Aviation week article on SpaceX reusability

[john smith 19]

Currently, SpaceX has 13 active boosters. Additionally, there are 10 more boosters that have been spotted in either testing or transit.

It has been speculated that B1049 will be expended after it's next mission. Based on the available mission profile, it appears the 4 FH core boosters will be expended after their first launch as well.

The true number of launches with just the current boosters likely is between 80 and 160 - without SpaceX deciding to certify some of the later ones to 20 flights.

Based on the number of FH launches scheduled in the next 5 years, SpaceX will have to make up to 9 core boosters in that time frame, possibly more. I would not be surprised if SpaceX also makes several boosters in that time period.

I personally don't see the F9/FH being retired prior to Starlink Gen2 being at least close to full deployment. That easily could take up to 9 years taking into account the shear number of launches needed.

Interesting.

Until Starlink a launcher that could deploy 60 satellites would be expected to be able to deploy most constellations in a single launch (excepting Iridium). A different world.

[wannamoonbase]

Currently, SpaceX has 13 active boosters. Additionally, there are 10 more boosters that have been spotted in either testing or transit.

It has been speculated that B1049 will be expended after it's next mission. Based on the available mission profile, it appears the 4 FH core boosters will be expended after their first launch as well.

The true number of launches with just the current boosters likely is between 80 and 160 - without SpaceX deciding to certify some of the later ones to 20 flights.

Based on the number of FH launches scheduled in the next 5 years, SpaceX will have to make up to 9 core boosters in that time frame, possibly more. I would not be surprised if SpaceX also makes several boosters in that time period.

I personally don't see the F9/FH being retired prior to Starlink Gen2 being at least close to full deployment. That easily could take up to 9 years taking into account the shear number of launches needed.

I agree that we will see F9/FH fly for sometime, a decade doesn't seem unreasonable.  The rate will taper after Starship is successful.  The out years will have some FH and F9's for NASA and DOD missions and F9's for human flights.  Maybe 4-6 per year in the later years.

[sghill]

The key items that can throw big spanners in the works are a)NASA contracts to supply ISS and b)SS is not orbit ready before the last F9 flies out.

The third big key item is an RUD of a reused booster well before the 15 launch expected lifetime. They'd have to alter all their key lifetime assumptions, and hence resulting fleet size.

[john smith 19]

The key items that can throw big spanners in the works are a)NASA contracts to supply ISS and b)SS is not orbit ready before the last F9 flies out.

The third big key item is an RUD of a reused booster well before the 15 launch expected lifetime. They'd have to alter all their key lifetime assumptions, and hence resulting fleet size.

True, unless it was caused by something that was obviously a one off event. I'm thinking something like FOD from something that was near/on the pad at launch?

Otherwise if it happened once it could happen again, until whatever triggered is identified.

As always in these situations the question is "Do you have very solid processes that have caught every error before it raises an issue, or have you just been lucky?"

I think the high launch rate drives a virtuous circle that keeps their staff tight and well focussed but we'll find if such a mishap does occur. Unfortunately the reverse argument doesn't work. Absence-of-evidences cannot be taken as implying an evidence-of-absence. 

[freddo411]

The key items that can throw big spanners in the works are a)NASA contracts to supply ISS and b)SS is not orbit ready before the last F9 flies out.

The third big key item is an RUD of a reused booster well before the 15 launch expected lifetime. They'd have to alter all their key lifetime assumptions, and hence resulting fleet size.

True, unless it was caused by something that was obviously a one off event. I'm thinking something like FOD from something that was near/on the pad at launch?

Otherwise if it happened once it could happen again, until whatever triggered is identified.

As always in these situations the question is "Do you have very solid processes that have caught every error before it raises an issue, or have you just been lucky?"

I think the high launch rate drives a virtuous circle that keeps their staff tight and well focussed but we'll find if such a mishap does occur. Unfortunately the reverse argument doesn't work. Absence-of-evidences cannot be taken as implying an evidence-of-absence. 

Reusability gives one a chance to see "almost failures", and to see the rate of decay of items that wear out.    This goes a long way toward preventing random RUDs that need long investigations because all the evidence is burned and/or scattered into tiny bits.

