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I don't understand how it can be an order of magnitude cheaper. There are more rocket engines to maintain, far more fuel, a more expensive launch structure and

I don't understand how it can be an order of magnitude cheaper. There are more rocket engines to maintain, far more fuel, a more expensive launch structure and generally more expense in all the ground operations. In a world where this can be launched for $2M, Falcon 9 can be launched for less than $1M.

crawshaw 5y ago
A falcon 9 launch expends the upper stage. Building the upper stage is now most of the cost of its launch.
deleted 5y ago
[deleted]
slownews45 5y ago
Fairing recovery on Felcon 9 is not perfect. Rumor was that alone was something like $5M per launch flushed.
simonh 5y ago
They expect each vehicle to cost $200m and to fly them 100 times each. Hence $2m per launch. Falcon 9 costs a lot more than that because the upper stage is expended each time and that costs mid single-digit millions, and the first stages may not last much beyond a few dozen launches without significant re-engineering which would also make them heavier.
- throwaway316943 5y ago
  Boy I hope they park them in orbit on the last launch and use them to build space habitats.
  - rbanffy 5y ago
    There was a plan to do that with shuttle tanks. If we used them, the ISS could have a humongous ring of habitable former tanks.
- Robotbeat 5y ago
  Actually, Elon once told me that they might be able to build Starship launch vehicles for less than Falcon 9 (say about $80 million new): https://twitter.com/elonmusk/status/1094793664809689089?s=20 https://twitter.com/elonmusk/status/1094793664809689089?s=20 100 reuses is not the limit either. The first stage in particular may be made for a lot more.
SEJeff 5y ago
The Falcon 9 can not be launched for less than $1M. Falcon 9 does not reuse the second stage. Elon has said that the second stage is approximately 20% of the cost of a Falcon 9 launch. A Falcon 9 needs to have some work done between each launch. Some of the Falcon 9 parts are not actually reusable (crush cores for the landing legs as an example). This is why they can not ever simply fill up a landed Falcon 9 booster, put a new second stage on it, and launch it again. The Starship / Superheavy combo is designed to be able to literally just refuel and go. The Falcon 9 booster is mostly made of aluminum, which is up to 60% more expensive than stainless steel. The Starship / Superheavy are stainless steel. Methane (Starship fuel) is massively cheaper than Kerosene (Falcon 9 fuel). Methane also has a much higher specific impulse, which means you can use less of it to get the same increase in velocity. Methane can be stored in liquid form in same temperature as oxygen, which means less insulation the two propellant tanks. Inversely, Kerosene will freeze at the temperatures required to get oxygen into liquid form. Basically, nothing you said is accurate.
- oses 5y ago
  The combination of Methane and the full flow staged combustion cycle also means significantly reduced coking in the engine, so it drastically prolongs the time between engine refurbishments.
  - ordu 5y ago
    Do you know how a reduced coking works? I've read about the raptor engine[1] and it explains how fuel rich hot mixture leads to coking, it explains how USA solved this problem before (by using hydrogen as a fuel), but how Musk managed to solve it? Partially burned methane should produce free carbon atoms, shouldn't it? Doesn't it raise a coking problem? [1] https://everydayastronaut.com/raptor-engine/ https://everydayastronaut.com/raptor-engine/
    - jjk166 5y ago
      In a conventional hydrocarbon fueled engine, you're using a fuel with hydrocarbon chains at approximately room temperature to cool the engine. With only a little heat addition, you get up to a temperature where these chains can shed hydrogens and convert their C-C-H bonds to C=C double bonds. These bonds in turn allow hydrocarbon chains to join together into larger molecules that can coagulate and stick to the walls. Methane on the other hand is starting out at a much lower temperature, and it's very difficult to get methane molecules to react with each other to form large molecules as you're not starting with any single C-C bonds. Isolated free carbon atoms (soot) aren't much of a problem.
thinkcontext 5y ago
The key to the price is that Musk is projecting it will be able to be reused many more times than Falcon 9, as well as a reusable 2nd stage.
nickik 5y ago
Rocket engines shouldn't be that cheap to maintain, they are designed to be very reusable, unlike Merlin they were designed for the beginning to be reusable. The whole reason for the full-flow staged cycle is to have much more reasonable internal temperatures. Methane as well was picked partially because its far more clean burning. There is no reason rocket engines couldn't be as reliable a jet engines. > far more fuel RP1 is very expensive. Methane is much cheaper, and they can even produce it local. Ox is very cheap and is basically gone turn into the cost of electricity and they are using local solar to make it. Helium is also a very expensive part of the Falcon 9. Starship avoids the use of helium. Additionally the Falcon 9 used TEE-TAB that is also expensive. And it used nitrogen as well, that not expensive but just one more thing to worry about. Falcon 9 has 6 different different consumables, Starship has 2. > generally more expense in all the ground operations This is wrong. The Falcon needed to have drone ships operating and tug boats for them as well, to catch the fairing they have another 1-2 boats out there to collect the fairing. Then the stages need to be brought into port, transported back to the launch site and so on. The fairing have to be refurbished as well. In additional Starship has multiple design upgrades that make it actually easier. Unlike Falcon 9 Upper stage, the Starship will be fueled from below, meaning there is no secondary fuel infrastructure for the upper stage. Not requiring the fueling of the consumables above also makes it much easier. Plus they were able to apply everything they learned from Falcon 9 and ground operations to this new launch vehicle and launch site. > In a world where this can be launched for $2M, Falcon 9 can be launched for less than $1M. Falcon 9 can not do that. First of all, you need to build an upper stage that cost you 5-10M. You can't build that Upper stage fast enough to reach the required flight rate. Falcon 9 is also more difficult to launch and prep for launch. It wasn't designed to be fully reusable and still need more checks and refurbishments. Now $2M is extreme, even if it is $10M or $20M that only really matters for stuff like Mars. If you can launch it anywhere under $100M its revolutionary vehicle for space flight.

