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Starship fuel costs
A few months ago we talked about whether time to start optimising for
fuel consumption is near. (The "A conversation with Elon Musk" thread in October) I found the following bit of information on https://en.wikipedia.org/wiki/SpaceX_Starship "In November 2019 Elon Musk estimated that fuel will cost $900,000 per launch and total launch costs could drop as low as $2 million". So assuming that Starship does live up to Elon's estimate (which I think is doubtful, but still a good ballpark figure), fuel costs could soon be 45% of total launch costs. Of course, to lower the cost of access to space right now, the important thing is to get rockets to be fully reusable and get total launch costs around $20 per kg. But it seems that this will be done soon. Once it is done, I think the 45% fuel costs will seem as a good place to reduce costs further. Alain Fournier |
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Starship fuel costs
On 2020-01-25 12:38 PM, Jeff Findley wrote:
Elon's vision for Starship is to use Tesla solar as power for the same Sabatier reaction that they plan to use on Mars to convert CO2 (from the atmosphere) and H2O into O2 and CH4 (methane). In that way, Starship propellant production would be completely carbon neutral. This is important to him since he plans on Starship being capable of being launched three times per day (no doubt most of those launches would be tankers to refuel Starships in LEO). I don't want to get into the weeds about carbon, but to call it carbon neutral you need to take into account the carbon that was consumed mining the elements and other processes used to manufacture those solar panels. All of that would need to be offset by the savings over launch with a traditional hydrocarbon fuel like kerosene along with the carbon emitted when those solar cells are eventually disposed of at the end of life, before the sheet balances. And given enough time it would. However you have to realize it is not enough to have a net carbon zero process to claim you are carbon neutral. The only way to reach that is if you balance it off against the *potential* emission of carbon had you not used the solar driven Sabatier process for fuel generation. Otherwise it will still not be *net* zero. It also assumes a certain amount of time of operation. If it's not in operation long enough the offset will not get you to net zero either. But strictly from an economics standpoint I agree with the point you raise and that Elon makes. That being able to generate your own fuel via solar is an essential cost savings if you want to have frequent launch operations (and don't forget across multiple sites). Not having to transport fuel and oxidizer to all those sites as opposed to being able to generate fuel locally is another significant ongoing cost consideration. Dave |
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Starship fuel costs
In article , says...
On 2020-01-25 12:38 PM, Jeff Findley wrote: Elon's vision for Starship is to use Tesla solar as power for the same Sabatier reaction that they plan to use on Mars to convert CO2 (from the atmosphere) and H2O into O2 and CH4 (methane). In that way, Starship propellant production would be completely carbon neutral. This is important to him since he plans on Starship being capable of being launched three times per day (no doubt most of those launches would be tankers to refuel Starships in LEO). I don't want to get into the weeds about carbon, but to call it carbon neutral you need to take into account the carbon that was consumed mining the elements and other processes used to manufacture those solar panels. All of that would need to be offset by the savings over launch with a traditional hydrocarbon fuel like kerosene along with the carbon emitted when those solar cells are eventually disposed of at the end of life, before the sheet balances. And given enough time it would. However you have to realize it is not enough to have a net carbon zero process to claim you are carbon neutral. The only way to reach that is if you balance it off against the *potential* emission of carbon had you not used the solar driven Sabatier process for fuel generation. Otherwise it will still not be *net* zero. It also assumes a certain amount of time of operation. If it's not in operation long enough the offset will not get you to net zero either. Which is why I said, "Starship propellant production would be completely carbon neutral". The manufacturing of Starship, or any other launch vehicle for that matter, would certainly not be carbon neutral. So, I'm not going to attempt to hold them to a higher standard than what they, or any other launch company, can currently achieve. Right now, the methane for the Raptors comes from the currently plentiful natural gas pulled from domestic wells. But, since natural gas wells on Mars seems more than a bit a bit far fetched, SpaceX will have to make due with manufacturing their own methane and oxygen on Mars. Might as well get started on that here on earth so the processes can be optimized. But strictly from an economics standpoint I agree with the point you raise and that Elon makes. That being able to generate your own fuel via solar is an essential cost savings if you want to have frequent launch operations (and don't forget across multiple sites). Not having to transport fuel and oxidizer to all those sites as opposed to being able to generate fuel locally is another significant ongoing cost consideration. Agreed. With the launch rate that Elon is planning, he simply won't want to continue to depend on outside sources for propellant. Vertical integration is one aspect of Musk's companies that helps to drive down costs in the long run. This is quite the opposite of traditional aerospace and automotive manufacturers who have spent decades outsourcing as much as they can. This leaves some of them in a position to not have a ready supply of things like state of the art rechargeable batteries or low cost liquid fueled rocket engines. That will become their downfall unless their suppliers can deliver on cost, reliability, and quantify. Jeff -- All opinions posted by me on Usenet News are mine, and mine alone. These posts do not reflect the opinions of my family, friends, employer, or any organization that I am a member of. |
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