Falcon Heavy - General Discussion

[bxr140]

...not only are there lots of potential commercial missions that only FH can do...

Just to add a little color I’d amend this a bit.

Save for interplanetary—which are by far the least likely, or at least the least frequent FH mission—the likely FH mission types are just ‘regular’ payloads that are better enabled by super heavy lift, and explicitly not payloads that ‘only FH can do’.

For a constellation launch, a big ass rocket just enables a lower launch price per unit, assuming you have sufficient volume for higher quantity of course. It’s a similar story for the unicorn dual/stacked payload deal that everyone is trying to figure out. For a servicing mission you just get to launch more fuel on your servicing vehicle, which of course improves that asset’s value proposition. For the currently expendable F9 missions you get to lightly cycle and then keep all three of your core stages.

As is evidence by the general lack of single payloads maxing out heavy lift capacity (see: the small number atlas launches with 5 solids and the small number of ariane single payload ECA launches) building big rockets is decidedly NOT a ‘build it and they will come’ deal. Hand waving past delta heavy, which really doesn’t count in context, the industry doesn’t want to build payloads that can only be launched on one kind of lifter. Everyone basically has an envelope that necessarily will work on a F9, an Atlas 5, an Ariane 5, and a Proton M, because the capability of those launchers is more or less the same anyway. It’s not coincidence.

Once BO gets off their ass and does something, we might start seeing mega payloads that can compete FH and NG. Until then, it will be interesting to see how much play FH actually gets...

 

[KarenRei]

For a constellation launch, a big ass rocket

Hand waving past delta heavy, which really doesn’t count in context, the industry doesn’t want to build payloads that can only be launched on one kind of lifter. Everyone basically has an envelope that necessarily will work on a F9, an Atlas 5, an Ariane 5, and a Proton M, because the capability of those launchers is more or less the same anyway.

Same applies to fairings. Nobody wants to build their payload past 4,5M because that's the standard ID on a number of launchers' fairings, and if you exceed that your options dramatically decline. If you design for a fairing that only works with one rocket and then it goes out of service, you're out of luck.

Speaking of that, it's a shame that FH fairings are the same size as F9. Understandable, but still a shame. It'd sure be nice if we could shift the standard max ID up some...

 

[jkn]

Also Iridium is planned to be 66 satellites in 6 orbital planes, so can't have too many in one launch.

That would make 11 satellites in orbital plane. It is not practical (perhaps impossible) if you launch 10 satellites with each launch. I think they have changed number of satellites and orbits from original 6*11.

 

[mongo]

That would make 11 satellites in orbital plane. It is not practical (perhaps impossible) if you launch 10 satellites with each launch. I think they have changed number of satellites and orbits from original 6*11.

Yeah, I couldn't figure that one out either (so completely glossed over it).
Base issue of satellites per plane is still valid though...

 

[ggr]

That would make 11 satellites in orbital plane. It is not practical (perhaps impossible) if you launch 10 satellites with each launch. I think they have changed number of satellites and orbits from original 6*11.

Note that the system was supposed to have 7 planes * 11 per plane, for 77, which is the atomic number of Iridium. But when they dropped back to 6 planes, they didn't change the name to Dysprosium. Can't imagine why not.

The constellation actually had 66 + 6 spares, twelve per plane. But after in-orbit failures, they launched more, and now they're being supplanted by Iridium Next, the second generation. (I worked on Globalstar, the competition.)

 

[AudubonB]

I finally don't have to go look at the periodic table to learn what the new name ought to have been. Have been delaying that forever. Thanks for doing my homework.

 

[dhanson865]

Beating my own in extremis horse here -

Is there any way to responsibly conjecture dimensions of the Starlink satellites, esp. vis-a-vis those of Iridium?

Over in "Investor", folks are champs at conjecturing....not so good at doing it responsibly, tho....

> Iridium Next satellites, each weighing 1,896 pounds (860 kilograms) at launch

vs Starlink:

> the internet communication satellites are expected to be in the smallsat-class of 100-to-500 kg (220-to-1,100 lb)-mass

>The satellites would be mass-produced, at much lower cost per unit of capability than existing satellites. Musk said "We’re going to try and do for satellites what we’ve done for rockets." "In order to revolutionize space, we have to address both satellites and rockets." "Smaller satellites are crucial to lowering the cost of space-based Internet and communications."

So Starlink will be half to 1/8th the weight of Iridium NEXT. I'd guess that the volume would scale similarly as the solar panels are folded during launch / before deployment.

The actual Starlink satelite might be smaller than the weight comparison would suggest but I'm thinking as the size decreases mounting hardware (which remains fixed in size or doesn't reduce as much as the satellite does) increases as a percentage of that volume used in the fairing.

