Building Less Expensive Rocket Launchers

The title of the April 15th, 2011 Aviation Week article "China Great Wall Confounded By SpaceX Prices" seems self explanatory but the article makes the point explicit by stating that "executives at China Great Wall Industry Corp. are finding it hard to believe that California-based Space Exploration Technologies Inc. (SpaceX) is offering lower launch prices than they can."

Space-X Falcon 9.

The article then goes on to state that "Chinese officials say they find the published prices on the SpaceX website very low for the services offered, and concede they could not match them with the Long March series of launch vehicles even if it were possible for them to launch satellites with U.S. components in them."

According to the SpaceX website, a Falcon 9 rocket launch, with an advertised lift capacity of 10,450 kg. (23,000 lb.) from Cape Canaveral, costs between $54 million - $59.5 million dollars.

What is the secret of Space-X?

According to the June 18th, 2010 article "Elon Musk on Why His Rockets Are Faster, Cheaper and Lighter Than What You’ve Seen Before" from the Private Equity website (peHUB), there are a number of good reasons for the Space-X success including vertical integration, less outsourcing and some good old fashioned and very basic common sense.

The article quotes Space-X CEO Elon Musk as stating:

Some of what we’ve done is really just common sense — for example, using the same propellant in the upper and lower stages means that operationally, you only need to have one set of fuel tanks. If you can imagine a situation where you have a kerosene first stage, hydrogen upper stage, and solid rocket side boosters, you’ve just tripled your cost right there.

Space-X CEO Elon Musk.

Also, the upper stage of Falcon 9 is simply a short version of the first stage. That may seem pretty obvious, but nobody else does that. They tend to create upper stage in a totally different way than they create the first stage.

The Merlin engine — we used it on the upper stage of Falcon 9, on the main stage of Falcon 9 and on the first stage of Falcon 1. So we get economies of scale in use of the Merlin engine.

Our tanks are friction steel welded, [aluminum] skin and stringer designed as opposed to machined aluminum, [giving us] a 20 fold advantage in the cost of materials, and our stage ends up being lighter …because geometrically, we can have deeper stringers.

Others are slowly beginning to put together more detailed assessments of the secrets behind the Space-X pricing. For example, the April 10th, 2011 post titled "Musk-Rocket Ramble" on the Ric's Rulez blog credits several specific choices with keeping costs down including:

• The decision to burn kerosene (RP-1) and liquid oxygen (LOX) for fuel instead of liquid hydrogen and LOX. Hydrogen, the lightest element, is difficult to cool and store as a liquid and not terribly dense even then so the fuel tank has to be quite large and complex. Kerosene is denser and much easier to store since it can be stored at room temperature. While NASA generally prefers hydrogen for it's greater specific impulse, most of the storage and cooling problems go away with kerosene, which provides substantial cost savings. LOX and kerosene are used in the lower stages of most Russian and Chinese boosters plus the first stages of the Saturn V and the Atlas V. LOX and liquid hydrogen are used in the upper stages of the Atlas V and Saturn V, the newer Delta IV rocket, the H-IIA rocket, and most stages of the European Ariane rockets.

Shuttle with side mounted solid rockets.

• The decision not to use solid fuel rockets strapped to the side of the liquid fuel launchers, as is the case with the space shuttle is the second key to lowering costs. Solid rockets are useful when there is a need for long-term storage (and solid fuel rockets make great intercontinental ballistic missiles) but are less useful when you simply need something light and powerful, which is the prime criteria for satellite launchers. A second, solid fueled system added to an existing liquid fueled system also adds an additional level of complexity, which also adds to costs.

Space-X Manager of Business Development Josh Brost went into a little more detail on his firms methodologies during the presentation "Space-X: Revolutionizing Access to Space" at the Canadian Space Commerce Association (CSCA) conference and annual general meeting, held on March 18th at the MaRS Discovery District. Brost credits Space-X's success in keeping costs down with the following:

Space-X Merlin engines.

• •Rockets assembled and integrated horizontally, not vertically, which Space-X considers less expensive and less hazardous.

• Cross-training of technicians in multiple areas to insure that there are no narrow skilled specialists waiting around for specific work.

• An intentional decision to build more than 70% of vehicle components in-house at one location, which assists with the development of a direct feedback loop between on-site engineers and technicians as they work together on projects.

• Strong in-house and on-site capabilities in multiple areas including precision machining & inspection, tank fabrication, variable polarity plasma arc and friction stir welding, composites, precision assembly, tooling design/ fabrication, avionics laboratory & environmental testing, propulsion assembly and numerical control tube bending.

According to Arny Sokoloff, CEO of Continuum Aerospace and President of the Canadian Space Commerce Association, there are a lot of local political concessions built into most rocket programs and the real key to cost control is minimizing the various locations where the work is being done by doing as much as possible in-house and at one location.

"This is the real secret of how they avoid the massive duplication of roles and the consequent cost overruns typical in aerospace development" states Sokoloff.