VehiclePrice (USD)LEO (tanker only)LEO (payload)GTO (2.27km/s)TLI (2.73km/s)LLO (4.04km/s)GEO (4.33km/s)TMI (4.30km/s)Falcon Heavy (recovery x3)$90M23.5318.118.006.663.653.123.17Falcon 9 (expendable)$92M24.9922.808.307.744.253.654.02
When he said it, he obviously meant it's about 10% performance loss is to SOME orbit. (probably LEO maximum payload).For other orbits, the difference is different, and probably much greater for high energy trajectories.And he may even have meant barge landing instead of RTLS of the side boosters in this number. (construction/buying another barge to atlantic was just announced)This payload table is simply FULL or errors, inconsistent numbers based on incorrect assumptions.
Quote from: sevenperforce on 02/20/2018 08:28 pmFalcon Heavy's base price is $90M. Sacrificing all three cores is a $30M x 3 markup, to $150M. Tracking so far. That's some interesting math there.
Falcon Heavy's base price is $90M. Sacrificing all three cores is a $30M x 3 markup, to $150M. Tracking so far.
Quote from: sevenperforce on 02/20/2018 08:49 pmElon has talked about orbital propellant transfer, and while this is very unlikely for the Falcon upper stage, I've also seen mission proposals where an empty upper stage is sent into orbit to dock with another vehicle and perform a burn BLEO. So I threw in one column where you'd merely be figuring out how much propellant you'd have left over.Then those numbers look like they have something badly wrong.first, the principle. We know that the second stage is undersized for FH. It would make sense to spend MORE fuel for 2nd stage burn, not less.Then some calculations:Expendable FH:F9/FH second stage + your adapter is ~4.5 tonnes, and has about 107500 tonnes of propellant.With 97 tonnes of fuel remaining, this means that the second stage would give it only ~328 m/s of delta-v.So the core would need to go to almost orbital velocity (with a 112-tonne 2nd stage as a payload)
Elon has talked about orbital propellant transfer, and while this is very unlikely for the Falcon upper stage, I've also seen mission proposals where an empty upper stage is sent into orbit to dock with another vehicle and perform a burn BLEO. So I threw in one column where you'd merely be figuring out how much propellant you'd have left over.
FH with reusable side boosters:With 87 tonnes of fuel remaining, this means that the second stage would give it only about 673 m/s of delta-vAnd with your reusable side boosters, the core would have to reach ~6.8km/s of staging velocity (in addition to the gravity losses).These don't seem like reasonable staging velocities, no way the boosters and core are capable of this.
Numbers for fully recoverable FH seem to be considerably lower in this than the NASA database.(which itself probably has too low numbers, based on old FH model)
Quote from: sevenperforce on 02/20/2018 04:19 pmElon recently let slip on Twitter that flying Falcon Heavy with parallel booster recovery only (expendable core) represents a 10% performance loss over fully-expendable but would only run about $95M.When he said it, he obviously meant it's about 10% performance loss is to SOME orbit. (probably LEO maximum payload).For other orbits, the difference is different, and probably much greater for high energy trajectories.And he may even have meant barge landing instead of RTLS of the side boosters in this number. (construction/buying another barge to atlantic was just announced)
Elon recently let slip on Twitter that flying Falcon Heavy with parallel booster recovery only (expendable core) represents a 10% performance loss over fully-expendable but would only run about $95M.
If the numbers are correct, then FH 3x recovery makes no sense, as you can fly an expendable F9 with less risks.Edit: could only make sense for a central core recovery for inspection, but not for all flights.
This whole mess does not add up for very simple reason: those are prices for customer, not cost for SpaceX.Things like "FH with middle core expended costs only 5 mln $ more" show it is fools' errand to try "what is true cost" kremlinology based on price alone. SpaceX can and will set up prices so certain behaviours are incentivized and other penalized. For example, they want reward customers for using FH fully reusable over F9 expendable.
Quote from: hkultala on 02/21/2018 08:26 amNumbers for fully recoverable FH seem to be considerably lower in this than the NASA database.(which itself probably has too low numbers, based on old FH model)Numbers for fully-recoverable FH are based on the advertised limit of 8 tonnes to GTO.
The spreadsheet - or at least more of the methodology needs spelled out.I did rough numbers, and if you assume that the '10% less' number originates from a lower velocity at MECO, at least at LEO and GEO, the loss is about the same for the first stage velocity, at around 250m/s.
Quote from: sevenperforce on 02/21/2018 12:35 pmQuote from: hkultala on 02/21/2018 08:26 amNumbers for fully recoverable FH seem to be considerably lower in this than the NASA database.(which itself probably has too low numbers, based on old FH model)Numbers for fully-recoverable FH are based on the advertised limit of 8 tonnes to GTO.Advertized limit for $90 million price tag. Not advertised limit of fully reusable.
