Starpipe Could Be the Ground System That Sets Starship Cadence
A potential bottleneck of Starship’s future launch rates might not be found in the skies but rather right under the feet of engineers and technicians working at Starbase. The upcoming project of SpaceX to lay down an 8-mile-long natural gas pipeline Starpipe and build a methane liquefaction facility at Starbase illustrates one principle of aerospace industry reusable heavy lift launchers can scale up only when their propellant chains do it as well.
It matters greatly since the propellant chain of Starship is impossible to scale up via trucking services. It is impossible since for each launch, 2.4 million liters of liquid methane is needed. The company has been transporting this propellant to the site by means of tanker trucks. The method works great for testing and low launch rates, but it is problematic to operate as the launch cadence rises. This logistics chain raises a number of problems in terms of traffic, loading time, scheduling and dependency on third parties delivery schedules. In the case of the rapid reuse of rocket hardware, such logistics chain becomes a potential bottleneck itself.
According to SpaceX, a construction of an 8-mile natural gas pipeline called Starpipe will be launched soon in Texas. The construction will finish before January 26, and the operation of this pipeline will start after that. The purpose of the construction of this pipeline is to supply the Starbase with the necessary fuel and allow SpaceX to increase the launch rate of Starship, its reusable super-heavy rocket. As it was noted, the diameter of this pipeline is 16 inches, but it is not enough to give an idea about the possible future launch rate. The pipeline diameter is only one element of the complex of ground infrastructure including fuel storage, processing and transfer facilities as well as a launch pad.
The real matter of importance in this situation is a new technology which is allowed by this pipeline. According to the documents, SpaceX is going to build an on-site liquefaction plant at Starbase which will produce liquid methane from piped natural gas. From the viewpoint of the launch operations, this means the transition from the distributed logistics chain of the methane fuel to the on-site processing.
The fact is easily overlooked if the whole discussion of the launch is limited to the engines, heat shields or recovery systems of rockets. High-cadence operations are usually limited by the least flexible element of the chain. In the case of the reusable very large rocket, the ground support equipment is not a secondary element of rocket but a part of the production system.
The fact is already illustrated by the case of Starbase. According to the current environmental authorization of Federal Aviation Administration, up to 25 orbital launches of Starship/Super Heavy from Boca Chica per year is approved. The information gives some idea about the currently authorized activities of the company, but it does not mean that the problem of propellant logistics is solved or future cadence increases are guaranteed. The launch rate will depend also on licensing, availability of the pads, site readiness and many other factors except fuel availability.
However, the fuel logistics becomes especially important in this case since it is one of the few bottlenecks which can be overcome with the help of the fixed infrastructure. A pipeline, a storage farm, a transfer network and a liquefaction plant do not solve all constraints of the launch system but reduce the dependency of the launches on the trucks and simplify the transition from the fuel source to the launch pad. From the industrial viewpoint, it means the transition from the batch delivery model to the industrial utility service model.
In addition, there is a wider lesson of the U.S. launch site case. Reusability is usually considered as a rocket attribute, but the launch cadence is essentially a problem of systems integration. One can design a rocket for rapid turnover and slow it down with the help of commodity handling, cryogenic conditioning, pad resetting or local transportation limitations. The ground infrastructure should be built to repeat, not perform a peak activity.
That is exactly why Starpipe deserves attention beyond the title of the energy infrastructure. If the goal of the Starship is a frequent flight, the launch site should function not as a test range supported by the convoy but as an industrial plant with its own facilities. The pipelines, liquefaction equipment, storage tanks and transfer devices are not as glamorous as the engines and flight tests but exactly these fixed assets determine whether reusable heavy launch can become routine or episodic. The main idea of the discussion is rather simple for the Starship, reusability does not determine the cadence by itself. The ground-side propellant integration may become even more important than the elements flying aboard the rocket.
By David Whitaker – Associate editor for AMI’s aerospace and drone systems desk, translating flight systems, aircraft programs, spaceflight, and UAV developments into readable technical stories.
