Author Topic: Battle of the Heavyweight Rockets - SLS could face Exploration Class rival (Read 310992 times)

Chris Bergin · « **on:** 08/30/2014 01:18 am »

http://www.nasaspaceflight.com/2014/08/battle-heavyweight-rockets-sls-exploration-rival/

Yeah, it had to be done.

Now this starts with a brief HLV history, including the run up to SLS, and then into SLS. Also covered BFR, with a bit more info and then intimated they could face off with each other.

As such, this is more a feature than a news article - as much as the latter is more my style. It's not going to please everyone and some of it is open for debate, but this is what I've come up with - along with having it checked by a few people involved.

Should be a fun thread!

Oh and I pumped in a few more of the amazing BFR renderings the L2 members have been creating via the envisioning work in L2 SpaceX. Special hat tip to Okan as I've been mainly using his beauties in the articles.

rayleighscatter · « **Reply #1 on:** 08/30/2014 01:31 am »

It's good to see NASA isn't cornering the market on giant rockets with no payloads

mike robel · « **Reply #2 on:** 08/30/2014 01:41 am »

Nice Job Chris. Being as I am hopeless addicted to the Saturn V, its a pity you didn't stick it in the article with a shot of its ultimate version, a towering thing with stretched S1C and SII stages, a 33 foot payload shroud, and 4 260 inch liquid strap ons with 2 F-1s each, for a total of 13(!) F-1s for the vehicle.

mr. mark · « **Reply #3 on:** 08/30/2014 01:50 am »

Chris loved the article but, say it isn't so. SpaceX has a long way to go towards this goal and up next is Falcon Heavy. We'll see what the future holds. I have a feeling this article is going to get some web time beyond nasaspaceflight.com

Thorny · « **Reply #4 on:** 08/30/2014 02:01 am »

We might be looking at a 21st Century version of the R100 vs. R101 airship contest of the 1920s.
Exciting times!

JazzFan · « **Reply #5 on:** 08/30/2014 02:12 am »

Quote from: Thorny on 08/30/2014 02:01 am

We might be looking at a 21st Century version of the R100 vs. R101 airship contest of the 1920s.
Exciting times!

Or worse, VHS vs. Betamax. I just want to see a purpose driven and mission capable HLV working and launching to the moon or Mars. Competition could be just what NASA needs to getting and keeping SLS on track. Another great job Chris.

Guspaz · « **Reply #6 on:** 08/30/2014 02:24 am »

Quote from: rayleighscatter on 08/30/2014 01:31 am

It's good to see NASA isn't cornering the market on giant rockets with no payloads

BFR has a defined payload (albeit one defined by somewhat vague specifications than actual design) and destination, unlike SLS. The demand for that payload (or rather the economics of it) are not yet proven. SpaceX might end up building BFR and MCT only to discover that they can't find anybody to pay for actual missions (or perhaps only a handful of missions), even if the costs are substantially lower.

That's my worry. I think that SpaceX can pull off BFR/MCT (even if I think their timelines are terribly unrealistic), but I'm not entirely sure that they'll be able to find enough demand to justify it. Even though it's likely to end up being both substantially more capable than SLS at a substantially lower cost, somebody still has to pay for the thing, and it's hard to see much demand for a 200mt-class vehicle.

KelvinZero · « **Reply #7 on:** 08/30/2014 02:35 am »

Not a BFR fan, and I still think there is a large element of political engineering and ironic humor behind the SpaceX rocket, but I love that methane glare. Great renderings!

dglow · « **Reply #8 on:** 08/30/2014 02:37 am »

Thank you, Chris, for a very prescient piece of writing.

Coastal Ron · « **Reply #9 on:** 08/30/2014 02:59 am »

Quote from: Guspaz on 08/30/2014 02:24 am

BFR has a defined payload (albeit one defined by somewhat vague specifications than actual design) and destination, unlike SLS.

Well said.

Quote

The demand for that payload (or rather the economics of it) are not yet proven. SpaceX might end up building BFR and MCT only to discover that they can't find anybody to pay for actual missions (or perhaps only a handful of missions), even if the costs are substantially lower.

A distinct possibility. And the difference will be that one BFR will have required $Billions of taxpayer money to find out if there truly was a need for an HLV, and the other one will have required none.

Proponent · « **Reply #10 on:** 08/30/2014 03:37 am »

Quote from: mike robel on 08/30/2014 01:41 am

Nice Job Chris. Being as I am hopeless addicted to the Saturn V, its a pity you didn't stick it in the article with a shot of its ultimate version, a towering thing with stretched S1C and SII stages, a 33 foot payload shroud, and 4 260 inch liquid strap ons with 2 F-1s each, for a total of 13(!) F-1s for the vehicle.

Cool! Is that the 24(L)?

notsorandom · « **Reply #11 on:** 08/30/2014 03:46 am »

We are talking about the biggest rockets to ever be made. Both bigger than the Saturn V. SLS has billions of dollars allocated to it and supporting its development. SpaceX's BFR has how much? They have a good number of Falcons manifested. However those are not free and only a portion of the money made off those will be able to be spent on HLV development. SLS is going to be powered by engines which already exist and have a long history of use. SpaceX is planning on developing the most advanced propulsion system ever made, a full flow stage combustion methane powered monster. Right now SLS hardware is being produced. SpaceX is just starting to do basic testing on their Raptor sub-components. To paraphrase a constant criticism against SLS where are the payloads for SpaceX's rocket? The MTC is not a trivial thing to produce at all. It is possibly going to be even more tricky than the BFR. I wish SpaceX luck as I am sure we all do but to believe their rocket and payload will be ready by the end of the decade seems wishful.