If there is a RUD, there are a dozen flown vehicles to examine, both for evidence of decay and for testing out possible failure theories.

[Hog]

The key items that can throw big spanners in the works are a)NASA contracts to supply ISS and b)SS is not orbit ready before the last F9 flies out.

The third big key item is an RUD of a reused booster well before the 15 launch expected lifetime. They'd have to alter all their key lifetime assumptions, and hence resulting fleet size.

True, unless it was caused by something that was obviously a one off event. I'm thinking something like FOD from something that was near/on the pad at launch?

Otherwise if it happened once it could happen again, until whatever triggered is identified.

As always in these situations the question is "Do you have very solid processes that have caught every error before it raises an issue, or have you just been lucky?"

I think the high launch rate drives a virtuous circle that keeps their staff tight and well focussed but we'll find if such a mishap does occur. Unfortunately the reverse argument doesn't work. Absence-of-evidences cannot be taken as implying an evidence-of-absence. 

Reusability gives one a chance to see "almost failures", and to see the rate of decay of items that wear out.    This goes a long way toward preventing random RUDs that need long investigations because all the evidence is burned and/or scattered into tiny bits.

If there is a RUD, there are a dozen flown vehicles to examine, both for evidence of decay and for testing out possible failure theories.

Everything you stated is true, and evidenced, although ignored(prior to STS-51L), during operations of the STS Solid Rocket Boosters.  Almost 4 decades ago in spaceflight history.  The SRMs were talking, but management wasn't listening.

[john smith 19]

Reusability gives one a chance to see "almost failures", and to see the rate of decay of items that wear out.    This goes a long way toward preventing random RUDs that need long investigations because all the evidence is burned and/or scattered into tiny bits.

If there is a RUD, there are a dozen flown vehicles to examine, both for evidence of decay and for testing out possible failure theories.

True, all of which discourages failures in the first place.

[MP99]

Docking Starship to ISS is not very different from docking Shuttle to ISS.

Given that it's about 13m longer than shuttle and designed to carry about 4x the mass of Shuttles payload bay (even if it came to orbit with only Shuttle's payload level) it's mass properties, such as 2nd moment of area, are going to be very different than Shuttles.

That's important because of the loads put on the docking adapter. I think of it as a pool cue. The sharp end is at the adapter but the heavy end is at the other end of the cue, only the heavy end is now 13m further away, able to excert much more torque on that interface.

Obviously with enough RCS control authority and fast enough acting control systems these issues can be overcome, if the will is there to do so.

We'll find out when Starship makes orbit. Starship docked to ISS will be quite a sight. 

If push came to shove, I'd think that Dragon could be launched inside Starship.

I'm sure it would require some modifications to Dragon, but possibly nothing drastic.

[DanClemmensen]

Docking Starship to ISS is not very different from docking Shuttle to ISS.

Given that it's about 13m longer than shuttle and designed to carry about 4x the mass of Shuttles payload bay (even if it came to orbit with only Shuttle's payload level) it's mass properties, such as 2nd moment of area, are going to be very different than Shuttles.

That's important because of the loads put on the docking adapter. I think of it as a pool cue. The sharp end is at the adapter but the heavy end is at the other end of the cue, only the heavy end is now 13m further away, able to excert much more torque on that interface.

Obviously with enough RCS control authority and fast enough acting control systems these issues can be overcome, if the will is there to do so.

We'll find out when Starship makes orbit. Starship docked to ISS will be quite a sight. 

If push came to shove, I'd think that Dragon could be launched inside Starship.

I'm sure it would require some modifications to Dragon, but possibly nothing drastic.

As we have discussed elsewhere, just leave a Dragon up there and use it to taxi crews back and forth between ISS and Starship.

[john smith 19]

As we have discussed elsewhere, just leave a Dragon up there and use it to taxi crews back and forth between ISS and Starship.

Certainly possible, but then we get into the question of what that extended period on orbit does to Dragon.

