Author Topic: Reuse business case  (Read 247169 times)

Online Surfdaddy

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Re: Reuse business case
« Reply #800 on: 07/05/2022 07:31 pm »
This chart  strikes me as quite misleading.

Longest coast, and time to separation, are indeed engineering challenges.  But in no way is making a second stage that can coast for six hours six times harder than creating a stage that can coast for one hour.  Likewise time to separation.

Similarly, increasing the number of burns does not scale in difficulty with the number of burns required.  Furthermore, it's not clear that one burn should be the baseline.  According to usage, there should be an additional column at the left, labelled "leo with booster recovery".  This should have 3 burns as the baseline.  Then only the direct-injection missions are as hard; all the others are *easier* by that metric, requiring only one or two burns.

It's quite a cute marketing piece.
Seems to me FH launched a payload to the vicinity of Mars, and Psyche also scheduled on a FH, which is commercial, not "USG" launcher.

Seems as if they chose the wrong reuse architecture and are now telling a story to justify their bad decisions.

Online meekGee

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Re: Reuse business case
« Reply #801 on: 07/05/2022 08:56 pm »

Droneship landing is really enabling for Falcon 9 reuse. and I suspect Starship will eventually go in that direction over time, as will Neutron, Terran-R, etc. It’s just too much of a performance improvement to ignore, IMHO. (Although Super Heavy is currently optimized for RTLS, not downrange recovery, but if they stretch it some more, it’ll be more optimized for down-range landing.)
Droneship is only useful when the payload mass exceeds the maximum that can be handled in an RTLS landing. There are currently no such payloads, so it's unclear that maintaining the whole Droneship support infrastructure is worthwhile. It's likely to be more cost-effect for those rare huge payloads to launch to a low orbit and then refuel the SS to reach the required orbit.
Exactly.  It's almost like SpaceX can dial-a-payload, if you know what I'm talking about.
Starlink is the ultimate optimization exercise.  They can load fewer and RTLS, but clearly the barge is cheap enough.
But normal LEO satellites can get a cheaper launch if they can RTLS, and clearly that still works.
You are describing F9 here, where droneships are optimal for certain payload masses. I was describing Starship, where I believe droneships will never be optimal for any payload mass. With F9, the only ways to increase max payload mass are droneship, expended booster, or Falcon Heavy, and launches all expend the second stage. With Starship, you can increase max payload mass by refuelling, or by expending either or both stages for really crazy and rare payloads that cannot be split. You can expend several SH per year for less money that maintaining a droneship infrastructure.  By contrast with F9, dividing a payload between two launches is cheap, so aggregating payloads and then using a droneship makes no sense.
Except it's the same story - downrange recovery allows increased performance at some cost.

With Starship, the RTLS numbers (capacity, cost) are good enough that RTLS will be much more common.

Why?  Because SH can turn around in hours, so even a few days at sea is super expensive.  F9 requires a few weeks anyway, so the cost of a few extra days is marginal.
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Offline LouScheffer

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Re: Reuse business case
« Reply #802 on: 07/05/2022 09:11 pm »
This chart  strikes me as quite misleading.
It's pretty wild putting delta-V and coast time on the same Y axis, and implying this describes how hard space is.

Getting twice the delta-V of LEO takes all the engineering we have.  New Horizons and Parker might have achieved it.   And it get exponentially harder from there.  6x, for a booster, is way beyond the grasp of human technology.

On the other hand, 6x the coast time is something you hand to your engineering team, and expect a no-fuss solution.  It's not trivial, nothing in rockets is, but it's straightforward.

If plotted on this chart, a direct-to-GPS orbit mission (20% extra delta-V, 3 burns, 4 hour coast, 4 hours to sep) looks much harder than the wildest extrasolar mission proposals with a StarShip hoisting a Centaur, hoisting a STAR-48.  Even that combination would be hard-pressed to hit 3x the delta-V, while having only 1 burn, no coast, and separation soon after launch.  Something is perhaps wrong with your chart when the GPS mission looks harder.

