Spanish energy company Repsol is partnering with aerospace technology developer PLD Space to develop renewable fuels for space vehicles.

The partnership would include feasibility studies to replace current fuels with alternatives produced from sustainable raw materials and the development of new renewable fuels, Repsol said on 20 October. The new fuels would be made in the Repsol Technology Lab for rocket propellants manufactured by PLD Space, specifically for MIURA recoverable micro-launchers.

As part of the agreement, Repsol said it would be developing new fuels from renewable or recycled raw materials, specifically from advanced biofuels made from waste as raw material or using synthetic fuels produced from renewable hydrogen and CO2 removed from the atmosphere.

Senior product design manager at Repsol Technology Lab’s Javier Aríztegui said the company would apply the knowledge it had acquired in the formulation of all types of fuels, including racing fuels, to develop a sustainable fuel for space vehicles.

PLD Space is developing two reusable micro-launchers - the suborbital MIURA 1 and orbital MIURA 5 - with the aim of providing commercial launch services to customers worldwide.

The company’s range of liquid-fuelled engines, called TEPREL, is powered by kerosene and liquid oxygen (KeroLOX). For MIURA 1, the firm currently uses Jet-A1 fuel, the fuel commonly used in aviation, while the fuel planned for MIURA 5 is RP-1, the standard for rocket engines.

“One of the challenges of the project is to maintain the same level of performance of the MIURA micro-launchers," PLD space propulsion manager Francesco Spalletta said.

“Our responsibility is to maintain vehicle performance while minimising its environmental impact.”

Repsol produces biofuels from sustainable sources such as vegetable oils, biomass, agricultural and forestry waste and used cooking oil.

During the first half of 2023, Repsol plans to open a new plant in Cartagena, Spain, to produce advanced biofuels from waste. The company is also planning to open a synthetic fuels plant in Bilbao, which is due to start demonstration phase production in 2024.

Repsol said these new plants would play a key role in the company’s goal of reaching a production capacity of 1.3M tonnes/year of renewable fuels in 2025 and more than 2M tonnes/year in 2030, moving towards zero net emissions in 2050.

Reusable rocket developer PLD Space has designed the suborbital MIURA 1 and the orbital MIURA 5, which have the capacity to send small satellites into space.

The company, which is based in Elche, Spain, plans to launch its MIURA 1 prototype in the second half of this year and to undertake its first real space transport mission with MIURA 5 in 2024.