A SUPERSONIC jet that could fly from London to New York in under four hours is preparing for take-off.
NASA’s X-59 – dubbed “Son of Concorde” – is having final safety checks before making a historic maiden flight.
5
5
5
The futuristic jet is projected to cruise at Mach 1.5, or around 990mph, potentially cutting the transatlantic journey down to just three hours and 44 minutes.
Standard commercial flights typically take seven to eight hours.
On August 18, 2025, NASA X-59 maintenance teams conducted a crucial hydrazine safety check at U.S. Air Force Plant 42, validating the toxic but vital backup system foir in-flight engine restart before the aircraft’s first flight.
Hydrazine, a highly corrosive chemical, poses significant health risks including skin burns and respiratory damage.
The safety check ensures the reliability of this critical system, which is one of several safety features being tested to ensure the X-59 can safely achieve quiet supersonic flight.
Unlike Concorde, which rattled windows with ear-splitting booms, the X-59 is designed to produce only a muted “sonic thump” – a softer sound likened to a car door slamming across the street.
The sleek aircraft is currently being tested at the U.S. Air Force Plant 42 in Palmdale, California, where engineers are scrutinising its safety systems.
Its maiden flight will be a low-altitude loop at about 240mph to check system integration, before ramping up to higher, faster test flights that will eventually break the sound barrier.
NASA Armstrong said on Friday: “As NASA’s one-of-a-kind X-59 quiet supersonic research aircraft approaches first flight, its team is mapping every step from taxi and takeoff to cruising and landing – and their decision-making is guided by safety.”
The X-59 has already notched up a series of milestones on the ground.
In July, engineers successfully carried out low-speed taxiing tests, with the stiletto-nosed plane moving under its own power for the first time.
NASA explained: “These checks help ensure the aircraft’s stability and control across a range of conditions, giving pilots and engineers confidence that all systems are functioning as expected.”
Project manager Lori Ozoroski said the research could finally end the 50-year ban on supersonic passenger flights over land.
She explained: “We had a commercial supersonic aircraft, the Concorde.
“But it was limited during its flights that it could not fly, say into, you know, somewhere in the middle of the U.S.
“You were not allowed to fly supersonic over land.
“So most of the flights were back and forth just over the ocean.
“And so again, that ban has been in place for 50 years, over 50 years in the US.
“A lot of international countries as well have similar bans.
“And so the whole goal of this research that we’re doing right now is to lift that ban and set a speed limit for commercial supersonic aircraft rather than a speed limit.”
She added: “The sound level is more like – we’ve done studies – it’s more like a car door closing, you know, across the street at your neighbour’s house rather than the very loud typical sonic boom.”
The 99.7ft-long jet with a 29.7ft wingspan has already undergone wind tunnel tests in Tokyo, where engineers blasted a scale model with supersonic airflow to simulate speeds of Mach 1.4 (925mph).
NASA hopes the plane’s sharp nose and long, slender wings will break up shockwaves into smaller ripples, preventing the huge ground-shaking blasts that plagued Concorde.
If successful, the “Son of Concorde” could usher in a new golden age of super-fast passenger travel, halving journey times across the Atlantic.
5
5
Supersonic and Hypersonic Jets
There are several types of hypersonic and supersonic jets. A breakdown of what’s been happening in the industry and what’s expected in the coming years.
Talon-A
- Built by Stratolaunch
- Reported speeds of Mach 5
- The first test flight conducted in 2024
X-59 Quesst
- Built by Nasa and Lockheed Martin
- Predicted max speeds of Mach 1.4
- The first test flight in 2025 – but subject to delays
Venus Stargazer M4
- Built by Venus Aerospace and Velontra
- Predicted max speeds of Mach 6
- First test flight in 2025
Quarterhorse MKII
- Built by Hermeus
- Predicted max speeds of Mach 2.5
- First test flight in 2026
Halcyon
- Built by Hermeus
- Predicted max speeds of Mach 5
- First test flight by 2030
Nanqiang No 1
- Built by China’s hypersonic plane programme
- Predicted max speeds of Mach 6
- First test flight in 2025
DART
- Built by Hypersonix Launch Systems
- Predicted max speeds of Mach 7
- First test flight in 2025