IIRC it's design target was something like 200+ days on orbit then back to earth (or re-entry) but this could leave it years in space.

The alternative is to bring a Dragon with them on each launch but one of the key selling points is it's esape system.  AFAIK that can't work inside SS payload bay.

[MP99]

Sorry - I wasn't thinking of crewed Dragon inside Starship, only cargo.

If NASA wants a LAS for crewed flights (as I would expect), then it would need to sit in the nose. Starship would need a nose to reenter - not sure how that could work. Maybe a dummy nose inside the cargo space?



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[DanClemmensen]

As we have discussed elsewhere, just leave a Dragon up there and use it to taxi crews back and forth between ISS and Starship.

Certainly possible, but then we get into the question of what that extended period on orbit does to Dragon.

IIRC it's design target was something like 200+ days on orbit then back to earth (or re-entry) but this could leave it years in space.

The alternative is to bring a Dragon with them on each launch but one of the key selling points is it's esape system.  AFAIK that can't work inside SS payload bay.

A taxi does not need to be a full-up Dragon, but you do need a Dragon up there as a lifeboat. I think the Dragon is also used for living space? In any event, you can swap out the taxi/Dragon/whatever by carrying it as uncrewed cargo on an uncrewed Starship as often as you need to. No need for LAS since no crew. Cargo Starship flights are supposed to be cheap. This decouples the whole LAS-for-crewed-Starship from the Dragon/taxi completely.  Once there are enough reliable crewed Starships, the taxi/lifeboat no longer needs to be EDL-capable, because a Starship can rescue the lifeboat crew.

If I were designing a space station, I would have the short-term experiments and the crew quarters in the Starship, so each crew comes up with its own quarters and experiments. Starships can stay on-station for as long as needed, from a week to six months or more. Only the long-term experiments stay on the much smaller long-term portion of the station. Among other things, It would be a lot easier to keep the place clean.

[john smith 19]

A taxi does not need to be a full-up Dragon, but you do need a Dragon up there as a lifeboat. I think the Dragon is also used for living space? In any event, you can swap out the taxi/Dragon/whatever by carrying it as uncrewed cargo on an uncrewed Starship as often as you need to. No need for LAS since no crew. Cargo Starship flights are supposed to be cheap. This decouples the whole LAS-for-crewed-Starship from the Dragon/taxi completely.  Once there are enough reliable crewed Starships, the taxi/lifeboat no longer needs to be EDL-capable, because a Starship can rescue the lifeboat crew.

For cargo that's viable, although it adds complexity.

If I were designing a space station, I would have the short-term experiments and the crew quarters in the Starship, so each crew comes up with its own quarters and experiments. Starships can stay on-station for as long as needed, from a week to six months or more. Only the long-term experiments stay on the much smaller long-term portion of the station. Among other things, It would be a lot easier to keep the place clean.

You do realize you're essentially repeating the design of Shuttle, right? It's like turning an 18 wheeler into an RV.   Using SS's payload bay to set the size of modules greatly raises the module size and mass limits, but leaving stuff in there is not a good choice. Likewise the power needs for such a module are likely to need substantial arrays which are better as left permanently on orbit.

[Robotbeat]

I think it may be a good idea to develop a jettisonable fairing for Starship. A big, highly-hammerheaded fairing, say 13m in diameter and 50m long. The fairing may be pretty massive, maybe 50t, but made of stainless steel so relatively inexpensive. Could even be recoverable, although likely used too rarely to justify that. Recover the stainless to recycle it I suppose.

Whether the upper stage portion is reusable or not, I think this would be a useful capability to have.

[matthewkantar]

A 50 ton fairing is around 30K USD in scrap, probably not worth the effort.

[DanClemmensen]

If I were designing a space station, I would have the short-term experiments and the crew quarters in the Starship, so each crew comes up with its own quarters and experiments. Starships can stay on-station for as long as needed, from a week to six months or more. Only the long-term experiments stay on the much smaller long-term portion of the station. Among other things, It would be a lot easier to keep the place clean.

