocketry: Space X's single minded determination to reduce the cost of rockets through reuse and to build a huge rocket to take people to Mars. This has fundamentally overthrown all presumptions - particularly NASA's of course. This now means that huge amounts of equipment and supplies can be taken to Mars.

2. Tonnage means infrastructure: Creating a small scale but comprehensive industrial infrastructure on Mars will now be much easier.

3. Robotics: There have been huge advances in automation and robotics. It is now possible to set up industrial processes as almost completely automated. It is now possible for robots to clean, do the washing up, cook your meals. This all translates into a few people being able to do a hell of a lot. Robot rovers will be able to explore and mine essentially by themselves.

4. 3D printing: The rise of 3D printing is hugely enabling to the Mars settlement project. It means spare parts can be produced, and industrial products can be made on a small scale.

5. Philanthroponomics: In the last 20 years we have seen the rise of internet multi-billionaires. Musk has been ploughing a lot of his own money into this project.There will be more.

6. Private companies can use sponsorship: NASA cannot use commercial sponsorship to fund its ventures. Space X can.

7. Energy on tap: I used to think that it would take some time before the settlement could produce its own photovoltaic panels. I no longer believe that to be the case. Given robotics, 3D printing and the huge cargo tonnage that Space X can deliver, a photovoltaic production line could be in place within a couple of years. This means the settlement will be completely energy-independent. Energy will not be a brake on development. Than main impediment to development will be the number of people who can be settled on Mars.

8. Journey time: We had got used to thinking in terms of 6-10 months for journey time to Mars but recent info suggests this could be much shorter - perhaps 3-4 months. That will make everything easier in terms of human health.

9. Riding a wave: It is clear that the Mars settlement project will in fact be coming to fruition at the same time as orbital tourism and lunar tourism. This will generate a huge amount of interest in space and Mars will be the beneficiary.

10. Politics: Obama was an urban activist, Chicago Democrat - Chicago was a centre of oppostion to space exploration (they were never part of the pork barrel benefit states!), preferring to prioritise welfare programmes on Earth. But now Trump is in the Presidency and he clearly favours a robust return to space.

kbd512 · 2018-05-13 18:37:35

1. The marginal cost of flying BFR has yet to be determined because the rocket has yet to be built. Don't count yer chickens... well, you should know the rest by now.

2. 150t is nothing in the industrial world. There are individual forging machines that weigh much more than that here on Earth. Until Mars has its own industrial base, someone on Earth can pull the plug at any time and kill the entire project. After Mars has its own industrial base, it doesn't matter what anyone on Earth thinks of what's happening on Mars. Good / bad / right / wrong / indifferent, after Mars is self sustaining it simply "is" and no opinion to the contrary will change that.

3. There's a robot that can do this, that, or the other quite well, but no single robot that can do all the tasks you just named off. For reasons pertaining to mass, someone will have to create a single robot that can do all of the things you just named off. That's why scientists are trying to create AI-enhanced anthropomorphic robots that are at least as good as humans are at a broad range of mundane tasks.

4. 3D printing is an absolutely mandatory enabling technology because other fabrication methods require too many machines that weigh too much for a fledgling colony to afford to have delivered to them.

5. Apart from Allen, Bezos, Gates, and Musk, I see no other billionaires who are all that interested in space exploration. I'm just thankful that we have the handful that we do have.

6. Private companies contribute little funding to highly speculative ventures because there's an inordinately high chance the ventures will fail.

7. Energy is already a brake on merely getting started. To simply refuel a single BFR, hundreds of millions of dollars of space flight rated solar panels are necessary. You're clearly unaware of what these things cost. They're more expensive than small nuclear reactors.

8. The only type of propulsion systems that are feasible for delivery of serious tonnage are the types that don't use fuel. To wit, only the electromagnetic sails have been flown in space and have any realistic hope of substantially reducing the propulsion mass requirements.

9. Apart from fabulously wealthy thrill seekers, it's not clear at all that anyone will spend their life savings to go to space. This is pure magical thinking on your part. The first colonists will have to be sponsored workers who construct the facilities for everyone else to use.

10. Presidents Clinton / Bush / Obama / Trump all talked a mighty big game regarding US space flight activities, but none have imposed a realistic deadline / mandate for NASA to achieve. Someone needs to light a fire under their rear ends to get them to moving towards a goal. I don't care if it's simply returning to the moon and eventually moving on to Mars, but it's past time to move forward.

