RS-68

[Aeneas]

Delta IV is already replaceable by Falcon Heavy, isn't it?

It could be in theory, but not the way that SpaceX has flown it so far.  Delta 4 Heavy can lift almost 14 tonnes to GTO.  Falcon Heavy with recovery of all three boosters as flown to date can lift 8 tonnes.  Falcon Heavy could beat Delta 4 Heavy payload to GTO only by expending the center core, I think.  Falcon Heavy will also need a bigger fairing and SpaceX will need to add vertical payload integration to win NSSL, both steps the company has apparently proposed.

 - Ed Kyle

Next step would be landing the side boosters on a drone ship, too. Would it be realistic to put and RL10-stage above 2. stage of the Falcon Heavy configuration?

[Welsh Dragon]

Delta IV is already replaceable by Falcon Heavy, isn't it?

It could be in theory, but not the way that SpaceX has flown it so far.  Delta 4 Heavy can lift almost 14 tonnes to GTO.  Falcon Heavy with recovery of all three boosters as flown to date can lift 8 tonnes.  Falcon Heavy could beat Delta 4 Heavy payload to GTO only by expending the center core, I think.  Falcon Heavy will also need a bigger fairing and SpaceX will need to add vertical payload integration to win NSSL, both steps the company has apparently proposed.

 - Ed Kyle

Next step would be landing the side boosters on a drone ship, too. Would it be realistic to put and RL10-stage above 2. stage of the Falcon Heavy configuration?

Permit me to do a Jim. No.*

*(SpaceX doesn't make RL10s, so would have to buy them. This goes against their philosophy and Aerojet wouldn't need to sell it to them. Also, they're pretty damn expensive. The real kicker is the lack of hydrogen infrastructure on the pad though. Lastly, if you're working on the assumption that Starship will be a success (as SpaceX will be), it would make no sense to upgrade Heavy.)

[baldusi]

I'd really love to know what justified Boeing losing EELV, given from what information is available it sure looks like they had the cheapest to develop, cheapest to fly, most capable, and highest-heritage vehicle.

They cheated... criminally so. They were left with some of the EELV because it was too late to swap for another bidder.

[brickmack]

I'd really love to know what justified Boeing losing EELV, given from what information is available it sure looks like they had the cheapest to develop, cheapest to fly, most capable, and highest-heritage vehicle.

They cheated... criminally so. They were left with some of the EELV because it was too late to swap for another bidder.

No, Boeing lost EELV before that. Then they bought McDonnell Douglas, who had won with their Delta IV bid. Then Boeing broke the law.

[edkyle99]

SpaceX says that the Falcon Heavy has the capability to put 26.7mT to GTO, so it can certainly exceed the mass capabilities of Delta IV Heavy. It is only a matter of what price the customer is willing to pay, and Elon Musk has said a fully expendable Falcon Heavy would be about $150M.

I have in my hands right now a copy of Launchspace magazine, September 2000 issue.  On page 41 it lists Delta IV Heavy prices in the $130-150 million per launch range, a fantastic reduction from the $365-435 million per launch for Titan IV listed on page 43.  I recall that when Titan IV development began, similar low-ball estimates were given.  Hopeful, but ultimately ridiculous price projections seem to always precede the actual implementation of these things, especially for big DoD missions.  But good luck to SpaceX, maybe they will break the trend.  It won't be easy on missions where they have to expend stages to meet customer performance requirements.

 - Ed Kyle

[dglow]

...
Hopeful, but ultimately ridiculous price projections seem to always precede the actual implementation of these things, especially for big DoD missions.  But good luck to SpaceX, maybe they will break the trend.  It won't be easy on missions where they have to expend stages to meet customer performance requirements.

IIRC SpaceX was already pricing their flights lower before they began recovering boosters.

[envy887]

SpaceX says that the Falcon Heavy has the capability to put 26.7mT to GTO, so it can certainly exceed the mass capabilities of Delta IV Heavy. It is only a matter of what price the customer is willing to pay, and Elon Musk has said a fully expendable Falcon Heavy would be about $150M.

