​

Understanding SpaceX reusability

by

SpaceX has had 62 successful launches and landed 28 times and reused boosters 15 times.

They have had 34 successful launches in 2017 and so far in 2018.

The new block 5 Falcon 9’s are coming back in good shape and SpaceX feels confident that they will be able to reuse them many times. They will work towards being able to reuse without refurbishment and get a two-day turnaround.

SpaceX is rapidly learning how to make rockets better and better for reusability.

SpaceX payloads vary quite a bit depending upon how the rockets are landed. The type of landing changes the fuel usage.

The SpaceX Falcon Heavy can put 15 tons to GTO in an expendable configuration. SpaceX Falcon Heavy can put about 8-10 tons to GTO in reusable modes.

70 thoughts on “Understanding SpaceX reusability”

  1. Other way around. Any payload that can’t use a reusable rocket is pretty expensive. Given a year or two nobody will want to launch on a fully expendable F9H. Such a launch will cost an extra hundred million or so.

  2. Other way around. Any payload that can’t use a reusable rocket is pretty expensive.Given a year or two nobody will want to launch on a fully expendable F9H. Such a launch will cost an extra hundred million or so.

  3. Rocket components are already running at the limits of materials, just to make them light enough. Adding requirements like resistance to salt water could be a real problem. Catching it doesn’t really add any material/design constraints.

  4. Rocket components are already running at the limits of materials just to make them light enough. Adding requirements like resistance to salt water could be a real problem.Catching it doesn’t really add any material/design constraints.

  5. Dunking in salt water makes it scrap, because to take it apart and clean it is more expensive than making a new one. Even the Crew Dragon capsule NASA is insisting the SpaceX land in water, will be torn down to the frame and almost everything scrapped. The frame can be pressure washed easily enough.

  6. Dunking in salt water makes it scrap because to take it apart and clean it is more expensive than making a new one. Even the Crew Dragon capsule NASA is insisting the SpaceX land in water will be torn down to the frame and almost everything scrapped. The frame can be pressure washed easily enough.

  7. A couple minutes in salt war IS bad. Also think about it this way, The salt water will get into everything. Basically, it will have to be completely broken down.

  8. A couple minutes in salt war IS bad. Also think about it this way The salt water will get into everything. Basically it will have to be completely broken down.

  11. The main reason is that salt water is very corrosive to equipment like that, and fairings are made of carbon composite so are very expensive (about $5 million, I think), so reusing it would be a better idea. Also, that is part of the reason why SpaceX considered re-usability on the Crew Dragon.

  12. The main reason is that salt water is very corrosive to equipment like that and fairings are made of carbon composite so are very expensive (about $5 million I think) so reusing it would be a better idea. Also that is part of the reason why SpaceX considered re-usability on the Crew Dragon.

  13. Can someone more knowledgeable than me explain why it is easier/better/more cost effective to try to catch the fairing than it is to make it reusable after a short dunk in the ocean? How bad can a couple of minutes of salt water submersion be? They really can’t make it resistant to that?

  14. Can someone more knowledgeable than me explain why it is easier/better/more cost effective to try to catch the fairing than it is to make it reusable after a short dunk in the ocean?How bad can a couple of minutes of salt water submersion be? They really can’t make it resistant to that?

  15. The fatigue life of structural materials, which is what most of a rocket is made from, is different from that. Each load cycle causes microcracks to grow, eventually becoming large cracks. For lightly-loaded materials, the number of cycles to failure are essentially infinite. But to save weight, rocket hardware is highly loaded (i.e. used near their stress limits). So the fatigue life is measured in tens to hundreds of cycles. That’s why they need to inspect the rocket after it lands, to make sure no cracks have grown to a dangerous size. They do this with airplanes, too. They do a visual inspection every flight, but on a regular basis they do more detailed inspection, looking for growing cracks. Airplanes are less highly stressed than rockets, so the detailed inspections don’t have to be done as often. Otherwise, they are both made from the same basic materials – mostly aluminum and carbon composites, so the way they age is similar.

  16. The fatigue life of structural materials which is what most of a rocket is made from is different from that. Each load cycle causes microcracks to grow eventually becoming large cracks. For lightly-loaded materials the number of cycles to failure are essentially infinite. But to save weight rocket hardware is highly loaded (i.e. used near their stress limits). So the fatigue life is measured in tens to hundreds of cycles. That’s why they need to inspect the rocket after it lands to make sure no cracks have grown to a dangerous size.They do this with airplanes too. They do a visual inspection every flight but on a regular basis they do more detailed inspection looking for growing cracks. Airplanes are less highly stressed than rockets so the detailed inspections don’t have to be done as often. Otherwise they are both made from the same basic materials – mostly aluminum and carbon composites so the way they age is similar.

  23. The question is, if you can split your payload, is it cheaper putting 15 tons up there in one launch, or two?

  24. The question is if you can split your payload is it cheaper putting 15 tons up there in one launch or two?

  26. So the reusability cost is a 40{22800fc54956079738b58e74e4dcd846757aa319aad70fcf90c97a58f3119a12} reduction in payload…that’s pretty stiff.

  29. Other way around. Any payload that can’t use a reusable rocket is pretty expensive. Given a year or two nobody will want to launch on a fully expendable F9H. Such a launch will cost an extra hundred million or so.

  30. Other way around. Any payload that can’t use a reusable rocket is pretty expensive.Given a year or two nobody will want to launch on a fully expendable F9H. Such a launch will cost an extra hundred million or so.

  31. Rocket components are already running at the limits of materials, just to make them light enough. Adding requirements like resistance to salt water could be a real problem. Catching it doesn’t really add any material/design constraints.