Oldfart1939 · 2018-05-13 19:06:32

Report by Ryan McDonald:

https://youtu.be/gnb9TLC803o

louis · 2018-05-13 20:11:47

kbd512 wrote:

1. The marginal cost of flying BFR has yet to be determined because the rocket has yet to be built. Don't count yer chickens... well, you should know the rest by now.

True. But we do the costs of the BFR are in effect being shared across several projects each with their own revenue stream: ISS supply, satellite launches, orbital internet, orbital tourism, lunar tourism and Earth-to-Earth transport. That has got to be a game-chnager in terms of taking a rocket to Mars.

kbd512 wrote:

2. 150t is nothing in the industrial world. There are individual forging machines that weigh much more than that here on Earth. Until Mars has its own industrial base, someone on Earth can pull the plug at any time and kill the entire project. After Mars has its own industrial base, it doesn't matter what anyone on Earth thinks of what's happening on Mars. Good / bad / right / wrong / indifferent, after Mars is self sustaining it simply "is" and no opinion to the contrary will change that.

Space X's Mission One as I understand is looking to take about 500 tonnes of cargo to Mars. That is a v. significant amount. 150t may be nothing in the world of Earth-sized infrastructure but we are talking about micro-communities on Mars, so - per capita - they will have a huge industrial infrastructure from the get-go. I think in the UK average waste is about 1 tonne per person...multiply that by say 20 to get your infrastructure and that gives you 20 tonnes per capita. If you have a six person mission to Mars, they will already be over 80 tonnes in terms of infrastructure on Mission One.

kbd512 wrote:

3. There's a robot that can do this, that, or the other quite well, but no single robot that can do all the tasks you just named off. For reasons pertaining to mass, someone will have to create a single robot that can do all of the things you just named off. That's why scientists are trying to create AI-enhanced anthropomorphic robots that are at least as good as humans are at a broad range of mundane tasks.

Well some industrial robots are already programmable multi-taskers. The real issue is that human labour will be the one thing in short supply on Mars. Whether it's nuclear or solar, energy won't be a problem. And for probably 80% of materials used on Earth, they will be there available for use on Mars. But human labour will be in short supply and that is why robots will be much more important on Mars than on Earth. It just makes much more economic sense, rather than trying to import lots of people from Earth.

kbd512 wrote:

4. 3D printing is an absolutely mandatory enabling technology because other fabrication methods require too many machines that weigh too much for a fledgling colony to afford to have delivered to them.

Glad we agree on something!

kbd512 wrote:

5. Apart from Allen, Bezos, Gates, and Musk, I see no other billionaires who are all that interested in space exploration. I'm just thankful that we have the handful that we do have.

NASA has probably put about $5 billion max. into lunar and Mars exploration since the Apollo missions. I think that puts it into context. The techogeeks have come in with billions behind them and revitalised space exploration. Even if Bezos isn't interested in Mars colonisation whatever he does in terms of orbital and lunar space will make Mars colonisation easier.

kbd512 wrote:

6. Private companies contribute little funding to highly speculative ventures because there's an inordinately high chance the ventures will fail.

I am not sure you understood what I meant here. Coca Cola has an annual marketing budget of about $3 billion. Nike, Adidas and other companies are in a similar league. NBC paid $4 billion for Olympics coverage over 8 years. The Mars Mission will be a huge sponsorship opportunity for companies and they will definitely want to be in. It's more a question of how Space X manages this huge investment. They need to maintain the integrity of the mission.

kbd512 wrote:

7. Energy is already a brake on merely getting started. To simply refuel a single BFR, hundreds of millions of dollars of space flight rated solar panels are necessary. You're clearly unaware of what these things cost. They're more expensive than small nuclear reactors.

Hundreds of millions of dollars split across six revenue-earning projects is really chicken feed! Once Space X are in the business of interplanetary travel these costs will fall dramatically. Most of the cost will have been development.

kbd512 wrote:

8. The only type of propulsion systems that are feasible for delivery of serious tonnage are the types that don't use fuel. To wit, only the electromagnetic sails have been flown in space and have any realistic hope of substantially reducing the propulsion mass requirements.