I have in my hands right now a copy of Launchspace magazine, September 2000 issue.  On page 41 it lists Delta IV Heavy prices in the $130-150 million per launch range, a fantastic reduction from the $365-435 million per launch for Titan IV listed on page 43.  I recall that when Titan IV development began, similar low-ball estimates were given.  Hopeful, but ultimately ridiculous price projections seem to always precede the actual implementation of these things, especially for big DoD missions.  But good luck to SpaceX, maybe they will break the trend.  It won't be easy on missions where they have to expend stages to meet customer performance requirements.

 - Ed Kyle

SpaceX expended a stage on STP-2. How much was that contract?

[butters]

With all the cautionary tales available to guide design engineers, there's no excuse for developing a new hydrolox booster engine unless you've gone mad enough to attempt an SSTO. Maybe in the coming decades, additive manufacturing technology will reach a point where many of the cooling challenges and plumbing complexities associated with linear aerospike nozzles will become practical to solve, which could justify another stab at that white whale.

If the objective is a high-thrust upper stage engine for a heavy earth departure stage, then the most reasonable approach is to ditch the gas generator and go with some variant of the expander cycle or a tap-off cycle depending on how much thrust is required. This makes flight-start much easier and more reliable. So one could argue that BE-3U is the spiritual successor to RS-68.

[edkyle99]

So one could argue that BE-3U is the spiritual successor to RS-68.

Except for thrust.  BE-4 (and Raptor too) is closer to RS-68 in that regard than BE-3U.   I still don't get it myself.  BE-4 still uses cryogenic fuel like RS-68, but has more pump-cycle complexity for less thrust and ISP than RS-68.  Less cost maybe, but we'll have to see about that.

 - Ed Kyle

[edkyle99]

SpaceX expended a stage on STP-2. How much was that contract?

Not on purpose.  The core stage intended to land OCISLY, but missed.

 - Ed Kyle

[dglow]

What in your opinion might constitute a fair LV comparison such that we could compare prices?

Assume ULA and SpaceX win NSSL awards. Vulcan is ULA's future so let's set aside DIVH. A FH, expending its center core and recovering its side boosters, would best be compared to Vulcan flying in what configuration?

[joek]

Except for thrust. ...  Less cost maybe, but we'll have to see about that.

Re-usability and commonality--which relates to cost?  Obviously not applicable to BE-3U for second-stage use, but as a derivative of BE-3 and interchangeability-commonality with BE-3, a consideration.  For BE-4, expect re-usability is definitely a factor.  Likely changing to an ablative nozzle as RS-68 would require significant changes and reduce interchangeability-commonality--not to mention re usability, so costs would go up.  Operative question for BE-3U is whether BE-3 has a future, and thus whether maintaining commonality is worth it.  If Blue intends to continue to produce New Shepard, likely yes.

In short, too many differences in goals-history between RS-68, BE-3, BE-3U and B-4 to make comparisons--and IMO off-topic for this thread

[joek]

...
Assume ULA and SpaceX win NSSL awards. Vulcan is ULA's future so let's set aside DIVH. A FH, expending its center core and recovering its side boosters, would best be compared to Vulcan flying in what configuration?

Not comparable.  ULA-Vulcan is not competing on LV pricing alone.

[su27k]

SpaceX expended a stage on STP-2. How much was that contract?

https://spaceflightnow.com/2019/06/25/falcon-heavy-launches-on-military-led-rideshare-mission-boat-catches-fairing/

The Air Force’s launch contract with SpaceX for the STP-2 mission was previously valued at $185 million, according to Lt. Col. Ryan Rose, chief of the small launch and targets division at Kirtland Air Force Base.

The launch is now costing the Air Force around $160 million, and a “big factor” in the cost reduction was the military’s agreement to fly the STP-2 mission with reused rocket boosters, Bongiovi said.

But I expect NRO launches will be more expensive since it requires vertical integration, someone will have to pay for the new MST.

[dglow]

...
Assume ULA and SpaceX win NSSL awards. Vulcan is ULA's future so let's set aside DIVH. A FH, expending its center core and recovering its side boosters, would best be compared to Vulcan flying in what configuration?

Not comparable.  ULA-Vulcan is not competing on LV pricing alone.

That's true. And it's also off-topic. My apologies.

