The innovative British company, Reaction Engines Ltd., has filed for bankruptcy after failing to secure additional funding for its ambitious projects. The company is renowned for its development of the Synergetic Air Breathing Rocket Engine (SABRE), a revolutionary engine concept designed for spaceplanes. The SABRE engine promised to enable spaceplanes to reach orbit without the need for boosters by utilizing a unique "precooler" design to extract oxygen from the air at lower altitudes.

Reaction Engines' flagship project, the Skylon spaceplane, envisioned a single-stage vehicle capable of transporting 17 tons to low Earth orbit. However, the development of Skylon was limited to the conceptual stage due to its exorbitant cost, estimated at over $10 billion. Despite the challenges, Reaction Engines persevered in developing key technologies for SABRE, securing funding from organizations such as the European Space Agency and attracting investments from aerospace giants like BAE Systems and Rolls-Royce. The company also established an American subsidiary, Reaction Engines Inc., in Colorado to test components of the SABRE engine technology, including its precooler.

The company's entry into administration, a process under UK law for restructuring or liquidating financially distressed companies, marks a significant setback for the development of advanced propulsion systems. While the most likely outcome appears to be liquidation, the administration process provides an opportunity for potential buyers or investors to acquire the company's valuable assets and technologies. The future of the SABRE engine and its potential applications remain uncertain, but the company's legacy as a pioneer in hypersonic propulsion will likely endure.