I think possibly you are failing to differentiate between cargo delivery and human delivery.

kbd512 wrote:

9. Apart from fabulously wealthy thrill seekers, it's not clear at all that anyone will spend their life savings to go to space. This is pure magical thinking on your part. The first colonists will have to be sponsored workers who construct the facilities for everyone else to use.

I wasn't actually arguing here for Mars tourism or arguing that huge numbers of people would be volunteering for permanent settlement in the early stages (on that I have never agreed with Musk). I was saying that the other near Earth tourism ventures will just make Mars a much more interesting prospect, especially for investors. Clearly for several years at least most residents on Mars will be "sponsored workers" as you put it. But it won't take long for huge revenue-earning enterprises to develop.

kbd512 wrote:

10. Presidents Clinton / Bush / Obama / Trump all talked a mighty big game regarding US space flight activities, but none have imposed a realistic deadline / mandate for NASA to achieve. Someone needs to light a fire under their rear ends to get them to moving towards a goal. I don't care if it's simply returning to the moon and eventually moving on to Mars, but it's past time to move forward.

As far as I am concerned NASA is out of the game as regards Mars and I think Trump has recognised that by essentially steering them towards a return to the Moon. Trump can't do much more given the nature of the pork barrel politics in the States.

louis · 2018-05-13 20:20:49

I like Ryan - he's very clear, good at explaining. And I agree that we can be hopeful we will see humans on Mars within the next ten years, given Space X's progress. However, I don't see much point in bigging up the InSight mission. It's a diversion as far as I am concerned and therefore a negative. NASA should be putting all their available resources into backing Space X's Mars Mission.

Oldfart1939 wrote:

Report by Ryan McDonald:
https://youtu.be/gnb9TLC803o

Oldfart1939 · 2018-05-13 20:50:05

louis wrote:

I like Ryan - he's very clear, good at explaining. And I agree that we can be hopeful we will see humans on Mars within the next ten years, given Space X's progress. However, I don't see much point in bigging up the InSight mission. It's a diversion as far as I am concerned and therefore a negative. NASA should be putting all their available resources into backing Space X's Mars Mission.
Oldfart1939 wrote:
Report by Ryan McDonald:
https://youtu.be/gnb9TLC803o

Louis-

I agree with your statement. NASA, however, is big on "not invented here."

kbd512 · 2018-05-14 04:31:07

Louis,

Point #1 - Perhaps, but cost sharing may be difficult. There will be a version of BFR for suborbital global transport, a tanker, a freighter, and a long duration space habitat version. If all of that seems like it mandates fundamentally different designs, that'd be because it does. Cost sharing is a TBD possibility, if and only if, substantial similarity between the different upper stages is possible and they are reusable with minimal maintenance and high average reliability.

Point #2 - Do the math on how much food 100 people need over one year. It's a big number.

ISS Astronaut Meal Weight Allowance:

.83kg/per meal * 3 meals per day * 100 people = 747kg/day

22,410kg/month

272,655kg/year

.12kg/per is packaging or trash

.12kg * 3 * 100 = 36kg/day

13,140kg of trash per year that must be recycled into new meal wrappers. Maybe we should think about bigger containers, rather than individually wrapped meals, considering how much every kilogram of material costs to send to Mars. I think you have to do this and you have to make food production a top priority, right behind oxygen and water.

Point #3 - So far as I'm aware, no such machine as I've described exists. It would take a DARPA level R&D effort to produce an AI-enabled robot with the basic feature set of a human. I would make this a priority for military and aerospace purposes. The US military and NASA needs a paramedic / engineer robot that can save lives and repair machinery. Apart from small aerial combat drones and bomb disposal robots with self-destruct programming that can't be overridden, I'm not in favor of ever giving any AI-enabled robot a weapon of any kind.

Point #4 - I don't post my responses simply to argue with you. I'm trying to instill in you, as best I know how, a form of cautious optimism tempered with knowledge of past research, development, and engineering programs to provide baseline understanding of how complex science and technology development projects typically proceed. In this age, humans don't go from never having sent a person somewhere to a colony without a lot of intermediary steps. There's a logical progression to the activities you advocate for.

Point #5 - I think Bezos is a realist who wants to build all the infrastructure required to do what Musk wants to do.

