Falcon Heavy Skepticism

The long anticipated Falcon Heavy should fly towards the end of this year. Many people seem to believe that this launcher is going to be the answer to the PorkLauncher, big private payloads, launch costs, reliability, and all the other competition. I tend to think it can be a good launch vehicle without being any of those things.

Up until recently, I thought bolting three or more first stages together for larger payloads was close to a no brainer, especially if those stages are getting reused. I saw little problem with using up to seven stages bolted together. A few recent articles have made me question my previous opinion. One about Elon Musk discussing the difficulties of  making three stages work together brought up a few interesting issues on the problem. Another by Rand Simberg going into some detail on dispatch reliability and complexity issues that I have not previously considered.

I have been skeptical of some of the claims made by people from outside the company since they started posting them. There are some that insist that the F9H is going to get costs per pound down to $50.00 or less. I still believe it is too early in the game to confidently predict such prices. It should be possible to be a fan of the SpaceX accomplishments without being a wild eyed fanboy that thinks Elon walks on water in the liquid phase. There are some more debatable points I have met relatively recently.

The F9H will be the death of SLS/Orion as soon as it flies seems to be fairly popular. This would seem to be against the history of government procurement programs. The logical arguments against developing the SLS/Orion system were as valid a decade ago as they will be when F9H flies. If it was about logic, a crew capsule would have been flying on an EELV before the Shuttle was retired. An orbital depot would have enabled any mission the SLS/Orion is purported to have. The SLS/Orion may go out with a whimper in the next decade. It is politically nearly impossible that it will be in direct response to the early flights of the F9H. A politician has a primary job of getting elected, and the SLS/Orion systems will last as long as they contribute to that primary job.

There seems to be a lot of belief that huge private payloads will be ready to go as soon as the LV is available. I don’t think this matches payload history on current launch vehicles. Ariane5 and Delta Heavy don’t seem to have a backlog of full weight payloads. It is common for there to be two or more full size satellites in an Ariane launch. For that matter, F9 doesn’t seem to have payloads that come close to the advertised capability. I believe that the F9H will be an infrequent launcher of specialty payloads that are just a bit more than the F9 and competitors can handle. Once proven, it is likely that the F9H will have single digit flights per year. Elon has mentioned that one of the reasons for the delays in getting the F9H on line is that there is little demand for it. Plenty of others have mentioned that the steadily increasing capability of the stock F9 also cuts into the demand for the heavy.

Launch costs are the choke point on space development and always have been. Many people believe that the F9H is going to solve this problem. The advertised prices seem to support their opinions. The normal method of figuring launch costs use dollars per pound as the metric of affordability. Dividing maximum payload by launch price supports ┬áthe belief in the F9H as the frontier enabler. My skepticism comes from some recent articles discussing technical issues I hadn’t previously considered. When the rubber hits the road, all three of the first stages in the F9H have to go through the same level of processing as in a normal F9 flight, plus be integrated into a complete F9H. The additional level of work required to make three stages into one makes it likely that the actual launch prices per pound will end up being higher for the F9H than for the stock F9.

I expect the F9H to be a fairly reliable launch vehicle. I can’t see it matching the parent vehicle in that respect. There will be some risk associated with three cores working together with aerodynamics, vibration, and structural loads that don’t apply to the F9. There will be the additional risk of individual reliability of four stages instead of two in the F9. Very low probability events per stage will have twice as many chances to manifest in the larger vehicle. There is also the likelihood IMO that the F9H will have a much lower flight rate than the stock F9 which could lead to a bit less proficiency in catching the minor issues. Bottom line is that unless the F9H flies a lot, there will always be some question as to its’ reliability relative its’ parent vehicle.

I find the opinions often expressed that the F9H will sweep the competition to be less well thought out than they should be. As long as there are many reasons to launch a variety of sizes and orbital inclinations, there will be a variety of launch vehicles to serve the various niches. From national launchers to smaller proprietary payloads to personal animosities, there will always be reasons to have other launchers by other countries and companies.

