Sunday, December 1, 2013

Will the SpaceX push to reusability make Arianespace obsolete?

Copyright 2013 Robert Clark

 By deciding on the solid-fueled Ariane 6, ESA is, unwittingly, betting on SpaceX to fail on reusability. For if SpaceX succeeds then the solid-fueled Ariane 6 becomes obsolete, with billions of dollars and years wasted. ESA would then have to start all over again to develop a liquid-fueled version which can be made reusable:

Musk lays out plans for reusability of the Falcon 9 rocket.
October 3, 2013 by Yves-A. Grondin
“The most important thing is that we now believe we have all the pieces of the puzzle (for recovery). If you take the Grasshopper tests, where we were able to do a precision takeoff and landing of a Falcon 9 first stage and you combine it with the results from this flight where we were able to successfully transition from vacuum to hypersonic, through supersonic, through transonic and light the engines all the way through and control the stage all the way through.
“We have all the pieces necessary to achieve a full recovery of the boost stage.”

Falcon 9 first stage in a controlled descent toward the Pacific Ocean. At this point, the stage was about 3 meters (9.8 feet) above the water. (Credit: SpaceX)

  I think it's a bad bet on ESA's part.

 Arianespace has already taken seriously the competition SpaceX offers for their expendable rockets:

SpaceX Challenge Has Arianespace Rethinking Pricing Policies
By Peter B. de Selding | Nov. 25, 2013

“I have sent a signal to our customers telling them that I could review our pricing policy, within certain limits,” Israel said in an interview with Les Echos, a French financial newspaper. “I think they have appreciated this.”
Israel’s comments came on the day when Space Exploration Technologies Corp. (SpaceX), after a decade of rattling Arianespace’s cage, is preparing its first-ever launch into the geostationary transfer orbit used by most commercial telecommunications satellites, and the place where most commercial revenue is made.
SpaceX Chairman Elon Musk taunted Arianespace again on Nov. 24, the day before his company’s scheduled launch of the SES-8 satellite owned by SES of Luxembourg.
“Unless the other rocket makers improve their technology rapidly, they will lose significant market share to the Falcon 9,” Musk said in a news briefing.
SpaceX President Gwynne Shotwell added: “Competition is always a good thing. It keeps people sharp. They [Arianespace and other competitors] may not look at it that way, but hopefully they’ll come to appreciate it in the future.”
“I am looking at our pricing policy and if we must adapt it to the competition, we will,” Israel said. “We’ll look at the overall efficiency of the Ariane business with a view to optimizing it.”
Israel said there are more small telecommunications satellites being designed now than ever, a fact he attributed in part to the arrival of SpaceX, which has stimulated the market.
 IF SpaceX succeeds in cutting prices by reusability, then no readjustment of the pricing will be effective. SpaceX is already undercutting them on pricing and if reusability really does cut the SpaceX prices again by a factor of 4 to 10 then ArianeSpace simply will not be able to compete.

 This will be all due to ESA's decision to go backwards in technology and not forwards in selecting a solid-fueled version of the Ariane 6. Every other space agency in the world will be able to adapt their liquid fueled rockets to make them reusable to match SpaceX's pricing. Only ESA will be left behind - both technically and economically.

 This becomes really bad because they will no longer have the smaller satellites to partially pay for the Ariane 5 launches. This could mean they also lose their entire Ariane 5 market as well! Their entire market for any of their launches will be gone all due to the choice to move backwards in technology.

 Ironically, this would mean their real reason for selecting the solid-fuel Ariane 6 would have no meaning as well. The actual reason why France and Italy want the solid-fueled Ariane 6 is to help defray the costs of the solid-fueled ballistic missiles of the French military and the solid-fueled Vega rocket largely built in Italy. But if SpaceX succeeds in cutting costs by reusability then neither the solid-fueled Ariane 6 nor the Vega, will be used because they will be priced far outside the market. So neither of them will wind up defraying the costs of other solid-fueled rockets in Europe anyway.

 Interestingly, IF SpaceX succeeds in their next test of reusability in Feb. 2014, this might provide an incentive for ESA to at least "hedge their bets" and engage in some development research of adding a second Vulcain to the Ariane 5 core. Then they would not be years behind the other space agencies in the world IF SpaceX succeeds in cutting costs by reusability. 

  Bob Clark


  1. I think if there is a successful Falcon 9 1st stage fly-back next year, ESA et al will panic and start several programs to try to catch up, including a flyback stage of some sort. It's even possible they will start to take the Skylon seriously. Skylon lends itself to a big Concorde/Airbus style program, which is very attractive to the European way of doing tech projects.

    1. I would certainly hope so. Another key fact is that by selecting the solid fueled version ESA is missing a golden opportunity to get a human spaceflight capability. So they are going backwards in this very important sense also.
      Here's to hoping SpaceX succeeds in that reusability test in Feb., 2014!

      Bob Clark

  2. Nobody in the orbit launch business is yet "thinking like an airplane". I doubt Spacex will ever achieve more than a factor 2 launch price reduction with their reusable first stage. And they get that at significantly-reduced payload, since they need the propellants to recover the stage. That raises cost per unit mass delivered, it does not reduce it.

