The interest in supersonic flight is gaining a renaissance in two ways; first, the potential revival of the Concorde from retirement eversince 2003, and the other, a revolutionary update to supersonic airplanes, spearheaded by NASA.

A group calling itself “Club Concorde International” has raised £120 million ($186 million) for its “return to flight” plan and hopes to get one of the decommissioned aircraft back in the skies by 2019, comprising of “ex-captains, ex-charterers and people passionate about Concorde, working together to keep Concorde in people’s hearts and minds.”

Club Concorde says it has its sights on two Concordes — both in France.

“The plan would be to purchase one of the Concorde and operate her as a private, heritage aircraft under neutral livery,” says the club on its website.

“All restoration to flight costs would be borne by Club Concorde International who would also finance the construction of maintenance/display hangars at both the French and UK bases.”

However, even if the enthusiasts have the money, putting a decommissioned plane back in the skies takes more than just capital.

“The greatest obstacle is the refusal by the aircraft’s manufacturer — formerly British Aerospace-Aerospatiale, now Airbus — to lend its support to a restoration,” said aviation journalist David Kaminski-Morrow, air transport editor of Flightglobal.com.

“Concorde is an immensely complex supersonic aircraft and the Civil Aviation Authority in the UK will not entrust the safe upkeep of its airframe and systems to a group of enthusiasts, regardless of their passion, without this technical support in place.

“If it isn’t there, the aircraft won’t be allowed to fly. It’s as simple as that.”

Sourcing a suitable Concorde will also be extremely difficult, added Kaminski-Morrow.

“Some have been treated better than others, but even the best-condition aircraft will need extensive maintenance checks and possible modification to bring it into line with civil aircraft mandates introduced since the end of Concorde service.

“Concorde was a unique aircraft type that demanded tailored parts, systems, maintenance techniques, and so on, and so few aircraft were built that there isn’t a vast pool of spares and engines to raid.”

Even if a suitable aircraft is identified, there’s the matter of obtaining it, said Kaminski-Morrow.

Fuel costs and actual acquisitions are also issues, as it requires technical support from Airbus, the manufacturer of the Concorde.

The group would face the same issues as airlines did when the plane was in commercial service: noise. It can only fly at supersonic speeds over the oceans or unpopulated areas.

Regardless, the Concorde has a market of wealthy business passengers, hence the push for its revival.

The Concorde indeed faces many hurdles if it is to fly in the skies again. But what if the noise and fuel economy issues can be done away with?

NASA has been working on a prototype supersonic aircraft, though still far from feasible, that aims to to be the successor of the Concorde, called the X-Plane.

It could fly passengers from New York to Los Angeles in as little as 2.5 hours.

“The trick to making airplanes quiet is to change the way the air flows around the airplane,” Juan Jose Alonso, a Stanford professor of aeronautics and astronautics, told Wired. Planes that break the sound barrier by reaching more than 786 miles per hour generate shock waves that eventually produce a distinct double “boom” sound. The noise created by the Concorde was measured at 106 decibels, but NASA thinks a redesign could get that down to 65 or 70 decibels.

Minimizing the sound of the shock waves could involve eliminating the cockpit window entirely, replacing it with a pointy-tipped fuselage, and putting the pilots in the middle of the plane. This would require video cameras for visual navigation.

Lockheed Martin is the company ironing out the details, having won a $20 million contract from NASA to design the blueprints. A working prototype would cost at least $300 million, and could be in the air as soon as 2019, according to NASA.

Among the challenges facing the effort to make the X-Plane a reality are the higher cost of fuel, as supersonic travel requires between two and three times as much fuel as conventional airplanes. The skinny shape of the plane could also prevent each flight from carrying enough passengers to make the aircraft economically viable.

Still, Peter Coen, a supersonic project manager at NASA Langley says that bringing back supersonic commercial air travel is entirely doable. He and his colleagues are experimenting with composite materials that could help produce a lighter airframe and engine specifications that could allow the X-Plane to use a third of the fuel required by the Concorde, he told Wired.

“We are chipping away at the efficiency gap between subsonic and supersonic aircraft,” he said.

(With reports from CNN and Inc.com)