Point #6 - A Mars mission will be a huge sponsorship opportunity for companies who want to risk putting their name on a venture that may blow up in their faces. All space exploration missions are sponsored by industry. Advertisement opportunities are certainly possible, in the same sense that Red Bull plasters their logos all over their air racing endeavors.

Point #7 - I'm trying to tell you that the cost of the Orbital ATK solar panels that would be required to refuel a BFR is as much as the development cost was for Falcon Heavy. It's about half a billion dollars just to purchase the panels. These are the only panels guaranteed to work 100% of the time on Mars because no engineering detail or expense has been spared. Consequently, the panels are really expensive. Do you think any corporation that wants to continue its existence is going to risk having their rocket stranded on Mars to save money?

People will die if the power equipment fails as at any point in time. No government in the world will sanction a mission with untested power generation technology just to save a little money and with exceptionally good reason.

Point #8 - The MagSail people say they can get people and cargo to and from Mars in a maximum of 1 week when Mars is furthest away from Earth. Any space agency or corporation worth their salt won't spend one red cent on propellant and propulsion if it doesn't have to. The technology generates both power and propulsion. All spacecraft need power and propulsion and every kilogram of anything delivered to orbit costs real money. Do the math on how much money chemical propellants cost.

Point #9 - There's no way of telling whether or not any revenue-earning enterprises will develop. Nobody will ship anything from Mars to Earth unless the propulsion is essentially free. See my last point.

Point #10 - I seem to have misplaced my crystal ball, but if yours can predict the future then that's fantastic. This seems to be more chicken counting to me.

GW Johnson · 2018-05-14 13:40:22

I've seen the 3-D desktop printers that make stuff out of plastics. I've also seen 3-D printers that make small parts out of metals: great big heavy, high-dollar machines with substantial power draw. You don't make metal parts with little, lightweight, easy to ship across space machines. Not at this time in history, not yet.

The early 3-D metal parts had mechanical properties no better than cheap sintered-metal powder parts, which is really bad. In recent years, a tiny minority have figured out how to create full-density parts of near-wrought strength, but these folks admit they are still short on elongation. That means the parts are still brittle compared to wrought parts. Maybe not too brittle, but even so, the price tag is very high for this.

What I'm trying to say is that this is a wonderful technology, but it is not yet mature. And because the limitations it still has are exploitable, getting high-quality stuff is very, very expensive. And it takes big, heavy, power-hungry machines to make the good stuff, which is still of limited size. Not easily transportable across space. Not yet.

This will indeed be the future of building colonies. But not quite yet. I don't recommend that you start holding your breath for this. You're gonna turn very blue.

GW

Last edited by GW Johnson (2018-05-14 13:43:33)

louis · 2018-05-14 13:53:52

kbd512 wrote:

kbd
Point #1 - Perhaps, but cost sharing may be difficult. There will be a version of BFR for suborbital global transport, a tanker, a freighter, and a long duration space habitat version. If all of that seems like it mandates fundamentally different designs, that'd be because it does. Cost sharing is a TBD possibility, if and only if, substantial similarity between the different upper stages is possible and they are reusable with minimal maintenance and high average reliability.

Come on, Space X have said themselves these will be fundamentally the same rockets and ships, so clearly the other applications would be expected to pay off their share of basic development costs. Of course, a lot of the development costs - the Raptor engines and the propellant tank development, have already been sunk, one presumes (unless Space X have borrowed money to cover that).

kbd512 wrote:

Point #2 - Do the math on how much food 100 people need over one year. It's a big number.
ISS Astronaut Meal Weight Allowance:
.83kg/per meal * 3 meals per day * 100 people = 747kg/day
22,410kg/month
272,655kg/year
.12kg/per is packaging or trash
.12kg * 3 * 100 = 36kg/day
13,140kg of trash per year that must be recycled into new meal wrappers. Maybe we should think about bigger containers, rather than individually wrapped meals, considering how much every kilogram of material costs to send to Mars. I think you have to do this and you have to make food production a top priority, right behind oxygen and water.

I think you got your math wrong there. I make it 249 kgs per day for 100 people.
But I think 2.49 kgs per person per day is a bit of an overestimate in any case. I think the figure is nearer 1.5 kgs (unless you are including drinking water). A 10oz steak is under 250 grams - and that's a lot of meat. Furthermore, if you take a good proportion of dried foods and use recycled water, you will get a significant reduction on mass.