  32. Rocket components are already running at the limits of materials just to make them light enough. Adding requirements like resistance to salt water could be a real problem.Catching it doesn’t really add any material/design constraints.

  33. Dunking in salt water makes it scrap, because to take it apart and clean it is more expensive than making a new one. Even the Crew Dragon capsule NASA is insisting the SpaceX land in water, will be torn down to the frame and almost everything scrapped. The frame can be pressure washed easily enough.

  34. Dunking in salt water makes it scrap because to take it apart and clean it is more expensive than making a new one. Even the Crew Dragon capsule NASA is insisting the SpaceX land in water will be torn down to the frame and almost everything scrapped. The frame can be pressure washed easily enough.

  35. Other way around. Any payload that can’t use a reusable rocket is pretty expensive.

    Given a year or two nobody will want to launch on a fully expendable F9H. Such a launch will cost an extra hundred million or so.

  36. Rocket components are already running at the limits of materials, just to make them light enough. Adding requirements like resistance to salt water could be a real problem.

    Catching it doesn’t really add any material/design constraints.

  37. A couple minutes in salt war IS bad. Also think about it this way, The salt water will get into everything. Basically, it will have to be completely broken down.

  38. A couple minutes in salt war IS bad. Also think about it this way The salt water will get into everything. Basically it will have to be completely broken down.

  39. Dunking in salt water makes it scrap, because to take it apart and clean it is more expensive than making a new one. Even the Crew Dragon capsule NASA is insisting the SpaceX land in water, will be torn down to the frame and almost everything scrapped. The frame can be pressure washed easily enough.

  42. The main reason is that salt water is very corrosive to equipment like that, and fairings are made of carbon composite so are very expensive (about $5 million, I think), so reusing it would be a better idea. Also, that is part of the reason why SpaceX considered re-usability on the Crew Dragon.

  43. The main reason is that salt water is very corrosive to equipment like that and fairings are made of carbon composite so are very expensive (about $5 million I think) so reusing it would be a better idea. Also that is part of the reason why SpaceX considered re-usability on the Crew Dragon.

  44. Can someone more knowledgeable than me explain why it is easier/better/more cost effective to try to catch the fairing than it is to make it reusable after a short dunk in the ocean? How bad can a couple of minutes of salt water submersion be? They really can’t make it resistant to that?

  45. Can someone more knowledgeable than me explain why it is easier/better/more cost effective to try to catch the fairing than it is to make it reusable after a short dunk in the ocean?How bad can a couple of minutes of salt water submersion be? They really can’t make it resistant to that?

  46. The fatigue life of structural materials, which is what most of a rocket is made from, is different from that. Each load cycle causes microcracks to grow, eventually becoming large cracks. For lightly-loaded materials, the number of cycles to failure are essentially infinite. But to save weight, rocket hardware is highly loaded (i.e. used near their stress limits). So the fatigue life is measured in tens to hundreds of cycles. That’s why they need to inspect the rocket after it lands, to make sure no cracks have grown to a dangerous size. They do this with airplanes, too. They do a visual inspection every flight, but on a regular basis they do more detailed inspection, looking for growing cracks. Airplanes are less highly stressed than rockets, so the detailed inspections don’t have to be done as often. Otherwise, they are both made from the same basic materials – mostly aluminum and carbon composites, so the way they age is similar.

  47. The fatigue life of structural materials which is what most of a rocket is made from is different from that. Each load cycle causes microcracks to grow eventually becoming large cracks. For lightly-loaded materials the number of cycles to failure are essentially infinite. But to save weight rocket hardware is highly loaded (i.e. used near their stress limits). So the fatigue life is measured in tens to hundreds of cycles. That’s why they need to inspect the rocket after it lands to make sure no cracks have grown to a dangerous size.They do this with airplanes too. They do a visual inspection every flight but on a regular basis they do more detailed inspection looking for growing cracks. Airplanes are less highly stressed than rockets so the detailed inspections don’t have to be done as often. Otherwise they are both made from the same basic materials – mostly aluminum and carbon composites so the way they age is similar.

  48. A couple minutes in salt war IS bad. Also think about it this way, The salt water will get into everything. Basically, it will have to be completely broken down.

  55. The question is, if you can split your payload, is it cheaper putting 15 tons up there in one launch, or two?

  56. The question is if you can split your payload is it cheaper putting 15 tons up there in one launch or two?

  58. So the reusability cost is a 40{22800fc54956079738b58e74e4dcd846757aa319aad70fcf90c97a58f3119a12} reduction in payload…that’s pretty stiff.

  62. The main reason is that salt water is very corrosive to equipment like that, and fairings are made of carbon composite so are very expensive (about $5 million, I think), so reusing it would be a better idea. Also, that is part of the reason why SpaceX considered re-usability on the Crew Dragon.

  63. Can someone more knowledgeable than me explain why it is easier/better/more cost effective to try to catch the fairing than it is to make it reusable after a short dunk in the ocean?

    How bad can a couple of minutes of salt water submersion be? They really can’t make it resistant to that?

  64. The fatigue life of structural materials, which is what most of a rocket is made from, is different from that. Each load cycle causes microcracks to grow, eventually becoming large cracks. For lightly-loaded materials, the number of cycles to failure are essentially infinite. But to save weight, rocket hardware is highly loaded (i.e. used near their stress limits). So the fatigue life is measured in tens to hundreds of cycles. That’s why they need to inspect the rocket after it lands, to make sure no cracks have grown to a dangerous size.

    They do this with airplanes, too. They do a visual inspection every flight, but on a regular basis they do more detailed inspection, looking for growing cracks. Airplanes are less highly stressed than rockets, so the detailed inspections don’t have to be done as often. Otherwise, they are both made from the same basic materials – mostly aluminum and carbon composites, so the way they age is similar.

Comments are closed.