    That being said, Spacex will put heavy pressure on Arianespace to do "something new", almost no matter what happens with recoverable Falcon-9 stages. But, reducing logistical tail has almost the same (if not more) effect on launch price. Arianespace can compete by addressing that area, even without any reusability stuff at all.

    For launch from Earth, you should not count out the utility of solids. Done right, they are cheap enough to just throw away, yet tough enough to reuse. "Done right" means a non-segmented case. And, done right, their logistical tail is very small (completely at variance with the shuttle SRB experience).

    The fit of the joint is (and always was) the Achilles heel of the shuttle SRB and any similar segmented-case designs. The whack you take hitting the sea, no matter how that is done, too often puts case segments out of reusable status, precisely because of segment fit-together issues. You can't even re-fit them together, much less get the stupid O-ring seals to work.

    The rest of solid motor refurbishment is both cheap and very well-developed. You can cartridge-load propellant segments in a big long case, there is no problem with that. Re-insulation is cheap. Propellant cast (especially cartridge-load) is cheap. It's nothing but a giant JATO bottle, if you treat the design process right.

    There is no other type of rocket that can match the frontal thrust density of the solid. Period. And it is frontal thrust density you need at ignition, not Isp. Period. Which is why solid strap-ons are so bloody popular. There's a very good engineering reason for that.


    1. Thanks for that, GW. Perhaps low cost solid-fueled orbital launchers can be done right by commercial space, but I don't have confidence it can be done using the usual government funded development approach. For instance both the new ESA Vega and JAXA Epsilon are both solids and the cost per kilo for their smaller payloads is in the $30,000 per kilo range. Admittedly smaller launchers don't have as good price per kilo rates, but this still seems high to me.
      If one did want to make a reusable non-segmented solid stage my bet would be on some of the Star series solids by ATK. Some of them have a surprisingly high mass ratio in the 20 to 1 range. When you consider some also have a vacuum Isp in the 290 s range this is almost enough to be an SSTO.

      Bob Clark

    2. Hi Bob:

      There are some long-case solids already out there and in use. None are being re-used. Yet the track record is good enough to be man-rated. These are the strap-ons being used with heavier-lift versions of Atlas-5 and Delta-4.

      Can you tell me what kind of ATK solid propellant gets 290 s Isp? The plain composites I am familiar with would only push about 260 in very large sizes. Ordinary double base is lower yet.


    3. On the Astronautix page on the Solids there are listed some Star-series solid motors that have a 290 s Isp:

      Bob Clark

    4. I see what the difference is. I was talking sea level Isp with a sea level nozzle expansion bell (260 s). What's listed on the Astronautix page for upper stage motors is vacuum Isp with huge vacuum-adapted expansion bells.

      The highest Isp solid I know of is AP-oxidized HTPB binder and about 20% aluminum powder, with all the solids at about 87% (that would be near Isp 260 s at sea level in large sizes). Those are shuttle SRB's no matter who made them. Same propellant at 20 inch diameter and sea level (SL) is about 254 s Isp: the ASALM-PTV booster. At 4 inch diameter and 88% solids, it was smoky Sidewinder. Just about the same 254 s Isp.

      You can't easily use AP with double base. AN is a lot less sensitive (and so safer). AN and aluminum make a smoky double base, AN without aluminum gets you a min smoke formulation. All the Isp's are 10-20 s of Isp lower than the corresponding AP-HTPB-aluminum-or-not.

      There were (and still are) very few outfits that could process 87% solids in composites. At the old McGregor tactical missile plant, we routinely processed 87% and even 88% solids, using pressure casting into vacuum. Traditional gravity feed casting, even into vacuum, simply will not work at that solids level. Reduce the solids to achieve gravity cast processing (mostly AP and aluminum if any), and you sharply reduce Isp.

      If you remove the aluminum in an AP-HTPB composite, you get reduced smoke at some Isp loss (around 7-10 s at SL), but your risk of combustion instability is far higher. Both propellant formulation and motor internal geometry (which changes drastically as the propellant burns!!!) affect stability in very fundamental ways.

      Double-base is inherently more difficult to manufacture, because you must handle straight nitroglycerin. Typically, the slow cook-off response is much better than AP-HTPB composite, but the sympathetic detonation and fragment impact responses are far worse. There are more manufacturing accidents.


    5. "And they get that at significantly-reduced payload, since they need the propellants to recover the stage."

      I am wondering how much propellant they would need for their vertical landing. The atmosphere slows the descent. So they would only need to kill terminal velocity for the vertical landing.

      I'm also wondering if the booster stage does a completely vertical ascent. If it imparts horizontal eastward velocity to the upper stage, the stage would have do a westward burn to return to the launch pad.

  3. I'm fairly sure that, if SpaceX successfully demonstrates reusability, Ariane 6 development will be put on the backburner. Several ESA concepts for Ariane 5 with liquid flyback boosters exist, and if SpaceX can commercialise it, those flyback boosters might be developed after all. It could be a stop gap for Skylon.

    These boosters are described here:,%20Comparative%20Study%20of%20Kerosene%20and%20Methane%20Engines.pdf

  4. Only a question about reusability of SpaceX first stage: if it has to came back to launch base it need a lot of propellant to do it. But, if Musk will bought a field on a Caribbean island on the route to orbit and have the first stage land on it, he will save a lot of propellant.