 

[e-FTW]

Iridium Next satellites, each weighing 1,896 pounds (860 kilograms) at launch

Wow, I had never thought of that. When looking at those beautiful images of those seemingly peaceful deployments, you don't realize how big and heavy those satellites might be. Not that it matters once they are in orbit, but still, they look tiny on the video.

 

[Ben W]

Wow, I had never thought of that. When looking at those beautiful images of those seemingly peaceful deployments, you don't realize how big and heavy those satellites might be. Not that it matters once they are in orbit, but still, they look tiny on the video.

It's deceiving; 860kg is the weight (mass) of a steel cube just 48cm on a side.Of course they're not solid steel, but they still might be fairly small and dense.

 

[ItsNotAboutTheMoney]

It's deceiving; 860kg is the weight (mass) of a steel cube just 48cm on a side.Of course they're not solid steel, but they still might be fairly small and dense.

I <heart> the Internet:

Iridium NEXT - Satellite Missions - eoPortal Directory

Spacecraft launch mass, power	~860 kg, 2 kW
Spacecraft size (launch configuration)	3.1 m x 2.4 m x 1.5 m
Deployed wingspan	9.4 m

 

[Ben W]

I <heart> the Internet:

Iridium NEXT - Satellite Missions - eoPortal Directory

So roughly half the size of a Tesla Model 3. (4.7m x 1.9m x 1.5m, 1740kg.)

 

[ecarfan]

Forget the Falcon Heavy’s payload and focus on where the rocket will go

Excellent article by Eric Berger analyzing the Falcon Heavy; its delayed development, the launch markets it can serve, and what the future might bring.

 

[ecarfan]

There is one significant point that was missing from that article, in my opinion. Berger writes, quote:

“Perhaps because it has taken so long to develop, the Falcon Heavy may already have passed its prime even before its first flight. “Part of me wonders if SpaceX is regretting having developed the Falcon Heavy, because in some ways they’ve already moved on,” Harrison, the defense expert, said. “It’s been a learning experience for SpaceX. They went out and tried to build a heavy lift version of the Falcon 9 in a traditional way, and I think they found out that’s probably not ideal.””

I think that is true, but Berger than fails to mention that in Elon’s 2017 IAC presentation he openly talked about how SpaceX plans to make it’s current rockets (F9 and FH) obsolete with the BFR. Elon knows that there is a limited market for the FH at this point, and he explained in his presentation how the payload cost to orbit is far cheaper with the BFR compared to the FH and F9.

Berger does a good job of describing the kinds of missions that the FH is well suited for at very cost effective prices; military missions currently served by the Delta IV Heavy rocket, NASA science missions to the outer solar system (beyond Mars), and the Moon.

However that is a very small market compared to what the F9 currently addresses, and missions to the Moon are dependent on Congress which is currently locked into funding the SLS. That is unlikely to change because of political considerations. Using the FH instead of the SLS for missions to the Moon would reduce launch costs by about a factor of 10. But the people in Congress who control the money are unlikely to decide to change to SpaceX from ULA.

So I suspect that no more than two FH vehicles will ever be built. They will make money. But the FH is only a small steppingstone on the way to the BFR. Not what Elon planned on back in 2011, but plans change and he doesn’t hesitate to make changes if he feels there is a better way.

 

[KarenRei]

No more than two? I strongly disagree with that. FH gives SpaceX experience with larger rockets, greater numbers of engines operating in tandem, landing at higher thrust, recovery from higher-DV scenarios, and a lot of other things. And it opens up a heavy lift market that customers will start building to; when you can launch a lot of payload cheaply, people... will. Yes, I'm sure if they could go back in time they'd point them to head directly for BFR. But BFR won't be around for quite some time, and in the meantime, SpaceX has a lot to learn.

SpaceX also has need for it themselves, even if other customers don't step up. Let's not forget SpaceX's big plan for how to fund BFR development: the world's largest LEO satellite constellation to provide global internet access. That's a huge number of launches, even with FH, and FH is supposed to be well cheaper than F9 per unit mass.

There's also invariably some huge intermediary steps en route to BFR - namely, CF tanks and methalox / raptor propulsion, both of which are immature (but particularly the former). And not just ground testing, but extensive launch and reentry testing. Is it really best for SpaceX to just do dummy payload testing of these things? Given the amount that they need to test to get the reliability fundamentally required for BFR, they might as well mainline them into evolutionary Falcon vehicles - designed to be obsoleted, yes, but the whole Falcon line is designed to be obsoleted. Obviously methalox would be a less dramatic evolutionary step than changing tankage materials; I'd expect when it comes time to test tankage they'll replace one whole stage with a CF equivalent, then go straight from there to BFR.