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Re: Reuse business case
« Reply #803 on: 07/06/2022 08:36 pm »
Moderator:

Thread locked. 🔒
Guess why?
 >:(

Off-topic stacked atop off-topic.  All within 24 hours.  70 posts worth.

Re-use business case in a ULA sub-forum does NOT mean "let's talk all about Starship."

Then into shipping modes, Boca Chica EIS, carbon footprints, rocket exhaust products.

A "sour-spot" or "lunatic convergence" for a Family Feud round "Top ways to force a thread lock on the NSF forum!" 🔐 ✨️ 👏 👌 👍

And, virtually all of the derail is done by veteran members.

Dammit, all of you know better.

I will unlock 🔑 🙂 the thread momentarily.  Stay on topic or lose your posts.  It's that bloody simple.

Added: The splinter thread Dan C created regarding methane as a "sustainable" rocket propellant went immediately off-topic, after his explicit thesis, off-topicness including ad hominem attacks, and again most of the posters are veterans. So that's another 40 posts gone.

<sarcasm>
110 posts vaporized and counting--a proud day in NSF history.👏 🥲
</sarcasm>
« Last Edit: 07/06/2022 10:53 pm by zubenelgenubi »
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Offline Paul451

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Re: Reuse business case
« Reply #804 on: 07/07/2022 12:46 pm »
Seems to me FH launched a payload to the vicinity of Mars, and Psyche also scheduled on a FH, which is commercial, not "USG" launcher.

As I mentioned in the Dark Time, "Commercial" vs "USG" in Bruno's chart/graph thing refers to payloads, not launchers.

For eg, only the USG has BEO payloads available for US launchers, whereas GEO is dominated by international commercial payloads.



And I'll add the speculation: This distinction is largely irrelevant to us. So I wonder if it is made for ULA internal (and parent companies) talking points. USG payloads are seen as ULA's domain, where they perceive they can charge more because of their magic "experience" pixie-dust. But, of course, that's not borne out by recent history, Artemis payloads and Psyche, where TheOtherCompany is winning government contracts on price too, thanks to reusability. In every domain, ULA will be competing with a reusable launcher, and it's only going to get worse. But it's possible that aging execs and shareholders haven't truly grokked that yet, and still think that ULA has no competition in certain areas.
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Offline Robotbeat

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Re: Reuse business case
« Reply #805 on: 07/07/2022 12:58 pm »
Well also, the spreadsheet was made a few years ago now, when SpaceX’s dominance wasn’t so complete and Falcon 9 hadn’t reached (and arguably exceeded) the reliability of Atlas V and had failures in recent memory. So there was reason to think the USG would pick the (at the time) more reliable ULA Atlas V.


But this is kind of an argument in reuse’s favor. Reliability is ultimately about flight history, and if you manage to get a good flight rate (which reusability can help with), you’ll usually get good reliability. And with rapid reuse and a high flightrate, you’ll quickly far exceed the flight history of expendable rockets.

If you think of really high reliability numbers, like 99.9%, that implies getting a flightrate on the order of 1000 every 10 years or less, which is really not very feasible with expendable rockets, at least with US labor rates. And 99.99% and 99.999% can only happen with the extremely low cost launch of fully and highly reusable rockets. And being fully reusable also makes inspection after flight possible as well as shakedown flights on new rockets to catch manufacturing defects.


And it goes the other way. What’s the use of a highly reusable rocket that can fly 1000 times if the reliability is only 95%, so it fails after just 20 launches? So reuse both enables and requires high reliability. Which is problematic for expendable rockets as they can claim neither reliability nor low cost. The only option left is basically as munitions: if you need to launch dozens of flights in an hour or so to replenish a constellation in a war or something.
« Last Edit: 07/07/2022 01:07 pm by Robotbeat »
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Offline Paul451

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Re: Reuse business case
« Reply #806 on: 07/26/2022 06:29 am »
What’s the use of a highly reusable rocket that can fly 1000 times if the reliability is only 95%, so it fails after just 20 launches?

