Will the Big Falcon Rocket Eat the SLS?

(This is Part II of the series on SpaceX rockets vs SLS. For Part III, click here)


Apparently, something momentous occurred on Friday and I missed it.

I know, I know…but it does happen.

The first Bangladeshi communications satellite was successfully put into orbit by the first Block 5 Falcon 9 rocket. My congratulations to SpaceX and Bangladesh for this monumental achievement.

On June 4th, 2010, SpaceX launched the first of their series of Falcon 9 rockets. From its beginning, it was built to refly. However, since landing and reflying orbital rockets efficiently was a totally new concept, they had to first take some time to learn how to do that.

ORBCOMM-2 First-Stage Landing

Through repeated launches, fiery crashes, landings, refurbishments, design improvements and component additions/improvements, the new Block 5 Falcon 9 rocket is finally manufactured from the ground up for the dedicated purpose of achieving the closest thing to routine space flight that this rocket can do.

Built to fly more than ten times each, with (maybe) a 24 hour turnaround and more than double the initial thrust of the first Falcon 9, this is the final version of that rocket and will be used for all Falcon launches from now on, including Falcon Heavy, going forward. SpaceX will now stop improving this rocket and put all of their research and development work into their new ride, the Big “Falcon” Rocket (BFR), which Elon says he wants to start hop-testing next year.

Block 5 culminates the reusability goals for the Falcon 9 and Falcon Heavy rocket lines, having been built on the knowledge base of 2 years of refurbishing and reflying boosters.

They did this in several ways…more robust internals, heat protection instead of paint, bolting the engines on instead of welding them, self-retracting legs, titanium grid-fins, and better heat-shielding for the engines.

But another thing that folks are talking about is a last major upgrade to the Merlin Engine. All told, this new version of the Falcon 9 supposedly has more than twice the initial thrust of the first-ever Falcon 9. Elon says that it can lift roughly 8% more weight to LEO than the Falcon Full Thrust rockets they’ve been flying for the past two years or so.

Something folks aren’t talking about is what those short turnaround times are going to do to the usual 2 year-plus launch lead times…another key point of competition in the launch services industry. If SpaceX can ever catch-up on the backlog in its launch manifest, they’ll be able to use those short turnarounds to start chopping lead times and saturate the market, and launch reservations at Kennedy Space Center and Vandenberg Air Force Base, with cheap F9 and FH rides.

What about NASA’s Space Launch System? Back in February 2015 I wrote here about how staged improvements to the engines had brought about the Falcon Full Thrust upgrade that would fly SES 9 in April 2016. That article does a little math and speculates that the Falcon Heavy with those same Full Thrust boosters would be a “stone throw away” from the low-end of NASA’s upcoming Space Launch System. Throughout last year and into this year, and especially since the Falcon Heavy test flight, that article has seen much heavier traffic on this blog than anything else I’ve ever written here, due to folks web-searching for information on that rivalry. Even now, every time a Falcon 9 launches or someone important is on the news talking about this stuff, the page gets another flurry of hits. I’ve been using it as kind of a measuring stick for interest in the new space race.

The Falcon Heavy test flight used three Falcon 9 Full Thrust boosters. Wikipedia has these numbers for the Falcon Heavy’s lift capacity to LEO, but I don’t know if it is referring to the Falcon Full Thrust or the new Block 5. It looks an awful lot like the number that I saw when I researched the earlier article on Falcon Heavy Full Thrust…

“63,800 kg (140,700 lb)”

Is this number in wikipedia really based on the Falcon Heavy Full Thrust? Or is it the Mark 5? If it refers to the Falcon Full Thrust, and if that same 8% improvement applies equally to the Falcon Heavy and the Falcon 9, then when the FH flies that demo mission for the U.S. Air Force in October, its lift capacity will be 70,180 kg to Low Earth Orbit. It’s possible SpaceX knows this and is shying away from bragging about it for now to avoid political resistance to that Air Force launch.

Wikipedia still uses the same numbers for NASA’s Space Launch System (SLS) that I used back in 2015…

“70,000 to 130,000 kg (150,000 to 290,000 lb)”

So when the SLS debuts next year (or so) with the EM-1 mission, with the weakest planned variant of the rocket, it might not be the biggest boy on the block! I’m still waiting for some real experts to verify this for me and I’ll update this article with a clarification when I get several good answers in one direction or another. Even if FH does top out at 64K kg, then the upper-end Falcon is still almost as mighty as the lower-end SLS.

