SpaceX will develop vacuum version of Raptor for version 2 of BFS

SpaceX changed the engines for the SpaceX BFS. They are all using non-vacuum engine nozzles.

This reduces the amount of payload that will be taken to space in the first version. It seems to reduce it from 150 tons to 100 tons.

In order to reduce the development risk and cost. They will only make a sea-level version of the Raptor engine.

There is an outer ring of cargo sections. Each one of the cargo sections can be replaced with a vacuum nozel of the Raptor. You would lose two cargo racks for each vacuum engined Raptor.

Replacing with cargo with vacuum engines will significantly boost the payload capability and power the SpaceX BFR and BFS.

60 thoughts on “SpaceX will develop vacuum version of Raptor for version 2 of BFS”

  1. might as well make it a single stage to orbit for smaller payloads, second stage is largely justified by the presence of vac optimized thrusters with the advent of composite materials in ship’s structure, need a bigger tank though

  2. Getting closer to Falcon Heavy year after year… Which honestly I thought was good enough already, but I guess this one is better because it still is fully reusable as per the latest update, and it can work as a planetary lander. And it has some potential payload growth capability, which they have already demonstrated with Falcon 9.

  3. Getting closer to Falcon Heavy year after year…Which honestly I thought was good enough already but I guess this one is better because it still is fully reusable as per the latest update and it can work as a planetary lander.And it has some potential payload growth capability which they have already demonstrated with Falcon 9.

  4. might as well make it a single stage to orbit for smaller payloads second stage is largely justified by the presence of vac optimized thrusters with the advent of composite materials in ship’s structure need a bigger tank though

  5. Getting closer to Falcon Heavy year after year… ” The re-usable payload of this one is 2.5 times the re-usage payload of the FH. What are you smoking?

  6. Getting closer to Falcon Heavy year after year… “”The re-usable payload of this one is 2.5 times the re-usage payload of the FH. What are you smoking?”””

  7. On a closer look, it is noted in small dark gray font on a black background in the capabilities & services page. But not mentioned at all in the main FH page. So you’re right that that’s the expendable figure, but I wouldn’t call this *clearly* states. You have to dig for it.

  8. Vacuum engines have enlarged bells to expand the diverging flow until the pressure is less than atmospheric. If you test a vacuum engine at sea level, without using a vacuum chamber, the exhaust flow can separate from the bell due to air flowing into the engine from the edges. This can cause vibration problems, invalidate your test results, and so forth. Smaller vacuum engines are actually tested in vacuum chambers for this reason. But, try finding a vacuum chamber large enough to do decent testing on the raptor.

  9. The website clearly states those performance figures are foe expendable launches. FH delivers about 60% of expendable payload in a reusable launch. 40ish against 100ish.

  10. is any engines tested in vacuum? that is outside of ion and similar, but I think that testing an large rocket engine would be very hard as it would not stay vacuum for long. Think its 3 reasons, first is that they will only use the ground level ones for the jump testing, second 7 engines give an better abort and engine out margin, last even 100 ton to leo is a lot, you will be volume limited rater than mass unless you launch fuel, the tankers will use the vacuum version probably the mars ships to.

  11. In start-up terms, this is called an MVP, or Minimal Viable Product. You deliver the smallest and simplest possible product that is still useful, then improve it and add more features later. This lets you minimize the time and cost to get the first customers, get earlier customer feedback, etc. BFR is expensive, so it makes sense to focus on the minimal set of features first.

  12. The one major thing BFS can do that FH can’t, is refuel in orbit. That significantly increases the payload beyond LEO. FH payload to Mars is listed as ~17 tons. The previous version of BFS’ could deliver between ~75 to ~100 tons to Mars, if fully refueled in LEO (depending on how much it can aerobrake). So this one might do ~50-75 tons, maybe. Similar for the Moon, I guess, but I don’t have the numbers. That is, providing they didn’t remove the refueling function. It’s not clear how refueling is intended to work in this new version. But I doubt they removed the most important feature.

  13. SpaceX site lists FH payload to LEO as 63.8 tons, though it’s unclear if that’s reusable or expandable. If that’s the reusable payload, and the 1st version BFR/BFR is downgraded to 100 tons as this article claims, then that’s only 1.5 times.

  14. On a closer look it is noted in small dark gray font on a black background in the capabilities & services page. But not mentioned at all in the main FH page. So you’re right that that’s the expendable figure but I wouldn’t call this *clearly* states. You have to dig for it.

  15. Vacuum engines have enlarged bells to expand the diverging flow until the pressure is less than atmospheric. If you test a vacuum engine at sea level without using a vacuum chamber the exhaust flow can separate from the bell due to air flowing into the engine from the edges. This can cause vibration problems invalidate your test results and so forth.Smaller vacuum engines are actually tested in vacuum chambers for this reason. But try finding a vacuum chamber large enough to do decent testing on the raptor.

  16. The website clearly states those performance figures are foe expendable launches. FH delivers about 60{22800fc54956079738b58e74e4dcd846757aa319aad70fcf90c97a58f3119a12} of expendable payload in a reusable launch. 40ish against 100ish.