crawshaw 5y ago

A falcon 9 launch expends the upper stage. Building the upper stage is now most of the cost of its launch.

deleted 5y ago

[deleted]

slownews45 5y ago

Fairing recovery on Felcon 9 is not perfect. Rumor was that alone was something like $5M per launch flushed.

simonh 5y ago

They expect each vehicle to cost $200m and to fly them 100 times each. Hence $2m per launch. Falcon 9 costs a lot more than that because the upper stage is expended each time and that costs mid single-digit millions, and the first stages may not last much beyond a few dozen launches without significant re-engineering which would also make them heavier.

throwaway316943 5y ago
Boy I hope they park them in orbit on the last launch and use them to build space habitats.
- rbanffy 5y ago
  There was a plan to do that with shuttle tanks. If we used them, the ISS could have a humongous ring of habitable former tanks.
Robotbeat 5y ago
Actually, Elon once told me that they might be able to build Starship launch vehicles for less than Falcon 9 (say about $80 million new): https://twitter.com/elonmusk/status/1094793664809689089?s=20 https://twitter.com/elonmusk/status/1094793664809689089?s=20 100 reuses is not the limit either. The first stage in particular may be made for a lot more.

SEJeff 5y ago

The Falcon 9 can not be launched for less than $1M. Falcon 9 does not reuse the second stage. Elon has said that the second stage is approximately 20% of the cost of a Falcon 9 launch. A Falcon 9 needs to have some work done between each launch. Some of the Falcon 9 parts are not actually reusable (crush cores for the landing legs as an example). This is why they can not ever simply fill up a landed Falcon 9 booster, put a new second stage on it, and launch it again. The Starship / Superheavy combo is designed to be able to literally just refuel and go. The Falcon 9 booster is mostly made of aluminum, which is up to 60% more expensive than stainless steel. The Starship / Superheavy are stainless steel. Methane (Starship fuel) is massively cheaper than Kerosene (Falcon 9 fuel). Methane also has a much higher specific impulse, which means you can use less of it to get the same increase in velocity. Methane can be stored in liquid form in same temperature as oxygen, which means less insulation the two propellant tanks. Inversely, Kerosene will freeze at the temperatures required to get oxygen into liquid form. Basically, nothing you said is accurate.

oses 5y ago
The combination of Methane and the full flow staged combustion cycle also means significantly reduced coking in the engine, so it drastically prolongs the time between engine refurbishments.
- ordu 5y ago
  Do you know how a reduced coking works? I've read about the raptor engine[1] and it explains how fuel rich hot mixture leads to coking, it explains how USA solved this problem before (by using hydrogen as a fuel), but how Musk managed to solve it? Partially burned methane should produce free carbon atoms, shouldn't it? Doesn't it raise a coking problem? [1] https://everydayastronaut.com/raptor-engine/ https://everydayastronaut.com/raptor-engine/
  - jjk166 5y ago
    In a conventional hydrocarbon fueled engine, you're using a fuel with hydrocarbon chains at approximately room temperature to cool the engine. With only a little heat addition, you get up to a temperature where these chains can shed hydrogens and convert their C-C-H bonds to C=C double bonds. These bonds in turn allow hydrocarbon chains to join together into larger molecules that can coagulate and stick to the walls. Methane on the other hand is starting out at a much lower temperature, and it's very difficult to get methane molecules to react with each other to form large molecules as you're not starting with any single C-C bonds. Isolated free carbon atoms (soot) aren't much of a problem.

thinkcontext 5y ago

The key to the price is that Musk is projecting it will be able to be reused many more times than Falcon 9, as well as a reusable 2nd stage.

nickik 5y ago

Rocket engines shouldn't be that cheap to maintain, they are designed to be very reusable, unlike Merlin they were designed for the beginning to be reusable. The whole reason for the full-flow staged cycle is to have much more reasonable internal temperatures. Methane as well was picked partially because its far more clean burning. There is no reason rocket engines couldn't be as reliable a jet engines. > far more fuel RP1 is very expensive. Methane is much cheaper, and they can even produce it local. Ox is very cheap and is basically gone turn into the cost of electricity and they are using local solar to make it. Helium is also a very expensive part of the Falcon 9. Starship avoids the use of helium. Additionally the Falcon 9 used TEE-TAB that is also expensive. And it used nitrogen as well, that not expensive but just one more thing to worry about. Falcon 9 has 6 different different consumables, Starship has 2. > generally more expense in all the ground operations This is wrong. The Falcon needed to have drone ships operating and tug boats for them as well, to catch the fairing they have another 1-2 boats out there to collect the fairing. Then the stages need to be brought into port, transported back to the launch site and so on. The fairing have to be refurbished as well. In additional Starship has multiple design upgrades that make it actually easier. Unlike Falcon 9 Upper stage, the Starship will be fueled from below, meaning there is no secondary fuel infrastructure for the upper stage. Not requiring the fueling of the consumables above also makes it much easier. Plus they were able to apply everything they learned from Falcon 9 and ground operations to this new launch vehicle and launch site. > In a world where this can be launched for $2M, Falcon 9 can be launched for less than $1M. Falcon 9 can not do that. First of all, you need to build an upper stage that cost you 5-10M. You can't build that Upper stage fast enough to reach the required flight rate. Falcon 9 is also more difficult to launch and prep for launch. It wasn't designed to be fully reusable and still need more checks and refurbishments. Now $2M is extreme, even if it is $10M or $20M that only really matters for stuff like Mars. If you can launch it anywhere under $100M its revolutionary vehicle for space flight.