SpaceX Payload capability summary for different vehicle and landing combinations

[M.E.T.]

Our four Falcon Heavy options are:

1) Falcon Heavy Side Boosters RTLS, Centre Core ASDS
2) Falcon Heavy 3 Cores ASDS
3) Falcon Heavy Side Boosters ASDS, Centre Core Expendable
4) Falcon Heavy Expendable.

Options 2 and 3 require multiple ASDS, so they should be labeled "theoretical" or something like that.

We're missing an option, Falcon Heavy Side Boosters RTLS, Centre Core Expendable.

The likely scenarios:

1) FH Side Boosters RTLS, Center Core RTLS
2) FH Side Boosters RTLS, Center Core ASDS (Red Dragon?)
3) FH Side Boosters RTLS, Center Core Expendable (Red Dragon?)

IMO everything else is very unlikely or only for performance advertisement

Really? I would have thought that all three cores expendable would be a very real option, particularly for a Moon or Mars mission.

[Proponent]

Suggestions are welcome for further expansions or changes to the list.

I think it might make edkyle99 happy if you kept track (maybe in parentheses) of the heaviest payload actually flown in each configuration.

[Jim]

A liquid booster 2*core radius away from the centerline, throttled to 50%, applies the same torque as a similar thrust solid located 1 radius away from the centerline.  And in this case, it's applying thrust, so the upper attach points are still in compression.   But obviously you'd need to do the analysis - that's why I said IF the structure can stand it.

Meaningless.  The point was that SRM's are smaller and attach differently.  They attach to an area on the tank that is reinforced to take asymmetrical SRM attachments.  The three core heavies use an upper attach point that requires minimal mods by using opposing loads. 

[Jim]

So if two boosters aim for coordinates 20m apart by GPS, then this part of the position calculation should be more than accurate enough, even if the individual GPS locations are meters off.

No, then one is going to land in the water.

 

Given the accuracy they have demonstrated,

Which isn't enough to support two on the same barge.  See current landing

[M.E.T.]

Suggestions are welcome for further expansions or changes to the list.

I think it might make edkyle99 happy if you kept track (maybe in parentheses) of the heaviest payload actually flown in each configuration.

In fact, my thinking was that the heaviest payload actually flown in each configuration would be a key source of validating minimum payload capacities for each combination. In a sense, I would like this list to reflect a "No less than" payload estimate for each configuration, much like the "No earlier than" dates used for launch schedules.

Maybe a second figure could be added for "Upper extreme estimate" for each configuration, if people feel that way.

Also, I'm not sure if I am on the forum frequently enough to keep it updated, and I would love if there was a way for multiple people go update it as more information becomes available. It is the reference source that excites me, as it brings into stark focus the trade-offs, options and decision criteria for selecting appropriate configurations for different payloads and destinations.

[RotoSequence]

Which isn't enough to support two on the same barge.  See current landing

For reference, see here: https://i.imgur.com/IREsB6H.jpg

[RonM]

Which isn't enough to support two on the same barge.  See current landing

For reference, see here: https://i.imgur.com/IREsB6H.jpg

When you consider how wide the booster is with the legs extended, they would need two areas at least as wide as the white circle. The barge is a little too small for that.

[stcks]

Really? I would have thought that all three cores expendable would be a very real option, particularly for a Moon or Mars mission.

Well, it was just my opinion. I can't see SpaceX tossing away three cores in one mission. Maybe if the price is right but thats one very expensive launch for a few extra tonnes TMI

[saliva_sweet]

In fact, my thinking was that the heaviest payload actually flown in each configuration would be a key source of validating minimum payload capacities for each combination. In a sense, I would like this list to reflect a "No less than" payload estimate for each configuration

Then you could use currently demonstrated F9 performances as minumum estimates as we know block 5 will be more powerful.

[M.E.T.]

