That Falcon Heavy 8 MT figure for three core recovery feels like it's been sand bagged a bit. It represents a 70+% loss in performance over fully expendable or expending just the core.
If it's a sandbag, it's not much of one. Three-core recovery requires RTLS on the side boosters and a very long braking burn (either boostback or longer entry burn) on the core, while two-core recovery represents dual ASDS landings for the side boosters but at a generally more benign speed than we've seen with Falcon 9. It's a huge difference.
Recall that an expendable Falcon 9 bills at $92M, while a triple-core-recovery FH is $2M cheaper. If triple recovery FH could deliver more payload than an expendable Falcon 9, it would surely cost more.
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?
But perhaps most surprising was a statement made by Mr. Musk the day before Falcon Heavy’s first launch. During that teleconference, Mr. Musk stated that the overall price for a Falcon Heavy could reduce significantly once Falcon Heavy flies in its fully reusable configuration – essentially lowering its price to just $62 million dollars or the price of a regular, brand new Falcon 9.
Well, you know Falcon Heavy is essentially, from a cost standpoint, it's Falcon 9 plus two side boosters. And we expect to recover all three cores, or at least two of the three cores on every flight. Now this is a development flight, so who knows what'll happen on this flight. But being able to reuse those rocket booster cores means that the expendable portion of the Falcon Heavy flight is the same as a Falcon 9 flight. On Falcon 9 we expend the upper stage. We are in the process of recovering the fairing, we're getting better and better at recovering the fairing. So we expect to recover the fairing and the booster, the first stage of Falcon 9. Like I said, only the second stage will be expended. And what's interesting is for Falcon Heavy, it's the same amount that's expended, just the upper stage. So it means we're able to offer heavy, arguably super heavy lift, nearing super heavy lift capability for not much more than the cost of a Falcon 9.
Quote from: sevenperforce on 02/20/2018 05:40 pmIf it's a sandbag, it's not much of one. Three-core recovery requires RTLS on the side boosters and a very long braking burn (either boostback or longer entry burn) on the core, while two-core recovery represents dual ASDS landings for the side boosters but at a generally more benign speed than we've seen with Falcon 9. It's a huge difference.Hmm, side booster landings on the drone ships should be faster reenty than single stick F9 because the increased T/W ratio makes it go faster (even with throttled centre core). The burn time of the side boosters should be identical, hence the velocity should be higher for FH.
LEO tanker performance assumes that the payload is nothing but an International Docking Adapter (mass: 526 kg), so that it could be docked to a vehicle waiting in LEO for an ejection burn.
Quote from: sevenperforce on 02/20/2018 04:19 pmLEO tanker performance assumes that the payload is nothing but an International Docking Adapter (mass: 526 kg), so that it could be docked to a vehicle waiting in LEO for an ejection burn.umm.. I don't undestand what you mean by this. Fuel remaining in the tank after reaching the orbit with this?
Right. 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.
Does LEO tanker include the fact that it doesn't need a fairing, which must save a fair bit of weight and drag.I note that the price of FH all recovered + f9 recovered, with F9 launching a payload, and FH launching expendable is the same, and the capability to high energy orbits doing this is also comparable.Is the 'tanker' mass including or excluding the stage?Capability with FH expendable as tanker goes up really quite a lot.I note my 'F9 moon lander' thread. https://forum.nasaspaceflight.com/index.php?topic=45010.0
Rather than building a completely new fairing, they'd probably just put on a regular clamshell. Other option is to cover it with the nosecone from the Dragon 1.
Quote from: sevenperforce on 02/20/2018 09:33 pmRather than building a completely new fairing, they'd probably just put on a regular clamshell. Other option is to cover it with the nosecone from the Dragon 1. I think I was assuming the booster fairings would fit, but I guess the attachments are rather different, and there is no provision for them to come off.In principle, the airflow seems not to be a problem, as S2 of course is gone when all the boosters are doing anything aero.
Quote from: hkultala on 02/20/2018 08:38 pmQuote from: sevenperforce on 02/20/2018 04:19 pmLEO tanker performance assumes that the payload is nothing but an International Docking Adapter (mass: 526 kg), so that it could be docked to a vehicle waiting in LEO for an ejection burn.umm.. I don't undestand what you mean by this. Fuel remaining in the tank after reaching the orbit with this?Right. 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.
Falcon Heavy's base price is $90M. Sacrificing all three cores is a $30M x 3 markup, to $150M. Tracking so far.
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.
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.
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)
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?
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?
Quote from: envy887 on 02/23/2018 03:16 amQuote 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? The people who pay the bill.
Musk: The Merlin engines, the engine thrust is going to increase by approximately 8%, to 190,000 pounds of thrust at sea level. We think there's probably a little more room there, maybe going up to 10% or so.
From the transcript of the post-launch conference of the first block 5 launch by internetftwQuoteMusk: The Merlin engines, the engine thrust is going to increase by approximately 8%, to 190,000 pounds of thrust at sea level. We think there's probably a little more room there, maybe going up to 10% or so. A quick estimate approximates full thrust expendable performance at 18650kg or so, out of Canaveral to 180km.This is low, but at least in the order of magnitude.Increasing the liftoff thrust from 7000kN to 7560kN and the second stage by the mentioned 5% takes this to 19180kg, or 3% increase.Adding that extra couple of percent only bumps it by a hundred kg.This would presumably help lots more on expendable core FH launches.
a marginal cost for a Falcon 9 launch down, fully considered, down under five or six million dollars.
we intend to demonstrate two orbital launches of the same Block 5 vehicle within 24 hours no later than next year.