At the end of the day, I expect the Falcon 9 Heavy to be a good launcher with fair reliability. I don’t expect it to be the greatest or the cheapest, just a good machine for the intended purpose.

 

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johnhare

johnhare

I do construction for a living and aerospace as an occasional hobby. I am an inventor and a bit of an entrepreneur. I've been self employed since the 1980s and working in concrete since the 1970s. When I grow up, I want to work with rockets and spacecraft. I did a stupid rocket trick a few decades back and decided not to try another hot fire without adult supervision. Haven't located much of that as we are all big kids when working with our passions.
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13 Responses to Falcon Heavy Skepticism

  1. Paul D. says:

    A growth path I see for FH is with a fully reusable upper stage. The payload mass penalty for that will be substantial, so it’s going to require that reusability of the lower stage cores be mature and cost effective so that the cost of a F9/FH launch would be dominated by the cost of expending the second stage.

    Another possibility is to use the FH upper stage (with expanded tanks and no payload) as a propellant tanker vehicle. A variant of this would be to put a LOX/methanr or even LOX/LH2 stage on top.

    On the other hand, a “mini-ITS” may make this moot.

  2. John,
    I’m glad you wrote this. F9 is already one of the cheapest vehicles on the planet, so I wouldn’t be surprised if FH is also one of the cheapest. But I also think you’re right that people who look just at best-case fully-packed $/kg for FH are being naive.

    Paul,
    I agree that in theory the much higher payload capacity of FH could allow full-reuse, but the payload penalty for core and US reuse (using techniques I think SpaceX is likely to use) will be pretty steep. I’m skeptical that a fully-reusable FH is really the answer. As much as I think mini-ITS is still oversized it seems like a more likely path to the truly low-cost, high-reusability future we’d all like to see.

    ~Jon

  3. matterbeam says:

    Hi!

    Thank you for mentioning these issues. Could you link the analysis by ‘Rand Simberg’?

    I do maintain some optimism. Satellite manufacturers generally work within a budget and a payload capacity. Just having an F9H available might push some manufacturers to develop larger satellites… but there will be a significant delay between the F9H coming online and a new generation of big satellites coming to market.

  4. johnhare john hare says:

    Check out his transterrestrialmusings blog for September 1. I followed links from that article as well. Interesting stuff.

  5. AMS says:

    I could see it settling out that the F9H is more expensive per kg than the F9 but part of what you’re paying for is being able to lift all your mass/volume at once. Once F9 reusability is down to their 24hr turn around target and it’s not a matter of months to get a launch up, it’ll be a case of one F9H launch for the big non-breakdown parts and several F9 launches to get the bulk mass up.

  6. Paul451 says:

    Looking at the prices SpaceX lists, which it tends to actually sell launches at, I’m not seeing where FH can be more expensive /kg than F9. SpaceX has had problems in development, but they haven’t pushed out the price, suggesting they don’t expect the actual operations to be more expensive than originally intended.

    (Whether FH develops a significant market IMO depends on how quickly the next-shiny-thing is developed. If the 9m ITS comes along quickly, the Falcon line will be shut down entirely the moment existing contracts allow it. Why would you operate a partly expendable system in parallel when you have a fully reusable one? OTOH, if ITS experiences the development hell that FH has, then FH will become a major player.)

    Re: Reliability.

    The differences between F9 and FH don’t seem to be random elements. If the aerodynamics works, it works. If the staging works, it works. They aren’t things that can sometimes work, sometimes unexpectedly fail. Everything else (the stuff that is subject to Mr Murphy) is just F9-derived. Engines, fuel tanks, landing, recovery/turnaround. And is thus proofed by F9’s flight-rate in addition to FH’s. (Of course, FH could launch “successfully” but have actually been nearly vibrated to pieces, and SpaceX knows that from their sensors, but doesn’t tell us. That’s a different thing.)