The price point has been put up to the web page 5.5.2016. Back then they had no operational block 5 engines, and the number is probably based on block 3 engines, not block 5 engines.5.5.2016 (and much later also) the maximum payload of FH was listed as 55400 kg. As the maximum payload has increased by 15% since, probably also the reusable payload has increased by about similar amount (but probably even more, as there have been also other advances that help especially reusable payload, like 3-engine landing burn, and the better T/W also helps reusable payload more, as the side boosters run out of fuel faster, after moving shorter horizontal distance, so less flyback distance).So now they have updated their maximum payload number for block 5 engines, but their pricing number is still based on the block 3 reusable payload.So, if you want to base your FH GTO performance on the FH adverticed pricing numbers, use at least 9.2 tonnes to GTO instead.
NASA LSP updated the numbers for FH in the last couple weeks
Quote from: hkultala on 02/21/2018 01:18 pmQuote from: sevenperforce on 02/21/2018 12:35 pmQuote from: hkultala on 02/21/2018 08:26 amNumbers for fully recoverable FH seem to be considerably lower in this than the NASA database.(which itself probably has too low numbers, based on old FH model)Numbers for fully-recoverable FH are based on the advertised limit of 8 tonnes to GTO.Advertized limit for $90 million price tag. Not advertised limit of fully reusable.Well, Elon said that two-core recovery is $95M and expendable is $150M, so the only other option is three-core recovery.
QuoteThe price point has been put up to the web page 5.5.2016. Back then they had no operational block 5 engines, and the number is probably based on block 3 engines, not block 5 engines.5.5.2016 (and much later also) the maximum payload of FH was listed as 55400 kg. As the maximum payload has increased by 15% since, probably also the reusable payload has increased by about similar amount (but probably even more, as there have been also other advances that help especially reusable payload, like 3-engine landing burn, and the better T/W also helps reusable payload more, as the side boosters run out of fuel faster, after moving shorter horizontal distance, so less flyback distance).So now they have updated their maximum payload number for block 5 engines, but their pricing number is still based on the block 3 reusable payload.So, if you want to base your FH GTO performance on the FH adverticed pricing numbers, use at least 9.2 tonnes to GTO instead.I can certainly accept that the FHRx3 payload to GTO has increased, but what's the basis for the 9.2-tonne number?
Quote from: IRobot on 02/21/2018 10:10 amIf the numbers are correct, then FH 3x recovery makes no sense, as you can fly an expendable F9 with less risks.Edit: could only make sense for a central core recovery for inspection, but not for all flights.But a Falcon Heavy with three-core recovery is cheaper.
Quote from: envy887 on 02/21/2018 01:51 pmNASA LSP updated the numbers for FH in the last couple weeksThey don't look updated to me and those two graphs look identical to me?
Quote from: sevenperforce on 02/21/2018 12:35 pmQuote from: IRobot on 02/21/2018 10:10 amIf the numbers are correct, then FH 3x recovery makes no sense, as you can fly an expendable F9 with less risks.Edit: could only make sense for a central core recovery for inspection, but not for all flights.But a Falcon Heavy with three-core recovery is cheaper.They are very similar prices, so an expendable F9 has less risk and no recovery costs.
Quote from: sevenperforce on 02/21/2018 01:30 pmI can certainly accept that the FHRx3 payload to GTO has increased, but what's the basis for the 9.2-tonne number?Linear extrapolation from the maximum LEO payload increase between 5.5.2016(block 3) and current (block 5)63.8 / 54.4 = 1.15 1.15 * 8 = 9.2Extrapolation from expendable GTO capacities gives even bigger increase26.7 /22.2 = 1.201.20 * 8 = 9.6And extrapolation from expendable TMI capacities even more.16.8 / 13.6 = 1.2351.235 * 8 = 9.9The payload size and stage2 delta-v for 3-S1 recoverable is closest to the TMI of the expendable, so from these 3 numbers we should use that as our basis.So actually the payload of FHR to GTO should be in the range of ~10 tonnes. (if the original 8 tonnes was to full capacity of block 3)
I can certainly accept that the FHRx3 payload to GTO has increased, but what's the basis for the 9.2-tonne number?
I think people might be giving these prices a little too much credibility. How can expended side boosters raise the price $55 million, but an expended core only $5 million?
Quote from: Nomadd on 02/20/2018 07:38 pm I think people might be giving these prices a little too much credibility. How can expended side boosters raise the price $55 million, but an expended core only $5 million?SpaceX can charge whatever price they want. An expended F9 could be $6 billion per flight and reused FH 3 for a nickel. Who says it has to make sense?