In a presentation earlier this year, Ukrainian space company KB Yuzhnoye made a splash by unexpectedly revealing an exotic shuttle-like space vehicle. The presentation shows a bullet-shaped design that looks more like a plane than a traditional rocket—and unlike anything seen from the famous Ukrainian rocket makers before.
Of course, these images could be just a hypothetical picture on a computer screen, but the same presentation also shows active work at Ukrainian test facilities and even some experimental hardware, which was clearly related to the unusual space plane. This mysterious spacecraft is much more than just a simple brainstorming exercise.
At the time of writing, there was no official explanation connecting these pieces of the puzzle, but sources told
Popular Mechanics the unusual “space plane” is actually a partially reusable satellite launcher being developed at Ukraine’s KB Yuzhnoye and Saudi Arabia is covering the bill.
Unlikely Allies
KB Yuzhnoye was a major rocket and space development company in the former Soviet Union. Its engineers developed several generations of Soviet space launchers and powerful ballistic missiles, as well as numerous spacecraft. After Ukraine's independence, the company continued working with Russia but also built boosters for the U.S. Antares rocket and engines for the European Vega launcher.
Meanwhile, Saudi Arabia is currently emerging as a new high-tech and military powerhouse with wide ranging ambitions in aerospace. Its prince also has widely ambitious plans to build
the city of the future.
Although the two seem like strange allies, Ukraine and Saudi Arabia have cooperated on a number of aerospace projects, including the
Grom-2 tactical ballistic missile, a scientific sounding rocket, a traditional medium-size satellite launcher, and an anti-aircraft missile.
But this aircraft, like the one detailed in this presentation, would be a new challenge for both countries.
The Engines of Space Industry
In 2013, a Saudi-based center called
King Abdulaziz for Science and Technology or KACST began funding a Ukrainian-designed hypersonic aircraft, which would carry a throwaway rocket capable of delivering small satellites into orbit.
The most interesting detail in the proposed design is the 30-ton unpiloted aircraft serving as the first stage of the two-stage launch system. The aircraft is supposed to be propelled with a combination of turbojet engines and ramjet propulsion.
The ramjet engine lacks its own compressors needed to suck air into the combustion chamber to facilitate the thrust-producing combustion of liquid fuel. This means the ramjet can activate only after some other engine—in this case a turbojet—accelerates the vehicle to a high speed forcing air into the ramjet’s air inlet.
But once it does, the ramjet is capable of further accelerating its host aircraft to speeds unreachable with traditional aviation engines. At the same time, the ramjet is more efficient than a rocket engine, because it does not need oxidizer for fuel combustion.
In the Saudi-Ukrainian project, the ramjet will accelerate the vehicle between Mach 4 and 6. Climbing at a steep angle between 40 and 50 degrees, the carrier aircraft will reach an altitude between 25 and 30 kilometers, where the seven-ton expendable rocket will separate and fire its own traditional engine.
It will be able to haul small satellites with a mass of at least 220 lbs about 310 miles above the Earth.
The Big Business of Small Satellites
It appears this still unofficial project wants to compete in the emerging business of sending small satellites skyward, especially into polar orbits. In the next few years and decades, better and better satellite constellations could provide on-demand views of the Earth’s surface,
internet access, and various communications and navigation services.
Currently, a number of other contenders
are trying to corner the market on small satellite launches, including SpaceX's Falcon rockets, India's PSLV small launcher, and
Russia's steadfast Soyuz rockets, not to mention the
New Zealand-based Electron rocket about ready to enter the fray.
But the ultimate goal is trying to get the cost of delivery as low as possible, and that’s where Ukraine's hypersonic aircraft-based system could have an edge over traditional rockets. The biggest unknown remains its exotic ramjet engines, which have never been in operational use and carry with them a high risk of engineering problems.
Sources familiar with the matter tell
Popular Mechanics that while the Ukrainian space industry is a rocket pro, this type of vehicle isn't KB Yuzhnoye’s specialty as engineers would have to tackle new problems of propulsion, aerodynamics, and heat-resistant materials. The Ukrainian space industry would also need a large-scale testing and manufacturing base for building full-scale prototypes, airframes, and engines.
A ramjet space plane is an ambitious idea—most space projects have to be—but this one still has a ways to go before its ready for launch.