Elon Musk on BBC Radio 4 - Mars for $250-500,000K

[DLR]

http://www.bbc.co.uk/news/health-17439490

"My vision is for a fully reusable rocket transport system between Earth and Mars that is able to re-fuel on Mars - this is very important - so you don't have to carry the return fuel when you go there," he said.

"The whole system [must be] reusable - nothing is thrown away. That's very important because then you're just down to the cost of the propellant.

"We will probably unveil the overall strategy later this year in a little more detail, but I'm quite confident that it could work and that ultimately we could offer a round trip to Mars that the average person could afford - let's say the average person after they've made some savings."

Elon Musk believes it is possible to drop space launch costs by several orders of magnitude, so that a one-way trip to Mars becomes affordable to a middle class person, opening the planet up for colonization by determined individuals and private foundations.

How could such a "ticket price" become a reality? What are the technological requirements?

My thoughts are:

1) Fully Reusable Earth-to-Orbit transportation system operating in an airplane-like fashion, with total flight costs no higher than 10x the propellant costs.

This translates to around $100 per kg to orbit. 

2) LEO to L2 ferry, running on propellant delivered from Earth or the Moon (if cheap enough, for lunar-derived propellants it would be difficult to compete with $100 per kg to orbit)

3) SEP ferry or cycler to Mars

5) fully reusable Mars lander with propellant sourced from Mars or Phobos.

A problem I see: it will be difficult for such a transportation system to return the initial investment quickly enough because of the limited launch windows for Mars.


Any thoughts on that matter?

[Jim Davis]

Any thoughts on that matter?

The price will only fall to those levels if there is demand for those services at much higher prices. The 1,000,000th Mars colonist might only have to pay $500,000 but the first ones will be paying (or someone will be paying) orders of magnitude higher.

The computer analogy is helpful here. Sure, the cost of processor speed, memory, etc are very low today but only because people were willing to pay orders of magnitude higher prices in the past.

I think Musk is kidding himself if he thinks the first Mars colonists can be sent for $500,000/head.

[go4mars]

I think Musk is kidding himself if he thinks the first Mars colonists can be sent for $500,000/head.

Musk guessed at this price as being 10 years after the first colonists and predicted that the first people would be paying a lot more. 

[go4mars]

1) Fully Reusable Earth-to-Orbit transportation system operating in an airplane-like fashion, with total flight costs no higher than 10x the propellant costs.

If you mean in terms of reusability and turnaround, then I agree.  If you mean horizontal takeoff and landing, then I disagree. 

This translates to around $100 per kg to orbit. 

Methane is a lot cheaper than jet fuel! 

2) LEO to L2 ferry, running on propellant delivered from Earth or the Moon (if cheap enough, for lunar-derived propellants it would be difficult to compete with $100 per kg to orbit)

I think it will be a direct-throw reusable rocket.  A really BFR.  Multiple nearly identical systems will be launched and collected in orbit over the course of ~2 years.  These parts will have 3 components.  The big, wide upper stage, a transfer module for people to live in en route, and a base system which will stay on Mars for 1-way ticket purchasers.  The transfer module will land also, and provide amenities to be a crude base for the duration.  If it is a 2-way ticket, the base module will not be included (other stuff/supplies will go instead).  A few days before maximum orbital conditions for a Hohman transfer, dragon capsules stuffed with people will fly to these on-orbit systems, attach, and folks will embark in the transit module; leaving for Mars, and bringing their dragons.  The whole works will land on Mars in separate pieces.  The dragon will land separately from the US and the base module and the transit module (but very close to eachother).  During the stay, the components refuel (ISRU from the atmosphere), to be able to launch back.  Then dragon will fly back to the top of the US and the US once refueled will send the dragon and transit module back to orbit.  Part of the reason that the in-space transfer module makes it to the surface as well, is for added redundancy and simplicity. It also has an ISRU methane system.  A large part of the in-transit module doubles as a proppellant tank (similar to wet lab ideas).  I think all three returning parts will land on Earth.   The US, the dragon, and the transfer module.  The transfer module will need to be cleaned and re-stocked.  That might happen in space, but I think it would be simpler (cheaper) to land it. 

Eventually, once demand is really well proven, a large, very high isp cycler will be constructed, capable of taking large amounts of people and equipment much less expensively.  The return journey to Earth may include some stuff from Mars (rather than sending it mostly empty). 

What do you think doctor?