  17. is any engines tested in vacuum? that is outside of ion and similar but I think that testing an large rocket engine would be very hard as it would not stay vacuum for long.Think its 3 reasons first is that they will only use the ground level ones for the jump testing second 7 engines give an better abort and engine out margin last even 100 ton to leo is a lot you will be volume limited rater than mass unless you launch fuel the tankers will use the vacuum version probably the mars ships to.

  18. In start-up terms this is called an MVP or Minimal Viable Product. You deliver the smallest and simplest possible product that is still useful then improve it and add more features later. This lets you minimize the time and cost to get the first customers get earlier customer feedback etc. BFR is expensive so it makes sense to focus on the minimal set of features first.

  19. The one major thing BFS can do that FH can’t is refuel in orbit. That significantly increases the payload beyond LEO. FH payload to Mars is listed as ~17 tons. The previous version of BFS’ could deliver between ~75 to ~100 tons to Mars if fully refueled in LEO (depending on how much it can aerobrake). So this one might do ~50-75 tons maybe. Similar for the Moon I guess but I don’t have the numbers.That is providing they didn’t remove the refueling function. It’s not clear how refueling is intended to work in this new version. But I doubt they removed the most important feature.

  20. SpaceX site lists FH payload to LEO as 63.8 tons though it’s unclear if that’s reusable or expandable. If that’s the reusable payload and the 1st version BFR/BFR is downgraded to 100 tons as this article claims then that’s only 1.5 times.

  21. On a closer look, it is noted in small dark gray font on a black background in the capabilities & services page. But not mentioned at all in the main FH page. So you’re right that that’s the expendable figure, but I wouldn’t call this *clearly* states. You have to dig for it.

  22. On a closer look it is noted in small dark gray font on a black background in the capabilities & services page. But not mentioned at all in the main FH page. So you’re right that that’s the expendable figure but I wouldn’t call this *clearly* states. You have to dig for it.

  23. Vacuum engines have enlarged bells to expand the diverging flow until the pressure is less than atmospheric. If you test a vacuum engine at sea level, without using a vacuum chamber, the exhaust flow can separate from the bell due to air flowing into the engine from the edges. This can cause vibration problems, invalidate your test results, and so forth. Smaller vacuum engines are actually tested in vacuum chambers for this reason. But, try finding a vacuum chamber large enough to do decent testing on the raptor.

  24. Vacuum engines have enlarged bells to expand the diverging flow until the pressure is less than atmospheric. If you test a vacuum engine at sea level without using a vacuum chamber the exhaust flow can separate from the bell due to air flowing into the engine from the edges. This can cause vibration problems invalidate your test results and so forth.Smaller vacuum engines are actually tested in vacuum chambers for this reason. But try finding a vacuum chamber large enough to do decent testing on the raptor.

  25. The website clearly states those performance figures are foe expendable launches. FH delivers about 60% of expendable payload in a reusable launch. 40ish against 100ish.

  26. The website clearly states those performance figures are foe expendable launches. FH delivers about 60{22800fc54956079738b58e74e4dcd846757aa319aad70fcf90c97a58f3119a12} of expendable payload in a reusable launch. 40ish against 100ish.

  27. is any engines tested in vacuum? that is outside of ion and similar, but I think that testing an large rocket engine would be very hard as it would not stay vacuum for long. Think its 3 reasons, first is that they will only use the ground level ones for the jump testing, second 7 engines give an better abort and engine out margin, last even 100 ton to leo is a lot, you will be volume limited rater than mass unless you launch fuel, the tankers will use the vacuum version probably the mars ships to.

  28. is any engines tested in vacuum? that is outside of ion and similar but I think that testing an large rocket engine would be very hard as it would not stay vacuum for long.Think its 3 reasons first is that they will only use the ground level ones for the jump testing second 7 engines give an better abort and engine out margin last even 100 ton to leo is a lot you will be volume limited rater than mass unless you launch fuel the tankers will use the vacuum version probably the mars ships to.

  29. In start-up terms, this is called an MVP, or Minimal Viable Product. You deliver the smallest and simplest possible product that is still useful, then improve it and add more features later. This lets you minimize the time and cost to get the first customers, get earlier customer feedback, etc. BFR is expensive, so it makes sense to focus on the minimal set of features first.

  30. In start-up terms this is called an MVP or Minimal Viable Product. You deliver the smallest and simplest possible product that is still useful then improve it and add more features later. This lets you minimize the time and cost to get the first customers get earlier customer feedback etc. BFR is expensive so it makes sense to focus on the minimal set of features first.

  31. The one major thing BFS can do that FH can’t, is refuel in orbit. That significantly increases the payload beyond LEO. FH payload to Mars is listed as ~17 tons. The previous version of BFS’ could deliver between ~75 to ~100 tons to Mars, if fully refueled in LEO (depending on how much it can aerobrake). So this one might do ~50-75 tons, maybe. Similar for the Moon, I guess, but I don’t have the numbers. That is, providing they didn’t remove the refueling function. It’s not clear how refueling is intended to work in this new version. But I doubt they removed the most important feature.

