I agree it won’t be as important as autonomy. I think even in the optimistic loads-of-manufacturing-and-asteroid-mining case, the effect on the economy would be an order of magnitude less than the effect of autonomy.
FWIW, I don’t agree with your calculation of $220,000 for a trip to space. That’s $200,000 of preflight screening and training, $6,000 for the mass of the passenger and the five-times-larger mass of all the seating, food, etc. that supports them, and the rest for crew etc. But this seems way too high to me: Why should crew cost more than passenger, per passenger? The cost of inspections is already factored in to Musk’s $10/kg figure. And most of all, why should training and screening cost $200,000? We don’t have to undergo anything nearly that intense to go on an international flight.
I was thinking of the cost to design and launch the space hotel to visit, the cost of operations for the vast company needed to support all this, and so on. On further thought, I think I will agree with you partially and reduce those overheads for the sake of argument. But the crew dragon is 12055 kg to launch 90*6 astronauts of payload. Or a 20:1 ratio of spacecraft mass to crew mass. Going bigger to a 100-seat spacecraft does allow for a better ratio, but it would still be at least 10:1. So if a person weighs 90 kg (average adult), they need 900 kg worth of spacecraft to visit the space hotel. Or $9000 for the single person transit costs. Plus the cost to launch and maintain the hotel and launch vehicles.
I don’t know what the other costs are going to be, just they will be governed by the high cost to reach orbit as well as very expensive mishaps whenever a rocket blows up or crashes, which will still happen at this scale. So maybe 50-100k per person for a week in space?
I’m pretty sure the $10/kg to LEO figure already takes the mass of the Starship into account. It’s $10/kg of cargo delivered to LEO, the weight of the spacecraft does not count towards the cargo weight.
Look, not only is SpaceX taking point-to-point travel on Earth seriously, the US military is too. If the sorts of numbers you are giving were correct, how would this make sense?
Well, the other way to check if I am right or wrong is to back calculate the rocket equation. Instead of relying what I say, what’s the payload mass to propellant mass of the BFR? Saturn V (the rocket equation is the same for the BFR, and it is using recoverable boosters and a compromise fuel (liquid CH4) so I expect it to perform slightly worse) it’s 6.5 million pounds total rocket mass, 85% payload, to 261,000 lbs to LEO. So 4% of the mass is payload, 85⁄4 = 21.25 kg of propellant for every kilogram of payload.
Ok, CH4 + 202 = CO2 + 2H20
1⁄3 of the mass is the CH4, while 2⁄3 is O2. That helps a lot as liquid oxygen is cheaper, only 16 cents per kilogram. So $2.26 for the liquid oxygen.
Well, how much does 7.08kg of liquid methane cost? (note that BFR needs purified methane and cannot use straight natural gas)
2.757 gge * 1.14 = 3.14 therm. Average prices presently per therm are $0.92. So $2.89 for the unpurified fuel. Then you need to purify it to pure methane (obviously with some loss of energy/gas/filter media) and liquify it. I am going to assume this raises the cost 50%. So $4.33 for the natural gas. Total cost per kg for the fuel is $4.33+2.26 = $6.59.
$10 a kg for payload to LEO, including the rocket, seems rather optimistic. Remember the rocket needs repair and will occasionally blow up. Helicopters and other much lower energy terrestrial machines, the maintenance + repairs are often either similar or more expensive than the price of the fuel. I would expect the real minimum cost per kg to be at least 3 times the cost of fuel: 2 units of repair/replacing exploded rocket parts for every kg of propellant. Or $19.78 per kg, which would be phenomenal results compared to today’s $2720 a kg (using spaceX now), and just half as good as Elon Musk’s promise.
Hard laws of nature here. I want to go to space as well but it takes a literal swimming pool of fuel under you to do it, and while SpaceX has made some impressive advances, it doesn’t change the basic parameters of the problem.