 

[Grendal]

Great article. Great commentary on the future possibilities for FH too.

So my opinion on this is that once SpaceX has a fully block 5 FH that they will make only two or three of them unless a big project comes up where more are needed. Two or three B5 FH should be able to cover 6 to 8 FH launches every year for the next 10 years. There will be more demand for FH once it has flown and shown to be successful. SpaceX already has a manifest of 4 or 5 launches for FH that we know of. This last year we saw SpaceX launch older FH payloads on expendable F9s. Once Block 5 F9 are built, SpaceX will not want to ever allow a Block 5 to be expended. So every heavier satellite will be launched on an actual recoverable FH. That gives SpaceX the ability to launch almost every commercial, government, and military payload currently needed. From there it comes down to demand from customers. Demand will increase for heavier payloads simply because the capability exists.

 

[Ulmo]

No more than two?

Well, I thought it was going to be 2, but ok, how about 4?

Great article. Great commentary on the future possibilities for FH too.

So my opinion on this is that once SpaceX has a fully block 5 FH that they will make only two or three of them unless a big project comes up where more are needed. Two or three B5 FH should be able to cover 6 to 8 FH launches every year for the next 10 years. There will be more demand for FH once it has flown and shown to be successful. SpaceX already has a manifest of 4 or 5 launches for FH that we know of. This last year we saw SpaceX launch older FH payloads on expendable F9s. Once Block 5 F9 are built, SpaceX will not want to ever allow a Block 5 to be expended. So every heavier satellite will be launched on an actual recoverable FH. That gives SpaceX the ability to launch almost every commercial, government, and military payload currently needed. From there it comes down to demand from customers. Demand will increase for heavier payloads simply because the capability exists.

Ok, 3, but reused a lot, as needed. You convinced me they might have a lot of good reasons to try FH for a lot of missions, but I think complications will sour our interest in FH, at the same time that all development is being put into BFR, which I think is an excellent strategic move, to do BFR earlier rather than fulfilling the dream of the earlier idea that turned out to be too small, passive, and weak of an idea.

 

[Matias]

Heavier payloads. There are already two FH missions scheduled for later this year; Arabsat 6A and SPT-2 (US Air Force), and potentially the lunar “space tourist” mission. More will come in the future now that the lift capability is available.

Falcon 9 FT can deliver 8,300 kg to GTO and Arabsat 6A weight is less than 7000kg, so it could be delivered with Falcon 9FT.

 

[jkn]

Well, I thought it was going to be 2, but ok, how about 4?

Ok, 3, but reused a lot, as needed. You convinced me they might have a lot of good reasons to try FH for a lot of missions, but I think complications will sour our interest in FH, at the same time that all development is being put into BFR, which I think is an excellent strategic move, to do BFR earlier rather than fulfilling the dream of the earlier idea that turned out to be too small, passive, and weak of an idea.

I don't see any reason to call FH a weak idea. I can imagine good reasons why it is late: F9 has been developed to carry much heavier loads, so need for FH is reduced. It is difficult to develop FH from F9 components, when those components are changing. I haven't seen any numbers how much capacity of FH has increased.

Mass to orbit is very expensive. That's is why single stage to orbit design is a bad idea. Dropping unnecessary parts midway will give huge advantage. When those parts can be reused, costs will not increase. Costs are set by expandable parts, not by reusable parts, so FH will have lower cost / cargo mass. FH with fuel cross feed is a 3 stage rocket. It would be more efficient than 2 stage rocket. I believe they will do it, if there is a client who needs it before BFR is ready.

FH may fail. We shall see. But BFR could also be too large step. It may also fail or be delayed by years. It is very good to have F9 and FH as a back up. Nobody else has dared to plan anything like BFR.

 

[KarenRei]

Falcon 9 FT can deliver 8,300 kg to GTO

In expendable mode. But SpaceX is trying to get rid of expendable flights. GTO max payload is 5500 in a reusable config.

The idea is that the payload for expendable F9s would be pushed off onto FH instead, and all rockets will move to full reusable.

 

[Matias]

In expendable mode. But SpaceX is trying to get rid of expendable flights. GTO max payload is 5500 in a reusable config.

The idea is that the payload for expendable F9s would be pushed off onto FH instead, and all rockets will move to full reusable.

Is there public price tag for Falcon Heavy reusable vs Falcon 9 FT expendable?

Expendable prices; "$62 million price tag on a modern Falcon 9 rocket --And the Falcon Heavy price is now $90 million"

Forget the Falcon Heavy’s payload and focus on where the rocket will go