Topics: Aerodynamics, ESA, NASA, Space Exploration, Spaceflight
The pursuit, exploration and utilization of the space environment can be misinterpreted as a luxury. History portrays space as an exclusive domain for global powers looking to demonstrate their prowess through technological marvels, or the stage for far-off exploration and scientific endeavour with little impact on daily life. However, the benefits of space are already woven into our everyday routines and provide utilities and resources on which the society has grown dependent. If these were suddenly to disappear and the world were to experience just “a day without space”, the consequences would be evident to all.
The utilization of space is set to become more important still. A new vision for the future is starting to emerge that will feature even more innovative uses of space, ranging from space-based manufacturing and energy production to global Internet connectivity. Space-debris management is also receiving greater focus alongside lunar and Martian exploration, and even space tourism.
While some of these new innovations may sound like they are confined to the realm of science fiction, there are already companies furthering the technology to turn them into reality.
Conventional rocket vehicles are propelled by a fuel (liquid hydrogen, kerosene or methane) and an oxidizer (liquid oxygen) carried within the vehicle body. When the fuel and oxidizer combust, mass is projected out of the back of the rocket, creating thrust. However, this approach – and especially the use of heavy on-board liquid oxygen – is constrained by Tsiolkovsky’s rocket equation. It basically tells us that everything carried on board a vehicle has a penalty in the form of the additional propellant, and structural mass of the vehicle, needed to get it off the ground. In other words, this approach hampers mission performance, mission payload and mission time.
SABRE, on the other hand, is a hybrid air-breathing rocket engine. During the atmospheric segment of its ascent, it will use oxygen from the atmosphere instead of carrying it inside the vehicle, before switching to on-board oxygen upon leaving the atmosphere. A SABRE-powered launch vehicle will therefore have lower mass for a given payload than a conventional rocket vehicle. This mass benefit can be traded for systems that will enable reusability and aircraft-like traits, such as wings, undercarriage and thermal-protection systems – all the features needed to fly the same vehicle over and over again, achieving hundreds of launches.
Air-breathing rocket engines: the future of space flight, Oliver Nailard, Physics World