ESA astronaut Alexander Gerst is all set for his Blue Dot mission to the International Space Station in May. Crewmates Reid Wiseman and Maxim Surayev will hold a media conference on Tuesday 18 March and ESA is inviting you to ask questions via Twitter.

Alexander is putting the finishing touches to his training in the US and Russia before he heads to the Baikonur launch site in Kazakhstan about a week before launch, set for 28 May. Their Soyuz spacecraft will dock with the microgravity laboratory orbiting 400 km above Earth at 28 800 km/h around six hours after its launch. Alexander will serve as a flight engineer for Expedition 40 and 41 before he returns to Earth in November 2014.

During their six months in space, Alexander and his crewmates will assist in the docking and unloading of six visiting spacecraft that ferry supplies and experiments. Alexander is prime operator for Europe’s fifth and last Automated Transfer Vehicle, George Lemaitre. He will monitor the arrival and docking of the vessel and take responsibility for distributing the items held in its cargo bay.

Alexander’s science roster includes the first use of the Electromagnetic Levitator. This furnace can melt and solidify metal alloys away from the container’s walls, helping scientists to understand the solidification and physical properties of molten alloys.

ESA is offering you the chance to ask the astronauts a question during the press conference via Twitter. Send your questions in English on any topic. The best questions will be asked at the media conference that can be followed live on NASA television 18:00–19:00 GMT (19:00–20:00 CET) on 18 March.

Post questions to @ESA using hashtag #bluedot. The deadline for receiving the questions is 12:00 GMT (13:00 CET) on Monday 17 March.