Zed_Noir · « **Reply #12 on:** 08/30/2014 04:01 am »

Nice article Chris.

Just one thing that sounds strange to me. A measly 10 meter core! Was under the impressions that it will be more likely around 12+ meter from some of the interviews from Gwynne Shotwell and other SpaceX people have done. Unless you have some inside information.

I am guessing next year will the debut of the Falcon Heavy and Dragon V2 in their prototype/development versions at least. So the year afterwards should see definitive description of the SpaceX BFR. Hoprfully at least a name.

It will be amusing to see where SpaceX will launch their BFR from and they move the BFR there.

sdsds · « **Reply #13 on:** 08/30/2014 04:02 am »

I'm guessing this ends up being not so much a battle of rockets as a battle of schedule slips!

Zed_Noir · « **Reply #14 on:** 08/30/2014 04:19 am »

Quote from: notsorandom on 08/30/2014 03:46 am

We are talking about the biggest rockets to ever be made. Both bigger than the Saturn V. SLS has billions of dollars allocated to it and supporting its development. SpaceX's BFR has how much? They have a good number of Falcons manifested. However those are not free and only a portion of the money made off those will be able to be spent on HLV development. SLS is going to be powered by engines which already exist and have a long history of use. SpaceX is planning on developing the most advanced propulsion system ever made, a full flow stage combustion methane powered monster. Right now SLS hardware is being produced. SpaceX is just starting to do basic testing on their Raptor sub-components. To paraphrase a constant criticism against SLS where are the payloads for SpaceX's rocket? The MTC is not a trivial thing to produce at all. It is possibly going to be even more tricky than the BFR. I wish SpaceX luck as I am sure we all do but to believe their rocket and payload will be ready by the end of the decade seems wishful.

Musk has the Tesla motors card to play for cash. So if the next generation Tesla car rolls out successfully (not quite a sure thing) than he will be able to fund the BFR development from around 2017 with about $1B annually with other revenue steams from Solar City, batteries sales and SpaceX launches.

Proponent · « **Reply #15 on:** 08/30/2014 04:49 am »

Another great piece -- thanks very much, Chris!

I would make one suggestion, however. The tenth paragraph may propagate a common misconception:

Quote

That review [the Augustine Committee] also discussed the Flexible Path approach, which recommended a monster 200 metric ton human rated “Exploration Class” launch vehicle as a future proof rocket.

This correctly states that the Augustine Committee made recomendations as to the characteristics of a very large rocket. However, it may also suggest, incorrectly, that that Augustine recommended that a very large rocket be built. In fact, both both big rockets (e.g., SLS sized) and relatively small rockets were considered. Specifically, Augustine specifies minimum launch vehicle capabilities to LEO of "roughly" 50 metric tons to LEO (Sec. 5.2.1, p. 66) and of 40-60 metric tons (Sect. 6.5.3, p. 94). It discusses the plusses and minuses of using rockets of this size as opposed to larger rockets, but nowhere does it recommend one over the other.

It's easy to see why so many people think Augustine recommends a monster rocket:

* Augustine devotes many more pages to big rockets than to smaller ones;
* Congressional discussion has all but ignored the alternatives to big rockets;
* Augustine uses the term "super-heavy" (Sect. 5.2.1, p. 64 and elsewhere) to mean anything larger that the 25-metric-ton Delta IV, so while it does clearly recommend heavy lifters by its own terms, many will misinterpret that to imply something much larger than 50 metric tons.

breadfan · « **Reply #16 on:** 08/30/2014 04:58 am »

Great article! One question though - is there a commonly accepted definition for "exploration-class rocket" (or a list of rocket 'classes' in general) or is that just another term for SHLV?

QuantumG · « **Reply #17 on:** 08/30/2014 05:05 am »

Quote from: breadfan on 08/30/2014 04:58 am

Great article! One question though - is there a commonly accepted definition for "exploration-class rocket" (or a list of rocket 'classes' in general) or is that just another term for SHLV?

It can be experimentally determined by playing launch coverage on television at the same time as a major football game and seeing how many viewers switch over.

Burninate · « **Reply #18 on:** 08/30/2014 05:13 am »

"SpaceX’s monster rocket will utilize nine Raptor engines on a 10 meter diameter core, with the potential to advance the vehicle to a triple core."

This is somewhat obsolete, I think, unless you're using newer info I'm not aware of. The more recent simulations seemed to be pointing at a single ~15m core, in order to keep height manageable. The triple-10m-core theory was largely about the older, smaller estimates for engine thrust, combined with overly ambitious payload goals. Since we now know that thrust is much higher than initially projected, a triple core isn't necessary to meet payload goals.

Tomness · « **Reply #19 on:** 08/30/2014 05:14 am »

Hot Damn, I ve been waiting for this ewwy goodness all week. My hat is off to Chris B. Wish I had some popcorn while I read this article. Even with all teasing spacex has been dropping I can't wait for this rocket to blast off, specially the Tri-core Version. Our generation has never had the pleasure of seeing a Saturn V launch. I would love for them to human rate F1-B and J2-X and make Saturn C-8. I know it was just a paper rocket but they knew then that Saturn V wouldn't get us to Mars. I love BFR and Rapter features, though not much news yet. The dress is going to come off this lovely Maiden in the not too distant future and Elon is going to make his dream come alive.