Not seeing the argument for this. Provided reusability doesn't increase the vehicle costs (both in per-unit manufacturing and per-flight refurbishment) by 20-fold, you are still saving money with reusability.

(Obviously, low reliability on any vehicle reduces your market for payloads, but that isn't about reusability vs expendability, per se.)
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Offline Robotbeat

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Re: Reuse business case
« Reply #807 on: 07/26/2022 04:21 pm »
What’s the use of a highly reusable rocket that can fly 1000 times if the reliability is only 95%, so it fails after just 20 launches?

Not seeing the argument for this. Provided reusability doesn't increase the vehicle costs (both in per-unit manufacturing and per-flight refurbishment) by 20-fold, you are still saving money with reusability.

(Obviously, low reliability on any vehicle reduces your market for payloads, but that isn't about reusability vs expendability, per se.)
The point is you cannot achieve high reuse (1000 reflights) without high reliability. It’s like not possible kind of by definition. So if you focus on high reuse (1000 reflights on average or better), you’ll ALSO get high reliability, higher than any expendable has statistically demonstrated.
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Offline JayWee

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Re: Reuse business case
« Reply #808 on: 07/26/2022 05:04 pm »
What’s the use of a highly reusable rocket that can fly 1000 times if the reliability is only 95%, so it fails after just 20 launches?

Not seeing the argument for this. Provided reusability doesn't increase the vehicle costs (both in per-unit manufacturing and per-flight refurbishment) by 20-fold, you are still saving money with reusability.

(Obviously, low reliability on any vehicle reduces your market for payloads, but that isn't about reusability vs expendability, per se.)
Or stated differently to Robotbeat:
There's no point in designing a vehicle/engines for 1000 launches if it, statistically, blows up after 20.
« Last Edit: 07/26/2022 05:22 pm by JayWee »

Offline deadman1204

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Re: Reuse business case
« Reply #809 on: 07/27/2022 02:02 pm »
Why is anyone even talking about 1000 flights/uses. Its the height of stupidity, that number is probably around the total number of orbital launches the US has ever done.

Online DanClemmensen

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Re: Reuse business case
« Reply #810 on: 07/27/2022 02:25 pm »
Why is anyone even talking about 1000 flights/uses. Its the height of stupidity, that number is probably around the total number of orbital launches the US has ever done.
Because Elon has a vision and he has spoken of this number. Sure, it's crazy, but Elon's crazy visions have actually come true in the past, so maybe this one will too. He has spoken of 1000 restarts for a Raptor, and he has spoken of "thousands" of ships in the Mars fleets, I don't think this would be thousands of reuses for any individual Starship. Logistically, the SH will get the most reuses, because one SH boosts many SS.

Online freddo411

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Re: Reuse business case
« Reply #811 on: 07/27/2022 02:25 pm »
Why is anyone even talking about 1000 flights/uses. Its the height of stupidity, that number is probably around the total number of orbital launches the US has ever done.

Orbital rocket flight rate looks to be on an exponential growth curve. At least it does now that commercial rocket flights are the dominant driver.

SX F9 already has more flights than any other commercial rocket.  Communication constellations are providing the demand…why wouldn’t we expect the future to have thousands of flights?


Online DanClemmensen

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Re: Reuse business case
« Reply #812 on: 07/27/2022 02:36 pm »
Why is anyone even talking about 1000 flights/uses. Its the height of stupidity, that number is probably around the total number of orbital launches the US has ever done.

Orbital rocket flight rate looks to be on an exponential growth curve. At least it does now that commercial rocket flights are the dominant driver.

