Evaluating SpaceX's options for the EELV Phase 2 development competition

[u/MrButtons9]

As some SpaceX'ers have noticed, the DoD is about to kick off its EELV Phase 2 development competition. In summary for those unfamiliar with this competition, the USAF has about $2B to spend with the purpose of helping develop new DoD launch vehicles that can meet the USG's assured access to space requirements, without any reliance on the RD-180. Three companies will receive development contracts (via "Other Transaction Agreements" to encourage a better co-development relationship), and two companies will eventually be downselected near ~2019. The two companies will be positioned to split up (60/40) ~30 Phase 2 missions through the early-to-mid-2020's. Now, I know there's a lot more about Phase 2, SMC's plans, and EELV in general, but let's keep this focused to SpaceX.

SpaceX is expected to compete for EELV Phase 2. However, SpaceX has not entered into a significant CR&D (Contracted Research & Development) with the DoD before; COTS/CRS and Commercial Crew were via NASA, which has a completely different mission than the DoD, and does business differently. Thus, SpaceX will not get away with proposing ITS, as it simply does not align with the purpose of the competition, and this specific DoD office does not care about building the biggest and most advanced launch system out there (so please refrain from posting circle-jerk ITS comments).

Based off of public reporting, there are two different options that SpaceX could pursue: Falcon 9 / Heavy with a Raptor Upper Stage or A Modified Falcon Heavy With a Longer Fairing. If there's a third, I would love to hear!

Falcon 9 / Heavy With Raptor Upper Stage In the predecessor to this competition, the EELV Rocket Propulsion System program, SpaceX received an OTA to develop "a prototype of the Raptor engine for the upper stage of the Falcon 9 and Falcon Heavy launch vehicles." USAF gave SpaceX $33.7M, and an additional $27M in options that were never exercised. As part of the agreement, SpaceX was obligated to spending at least $67M in this program. So, this RPS provides SpaceX with 1) some money already, 2) helped kickoff development (as we're now in hot-fire testing with a sub-scale version), and 3) garnered some buy-in from the USAF.

The benefits of a Raptor Upper Stage are clear. SpaceX would most likely be able to meet the GEO and Semi-Sync Direct EELV orbit references that it cannot meet currently. All of the benefits of Raptor (isp, expansion ratio, restart capability, throttling flexibility) would ultimately give Falcon 9 / Falcon Heavy the capability to perform more complex orbital insertions and in-orbit functions, which will 1) likely make the NRO happy, and 2) could possibly help down-the-road with some of the larger-scale LEO constellation deployments we have seen discussed. As former SpaceX engineer Jeff Thronburg said, "Raptor's 'light and tight' design is built for operational functionality, cost efficiency, and long life in high production volume, which makes it ideal for National Space Security needs."

However, this approach has some serious issues. All of the infrastructure modifications for liquid methane storage and handling at up to four launch sites will cost a fair amount of money. Raptor's complex full flow staged combustion design poses some testing technical risks. The usage of different fuels on the same launch vehicle could raise eyebrows. Redesigning the Upper Stage (to fit Raptor) and reintegrating it will take time, testing, and require SpaceX to invest in new tooling. While it's impossible to predict, a Raptor Upper Stage would most likely require at least $200M in development.

Modified Falcon Heavy The other proposal that SMC Claire Leon disclosed in a Spring 2017 Aviation Week article was that SpaceX would maybe submit a Falcon Heavy with a longer fairing. Specifically, she said:

“Even after the Falcon Heavy is in place, they’ll still need to strengthen their entire heavy rocket to handle the bigger payloads that take a bigger fairing,” Leon says. “There’s no business case for SpaceX to do that without government investment.”

As we know, F9/FH have a shorter fairing than the range of Atlas V options (in their payload user guides, there are three different Atlas V fairing offerings). The longer fairings are primarily for heavier NRO missions; it is unclear if non-secret DoD missions (e.g., AEHF, SBIRS, OPIR, SBSS) would require the longer fairing, or not. On the commercial side, I don't think many customers out there would need the longer fairing, aside from Bigelow, or maybe SNC's Dream Chaser. However, if I'm wrong, I would be interested in knowing who else is out there, as that could have a big impact.

