In March 2017, SpaceX launched a recovered Falcon 9 booster on its second mission for the first time. What followed changed the industry, proving that reuse wasn't just viable but economically beneficial for a launch services provider. Since that 2017 milestone, European industry leaders have used a near-identical excuse for why Europe wasn't neck-deep in developing a reusable rocket in the same vein as Falcon 9. The excuse was that Europe just didn't have the launch frequency needed to make reuse viable.
SOURCE: Europe in Space
"Moreover, for overall economic benefits, it is key to launch as many times as possible, to compensate for the loss of manufacturing cadence. So, it may not bring the same advantages in Europe than in the U.S., where you have a huge institutional market with many guaranteed launches to deliver."
Arianespace CEO Stéphane Israël - 2017
"Let's say we had ten guaranteed launches per year in Europe and we had a rocket that could be reused ten times - then we would build exactly one rocket per year. That doesn't make sense. I can't say to my teams: 'Bye, see you next year'!"
ArianeGroup CEO Alain Charmeau - 2018
"Given the number of launches that SpaceX does, there was an economic equation which made reuse extremely favourable. Whereas when the Ariane 6 program was launched with an objective of four institutional launches and five commercial launches, reuse was not economically interesting."
ArianeGroup CEO Martin Sion - 2024
In an announcement from the German aerospace agency DLR's Institute of Space Systems, this ongoing narrative was directly challenged. The announcement included the release of six separate studies that offered a comprehensive overview of launch systems with reusable first stages. The agency stated that one of the key takeaways was that "the reusability of first stages becomes economically attractive even with low annual launch numbers."
The DLR European Next Reusable Ariane (ENTRAIN) programme is focused on studying approaches to developing a reusable rocket first stage for a future European launcher, comparing Vertical Take-Off, Vertical Landing (VTVL), and Vertical Take-Off, Horizontal Landing (VTHL) concepts. Phase 1, completed in 2018, assessed various configurations and selected the most promising designs. Phase 2 focuses on detailed system analysis, aerodynamics, structural impacts, and descent dynamics. The programme's overarching goal is to support the development of cost-effective, competitive European reusable launch systems by determining the most efficient recovery method based on technical, operational, and economic factors.
As part of the ENTRAIN programme, DLR has published six studies (linked below) exploring vehicle configurations, propulsion systems, and the economic feasibility of developing and operating VTVL and VTHL systems. Among its key findings, the series challenges the notion that a modest European launch cadence of fewer than ten flights per year prevents reusability from being economically viable.
The studies consider a large two-stage RLV with a reusable first stage that carries a non-recurring cost of €13 billion for development and an average launch cost of €186 million. The large two-stage ELV counterpart has a non-recurring development cost of €8 billion but a heftier €314 million price tag per launch. Both vehicles feature a payload capacity of 7.5 tonnes to geostationary orbit.
In an analysis of various VTVL and VTHL configurations, the studies found that reusable launch vehicles (RLVs) could outpace expendable launch vehicles (ELVs) in cost efficiency even at a mere 2.6 launches per year over 20 years. "The fully expendable launch vehicles are, on average, 36-41% more expensive than their equivalents with reusable first stags," one paper states. The breakeven point, where RLV costs equal ELV costs, occurs at around 40 launches.
"Across all 5,000 launch market scenario samples considered in this study, launchers with reusable first stages enable significant cost savings compared to fully expendable versions."
The studies do not explicitly address Charmeau's point that producing only a single rocket or first stage per year for all of Europe's launch needs may be impractical from a manufacturing standpoint. However, this misrepresents the practical realities of reusable rockets. With ten launches per year, roughly one per month, a first stage would need to be recovered, refurbished, and returned to the launch pad within that tight timeframe. Even if that were possible, it would leave little to no room for delays. A fleet of reusable first stages would, as a result, be necessary to maintain operational flexibility. Beyond that, we must also account for refurbishment operations and the ongoing production of expendable upper stages. The idea that reusability means telling your team, "Bye, see you next year!" after building just one rocket is simply laughable.
While much of the analysis in these studies serves as a direct challenge to the claims made by European industry leaders, one sentence stands alone as the most damning of all.
"This comparison suggests that the estimated development costs for the most similar ENTRAIN launcher align reasonably with the costs observed in the Ariane 6 development program," explained the study.
Not only is this an indictment of the amount of money spent on Ariane 6, but it also dismantles the argument that reusability is inherently too expensive for Europe. If a partially reusable launcher could be developed for a similar cost, then the reluctance to pursue reusability appears to be less about financial feasibility and more about entrenched industry stalwarts and resistance to change. Not that this conclusion comes as much of a surprise to anyone paying attention.