[go4mars]

3) SEP ferry or cycler to Mars

Eventually.  But I don't see that as part of the current architecture.  I would be happy to be wrong though!  Argon is really cheap on Mars for example (1.6% of the atmosphere).

5) fully reusable Mars lander with propellant sourced from Mars or Phobos.

What kind of propellant do you think Phobos has?

A problem I see: it will be difficult for such a transportation system to return the initial investment quickly enough because of the limited launch windows for Mars.

Indeed.  Needs a philanthropic multi-billionaire.  Elon isn't rich enough for this yet.  But I think he will be. 

If he cracks the reusability nut, he will be.  If he doesn't, he can still do a lot with money that he is growing in Tesla and Solar City. 

[yamato]

I think there are three key komponents, that for sure are part of his vision: reusable rockets, methane propulsion and ISRU.

They are connected with each other - for reusable rockets, you appreciate better Isp, to make the necessary weight trade-offs. Methane has better Isp than kerosene, and is cheaper. For ISRU, you need fuel that can be from mars resources, which is methane. If you already use it in rockets, better for you.

[Aeroman]

Would more launch windows open up as well as shortened transit times and radiation exposure if the VASIMIR enginer proves out?

Aeroman

[go4mars]

Would more launch windows open up as well as shortened transit times and radiation exposure if the VASIMIR enginer proves out?

Aeroman

http://www.marssociety.org/home/press/tms-in-the-news/thevasimrhoax

[MP99]

1) Fully Reusable Earth-to-Orbit transportation system operating in an airplane-like fashion, with total flight costs no higher than 10x the propellant costs.

This translates to around $100 per kg to orbit.

If each person needs 5t of supplies for the round trip, that would consume the whole budget just in launch-to-LEO.

cheers, Martin

[MP99]

Any thoughts on that matter?

The price will only fall to those levels if there is demand for those services at much higher prices. The 1,000,000th Mars colonist might only have to pay $500,000 but the first ones will be paying (or someone will be paying) orders of magnitude higher.

The computer analogy is helpful here. Sure, the cost of processor speed, memory, etc are very low today but only because people were willing to pay orders of magnitude higher prices in the past.

I think Musk is kidding himself if he thinks the first Mars colonists can be sent for $500,000/head.

That's supposed to be ten years in.

I'm afraid I don't see how the price could come down that far that fast (opportunities are so far apart that you can only recover fixed costs very slowly, and it seems unlikely hundreds of people would choose to invest those sort of figures to move somewhere as part of nearly-the-first-wave).

cheers, Martin

[Robotbeat]

I think it's possible for a Mars trip to get down to half a million, but incredibly unlikely to occur within the next 2 or 3 decades. As Musk likes to say, the physics says it's possible, that doesn't mean it will happen.

[go4mars]

it seems unlikely hundreds of people would choose to invest those sort of figures to move somewhere as part of nearly-the-first-wave).

Pure speculation, but if the first 100 customers could do it for $10 million each, and the ticket was round trip, I bet that first $1 billion would show up.  This assumes that the big first stage booster would already exist (rightly or not). 

There are more than 1 million decamillionaires (people who could financially afford this scenario).  So 1 in 10000 of people who could afford it would need to go (in the first & expensive wave).  Remember, this assumes fully reusable hardware.  So if the first wave of 100 people went, they would probably bear the brunt of expense for building the first trip. 

In the 2 years between, the reusable first stage booster would need to find a new market (like hypersonic ballistic point to point travel on Earth and/or near earth space tourism) to help offset costs. 

The next round would probably cost the same because the hardware from trip one hasn't come back yet (I think).  But on trip 3 and 4 (conjunctions 3&4), there would be 200 people going, with perhaps an averaged cost of $5 million (because the first stuff gets reused in addition to new equipment).  etc.  Things snowball cheaper as more hardware is able to be reused, and production and operations optimizations are made (I'll assume these savings get offset by stuff that gets used up like food).   

Trips 5 & 6 would have 2 sets of used hardware and one set of new.  So $3.3 million/person for the 300 people going.  Trips 7&8 would have 400 people and cost $2.5 million.  Trip 9&10 have 500 people and cost $2 million.  Trip 11&12 cost $1.6 million/person....trip 39 & 40 cost $500000/person.  The target. 

Or better yet...  If trip consumables cost $500k, and no new hardware is made after the first trip, then the trip on conjunction 3 (about 10 years...) costs only $500k. 


