Virgin Orbit's historic LauncherOne test flight may happen today

Sir Richard Branson’s Virgin Orbit was forced to delay the historic first orbital test flight of its LauncherOne vehicle due to equipment problems.

The vehicle, designed to deliver small satellites into orbit, had been due to take off from the Mojave Air and Space Port in California at 5.30pm BST yesterday.

But on Sunday afternoon, the Virgin Orbit team said a sensor was ‘acting up’.

In a post on the project’s Twitter account, they said: ‘We completed fuelling of our LauncherOne rocket yesterday for our Launch Demo.

‘Everything has been proceeding smoothly: team, aircraft, & rocket are in excellent shape. However, we have one sensor that is acting up. Out of an abundance of caution, we are offloading fuel to address.’

A second tweet said: ‘This means we are scrubbed for today. Currently, it appears we’ve got a straightforward path to address this minor sensor issue and recycle quickly.

‘The crew are already hard at work putting that plan into action.’

A spokesman for Virgin Orbit told the PA media news agency the crew have a new window for the launch between 6pm and 10pm BST today, May 25.

The aim of the endeavour is to test that each part of the process works as planned once the launch vehicles graduate to operational status.

The launch process will see LauncherOne released from under the wings of the company’s modified Boeing 747 carrier aircraft in mid-air before igniting its own rocket in order to reach Earth’s low-orbit.

Should LauncherOne successfully hit an altitude of 50 miles, it will mark the first time this kind of launch system has reached space.

At a press briefing on Saturday, Virgin Orbit’s vice-president of special projects Will Pomerantz said that, although he was aware that ‘about half’ of an aerospace company’s first full flights fail, he was confident in the work that the team behind the project had done to get to this moment.

‘You essentially get to a point where you have looked under every rock and verify that there’s nothing more for you to do to verify that the system is ready,’ Mr Pomerantz said.

‘That’s what we have done. We’ve gone through an enormous amount of tests, we’ve essentially done everything that we can think of that we should do, including fill the rocket up with cryogenics and fuel and pressure and fly it out to the drop.’