SX F9 already has more flights than any other commercial rocket.  Communication constellations are providing the demand…why wouldn’t we expect the future to have thousands of flights?
The current demand spurt is driven by Starlink. Possibly there will be one or two other constellations, but eventually the number of LEO comms satellites will saturate the market and/or will be regulated to stop the space junk chaos. At that point, actual build-out will cease and be replaced by a one-for-one upgrade strategy, replacing satellites with bigger newer satellites. I don't "see "thousands" of launches needed for this. Some new demand will need to evolve. If launch cost is radically lowered, maybe something like asteroid mining will become cost-effective.

Offline whitelancer64

Re: Reuse business case
« Reply #813 on: 07/27/2022 02:38 pm »
Why is anyone even talking about 1000 flights/uses. Its the height of stupidity, that number is probably around the total number of orbital launches the US has ever done.

The USA exceeded 1,000 total launches to orbit sometime around the year 2000.

The USSR / Russia is near 3,000 total launches to orbit.

The total for everyone else exceeded 1,000 fairly recently.

The current global total for successful launches to orbit is approximately 5,500. The global average is approximately 80 launches per year, although there has been considerable variation.

Everything I'm saying is approximate because I couldn't find any total numbers more recent than 2019, just charts.
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Online meekGee

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Re: Reuse business case
« Reply #814 on: 07/27/2022 02:48 pm »
Why is anyone even talking about 1000 flights/uses. Its the height of stupidity, that number is probably around the total number of orbital launches the US has ever done.

Orbital rocket flight rate looks to be on an exponential growth curve. At least it does now that commercial rocket flights are the dominant driver.

SX F9 already has more flights than any other commercial rocket.  Communication constellations are providing the demand…why wouldn’t we expect the future to have thousands of flights?
The current demand spurt is driven by Starlink. Possibly there will be one or two other constellations, but eventually the number of LEO comms satellites will saturate the market and/or will be regulated to stop the space junk chaos. At that point, actual build-out will cease and be replaced by a one-for-one upgrade strategy, replacing satellites with bigger newer satellites. I don't "see "thousands" of launches needed for this. Some new demand will need to evolve. If launch cost is radically lowered, maybe something like asteroid mining will become cost-effective.
It never saturates due to continuous replacement.
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Offline Robotbeat

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Re: Reuse business case
« Reply #815 on: 07/27/2022 02:52 pm »
Why is anyone even talking about 1000 flights/uses. Its the height of stupidity, that number is probably around the total number of orbital launches the US has ever done.
Because that’s what Starship is being built for. F9 alone looks to be likely to meet or exceed 20 flights per booster (at least on the veteran boosters) before it’s retired, and Falcon 9 is now launching more to orbit than the rest of the world combined, and it’s only partially reusable. Imagine telling JFK “well, we can’t go to the Moon because a single Saturn V would need more mass launched than has ever been done before.” Same flawed logic.

It’s the height of stupidity to just dismiss something because it hasn’t been done before or is beyond the status quo.

Dismissing high reuse out of hand as “stupidity” is begging the question for this topic. It’s not gonna fly here.

Also, it’s missing the point. I picked a reuse number high enough to make the point that successful operational reuse, especially very high reuse, implies high reliability. To get to 1000 uses per vehicle on average, your reliability will HAVE to be much higher than any expendable has demonstrated statistically. And this applies to a less strong degree to 20 flights (already nearly in the ballpark) and 100 flights.
« Last Edit: 07/27/2022 02:57 pm by Robotbeat »
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Offline Robotbeat

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Re: Reuse business case
« Reply #816 on: 07/27/2022 02:56 pm »
Why is anyone even talking about 1000 flights/uses. Its the height of stupidity, that number is probably around the total number of orbital launches the US has ever done.

Orbital rocket flight rate looks to be on an exponential growth curve. At least it does now that commercial rocket flights are the dominant driver.