In the rocket industry, the ‘payload’ is the piece that reached orbit. That is how it is defined. You technically can occupy the entire upper portion of a Dragon spacecraft (the entire section above the second stage inside the fairing) with your mega-satellite. That entire satellite is ‘payload’ and the source of the ‘payload to LEO/geostationary orbit’ that gets quoted as the capability of the spacecraft.
You have to assume that “$10” figure is the lowest number possible, which means Musk is accounting for the entire payload.
That is a reasonable argument, but I think I’m still right: According to wikipedia, the starship’s payload to orbit capacity will be 100,000 kg, and the starship by itself, completely empty, weighs 120,000 kg. So it is impossible that the mass of the starship be included in the calculation of payload capacity, even though the starship does reach orbit.
So we can calculate the (optimistic) price per kg to orbit as follows: 100,000 kg per launch of Starship, cost per launch of Starship = cost of fuel + cost of vehicle + maintainance, I remember reading somewhere that the cost of fuel will be around $1M give or take a factor of 2, cost of vehicle is said by OP to be $5M, so basically $0 amortized over even just a few dozen launches… yeah it looks entirely plausible that it could be about $2M per 100,000 kg to orbit, which comes out to $20/kg. And if the price of fuel or maintainence drops it could go even lower.
EDIT: Now I see your calculation above. So fuel costs only $6.59 per kg of payload? That’s awesome! It’s actually less than $1M! So yeah, the $10/kg figure seems like a reasonable optimistic (i.e. in the long run, after all the kinks are worked out and economies of scale realized) estimate. I think we’ll hit it in 15 years, give or take 10.
The article I cited above suggests that Musk sees fuel costs as 900,000$/per lunch and total costs as 2,000,000$ per lunch which indicates $20/kg as payload costs.
I don’t think $10/kg will be achieved with starship but it might be with the next iteration that can afford to build even bigger rockets. Plans to produce the methan onsite with solar cells might also reduce propellent costs.
I agree it won’t be as important as autonomy. I think even in the optimistic loads-of-manufacturing-and-asteroid-mining case, the effect on the economy would be an order of magnitude less than the effect of autonomy.
FWIW, I don’t agree with your calculation of $220,000 for a trip to space. That’s $200,000 of preflight screening and training, $6,000 for the mass of the passenger and the five-times-larger mass of all the seating, food, etc. that supports them, and the rest for crew etc. But this seems way too high to me: Why should crew cost more than passenger, per passenger? The cost of inspections is already factored in to Musk’s $10/kg figure. And most of all, why should training and screening cost $200,000? We don’t have to undergo anything nearly that intense to go on an international flight.
I was thinking of the cost to design and launch the space hotel to visit, the cost of operations for the vast company needed to support all this, and so on. On further thought, I think I will agree with you partially and reduce those overheads for the sake of argument. But the crew dragon is 12055 kg to launch 90*6 astronauts of payload. Or a 20:1 ratio of spacecraft mass to crew mass. Going bigger to a 100-seat spacecraft does allow for a better ratio, but it would still be at least 10:1. So if a person weighs 90 kg (average adult), they need 900 kg worth of spacecraft to visit the space hotel. Or $9000 for the single person transit costs. Plus the cost to launch and maintain the hotel and launch vehicles.
I don’t know what the other costs are going to be, just they will be governed by the high cost to reach orbit as well as very expensive mishaps whenever a rocket blows up or crashes, which will still happen at this scale. So maybe 50-100k per person for a week in space?
I’m pretty sure the $10/kg to LEO figure already takes the mass of the Starship into account. It’s $10/kg of cargo delivered to LEO, the weight of the spacecraft does not count towards the cargo weight.
Look, not only is SpaceX taking point-to-point travel on Earth seriously, the US military is too. If the sorts of numbers you are giving were correct, how would this make sense?
