US military officials are in the process of building the next generation of highly-secretive stealth bombers which will reportedly boast Star Trek-inspired cloaking technology.

A crack team of engineers is currently designing and testing advanced methods of evading radar systems and reducing heat signatures for the B 21 bomber – also known as "The Raider."

The long-range bomber, being developed as part of an $80 billion contract won by Northrop Grumman, is shaped like a bat and each one will cost roughly $550 million to make, according to The Times.

The new technology will aim to resemble the type of invisibility popularised by the Klingons in Star Trek.

US military officials have been quoted in national security publications as saying the technology is now needed in order to stay up-to-date with the cutting-edge combat systems coming out of Russia.

The bomber is now under development in a heavily-guarded facility in Los Angeles, known as Plant 42.

Details of the weapon systems it will have remain classified, but Grumman is advertising the new bomber on its website. It is being made to eventually replace the outdated B-52 bombers, the firm has said.

In a report published 10 November, the Los Angeles Times revealed Plant 42 is currently staffed by 3,000 employees – but is expected to have more than 5,000 experts by 2019.

While schedules are not clearly defined, the military has said it expects the new bomber to be ready by the mid-2030s. The Times reported the US Pentagon is expecting 100 to be made.

The B-21 will eventually have a nuclear weapons capbility but will not carry those until two years after it becomes operational, reports suggest. There are also loose plans for autonomous flight.

Colonel Mace Carpenter, a former US combat pilot, said the Raider will be equipped with the latest in advantaged stealth technology but will still need to be manned by experts.

"Stealth is not about making an aircraft completely unseen but harder to see," he added.

Last week, US General Robin Hand, head of the Air Force's Global Strike Command, opened up in an interview with National Defense about development of the bomber. He revealed he has been "engaging frequently" with Northrop Grumman to keep the project on track.

"It is really important that we get the B-21 on time, on cost," he stated.

"At this stage of the journey — and it is still in its infancy stage — I am thrilled. I believe we have the opportunity with the B-21 to be a benchmark acquisition program with us and Northrop.

"And I say that because we have been partners for the last 30 years on stealth, low observable [technologies], so we already have a track record. And we have the benefit to draw the lessons learned on what went well and didn't go so well with the B-2 and apply those to this."

He said "a resurgent Russia made us look at some things differently and served as a wake-up call."

Earlier this year, Russia revealed its very first stealth fighter jet, the Sukhoi Su-57, or what the Russian press refers to as the "Ghost." Russia estimates that the model will be operation next year.

In recent years, China has also shown off its J-31 stealth fighter in a bid to demonstrate the progress of its high-end arms development.