  32. The one major thing BFS can do that FH can’t is refuel in orbit. That significantly increases the payload beyond LEO. FH payload to Mars is listed as ~17 tons. The previous version of BFS’ could deliver between ~75 to ~100 tons to Mars if fully refueled in LEO (depending on how much it can aerobrake). So this one might do ~50-75 tons maybe. Similar for the Moon I guess but I don’t have the numbers.That is providing they didn’t remove the refueling function. It’s not clear how refueling is intended to work in this new version. But I doubt they removed the most important feature.

  33. SpaceX site lists FH payload to LEO as 63.8 tons, though it’s unclear if that’s reusable or expandable. If that’s the reusable payload, and the 1st version BFR/BFR is downgraded to 100 tons as this article claims, then that’s only 1.5 times.

  34. SpaceX site lists FH payload to LEO as 63.8 tons though it’s unclear if that’s reusable or expandable. If that’s the reusable payload and the 1st version BFR/BFR is downgraded to 100 tons as this article claims then that’s only 1.5 times.

  35. Getting closer to Falcon Heavy year after year… ” The re-usable payload of this one is 2.5 times the re-usage payload of the FH. What are you smoking?

  36. Getting closer to Falcon Heavy year after year… “”The re-usable payload of this one is 2.5 times the re-usage payload of the FH. What are you smoking?”””

  37. On a closer look, it is noted in small dark gray font on a black background in the capabilities & services page. But not mentioned at all in the main FH page. So you’re right that that’s the expendable figure, but I wouldn’t call this *clearly* states. You have to dig for it.

  38. Vacuum engines have enlarged bells to expand the diverging flow until the pressure is less than atmospheric. If you test a vacuum engine at sea level, without using a vacuum chamber, the exhaust flow can separate from the bell due to air flowing into the engine from the edges. This can cause vibration problems, invalidate your test results, and so forth.

    Smaller vacuum engines are actually tested in vacuum chambers for this reason. But, try finding a vacuum chamber large enough to do decent testing on the raptor.

  39. is any engines tested in vacuum? that is outside of ion and similar, but I think that testing an large rocket engine would be very hard as it would not stay vacuum for long.

    Think its 3 reasons, first is that they will only use the ground level ones for the jump testing, second 7 engines give an better abort and engine out margin, last even 100 ton to leo is a lot, you will be volume limited rater than mass unless you launch fuel, the tankers will use the vacuum version probably the mars ships to.

  40. might as well make it a single stage to orbit for smaller payloads, second stage is largely justified by the presence of vac optimized thrusters with the advent of composite materials in ship’s structure, need a bigger tank though

  41. might as well make it a single stage to orbit for smaller payloads second stage is largely justified by the presence of vac optimized thrusters with the advent of composite materials in ship’s structure need a bigger tank though

  42. In start-up terms, this is called an MVP, or Minimal Viable Product. You deliver the smallest and simplest possible product that is still useful, then improve it and add more features later. This lets you minimize the time and cost to get the first customers, get earlier customer feedback, etc. BFR is expensive, so it makes sense to focus on the minimal set of features first.

  43. The one major thing BFS can do that FH can’t, is refuel in orbit. That significantly increases the payload beyond LEO. FH payload to Mars is listed as ~17 tons. The previous version of BFS’ could deliver between ~75 to ~100 tons to Mars, if fully refueled in LEO (depending on how much it can aerobrake). So this one might do ~50-75 tons, maybe. Similar for the Moon, I guess, but I don’t have the numbers.

    That is, providing they didn’t remove the refueling function. It’s not clear how refueling is intended to work in this new version. But I doubt they removed the most important feature.

  44. SpaceX site lists FH payload to LEO as 63.8 tons, though it’s unclear if that’s reusable or expandable. If that’s the reusable payload, and the 1st version BFR/BFR is downgraded to 100 tons as this article claims, then that’s only 1.5 times.

  45. Getting closer to Falcon Heavy year after year… Which honestly I thought was good enough already, but I guess this one is better because it still is fully reusable as per the latest update, and it can work as a planetary lander. And it has some potential payload growth capability, which they have already demonstrated with Falcon 9.

  46. Getting closer to Falcon Heavy year after year…Which honestly I thought was good enough already but I guess this one is better because it still is fully reusable as per the latest update and it can work as a planetary lander.And it has some potential payload growth capability which they have already demonstrated with Falcon 9.

  47. might as well make it a single stage to orbit for smaller payloads, second stage is largely justified by the presence of vac optimized thrusters with the advent of composite materials in ship’s structure, need a bigger tank though

  48. Getting closer to Falcon Heavy year after year…

    Which honestly I thought was good enough already, but I guess this one is better because it still is fully reusable as per the latest update, and it can work as a planetary lander.

    And it has some potential payload growth capability, which they have already demonstrated with Falcon 9.

Comments are closed.