SX F9 already has more flights than any other commercial rocket.  Communication constellations are providing the demand…why wouldn’t we expect the future to have thousands of flights?
The current demand spurt is driven by Starlink. Possibly there will be one or two other constellations, but eventually the number of LEO comms satellites will saturate the market and/or will be regulated to stop the space junk chaos. At that point, actual build-out will cease and be replaced by a one-for-one upgrade strategy, replacing satellites with bigger newer satellites. I don't "see "thousands" of launches needed for this. Some new demand will need to evolve. If launch cost is radically lowered, maybe something like asteroid mining will become cost-effective.
”space junk chaos” is a troll. And besides, proper regulation would actually INCREASE the feasible megaconstellation size by making orbits safe enough to have higher satellite numerical density, and additional launches to clean up space debris could further increase launch demand.

Telecommunications is far more valuable than, say, platinum group metal mining will ever be.
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Offline JayWee

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Re: Reuse business case
« Reply #817 on: 07/27/2022 03:01 pm »
Why is anyone even talking about 1000 flights/uses. Its the height of stupidity, that number is probably around the total number of orbital launches the US has ever done.
If you announced 10 years ago that you want to build a satellite megaconstellation of 30,000 1.25ton satellites, you'd be laughed out too and considered totally crazy. Yet, here we are.

Online DanClemmensen

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Re: Reuse business case
« Reply #818 on: 07/27/2022 03:05 pm »
Why is anyone even talking about 1000 flights/uses. Its the height of stupidity, that number is probably around the total number of orbital launches the US has ever done.

Orbital rocket flight rate looks to be on an exponential growth curve. At least it does now that commercial rocket flights are the dominant driver.

SX F9 already has more flights than any other commercial rocket.  Communication constellations are providing the demand…why wouldn’t we expect the future to have thousands of flights?
The current demand spurt is driven by Starlink. Possibly there will be one or two other constellations, but eventually the number of LEO comms satellites will saturate the market and/or will be regulated to stop the space junk chaos. At that point, actual build-out will cease and be replaced by a one-for-one upgrade strategy, replacing satellites with bigger newer satellites. I don't "see "thousands" of launches needed for this. Some new demand will need to evolve. If launch cost is radically lowered, maybe something like asteroid mining will become cost-effective.
It never saturates due to continuous replacement.
That's what I said. Continuous replacement is a steady state that will not require the same cadence that was needed to build the constellation(s).
Pick some arbitrary numbers to get a rough-order-of-magnitude estimate: 10,000 satellites, two year replacement cycle, 50 satellites per launch.  That's 100 launches per year. You can do that with a single reusable launcher, and that launcher will take ten years to hit 1000 reuses.

Offline Robotbeat

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Re: Reuse business case
« Reply #819 on: 07/27/2022 03:09 pm »
Why is anyone even talking about 1000 flights/uses. Its the height of stupidity, that number is probably around the total number of orbital launches the US has ever done.

The USA exceeded 1,000 total launches to orbit sometime around the year 2000.

The USSR / Russia is near 3,000 total launches to orbit.

The total for everyone else exceeded 1,000 fairly recently.

The current global total for successful launches to orbit is approximately 5,500. The global average is approximately 80 launches per year, although there has been considerable variation.

Everything I'm saying is approximate because I couldn't find any total numbers more recent than 2019, just charts.
Global launch rate has increased dramatically in the last few years, now exceeding the Cold War peak, in part due to Falcon 9 reuse (but also a lot due to China, a new superpower adding superpower-like launch rates to the total).

2004     54
2005     55
2006     67
2007     68
2008     69
2009     78
2010     74
2011     84
2012      78
2013       81
2014      92
2015      86
2016     85
2017     90
2018    114
2019     102
2020  114
2021  144

(From Ed Kyle’s awesome website which shut down a few months ago 😭)

Last year beat the 1967 record for orbital launch attempts (was 139 in 1967).

I suspect it’ll be even higher this year. And with Kuiper and OneWeb and Starlink and Artemis, 2023 and 2024 should be higher still.
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