In fact, my thinking was that the heaviest payload actually flown in each configuration would be a key source of validating minimum payload capacities for each combination. In a sense, I would like this list to reflect a "No less than" payload estimate for each configuration

Then you could use currently demonstrated F9 performances as minumum estimates as we know block 5 will be more powerful.

I have the F9 ASDS GTO payload at 5,500kg. Not sure what the maximum LEO figure would be for for the F9 RTLS and ASDS configurations, as I assume that Dragon and other LEO flights haven't really pushed that boundary yet?

[envy887]

In fact, my thinking was that the heaviest payload actually flown in each configuration would be a key source of validating minimum payload capacities for each combination. In a sense, I would like this list to reflect a "No less than" payload estimate for each configuration

Then you could use currently demonstrated F9 performances as minumum estimates as we know block 5 will be more powerful.

I have the F9 ASDS GTO payload at 5,500kg. Not sure what the maximum LEO figure would be for for the F9 RTLS and ASDS configurations, as I assume that Dragon and other LEO flights haven't really pushed that boundary yet?

Iridium 1 was 9600kg to 625 km SSO and used an ASDS landing.

This page might be useful for "not less than" estimates: https://elvperf.ksc.nasa.gov/Pages/Query.aspx

Also useful for estimating: http://silverbirdastronautics.com/LVperform.html

[envy887]

Would it be possible to estimate the payload gain from booster ASDS landing vs booster RTLS? For both ASDS centre core landing and expendable centre core flights? Would the payload percentage gain be in double digits or not?

Here are some estimates by user nadreck from before the Block 5 thrust upgrades were announced:
http://forum.nasaspaceflight.com/index.php?topic=39181.msg1521480#msg1521480

The thrust upgrades will bump payloads to high energy orbits up about 10% across the board.

Are these numbers generally endorsed by knowledgeable members of the forum? I'd love to insert them into the table, as "No less than" figures.

They appear to be reasonably comparable to my own estimates for v1.2 performance. Perhaps include (est. min.) after the figure to indicate that they are estimates and lower bound values.

[TomH]

I think the 54 mt for FH fully expendable is from long before latest thrust upgrades and densified super cooled prop. I remember it going to 63 mt and later someone calculated (not a guess, but actual calcs) fully expendable Block 5 at 71 mt w/o cross feed and 72 mt w/ cross-feed. I will see if I can find the post. If so, will copy/link.

I would suggest adding fully expendable FH with crossfeed, just to show max theoretical mass. They probably will never add x-feed, but if they did, I could only see it on a fully expendable (using cores at the end of their lives) for the sake of getting some very heavy bird up. Again, it's highly unlikely ever to happen, but if it did, I think fully expendable is the only time they would do it.

[LouScheffer]

So if two boosters aim for coordinates 20m apart by GPS, then this part of the position calculation should be more than accurate enough, even if the individual GPS locations are meters off.

No, then one is going to land in the water.
 

Given the accuracy they have demonstrated,

Which isn't enough to support two on the same barge.  See current landing

On the contrary, take a look at the landing locations in the landing bingo..  The squares are about 3 meters on a side.  The boosters could be 30 meters apart, and if the center (midpoint) is where it was on this mission, both are on the deck even in the worst case alignment (offsets in direction of short edge).

And surely it's not beyond the bounds of possibility that they could spread them out along the long axis.

[TomH]

  The squares are about 3 meters on a side.  The boosters could be 30 meters apart, and if the center (midpoint) is where it was on this mission, both are on the deck even in the worst case alignment (offsets in direction of short edge).

And surely it's not beyond the bounds of possibility that they could spread them out along the long axis.

And are you sure the blast from the second landing would not blow over the first core? And if that doesn't happen, what if the first lands successfully, but the second hits the first, or tips and dominoes into it? Is the risk worth it?

[abaddon]

With cross feed, the boosters deplete much earlier and could RTLS without much perf loss.  Not that they will ever implement cross feed.