If you don't like this analysis, bump up the costs and try again as you see fit (but you must assume reusability as a baseline). 

[LegendCJS]

it seems unlikely hundreds of people would choose to invest those sort of figures to move somewhere as part of nearly-the-first-wave).

Pure speculation, but if the first 100 customers could do it for $10 million each, and the ticket was round trip, I bet that first $1 billion would show up.  This assumes that the big first stage booster would already exist (rightly or not). 

There are more than 1 million decamillionaires (people who could financially afford this scenario).  So 1 in 10000 of people who could afford it would need to go (in the first & expensive wave).  Remember, this assumes fully reusable hardware.  So if the first wave of 100 people went, they would probably bear the brunt of expense for building the first trip. 

In the 2 years between, the reusable first stage booster would need to find a new market (like hypersonic ballistic point to point travel on Earth and/or near earth space tourism) to help offset costs. 

The next round would probably cost the same because the hardware from trip one hasn't come back yet (I think).  But on trip 3 and 4 (conjunctions 3&4), there would be 200 people going, with perhaps an averaged cost of $5 million (because the first stuff gets reused in addition to new equipment).  etc.  Things snowball cheaper as more hardware is able to be reused, and production and operations optimizations are made (I'll assume these savings get offset by stuff that gets used up like food).   

Trips 5 & 6 would have 2 sets of used hardware and one set of new.  So $3.3 million/person for the 300 people going.  Trips 7&8 would have 400 people and cost $2.5 million.  Trip 9&10 have 500 people and cost $2 million.  Trip 11&12 cost $1.6 million/person....trip 39 & 40 cost $500000/person.  The target. 

Or better yet...  If trip consumables cost $500k, and no new hardware is made after the first trip, then the trip on conjunction 3 (about 10 years...) costs only $500k. 


If you don't like this analysis, bump up the costs and try again as you see fit (but you must assume reusability as a baseline). 

Airplanes are reusable and no one gets charged more on the first flight with ticket prices halving every subsequent use of the airplane.  Why would a rocket company do any differently?  If you are thinking of answering with reasons of risk mitigation, my reply would be that "that is what insurance is for."

[go4mars]

Airplanes are reusable and no one gets charged more on the first flight with ticket prices halving every subsequent use of the airplane.  Why would a rocket company do any differently?  If you are thinking of answering with reasons of risk mitigation, my reply would be that "that is what insurance is for."

Airplanes can turn around and fly again frequently because they aren't interrupted for years at a time between flights.  The Mars hardware would be. 

For the big booster, it would need a reasonable plan for high flight rate between Mars departures for your arguement to hold.   

Long term leases of things might be a better analogy.  Like a mining company that leases a tug-boat on a 3 year term.  They would probably bear the brunt of it's new price.  After 3 years, it's mostly profit and maintenence cost offset for the owner company during subsequent leasing. 

[Jim Davis]

I think Musk is kidding himself if he thinks the first Mars colonists can be sent for $500,000/head.

That's supposed to be ten years in.

He's still kidding himself if he expects orders of magnitude cost improvement on that time scale. The Ark of the Covenant, the Fountain of Youth, and dinosaurs would have to be found on Mars to generate the kind of activity necessary for that kind of improvement. Ten years is only about five launch windows.

For a more realistic perspective we're coming up on 10 years between SS1 and SS2. That's with 500 paid customers.

[Robotbeat]

I think Musk is kidding himself if he thinks the first Mars colonists can be sent for $500,000/head.

That's supposed to be ten years in.

He's still kidding himself if he expects orders of magnitude cost improvement on that time scale. The Ark of the Covenant, the Fountain of Youth, and dinosaurs would have to be found on Mars to generate the kind of activity necessary for that kind of improvement. Ten years is only about five launch windows.

For a more realistic perspective we're coming up on 10 years between SS1 and SS2. That's with 500 paid customers.

Yeah, I'm a little skeptical myself.

Maybe he needs to found a new religion? Maybe scientologists would want to go?

Though maybe we CAN have at least dinosaurs on Mars?

[mrmandias]

I think it will be a direct-throw reusable rocket.  A really BFR. 

That’s wasteful.  Doing it in stages allows other users of the earth to LEO stage or the LEO to L2 stage to help amortize your costs for that stage and bring down your overall expense.
Especially because you can’t launch to Mars all that frequently, so you need to have other uses for as much of your equipment as possible in the intervals between Mars launches.  Doing stages allows you to easily reuse the equipment for those stages for other purposes in the intervals between launches.

