For some people, supersonic air travel is the transport holy grail. Something we should be striving for at all costs because, of course, time is money. But now, airline engine maker Rolls Royce has turned its back on the idea and pulled out of its .

Colorado-based that could carry up to 88 passengers at a speed of mach 1.7, which is roughly 1,300mph. If the jet ever managed to take to the skies, it could cut the seven-hour New York to London flight time in half.

But to do this, it needs engines. that engine manufacturer Rolls Royce has pulled out of the project.

“We’ve completed our contract with Boom and delivered various engineering studies for their Overture supersonic program,” Rolls-Royce said in a statement shared with AIN Online.

“After careful consideration, Rolls-Royce has determined that the commercial aviation supersonic market is not currently a priority for us and, therefore, will not pursue further work on the program at this time. It has been a pleasure to work with the Boom team and we wish them every success in the future.”

Rolls Royce isn’t new to the world of supersonic passenger travel. It was, of course, , Concorde.

Back in the 1980s and 1990s, important people could hop between London and New York in less than three hours. Back then, incredibly rich individuals could jump on the Concorde and half their normal transatlantic journey time, while also .

And now, it appears that the environmental cost of going supersonic has gotten to Rolls Royce.

But what is Rolls Royce working on if it isn’t the vital task of making our flight times shorter? Well, it’s probably something to do with making aircraft more sustainable and efficient.

Air travel pumps out more than a billion tonnes of CO2 every year and accounts for . As such, plane makers are increasingly looking to develop engines that can run on sustainable fuels, such as hydrogen, synthetic gas or even electricity.

In Rolls Royce’s case, this has so far included working with a UK-based low cost carrier , and an expansion of its research into .

You know, the kind of stuff that is actually useful in today’s world, instead of .