[LouScheffer]

  The squares are about 3 meters on a side.  The boosters could be 30 meters apart, and if the center (midpoint) is where it was on this mission, both are on the deck even in the worst case alignment (offsets in direction of short edge).

And surely it's not beyond the bounds of possibility that they could spread them out along the long axis.

And are you sure the blast from the second landing would not blow over the first core? And if that doesn't happen, what if the first lands successfully, but the second hits the first, or tips and dominoes into it? Is the risk worth it?

Of course I'm not absolutely sure, but a back of the envelope calculation indicates no problem with the second core blowing over the first. 

We know the landed stage masses about 27 tonnes.  So the rocket exhaust will generate about 30 tonnes-force (it's a hoverslam).  This will hit the deck and spread out in a circle.  Assume the other booster is 30m away.  So we draw a circle of radius 30m, which will have a circumference of about 200m.  The landed booster is about 4m wide, so it blocks 1/50 of the outflow.  So we can guess the force as 1/50 of 30 tonnes-force, or about 0.6 tonnes-force pushing the booster away.  But the booster has a downforce of 27 tonnes, a footprint of more than 10% of its height, and a center of gravity very close to the deck.   Therefore the force will not be enough to either tip it over or cause it to skid on the deck.  Now of course this is a super-crude estimate, but it would have to off by an awful lot for this to be a problem. 

As for the boosters colliding, SpaceX was shooting for 10m accuracy. So if they are 30m apart, it would take a 3 sigma error to make them hit, which should be rare enough.  Of course the legs stick out, but they can reduce the odds of the legs colliding by clocking the boosters such that one is a 0 degrees, and one 45 degrees.

[Coastal Ron]

Maybe I saw it in L2, in which I don't expect anyone to copy it to the public side, but has anyone on the public side calculated the following yet:

Falcon 9 Reusable - Payload to LEO
Falcon Heavy Reusable - Payload to LEO

Since all launcher providers typically provide capacity to LEO as well as GTO, knowing what the capacity to LEO for a reusable SpaceX launcher would help to make cost comparisons.

Thanks.

[envy887]

Maybe I saw it in L2, in which I don't expect anyone to copy it to the public side, but has anyone on the public side calculated the following yet:

Falcon 9 Reusable - Payload to LEO
Falcon Heavy Reusable - Payload to LEO

Since all launcher providers typically provide capacity to LEO as well as GTO, knowing what the capacity to LEO for a reusable SpaceX launcher would help to make cost comparisons.

Thanks.

Musk said that the payload hit is 15% for ASDS and 30% for RTLS, for F9 to LEO (presumably to ISS?).

This paper calculated a 20%/40% payload hit to 200 km circular LEO:

http://www.sei.aero/eng/papers/uploads/archive/SpaceWorks%20VTVL%20Study%20-%20Release.pdf

[M.E.T.]

Maybe I saw it in L2, in which I don't expect anyone to copy it to the public side, but has anyone on the public side calculated the following yet:

Falcon 9 Reusable - Payload to LEO
Falcon Heavy Reusable - Payload to LEO

Since all launcher providers typically provide capacity to LEO as well as GTO, knowing what the capacity to LEO for a reusable SpaceX launcher would help to make cost comparisons.

Thanks.

Musk said that the payload hit is 15% for ASDS and 30% for RTLS, for F9 to LEO (presumably to ISS?).

This paper calculated a 20%/40% payload hit to 200 km circular LEO:

http://www.sei.aero/eng/papers/uploads/archive/SpaceWorks%20VTVL%20Study%20-%20Release.pdf

OK, I've added the more conservative 20% and 40% payload penalty estimates for F9 LEO reusable configurations. They don't seem to hold true for the F9 GTO configurations, as the drop from 8,300kg expendable to 5,500kg ASDS is already more than 30%. Unless I'm missing something, the GTO penalties are higher than the LEO penalties.