1) Fully Reusable Earth-to-Orbit transportation system operating in an airplane-like fashion, with total flight costs no higher than 10x the propellant costs.

This translates to around $100 per kg to orbit.

If each person needs 5t of supplies for the round trip, that would consume the whole budget just in launch-to-LEO.

cheers, Martin

The key here is to make supplies as reusable as possible.  In other words, recycle.  This will require equipment, but if the equipment can be reused from trip to trip it supplies becomes another amortizable item instead of a consumable.

The trade-off here, of course, is increasing the cost, bulk, and complexity of recycling equipment as the efficiency of recycling increases.

Air and water in particular should be fairly recyclable.  I can't immediately find the ISS figure, but those should give us a good idea.   100% recyclability won’t happen, so you’ll need at least some air and water per individual.
Food is different.  I bet that almost any systems for recycling foodstuffs would be prohibitively expensive in the near term.  Assume that almost all food will have to be a consumable.
The average American consumes 4-5 pounds of food per day.  You can probably bring that figure down by using calorically dense foods and reconstituting food with recycled water.  You can’t be too spartan, though, since Musk’s spacefarers are rich folk who are paying for the experience.  Be optimistic and say 3 pounds a day.
A conventional Hohmann transfer orbit to Mars is about 9 months.  They’re probably too infrequent for what Musk is talking about, but I have no idea which of many other alternatives he’d have in mind, so let’s just go with it.  So each person would need around 800-900 pounds for a one-way trip.  Obviously faster missions would require less consumables and require a rich person to not have to take as long a sabbatical, so the trade-offs may be in favor of more energetic trajectories.
This is all speculation.  I’d love to see actual figures about ISS consumption per astronaut of food, water, air, and other supplies.  But even noodling around in this post tells me that whatever Musk has in mind, its probably highly dependent on some fairly efficient recycling of air and water, and ultimately probably on food production on Mars so you don’t have to carry your inbound food outbound.

[go4mars]

That’s wasteful.  Doing it in stages allows other users of the earth to LEO stage or the LEO to L2 stage to help amortize your costs for that stage and bring down your overall expense.
Especially because you can’t launch to Mars all that frequently, so you need to have other uses for as much of your equipment as possible in the intervals between Mars launches.  Doing stages allows you to easily reuse the equipment for those stages for other purposes in the intervals between launches.

Really big reusable boosters give diameter and simplicity.  Not that I'm wrong and you are right (or vice versa).  Just different philosophies.  A big booster can also take things like nuclear reactors and other things that are less practical to break into tiny components.  Also, a really big diameter heatshield is useful upon arrival. 

I also think that reusable 1st stage boosters that are small are harder to justify in the time between.  An intercontinental hypersonic commuter would probably pay less for seat if sharing a ride with a few hundred folks instead of just a few buddies.  I think that's the killer app.   

[MP99]

Airplanes are reusable and no one gets charged more on the first flight with ticket prices halving every subsequent use of the airplane.  Why would a rocket company do any differently?  If you are thinking of answering with reasons of risk mitigation, my reply would be that "that is what insurance is for."

See discussion of how expensive the Stratolaunch airplane will be if it is only used a few times a year without sharing costs with other uses.

This infrastructure will be used only every other year (only slightly better if both conjunction & opposition opportunities are used).

Planes may be amortised over many flights, but with so few Mars opportunities, the hardware must be amortised over a tiny number.

cheers, Martin

[Blackjax]

A couple thoughts.

First, on the question of pricing.  For the very first trip (the one paying for a lot of the initial infrastructure to be designed, built, and flown, it might make sense to not have an upfront price.  There are a lot of Auction Strategies which might be a more prudent way to do this.  Perhaps some variant of a Vickrey auction with a reserve price and the caveat that enough bids above the reserve price must occur to fill all the seats or the mission does not fly.

Second is the issue of food.  While I am sure that prepackaged foods will constitute a significant fraction of the food consumed on the trip, I suspect that they'd also grow some as well, even if it is only simple things like spirulina.  In particular, urine makes an excellent easily recyclable fertilizer and using it will help reduce the load on mechanical systems which would otherwise do the work.  Growing plants (even simple ones) also helps reduce the load on oxygen recycling systems.  So I doubt the food mass calculations are as simple as people are figuring because there are synergies if you treat the system a little more holistically and given a trip time of 9 months every advantage you can get may matter.