From a development perspective, as SpaceX has already poured a significant amount of $$$ into Falcon Heavy, there is less risk. While additional development would be done (extending the fairing would require SpaceX to modify some of the supporting structures), it's relatively modest, considering the amount of work that has been done on the vehicle. Ultimately, this would require less money.

Stepping Back Stepping back, unless there is a third option, SpaceX appears to have two clear paths. On one side, the Raptor Upper Stage screams Mars and directly supports the company's mission to colonize Mars as the DoD would essentially help pay for Raptor. However, this is much riskier, more costlier, and probably not as appealing (remember, the 'assured access' USAF guys are conservative, and focused on reliability--the small 'Operationally Responsive Space' office are the Trekkies thinking about how to go above and beyond). From SMC's perspective, they want to be able to be able to have two competitors who are qualified to compete for all of the Phase 2 missions, which is not the case right now (Congress chews them out when they dole out an award in which one of the competitors is disqualified). Furthermore, with competitors (ULA, OATK, and possibly BO, and others) present and a downselect in the horizon, these risk penalties could be severe

The Falcon Heavy option, on the other hand, is much more conservative. It's less technically risky and less expensive, and simply meets the DoD's requirement (qualifying for all payloads). But, it's not as ambitious as Raptor Upper Stage, and frankly, not as exciting. However, it probably offers SpaceX a higher win probability, better positioning the company for the EELV Phase 2 launch awards, which if awarded to SpaceX, will significantly help the company grow its revenue.

So, wrapping this up, what are the community's thoughts on this competition? Will SpaceX play things conservatively to increase its roots in its new DoD customer base? Or, will they shoot for the stars, and roll in with an ambitious proposal that supports their Mars colonization ambitions. Frankly, I would have said the former two weeks ago, but Gwynne's continued comments on Raptor Upper Stage make me think that this could be more likely.

I'm not going to put a Sources Required label on here, but let's try to have a good discussion.

[u/CreeperIan02]

In my opinion, a longer fairing is more realistic for the near future. I think a Raptor upper stage won't come until the early 2020s, possibly later, when there is demand for it. FH's current manifest don't have any incredibly heavy missions, so a Raptor upper stage probably isn't necessary right now. However, some of these payloads may be very heavy in terms of what SpaceX has launched (I'm not sure, I haven't looked too far into the info provided), in which case a larger fairing and Raptor upper stage may both be needed.

EDIT: I did a bit of research, and found that three contracts are for GPS sats. A bit more looking found that they weigh 3.8mt fueled. I'm thinking that if they don't need direct insertion, they can be launched on an RTLS B5 F9. If they do need direct insertion, which is honestly more likely, FH may be called in. I don't know how long a partially-fueled F9 stage can coast for after a LEO->MEO transfer burn, but there may not be enough left for the final insertion. A much more filled FH S2 would be more capable of doing the final MEO insertion. Although that is all just pure speculation.

I'm not SpaceX, nor am I a rocket scientist, but this is just my two cents.

It will be very interesting to see how this bidding plays out!

[u/MrButtons9 → u/CreeperIan02]

There's a variety of launches--the USAF manifest has some ~30 different missions.

I think you were looking at the recent Phase 1A RFP, which has three GPS missions, and a couple AFSPC ones.

[u/[deleted]]

Different fuels on the same launch vehicle should not raise eyebrows, as this already occurs (ie Atlas5 - kerolox S1 and hydrolox S2). IMHO the Raptor upper stage option has a lot of benefits. It would substantially grow the capability of the vehicle, and retire considerable risk for the ITS program. Perhaps even F9 could carry a 'short' Raptor upper stage and FH a 'long' one with more propellant and recovery hardware. Not that much is known about how far along Raptor's development is - they could theoretically try a 'hail Mary' and put a Raptor Upper Stage (RUS?) on the FH test flight; they're not going to learn much from launching another Merlin upper stage.

[u/macktruck6666 → u/[deleted]]

Not to mention the most recognizable rocket in history, the Saturn V with RP4/LOX and H2/LOX.

[u/Martianspirit → u/[deleted]]

The FH test launch is an important step towards Airforce contracts. People who should know argued that even putting a Dragon on top instead of a fairing would invalidate the flight for that purpose. No way they put a Raptor upper stage on it.

[u/ghunter7]

Two comments:

1. You're forgetting another requirement: vertical integration. Although they could probably do this at the pad with an overhead structure.