Nevertheless, I accept that food production will be a significant priority once we move beyond 10 people. I envisage that on Mars we will be growing most of our food fresh, apart from a few "treat meals" once or twice a week (imported from Earth). That will involve a significant power input as long as the farming is indoor.

kbd512 wrote:

Point #3 - So far as I'm aware, no such machine as I've described exists. It would take a DARPA level R&D effort to produce an AI-enabled robot with the basic feature set of a human. I would make this a priority for military and aerospace purposes. The US military and NASA needs a paramedic / engineer robot that can save lives and repair machinery. Apart from small aerial combat drones and bomb disposal robots with self-destruct programming that can't be overridden, I'm not in favor of ever giving any AI-enabled robot a weapon of any kind.

There are plenty of robots with impressive but discrete skill sets that could be very useful on a planet where human labour is in extreme shortage e.g.
https://www.youtube.com/watch?v=mKCVol2iWcc
In terms of robot activity, our approach needs to be to design in robot use.
There is no need to develop a human-copy robot.

kbd512 wrote:

Point #4 - I don't post my responses simply to argue with you. I'm trying to instill in you, as best I know how, a form of cautious optimism tempered with knowledge of past research, development, and engineering programs to provide baseline understanding of how complex science and technology development projects typically proceed. In this age, humans don't go from never having sent a person somewhere to a colony without a lot of intermediary steps. There's a logical progression to the activities you advocate for.

I would place the emphasis elsewhere…there are also times when everything comes together. The technology for PC computers and the internet was there in the 1970s but the real explosion in use came in the late 80s/early 90s. My view is that, subject to successful BFR development, we are now at a similar tipping point.

kbd512 wrote:

Point #5 - I think Bezos is a realist who wants to build all the infrastructure required to do what Musk wants to do.

Well Space X are out in front at the moment I would say. But the more the merrier.

kbd512 wrote:

Point #6 - A Mars mission will be a huge sponsorship opportunity for companies who want to risk putting their name on a venture that may blow up in their faces. All space exploration missions are sponsored by industry. Advertisement opportunities are certainly possible, in the same sense that Red Bull plasters their logos all over their air racing endeavors.

I imagine companies will buy options, and that if the Mission testing is successful they will go live with their sponsorship.

kbd512 wrote:

Point #7 - I'm trying to tell you that the cost of the Orbital ATK solar panels that would be required to refuel a BFR is as much as the development cost was for Falcon Heavy. It's about half a billion dollars just to purchase the panels. These are the only panels guaranteed to work 100% of the time on Mars because no engineering detail or expense has been spared. Consequently, the panels are really expensive. Do you think any corporation that wants to continue its existence is going to risk having their rocket stranded on Mars to save money?
People will die if the power equipment fails as at any point in time. No government in the world will sanction a mission with untested power generation technology just to save a little money and with exceptionally good reason.

I am will to bet that the vast majority of that $500 million is development costs. We will now be in the marginal cost zone.
Space X already use PV panels on the Dragon. Never heard of them failing.

kbd512 wrote:

Point #8 - The MagSail people say they can get people and cargo to and from Mars in a maximum of 1 week when Mars is furthest away from Earth. Any space agency or corporation worth their salt won't spend one red cent on propellant and propulsion if it doesn't have to. The technology generates both power and propulsion. All spacecraft need power and propulsion and every kilogram of anything delivered to orbit costs real money. Do the math on how much money chemical propellants cost.

Chemical propellants are not a large proportion of overall mission costs. Development costs, rocket construction and ground control are the biggies.

kbd512 wrote:

Point #9 - There's no way of telling whether or not any revenue-earning enterprises will develop. Nobody will ship anything from Mars to Earth unless the propulsion is essentially free. See my last point.

There are plenty of things that can be exported from Mars beginning with regolith, meteorites, unusual minerals, luxury watches, lightweight luxury clothing, and Mars souvenirs.
People often make the mistake of thinking that the Mars settlement cannot subsidise transit, but they can using either a convertible currency or dollars if dollars circulate within the settlement.

kbd512 wrote:

Point #10 - I seem to have misplaced my crystal ball, but if yours can predict the future then that's fantastic. This seems to be more chicken counting to me.