You do realize you're essentially repeating the design of Shuttle, right? It's like turning an 18 wheeler into an RV.   Using SS's payload bay to set the size of modules greatly raises the module size and mass limits, but leaving stuff in there is not a good choice. Likewise the power needs for such a module are likely to need substantial arrays which are better as left permanently on orbit.

If it's better to leave the panels in space, then by all means do it. Send them up like any other long-term module. To the extent that this model matches Shuttle, that's fine with me. Shuttle flew 134 times and was by far the longest-running crewed US space program. It "failed" because it was too expensive, but if successful Starship will be less expensive by at least an order of magnitude. But SS for crew quarters and "short-term" lab space is very different than Shuttle, because this "lab" Starship is not also designed to deliver large modules.

Why is "leaving stuff in there" a bad choice? This stuff does not have to stay in space as it is being used for short-term experiments. By leaving it in the "lab" Starship you can bring it back to Earth and service it in relative comfort using specialized equipment and personnel rather than using astronauts in free fall with more limited equipment.

We are now drifting far off topic, so perhaps a different thread?

[wannamoonbase]

I think it may be a good idea to develop a jettisonable fairing for Starship. A big, highly-hammerheaded fairing, say 13m in diameter and 50m long. The fairing may be pretty massive, maybe 50t, but made of stainless steel so relatively inexpensive. Could even be recoverable, although likely used too rarely to justify that. Recover the stainless to recycle it I suppose.

Whether the upper stage portion is reusable or not, I think this would be a useful capability to have.

Although I love the idea of what hardware would require such a fairing, it's hard to imagine what is needed beyond the 9 meters, at this time anyway.

An expendable upper stage with a 9 meter fairing is a mental image in my mind.  I know the the Elon and SpaceX amazing peoples hate when I bring up an expendable upper stage.  But think of the volume and mass to LEO!

Frankly, if SS is as cheap to make as it appears to be, then an expendable US for 100+ MT to LEO would be a huge bargain.

And if you can reuse the fairing, then rinse repeat!

[AC in NC]

An expendable upper stage with a 9 meter fairing is a mental image in my mind.

How much extra payload does jettisoning the fairing add? 

My mental counter-image is precisely what we have today except that the top of SS detaches at the top of the tanks, SS with Payload backs out of it, deploys Payload, reattaches, and comes only with full reusability.  Same volume at the expense of the mass bump and the incremental complexity of a reattaching "nosecone".  Craxy?

[dglow]

An expendable upper stage with a 9 meter fairing is a mental image in my mind.

How much extra payload does jettisoning the fairing add? 

My mental counter-image is precisely what we have today except that the top of SS detaches at the top of the tanks, SS with Payload backs out of it, deploys Payload, reattaches, and comes only with full reusability.  Same volume at the expense of the mass bump and the incremental complexity of a reattaching "nosecone".  Craxy?

Hinged petals, a la Neutron, would be a simpler choice if full recovery was the objective IMO.

[mandrewa]

Currently, SpaceX has 13 active boosters. Additionally, there are 10 more boosters that have been spotted in either testing or transit.

It has been speculated that B1049 will be expended after it's next mission. Based on the available mission profile, it appears the 4 FH core boosters will be expended after their first launch as well.

The true number of launches with just the current boosters likely is between 80 and 160 - without SpaceX deciding to certify some of the later ones to 20 flights.

So counting it up, there are ninety-six flights left in the current thirteen active boosters.  That is if we assume an average of fifteen flights per booster.  And that doesn't include the new boosters that are in the pipeline or the side boosters which after supporting Falcon Heavy flights could be converted to regular Falcon 9 boosters.

Ninety-six flights will probably take SpaceX halfway through 2024.  And it will be a whole lot more flights if we count the boosters that are in the production pipeline.

SpaceX is prepared to do a lot more flights on the Falcon 9.  I would say that they have definitely not assumed in the Falcon 9 production pipeline that the Starship will work.

And it's really eleven active boosters that have been responsible for the flights so far this year.  Booster 1949 last flew in September 2021.  It's supposed to be expended on its next flight this November.  And Booster 1069 just returned to flight a few days ago after an accident from a flight from last December(?).