Space tourism is great. It is wildly expensive though. In the early 2000s, Airbus had an idea to make it cheaper by creating Migbus: strapping a transparent passenger capsule to the MiG-31 fighter jet.

There were a lot of periods described as “a gold rush in space". We are experiencing one of them now, with private space exploration being one of the hot topics in the aerospace industry. 

It did not as much start, as evolved from the previous “gold rush” in the early 90s – mid 2000s. As relatively cheap technology became available to westerners after the dissolution of the Soviet Union, and before the spaceflight got deregulated in the United States in 2004, a slew of private ventures popped up, promising an exciting adventure beyond the atmosphere, and a trip to former Soviet Union to go with it. 

EADS – the freshly formed European Aeronautic Defence and Space Company – at the time the manufacturer of Airbus aircraft and soon-to-be-renamed to Airbus itself, tried to jump on the trend. Its space-oriented subsidiary Astrium SI (later – EADS Space Transportation) conducted a series of studies exploring the market, evaluating competitors and looking for proposals that could rival them.

The Foxbat adventure

One of the most lucrative options to experience spaceflight at the time was offered by Space Adventures, the same company that sent the first tourist to ISS in 2001. In addition to providing a possibility to fly to orbit aboard the Russian Soyuz for $20 million, the company offered a cheaper option – a “flight to the edge of space” with MiG-25 fighter jet for just $10,000. 

Mikoyan MiG-25 Foxbat, a Cold War-era Soviet interceptor, was one of the fastest combat aircraft at the time, and had one of the highest operating altitudes. In 1977, it set the yet-unbroken flight altitude record for air-breathing vehicles by climbing to 37,650 meters – more than three times higher than typical cruising altitude of an airliner. Beyond 30,000 meters, the sky turns black during the day and the curvature of the horizon becomes apparent, giving a rather perfect illusion of being in space. Add to that several seconds of free fall during the dive back, speed of Mach 2.5, and you have an experience to match any spaceflight at the fraction of the cost.

The problem is, MiG-25 has just two seats and one of them has to be occupied by an experienced pilot. In the 60s, there actually were some serious proposals to turn the Foxbat into an airliner by adding a small passenger compartment in the nose, but those never materialized. While such an exclusivity could be considered a feature, larger amounts of passengers would definitely bring larger profits. 

Also, the flight was dangerous and required some serious training. The passenger had to learn all the emergency procedures and be prepared to eject if the ageing jet started misbehaving. Although there is no record of serious incidents, less serious ones happened rather often, as aircraft were bound to experience problems due to routinely operating at the edge of their possibilities. 

There had to be a better way to exploit high-flying Russian jets. It came at the turn of the 2000s.

Piggybacking on the Foxhound

In 2001, Alexander Van der Velden and Holger Stockfleth, former of them – senior engineer at Astrium, filed a patent in Germany. A lengthy name of “Device for supersonic transport” does not really pay it justice, but the gist of the idea was to attach the aforementioned device to the back of high-performance jet aircraft. Add large plexiglass windows, a parachute for safety, and you have something rather promising.

Astrium was an assignee, and proceeded to register it in patent offices of US, Russia, Australia, Japan, and European Union the next year. It is unclear how many people worked on the idea and how seriously it was really taken, but the patent was quite definitely not a bogus one. 

It cited problems with the safety of the ex-Soviet aircraft, describing a necessity to mount the passenger compartment on latches or explosive bolts. The capsule would have a life support system, canopy with 180° overhead view, and could sit between 4 and 12 people depending on the carrier – plus one flight attendant. Since such a contraption would result in immense drag, an additional rocket engine – either integrated into the capsule or a detachable one – would have to be fitted. Migbus patent drawing AeroTime News

A scheme, detailing the attachment and layout of the capsule, as well as additional modification of the aircraft. From the patent issued by United States Patent and Trademark Office in 2002. (Image: Astrium GmbH / Google Patents)

The patent used MiG-31 Foxhound as an example of a possible carrier. It was more advanced, more powerful and more robust successor to the Foxbat, but even its massive engines did not have enough power to carry the capsule at supersonic speeds, and it was just as difficult to control in the thin air of the stratosphere as any other aircraft. Therefore, the patent proposed attaching underbelly booster rocket, and adding multi-axis thrusters in the nose to improve controllability.

At some point Astrium signed a memorandum of understanding with MiG scientific-industrial complex, the former Mikoyan and Gurevich constructor bureau. EADS report, released in 2004, actually says that the capsule concept itself was designed by MiG and that there is a lack of technical information about the project because the flight characteristics of the fighter jet are still classified. But, it assures, the project moves forward: an application letter is filled to German airworthiness authorities, a model has been tested in a wind tunnel by MiG, and a German professor Peter Sacher has completed his preliminary evaluation of the concept. 

“No major showstopper was identified,” the report states, but the “project is now in stand-by as for the moment it is lacking of financial support.”

migbus render AeroTime News

Promotional render for the Migbus. (Image: EADS Space Transportation)

Several years later, the German patent was withdrawn and the U.S. patent expired due to “fee-related” causes. 

There are at least a couple of 3D renders floating around the Internet, showing Migbus in varying levels of detail. The simplistic one is from EADS space tourism report, and represents just a rough idea, without proper scale. A bit better one can be found in German newspapers of the period, depicting a bottle-shaped passenger capsule with a sharp nose, rocket boosters and a pair of additional stubby wings. No pictures of the wind testing model can be found anywhere, and the Russian side of the internet, which often displays peculiar fascination with similar crazy ideas, contains no information on "Mig" part of Migbus. This very well might indicate that the advanced state of the project within MiG, described by the report, could have been a bit exaggerated.

EADS completed its transformation into Airbus a decade later, with Astrium – now EADS Space Transportation  proposing and jettisoning at least several other space tourism ideas in the meantime. Then, the geopolitical situation got cold again and Russia modernized its remaining MiG-31s, returning them to active duty, and destroying any possibility of commercial use. 

While the process behind the fast demise of Migbus is not entirely clear, the craziness of the idea, and the difficulty of its execution, are rather apparent. Still, experiencing or just seeing it in flight, would have been something quite impressive