Now, just to clarify, the Falcon Heavy will probably not ever actually carry that maximum-mass payload. Reusing the rocket means saving some fuel so that the boosters can fly to a pad somewhere and land. That number that I just quoted is if they plan to fly the rocket only once, burn every last drop of fuel during the launch, release the second stage, and then abandon the entire first stage to just crash into the ocean…like SLS will do anyway. Also, the larger diameter payload fairing on SLS means it’ll have room at the nose of the rocket to mount much larger spacecraft than Falcon Heavy’s Falcon 9-sized payload fairing can. That makes SLS far more useful for crewed interplanetary travel and especially for launching modules for larger space stations. Lastly, the liquid hydrogen that the SLS’ left-over Space Shuttle engines burn works more efficiently in space than the RP1 kerosene used by the Merlin engines on Falcon, making SLS better suited than Falcon Heavy for interplanetary missions in that respect as well.

But most taxpayers won’t care about any of that. They’ll see the FH and SLS as near-equals at what is starting to boil down to less than 20% of the cost for Falcon Heavy. The public will begin to speculate that SpaceX will have replaced NASA, especially once the Falcon 9 starts flying the upcoming Crew Dragon to the International Space Station. Nothing can be further from the truth. NASA is a space agency, SpaceX is a launch services company. NASA has been providing SpaceX with a lot more technical assistance to get them this far than the other way around. The development of the Dragon spacecraft, and the Falcon 9 technology on which the Falcon Heavy Mark 5 relies, was achieved with a ton of NASA patronage. NASA and SpaceX do not compare in the same category as competitors but truth be told are actually partners in this New Space revolution.

In fact, I think that NASA instigated all of this. I think that they know they’re working themselves out of a job in the field of launch services and spaceflight. I think that they’re doing it on purpose because they know that as long as those things remain tied to Congressional politics they will never go anywhere.

The Falcon Heavy and the SLS don’t compete either, not really…as you saw from the other differences between the two rockets beyond just their respective throw-weights. The SLS won’t even have a decent second stage for it’s first flight or two. Falcon Heavy will likely fly dozens of times before the REAL monster, the Interplanetary version of the SLS, gets off of the paper and starts flying actual missions! So SLS and FH should never have to compete for anything important due mostly to timing. Even if NASA and Boeing can follow through with the idea of flying an extra wimpy SLS Block 1 in between, Falcon Heavy will still be in full operation for many years, and launch more than a dozen times, while SLS is still flying what are essentially R&D launches.

There is some danger to SLS if it doesn’t fly soon though. Falcon Heavy will fly the same or similar mass to the SLS test launch many times before the SLS first test flight even occurs. And every time a Falcon rocket goes up, more folks will hit Google and read this and other articles that say that SLS costs too much money to develop, much less fly, with an adequate and less expensive Commercial alternative available.

What is more likely to happen is that Falcon Heavy is too small to eat the SLS, and the SLS will be developed and flown to slowly to be eaten. A successful Falcon Heavy launch in October will herald the end of the heavy-lifter race, with SpaceX the next winner. SLS will have survived by virtue of having missed the race and being out of its weight class anyway. Sort of like a young grizzly sleeping in a cave as an adult black bear shambles on past the entrance.

The super-heavy lifting contest, on the other hand, starts next year. It’ll probably have more players in it than just SpaceX and NASA, no medium-lift payload fairings or half-baked second-stages, and those rockets won’t burn a drop of kerosene. For now it looks like the young SLS will fly and some sign of an actual development timeline for SpaceX’s Big Falcon Rocket (BFR) will be seen by the mid-2020s. We might also see something fly from elsewhere in the world in the heavy or super-heavy lift category.

The contenders for that race are still lining up at the starting line and we’ll talk about them in Part Three of this series…Will the MUCH Bigger Falcon eat the SLS? It will all depend on development times, with the SLS Block 1A and Block 2 the birds to beat.

Stay tuned.


~ by Bill Housley on May 12, 2018.

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