🚀 A more efficient European alternative to Starship

The more massive a rocket is, the less payload it carries relative to its total mass. SpaceX's Starship perfectly illustrates this rule. A German study proposes a much more efficient European alternative based on a different concept of reusability.

To demonstrate this, researchers from the German Aerospace Center (DLR) analyzed public telemetry data from Starship's first four test flights. Their study, published in the CEAS Space Journal, shows that these Starship versions, in fully reusable mode, can place approximately 59 tonnes (65 short tons) into low Earth orbit. That's equivalent to a Falcon Heavy in expendable mode. The version equipped with Raptor 3 engines could reach 115 tonnes (127 short tons) in reusable mode, or even 188 tonnes (207 short tons) in expendable mode.



Compared to this giant, the European RLV C5 concept aims for 70 tonnes (77 short tons) to orbit at one-third of Starship's total mass, using a different approach. It combines a reusable winged booster derived from the SpaceLiner project with an expendable upper stage. The booster glides through the atmosphere after separation and is captured in flight by a subsonic aircraft. This method avoids reserving fuel for vertical landing, freeing up mass for payload.

The efficiency figures are telling. Starship at liftoff weighs more than three times the RLV C5, yet its payload fraction per tonne propelled to orbit is only 40% in reusable mode. The RLV C5 achieves 74%. The difference comes from the partially reusable design, which is lighter. However, Starship's brute capacity makes it ideal for colossal projects like lunar or Martian bases, where volume trumps efficiency.

For Europe, the RLV C5 represents an intermediate step, using technologies already under study in the SpaceLiner program. This allows it to acquire sovereign heavy-lift launch capability without immediately investing in full reusability.


The air-capture recovery method may seem futuristic, but DLR has been studying it for years. A large subsonic aircraft would snag the booster in midair, avoiding extra mass such as braking fuel. Although technically challenging, this approach relies on existing concepts and could be developed faster than a fully reusable system.

As the authors note, the RLV C5 offers an efficient path for Europe to independently develop a partially reusable super-heavy launch capability. But for now, Starship already flies, even imperfectly, while the RLV C5 currently exists only on paper.