Well it’s high time the chickens were counted, I think.

louis · 2018-05-14 14:57:54

Looks like the technology is moving in the right direction...

https://www.digitaltrends.com/cool-tech … ine-grade/

We will have to see to what extent 3D printers can provide metal parts. CNC machines and industrial robots will probably be just as important or more important in the early stages. But clearly they will be v. useful for plastic parts.

I'd be interested in whether a small-scale blast furnace could be used on Mars to make steel. We have the carbon, the iron ore...calcium carbonate may be more difficult to source. But looking at YT videos of amateurs, professional craftspeople and big industrial concerns, I think something that can deliver molten steel in the 10s of kgs range would useful.

GW Johnson wrote:

I've seen the 3-D desktop printers that make stuff out of plastics. I've also seen 3-D printers that make small parts out of metals: great big heavy, high-dollar machines with substantial power draw. You don't make metal parts with little, lightweight, easy to ship across space machines. Not at this time in history, not yet.
The early 3-D metal parts had mechanical properties no better than cheap sintered-metal powder parts, which is really bad. In recent years, a tiny minority have figured out how to create full-density parts of near-wrought strength, but these folks admit they are still short on elongation. That means the parts are still brittle compared to wrought parts. Maybe not too brittle, but even so, the price tag is very high for this.
What I'm trying to say is that this is a wonderful technology, but it is not yet mature. And because the limitations it still has are exploitable, getting high-quality stuff is very, very expensive. And it takes big, heavy, power-hungry machines to make the good stuff, which is still of limited size. Not easily transportable across space. Not yet.
This will indeed be the future of building colonies. But not quite yet. I don't recommend that you start holding your breath for this. You're gonna turn very blue.
GW

Last edited by louis (2018-05-15 04:10:28)

kbd512 · 2018-05-14 16:41:45

Louis,

You're right, I did mess up the math for the food mass. I was tired and I'm sick, but couldn't sleep. The .83kg number comes from the meal mass allocation used for sustaining astronauts aboard ISS. It's still more food for two years than a BFR can carry. Even so, food production is still right behind oxygen and water production in order of importance. I agree that there are ways to reduce that mass. For example, NASA is testing meal replacement bars for breakfast to cut down on weight and make eating breakfast faster and cleaner. Right now, NASA is using the US Army's expertise to lighten the meals.

Regarding the solar panels, please find out who makes them. You can actually purchase solar panels for cube satellites online, but the costs are substantial. I reviewed the past contract costs for solar panels and output requirement to arrive at those figures and the reason the costs are so high is that space PV applications are in a state of constant development. The contract money pays for further development and refinement. Orbital ATK has this down to a science and their product is guaranteed to work. There's never been a failure, and no better performance track record exists than a 100% success rate.

Costs will come down when solar cells are 3D printed on a flexible substrate, but that's it. The technology is just expensive, as all advanced power production technologies are, and that's all there is to it. I'm not saying it's not worth spending the money on. I'm saying it's really expensive and that point has to be taken into consideration. US government excepted, $500M isn't chump change.

My point about chemical propellants has nothing to do with the cost of the product. Putting that product into orbit is the problem. If you never needed any substantial quantity of fuel to go to and from Mars once you're in orbit and could make the transit in a week or less, irrespective of Mars / Earth orbital alignments, then why would you expend the money / time / effort to make round trips in substantially slower chemically powered BFR's that require tons of fuel?

What if you could deliver a BFR fuel tanker to Mars orbit with all of its LOX/LCH4 aboard using a MagSail and just use that tanker to refuel BFR's in orbit to continually transfer passengers and cargo to the surface of Mars?

What if you had a split Mars fleet and Earth fleet of BFR's and used the Sun to obtain both power and propulsion without using fuel?

A MagSail is just an electromagnet that uses the energy output of the Sun to both provide power and propulsion.

louis · 2018-05-14 17:07:38

kbd512 wrote:

Louis,
You're right, I did mess up the math for the food mass. I was tired and I'm sick, but couldn't sleep. The .83kg number comes from the meal mass allocation used for sustaining astronauts aboard ISS. It's still more food for two years than a BFR can carry. Even so, food production is still right behind oxygen and water production in order of importance. I agree that there are ways to reduce that mass. For example, NASA is testing meal replacement bars for breakfast to cut down on weight and make eating breakfast faster and cleaner. Right now, NASA is using the US Army's expertise to lighten the meals.