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. With this figure, and the numbers already published by SpaceX, I was able to put together a pretty comprehensive table of Falcon family performance to virtually any destination. Took a lot of spreadsheet work, but it all came out pretty well.VehiclePrice (USD)LEO (tanker only)LEO (payload)GTO (2.27km/s)GTO2.45realTLI (2.73km/s)LLO (4.04km/s)GEO (4.33km/s)TMI (4.30km/s)Falcon Heavy (expendable)$150M96.9163.8026.7015+25.1716.6815.2216.80Falcon Heavy (recovery x2)$95M87.2257.4224.0313.5+???22.6515.0113.7015.12Falcon Heavy (recovery x3)$90M23.5318.118.00106.663.653.123.17Falcon 9 (expendable)$92M24.9922.808.306.57.744.253.654.02Falcon 9 (ASDS recovery)$62M17.0413.305.505.54.502.141.711.75Falcon 9 (RTLS recovery)<$62M11.749.413.513.52.700.850.520.56
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. With this figure, and the numbers already published by SpaceX, I was able to put together a pretty comprehensive table of Falcon family performance to virtually any destination. Took a lot of spreadsheet work, but it all came out pretty well.VehiclePrice (USD)LEO (tanker only)LEO (payload)GTO (2.27km/s)GTO2.45realTLI (2.73km/s)LLO (4.04km/s)GEO (4.33km/s)TMI (4.30km/s)Falcon Heavy (expendable)$150M96.9163.8026.7015+25.1716.6815.2216.80Falcon Heavy (recovery x2)$95M87.2257.4224.0313.5+???22.6515.0113.7015.12Falcon Heavy (recovery x3)$90M23.5318.118.00106.663.653.123.17Falcon 9 (expendable)$92M24.9922.808.306.57.744.253.654.02Falcon 9 (ASDS recovery)$62M17.0413.305.505.54.502.141.711.75Falcon 9 (RTLS recovery)<$62M11.749.413.513.52.700.850.520.56I note the recent tweet.From a slide in a presentation by Hans.As shown on twitterI have added a column in the table '2.45real' - this is the claimed payload to 2.45km/s, not the 2.27 used above.The estimated and real payloads are identical for F9 reusable, though to a higher energy orbit - actual full fat GTO, GEO-1800.F9 expendable is a little lower - is it possible that the recoveries are now using less propellant than thought, and that's where the margin to go all the way to GTO is coming from? The margin between 5.5 and 6.5 at GTO is about 320m/s.If this is coming from the first stage, this implies only 13 tons of propellant or so remaining in the first stage to do everything, and that is really impressive if true. (~1800m/s total delta-v to do entry and landing burns) Later tweets pointed me to the fact that spacexs website quotes 8.5 to GTO, so something funky is going on.A payload for only two recoveries was not given, so I estimated using the '90% of expendable' quote from Elon about FH payload in two recovery mode.FH recovery with all three cores to droneships gets an impressive 10 tons.
Quote from: speedevil on 10/03/2018 10:09 amQuote 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. With this figure, and the numbers already published by SpaceX, I was able to put together a pretty comprehensive table of Falcon family performance to virtually any destination. Took a lot of spreadsheet work, but it all came out pretty well.VehiclePrice (USD)LEO (tanker only)LEO (payload)GTO (2.27km/s)GTO2.45realTLI (2.73km/s)LLO (4.04km/s)GEO (4.33km/s)TMI (4.30km/s)Falcon Heavy (expendable)$150M96.9163.8026.7015+25.1716.6815.2216.80Falcon Heavy (recovery x2)$95M87.2257.4224.0313.5+???22.6515.0113.7015.12Falcon Heavy (recovery x3)$90M23.5318.118.00106.663.653.123.17Falcon 9 (expendable)$92M24.9922.808.306.57.744.253.654.02Falcon 9 (ASDS recovery)$62M17.0413.305.505.54.502.141.711.75Falcon 9 (RTLS recovery)<$62M11.749.413.513.52.700.850.520.56I note the recent tweet.From a slide in a presentation by Hans.As shown on twitterI have added a column in the table '2.45real' - this is the claimed payload to 2.45km/s, not the 2.27 used above.The estimated and real payloads are identical for F9 reusable, though to a higher energy orbit - actual full fat GTO, GEO-1800.F9 expendable is a little lower - is it possible that the recoveries are now using less propellant than thought, and that's where the margin to go all the way to GTO is coming from? The margin between 5.5 and 6.5 at GTO is about 320m/s.If this is coming from the first stage, this implies only 13 tons of propellant or so remaining in the first stage to do everything, and that is really impressive if true. (~1800m/s total delta-v to do entry and landing burns) Later tweets pointed me to the fact that spacexs website quotes 8.5 to GTO, so something funky is going on.A payload for only two recoveries was not given, so I estimated using the '90% of expendable' quote from Elon about FH payload in two recovery mode.FH recovery with all three cores to droneships gets an impressive 10 tons.Hans is sandbagging heavily. A previous block of F9 lifted the 6761 kg Intelsat 35e to 25.85° x 42742km x 296km, which is a considerably higher energy orbit than the one Hans listed. F9 B5 expended performance is definitely way more than 6500 kg.Also, 5500 kg to both 2.27 km/s and 2.45 km/s? That doesn't even make sense.
5500kg is perhaps an older number, to 2.27, than the 2.45 one.I agree there seem to be several inconsistencies.