  7. Andrew Swallow says:

    To replace the Falcon Heavy the ITS would need to have a cost per launch that is lower than the FH’s. Giving the FH a reusable upper stage and faring may make a significant cost difference when launching 30-40 tonne payloads.

    A reusable faring could act as a heat shield allowing the upper stage to reenter pointy pit forward like the Shuttle.

  8. Andrew Swallow says:

    c/pit/bit/

  9. DougSpace says:

    First of all, let’s stop using the term “Falcon 9 Heavy” when Elon, for 4-5 years now, has moved on to calling it “Falcon Heavy”. Second, as has been noted, the FH is mostly F9 hardware. So, the FH benefits by the flight rate of the F9s and so the FH fixed costs are largely covered by the F9s. With three lower stages and only one upper stage, the FH is something like the equivalent of 2.5 X that of a F9. Yet its payload delivery is considerably greater than 2.5 X. So I would be very surprised if the $/kg to LEO metric to LEO would be greater for the FH than the F9.

    Besides the “build it and they will come” argument that satellite makers will take advantage of the greater capability, my big hope and focus of my space advocacy efforts is that it should be the US space program that should take advantage of FH’s capability. A 63 tonne cryogenic lander starting in LEO could deliver about 10 tonnes to the lunar surface. Starting with one-way missions of ice-harvesting telerobots ten tonnes per low-cost launch could deliver enough hardware (on the first launch) to harvest and process enough lunar polar ice to refuel the lander in as little as 22 days. A refueled lander retrieving a FH-launched cargo module at EML1/2 would bring down about twice as much payload per each FH launch. At that point the FH would be as capable as the SLS Block 2 for cargo to the Moon. The FH should be America’s Moon rocket.

  10. Paul D. says:

    What we’re seeing is the BIG issue facing new space: are there new markets to justify the new capabilities.

    F9 has been taking market share in existing markets, mostly.

    If new markets don’t arise, then SpaceX will grow a bit more and then that will be it. Prices will decline, but not a whole lot else will happen. Or perhaps it will take more time than some may have hoped for new markets to arise. I suspect that will be what really happens. In that case, it could make sense to go slow with FH until these new uses are closer to deployment.

  11. Paul451 says:

    Andrew Swallow,

    “To replace the Falcon Heavy the ITS would need to have a cost per launch that is lower than the FH’s.”

    FH is a complex beast, if ITS works as advertised, its launch operations will be simpler. Maintaining a second production line of engines and cores, and all the infrastructure needed Falcon that doesn’t work for ITS (and vice versa), adds unnecessary expense for SpaceX.

    IMO, even F9 won’t compete against ITS. (That’s ITS as advertised. Obviously once reality sets in…)

  12. Paul D. says:

    BTW, I came across this rather old (2004!) web page the other day:

    http://home.earthlink.net/~peter.a.taylor/launch.htm

    “Why Are Launch Costs So High?”

    The author (Peter Taylor) went through 19 possible explanations, and shot most (all?) of them down. It would be interesting to revisit the list in light of SpaceX and their success with the Falcon 9 (which has reduced launch costs even if reuse doesn’t pan out economically.)

    My guess: launch costs didn’t come down because the cost-plus contract structures inhibited the kind of learning/optimization that SpaceX, with its different internal incentives, has performed.

  13. N/A says:

    One could argue that current industry common 5m payload shroud diameter might be a bottleneck to battlestar sized payloads, such that if SpaceX came up with a hammerhead or extrawide shroud, the market situation would change.

    The rough business plan of a single BA330 private station serviced by 6 Dragon flights a year to send up and retrieve space manufactured ZBLAN fiber appears to close now, assuming you can get the BA330 up at all.

    It’s a crying shame Tethers Unlimited couldn’t arrange a ride on a Heavy demo flight to launch a spiderfab demo with mad amounts of printing material to make a colossal structure. That would kick all the sat makers in the shins right there.

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