Sorry to hear you haven't been well. Hope you feel better soon.

I think if 0.83 kg represents a "meal" it probably includes liquid drinks then which can add a lot of mass. I doubt people are eating the equivalent of ten 10z steaks per day in terms of mass (which the 0.83 kg per meal figure implies). If it does include liquid drinks, then of course a lot of that can be covered by water recycling, which requires no additional mass, just power.

Upping intake of oils like olive oil will also reduce mass. They are incredibly calorific.

kbd512 wrote:

Regarding the solar panels, please find out who makes them. You can actually purchase solar panels for cube satellites online, but the costs are substantial. I reviewed the past contract costs for solar panels and output requirement to arrive at those figures and the reason the costs are so high is that space PV applications are in a state of constant development. The contract money pays for further development and refinement. Orbital ATK has this down to a science and their product is guaranteed to work. There's never been a failure, and no better performance track record exists than a 100% success rate.

I am myself sure that Orbital ATK will be part of the energy solution.

kbd512 wrote:

Costs will come down when solar cells are 3D printed on a flexible substrate, but that's it. The technology is just expensive, as all advanced power production technologies are, and that's all there is to it. I'm not saying it's not worth spending the money on. I'm saying it's really expensive and that point has to be taken into consideration. US government excepted, $500M isn't chump change.

PV panel costs have reduced at a precipitous rate since the late 70s and there is no suggestion that we have reached maturation with the technology:

https://www.google.co.uk/search?q=photo … yaPYPc1gwM:

kbd512 wrote:

My point about chemical propellants has nothing to do with the cost of the product. Putting that product into orbit is the problem. If you never needed any substantial quantity of fuel to go to and from Mars once you're in orbit and could make the transit in a week or less, irrespective of Mars / Earth orbital alignments, then why would you expend the money / time / effort to make round trips in substantially slower chemically powered BFR's that require tons of fuel?
What if you could deliver a BFR fuel tanker to Mars orbit with all of its LOX/LCH4 aboard using a MagSail and just use that tanker to refuel BFR's in orbit to continually transfer passengers and cargo to the surface of Mars?
What if you had a split Mars fleet and Earth fleet of BFR's and used the Sun to obtain both power and propulsion without using fuel?
A MagSail is just an electromagnet that uses the energy output of the Sun to both provide power and propulsion.

Well I only take into account proven or close to fruition technology.

I am sure MagSail or similar will eventually come into existence, as will space elevators, solar power satellite energy generation, and laser propulsion for launches. But I think there will be an economic boom on Mars even with old fashioned chemical propulsion, Space X having changed the economics via reuse essentially.

kbd512 · 2018-05-14 19:03:10

The food could undoubtedly be made lighter and their are NASA efforts underway to make that happen.

We're not using backyard solar panels on Mars. Space flight rated panels are not yet commodities. We're always going to be using the best that money can buy, so the falling manufacturing costs associated with the commodity panels is not applicable here. All space rated arrays are hand selected and hand built. There is no economy of scale to be had. That's why I said it was necessary to print arrays on flexible substrates. The cost, mass, and output of these systems needs to come to a point where they don't represent more cost than the rocket.

YBCO superconducting electromagnets are extremely well proven technology. This is a novel use of that technology, but it dramatically increases the payload fraction and dramatically lowers the cost to go somewhere because there is little associated propellant required to get from Earth orbit to Mars orbit. Here on Earth, cargo ships carry the vast majority of cargo between the continents. Space is an ocean of vacuum more vast than we can dream of, the "continents" are "planets" and we must carry massive loads across the ocean to do what Mr. Musk wants to do in any reasonable time frame. I don't want to ship 150t of cargo to Mars at a time. I want to ship 1,500t of cargo at a time and deliver it to the surface in 150t loads.