By way of explanation I was really asking that to Ed following the back & forth upthread. However, upon rereading his post, I think Ed's point wasn't about comparing prices but rather the general sentiment that historically launch providers find it difficult to keep initial costs estimates in check for DoD missions.

Still I do not see how recovering 'only' 58% of a FH will substantially impact SpaceX's position, especially given the other likely winners of Phase 2. But we'll see. And of course, the price of a good or service is not necessarily related to its cost.

[Coastal Ron]

SpaceX says that the Falcon Heavy has the capability to put 26.7mT to GTO, so it can certainly exceed the mass capabilities of Delta IV Heavy. It is only a matter of what price the customer is willing to pay, and Elon Musk has said a fully expendable Falcon Heavy would be about $150M.

I have in my hands right now a copy of Launchspace magazine, September 2000 issue.  On page 41 it lists Delta IV Heavy prices in the $130-150 million per launch range, a fantastic reduction from the $365-435 million per launch for Titan IV listed on page 43.  I recall that when Titan IV development began, similar low-ball estimates were given.  Hopeful, but ultimately ridiculous price projections seem to always precede the actual implementation of these things, especially for big DoD missions.  But good luck to SpaceX, maybe they will break the trend.  It won't be easy on missions where they have to expend stages to meet customer performance requirements.

Boeing and Lockheed Martin were bleeding cash and lobbying the U.S. Government to allow them to create a launch monopoly, so of course they were using every tool in their political belt to justify the merger. Once they merged it was easy to justify price increases and get away from it because the budgets were opaque.

SpaceX has not increased Falcon 9 prices for previously unblown 1st stages in 4 years, so they have very good price stability. That means Falcon Heavy is not likely to follow in the footsteps of Delta IV Heavy price-wise.

The challenge the RS-68 had, now that we speak of it in the past tense since we know the only launcher that uses it is End Of Life, is that it was created for a business environment where optimization was more important than price. As the commercial launch sector becomes more diverse, and as reusability increases, that business model is no longer supportable.

[Aeneas]

Except for thrust. ...  Less cost maybe, but we'll have to see about that.

In short, too many differences in goals-history between RS-68, BE-3, BE-3U and B-4 to make comparisons--and IMO off-topic for this thread

Don't worry: I opened the thread to rant about RS-68, so if it actually develops into a productive thread, keep the factual spirit going.

[Aeneas]

If the objective is a high-thrust upper stage engine for a heavy earth departure stage, then the most reasonable approach is to ditch the gas generator and go with some variant of the expander cycle or a tap-off cycle depending on how much thrust is required. This makes flight-start much easier and more reliable. So one could argue that BE-3U is the spiritual successor to RS-68.

Why not go crazy and use FFSC in a Raptor fashion of mass production and extreme reliability through heavy testing?

[Aeneas]

So one could argue that BE-3U is the spiritual successor to RS-68.

Except for thrust.  BE-4 (and Raptor too) is closer to RS-68 in that regard than BE-3U.   I still don't get it myself.  BE-4 still uses cryogenic fuel like RS-68, but has more pump-cycle complexity for less thrust and ISP than RS-68.  Less cost maybe, but we'll have to see about that.

 - Ed Kyle

That's true but BE-4 uses methane instead of hydrogen. So much less tank needed, smaller piping at the engine, and "only" ~90 instead of crazy low ~20 Kelvin to manage. Nonetheless, I love hydrogen because it burns so beautiful and has such amazing Isp-potential...

[butters]

If the objective is a high-thrust upper stage engine for a heavy earth departure stage, then the most reasonable approach is to ditch the gas generator and go with some variant of the expander cycle or a tap-off cycle depending on how much thrust is required. This makes flight-start much easier and more reliable. So one could argue that BE-3U is the spiritual successor to RS-68.

Why not go crazy and use FFSC in a Raptor fashion of mass production and extreme reliability through heavy testing?

That's the origin story of Raptor. It was a hydrolox FFSC for three years before they pivoted to methalox. Mars ISRU was one reason for that, but also, pumping LH2 to high pressures is very difficult. SpaceX knew they were gonna be up against it to develop the ox-rich LOX pump. They probably wanted to focus their attention on overcoming that challenge and avoid biting off more than they could chew on the fuel side on the engine. If it was too big a leap for SpaceX, it's too big a leap for most engine suppliers.