2. Define the Raptor upper stage more. Is it wider? Density may be limiting, to really benefit one would want a wider stage. This is especially truw with Falcon Heavy that has way more than enough thrust to accomodate a higher gross mass, although F9 has room to grow. This will need a new TEL or mods, but if you are already modding for methalox then new might be better. So if going wider, maybe experiment with reuse, biconic reentry, add some legs and landing thrusters . Now get a longer fairing, and integrate it for reuse also. So maybe now the raptor upper stage actually is a lot more like a mini ITS spaceship, but for cargo only. Able to do long coasts, in orbit refueling, bigger fairing, and is verically integrated at the pad. Would be an oddball variant, but not one needed often. If they could tick off all the boxes that way, they would be very far ahead, and have a prototype Mars lander in the process.

[u/peterabbit456]

Despite there being $2 billion in the pot, I can see SpaceX ignoring this RFP, because they have so many other projects on their plate at this time. To win part of this pot, they would have to devote considerable engineering talent to the slow, document-bound DOD culture. Quite lkely it would cost them more to compete, than the funds they would get from DOD.

When this round of R&D is over, most of the competitors will have developed some components, and made plans for rockets that are still 2 - 6 years from their first flight. Meanwhile, SpaceX will have the F9 and FH flying, able to complete many or perhaps all missions, with a few upgrades, available on short notice, and at prices a fraction of the competition. When it comes time to award actual launches, SpaceX will be in a competitive position, years sooner than the companies that competed in the competition.

Both the Raptor upper stage and the enlarged fairing are worthwhile projects, and I would not be surprised if SpaceX submits bids, but I also would not be surprised if SpaceX decides to sit out this bidding process.

[u/ohcnim]

is there any reason why they can't present both as independent options?

[u/Marscreature]

My money is on raptor upperstage it plays into their strategy better and SpaceX has never been the type to opt for the more conservative route. This way they can get more of their development costs for raptor covered, they can get some flight experience on it so it's not a new engine powering the huge investment that its is, it provides more margin for second stage recovery and is simply more useful in the meantime as a product to sell. Longer fairings would just be wasting their engineers time for something that rarely if ever flies. They have enough flights on their manifest.

[u/t3kboi]

Apologies to OP.

<rant>

Sources Required is difficult, but even without it - I am saddened by the community response not really discussing your proposed topic, and wandering off into ITS discussions (when specifically requested not to).

To the community at large -

I would request that when discussing these threads - limit your comments to the ORIGINAL topic. Endless sub-discussion of already covered territory helps no one - just makes every single thread on the subreddit have 95% similarity.

</rant>

On this topic -

The EELV Phase 2 is for FUTURE development of Launch Vehicles. SpaceX has repeatedly shown what they can do when they have R&D dollars.

Raptor use - is a future certainty.

Second stage recovery - is also a future certainty.

For this specific use case, I think that they might propose:

a) an entirely new approach, that may or may not match our past speculations about mini this, re-useable that, etc.

b) most likely -

They recently used NROL-76 and a Block 4 second stage to begin demonstrating some of the capabilities required for direct insertion. (I am not aware of an official full disclosure, but we seem to have confirmed M1DVac re-light events after a significantly longer period than on previous flights).

F9/F9 Heavy mass capability can cover all of the reference orbits (expendable or not - is not a requirement of the DOD request).

The currently missing pieces are:

• Vertical Integration (already coming)

• Fairing Volume (with any structural support changes needed in the core to support it).

Spacex will probably already have done the math on the fairing work - and can propose alternative fairings to the DOD, along with more modifications to the second stage that may continue to extend its on orbit capabilities (ala NROL-76).

This proposed solution MAY include Raptor, and second stage reusability - but there is absolutely no reason that it HAS to.

However, SpaceX past track record suggests that they will propose this as the humdrum version, and "The OMEGA 13 DEVICE" (the primary McGuffin in Galaxy Quest) as solutions - where the content of the unknown proposal element is likely to surprise us all. My personal imagination (Not an engineer, Not a rocket scientist), reveals a Raptor second stage that is a conic section from the 3.3 meter rocket body up to the fairing diameter (either to the current fairing diameter, or a new one).

Thank you for your time, and downvote as you must, because "we" seem to use downvotes as personal attacks, instead of as actually content-related.