Well, the other way to check if I am right or wrong is to back calculate the rocket equation. Instead of relying what I say, what’s the payload mass to propellant mass of the BFR? Saturn V (the rocket equation is the same for the BFR, and it is using recoverable boosters and a compromise fuel (liquid CH4) so I expect it to perform slightly worse) it’s 6.5 million pounds total rocket mass, 85% payload, to 261,000 lbs to LEO. So 4% of the mass is payload, 85⁄4 = 21.25 kg of propellant for every kilogram of payload.
Ok, CH4 + 202 = CO2 + 2H20
1⁄3 of the mass is the CH4, while 2⁄3 is O2. That helps a lot as liquid oxygen is cheaper, only 16 cents per kilogram. So $2.26 for the liquid oxygen.
Well, how much does 7.08kg of liquid methane cost? (note that BFR needs purified methane and cannot use straight natural gas)
Well, 1.14 Therm = 1 gge = 5.660 lb. So 21.25kg = 15.61 pound, 15.61 pound/5.660 = 2.757 gge.
2.757 gge * 1.14 = 3.14 therm. Average prices presently per therm are $0.92. So $2.89 for the unpurified fuel. Then you need to purify it to pure methane (obviously with some loss of energy/gas/filter media) and liquify it. I am going to assume this raises the cost 50%. So $4.33 for the natural gas. Total cost per kg for the fuel is $4.33+2.26 = $6.59.
$10 a kg for payload to LEO, including the rocket, seems rather optimistic. Remember the rocket needs repair and will occasionally blow up. Helicopters and other much lower energy terrestrial machines, the maintenance + repairs are often either similar or more expensive than the price of the fuel. I would expect the real minimum cost per kg to be at least 3 times the cost of fuel: 2 units of repair/replacing exploded rocket parts for every kg of propellant. Or $19.78 per kg, which would be phenomenal results compared to today’s $2720 a kg (using spaceX now), and just half as good as Elon Musk’s promise.
Hard laws of nature here. I want to go to space as well but it takes a literal swimming pool of fuel under you to do it, and while SpaceX has made some impressive advances, it doesn’t change the basic parameters of the problem.
In the rocket industry, the ‘payload’ is the piece that reached orbit. That is how it is defined. You technically can occupy the entire upper portion of a Dragon spacecraft (the entire section above the second stage inside the fairing) with your mega-satellite. That entire satellite is ‘payload’ and the source of the ‘payload to LEO/geostationary orbit’ that gets quoted as the capability of the spacecraft.
You have to assume that “$10” figure is the lowest number possible, which means Musk is accounting for the entire payload.
That is a reasonable argument, but I think I’m still right: According to wikipedia, the starship’s payload to orbit capacity will be 100,000 kg, and the starship by itself, completely empty, weighs 120,000 kg. So it is impossible that the mass of the starship be included in the calculation of payload capacity, even though the starship does reach orbit.
So we can calculate the (optimistic) price per kg to orbit as follows: 100,000 kg per launch of Starship, cost per launch of Starship = cost of fuel + cost of vehicle + maintainance, I remember reading somewhere that the cost of fuel will be around $1M give or take a factor of 2, cost of vehicle is said by OP to be $5M, so basically $0 amortized over even just a few dozen launches… yeah it looks entirely plausible that it could be about $2M per 100,000 kg to orbit, which comes out to $20/kg. And if the price of fuel or maintainence drops it could go even lower.
EDIT: Now I see your calculation above. So fuel costs only $6.59 per kg of payload? That’s awesome! It’s actually less than $1M! So yeah, the $10/kg figure seems like a reasonable optimistic (i.e. in the long run, after all the kinks are worked out and economies of scale realized) estimate. I think we’ll hit it in 15 years, give or take 10.
The article I cited above suggests that Musk sees fuel costs as 900,000$/per lunch and total costs as 2,000,000$ per lunch which indicates $20/kg as payload costs.
I don’t think $10/kg will be achieved with starship but it might be with the next iteration that can afford to build even bigger rockets. Plans to produce the methan onsite with solar cells might also reduce propellent costs.