Seafarers are being warned to avoid a large area of ocean south of Cork and Kerry tonight in case rocket debris falls from the sky.

The marine warning was issued by the Department of Transport as commercial space company Virgin Orbit prepares for a mid-air rocket launch over the ocean.

The rocket will be flown under the wing of a 747 jet Spaceport Cornwall to an altitude of 10,668m where it will be released in mid-air.

All going well, the rocket's engines will fire and propel it into space with its payload of nine satellites.

Launch

The jet is due to take off from Spaceport Cornwall sometime after 10pm.

The rocket will be released around midnight and will travel in a southerly direction as it ascends.

It may be visible from Cork or Kerry towards the southern horizon for around 60 seconds just after launch.

The warning will remain in place from 10:16pm until 00:16am, with all seafarers urged to avoid the area of ocean during and leading up to the launch period.

Area of ocean mariners are being warned to avoid for fear of falling rocket debris. Image: Dept Transport.

If the launch goes to plan there is no danger of any falling debris; however, the marine warning notes that there is a “low probability for the vehicle to produce dangerous debris if a mishap were to occur”.

“Mariners are advised to avoid the marine hazard area during and leading up to the launch period due to possible dangerous conditions from potential rocket debris,” it says.

Mariners are also urged to report any debris or pollution they may see as a result of any mishap during the launch.

Virgin Orbit launch windows. Image: Dept Transport

The launch is subject to weather constraints and Virgin Orbit has also announced a range of back-up launch dates in case the primary launch has to be postponed.

The warning has been issued to “all Shipowners, Fishing Vessel Owners, Agents, Shipmasters, Skippers, Fishers, Yachtsmen and Seafarers”.

Airlines that use the area have also been warned about the launch.