BFR-C - Cargo; orbit-to-surface cargo transport
BFR-F - Freighter; maximum cargo volume
BFR-P - Passengers; same pressurized volume as cargo, but equipped for long term habitation
BFR-T - Tanker; maximum propellant tankage

At Earth:
BFR-C delivers ten 150t loads to MagSail equipped BFR-F
BFR-P delivers 100 colonists to Mars using MagSail
BFR-T delivers LOX/LCH4 to MagSail equipped BFR-T

At Mars:
BFR-T stays in orbit and only leaves to return to Earth for refueling in LEO after BFR-C empties the fuel
BFR-F stays in orbit and BFR-C flies to and from Mars delivering the cargo from BFR-F in 150t loads
BFR-P transfers the colonists to BFR-C for immediate delivery to the surface of Mars

BFR-F and BFR-T eventually return to Earth, but BFR-C stays on Mars to continue making deliveries.

This scheme requires the following:

1 BFR-C for orbit-to-surface transport of cargo
1 BFR-F for orbit-to-orbit transport of cargo
1 BFR-P equipped for orbit-to-orbit transport of humans
2 BFR-T; one to refuel the other and the other equipped to refuel the BFR-C in Mars orbit
* 1 BFR-T stays on Earth and refuels the BFR-T that stays in orbit
* 1 goes to Mars and stays there to refuel BFR-C until deliveries are complete before returning to Earth for refueling

Thus, a series of 5 of these ships and MagSails, or perhaps a few more tankers, can make continuous trips

BFR-P is lightly loaded to make very fast transits
BFR-C, BFR-F, and BFR-T leave before the BFR-P and travel slower since they are much more heavily laden like true cargo ships

Last edited by kbd512 (2018-05-14 19:05:05)

Oldfart1939 · 2018-05-15 09:18:26

When I was in the Army, we occasionally ate things called "10 in 1 rations," instead of individual K rations on field exercises. That is, enough food in a serving to feed 10 hungry troopers. Stuff like baked beans, macaroni & cheese, scalloped potatoes, beef stew, etc. In my mind, having individual meals goes a bit heavy on the packing , and then the energy required to heat up 10 different things must also be considered. A 10 in 1 was exactly what an infantry squad could consume, and was very efficient, since it didn't waste time in the preparation of a meal. I seem to recall having roast beef slices in gravy, as well.

I've commented on necessary food elsewhere, but will repeat it here. All humans require approximately 2 % of their body weight daily as food intake. That is, a 200 pounder such as myself, needs 4 pounds of chow daily. There isn't any getting around it by "lighter rations," since these lighter rations usually need additional water for preparation. This 2% is food ready for consumption, not anything else. I use this number because it's a diet for those engaged in physical activity, not sitting in front of a screen somewhere. I don't know how many here have ever subsisted on MRE rations? They are specifically designed for short term use, and are terribly constipating; not really a good feature for long term health.

Last edited by Oldfart1939 (2018-05-15 09:19:21)

elderflower · 2018-05-15 09:33:49

Long distance, competitive solo sailors use dried packaged food. Their trips can take a couple of months or more (for example the Vendee Globe, round the world no-stop race. Obviously they don't need to recycle water, but they do need to desalinate it. In the boats they use weight is a major issue. As much of the race takes place in cold areas like the Southern Ocean and the North Atlantic, and is very physically demanding, they almost certainly need a lot more calories than our Martian Astronauts will. The nutritional problems thrown up by this kind of activity have already been solved.

GW Johnson · 2018-05-15 09:56:02

These freeze-dried camp and survivalist foods are lightweight, compact, and can be very tasty. They last for many years. They do require copious water, and free-surface cooking is required to get the tastiness correct. Free-surface water cooking simply requires artificial gravity, and an atmospheric pressure not all that different from air at sea level to 10,000 feet or so. Although a pressure cooker can compensate for lower atmospheric pressures.

The key here is "free-surface cooking" = "artificial gravity". The astronaut foods that you just heat in the packet just do NOT last as long as real freeze-dried stuff. So do the spin gravity, provide good food that really will last decades, and simplify your plumbing. You only need a few zero gee toilets temporarily, while maneuvering or docking. You do need a modified conventional toilet seat to contain the water while at zero gee, though. Relatively minor change.

And, if you have spin gravity for free-surface cooking, you can also use frozen foods. These can also be part of your radiation shield, because of the ice content in the frozen food. Which will also last for multiple years.

THAT is part of why I am such a fan of practical spin gravity schemes. The rest has to do with ethics: crew health. But y'all already know that.

GW

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