WASHINGTON          -     Two of the most exciting space missions of the 2030s are likely now to be launched within a year of each other. European Space Agency member states are poised to increase the organisation’s science budget on Thursday by 10%.

This would make it possible to align projects to build a big X-ray telescope and a trio of satellites to sense the collision of gargantuan black holes.

It’s important they fly together because the insights they’ll bring are highly complementary.

When black holes merge, they despatch vibrations across the fabric of space-time - so-called gravitational waves. And being violent events, these unions will potentially also emit high-energy radiation.

Scientists want the fullest picture possible and the Athena X-ray telescope and the Lisa observatory give them that opportunity.

“The idea is that there is light and sound together,” said Prof GüntherHasinger, Esa’s director of science.

“With gravitational waves, we hear the shaking Universe; and the light comes from the matter falling into the black holes - ‘the last cry of help’ that is radiating in X-rays,” he told BBC News.

Both projects are big technology efforts that will take a decade to prepare. And their complexity is such that Esa would normally only try to launch missions of their kind once every five years.

But the budget increase set to be approved here in Seville, Spain, at the agency’s triennial Ministerial Council, enables Athena and Lisa to be put on a similar development path.

It’s hoped the X-ray telescope can launch in 2031 and the gravitational waves observatory in 2032.

The uplift in Esa’s science funding to nearly €3bn (£2.6bn) over five years was one of the easiest discussions on the opening day of the Council. Research ministers didn’t raise a word against the proposal, which means it should go through without issue when the meeting closes on Thursday.

The Council is negotiating a wide-ranging package of space programmes valued at €12.5bn (£10.7bn) over three years, or €14.3bn (£12.3bn) when considered over five years. Another of the large ticket items is Earth observation, a key element of which is the recommended expansion of Copernicus, a suite of satellites called Sentinels that monitor the status of the planet.

Esa is already producing six sensor systems in this programme and it aims to start the planning for a further six after Seville. The agency asked for €1.4bn from ministers, and at the end of day one’s deliberations had already collected bids for €1.7bn, the BBC understands.