A group of scientists is launching what they say will be a new pacifist nation-state in space.
Asgardia "will become a place in orbit which is truly 'no man's land'," its website says.
The new "nation" aims to launch its first satellite late next year and hopes to one day be recognised by the UN.
But some experts have cast doubt on the viability of the plan, given international law prohibits national sovereignty claims in outer space.
"Citizens" of Asgardia, who will be scrutinised before admission, will eventually obtain passports, says Lena de Winne, a senior member of the project team who worked for the European Space Agency for 15 years.
"Clearly it's difficult to wrap your head around the concept [of] how can you be a citizen of something you cannot put your foot on," she told the BBC.
"But I'm a citizen of the Netherlands and I'm now in Paris… There is nothing unusual about it if you are a citizen of a land where you don't live and where you don't go."
The project is being directed by the Vienna-based Aerospace International Research Center, a private company founded by Russian scientist and businessman Dr Igor Ashurbeiyli.
He joked to reporters in Paris at an event announcing the project that he would not be surprised if the media labelled him a "crazy Russian rocket scientist" talking "utter nonsense".
Its website says the new nation, the name of which derives from a city in the sky in Norse mythology, "will offer an independent platform free from the constraint of a land-based country's laws".
The group says it will open up new opportunities in space for commerce, science and "peoples of all countries on earth".
Crowdfunded space state
Competitions are being held to decide a national anthem and flag design.
Professor Sa'id Mosteshar, director of the London Institute of Space Policy and Law, cast doubt on the idea that Asgardia would be recognised under international law.
"The Outer Space Treaty… accepted by everybody says very clearly that no part of outer space can be appropriated by any state," he said.
Given Asgardia will not be associated with a self-governing territory, with its 'citizens' remaining on earth, its prospects for recognition are slim, he added.
The project is being funded personally by Dr Ashurbeiyli at present, but the group have announced they will seek crowdfunding.
Already more than 50,000 people have applied to 'join' the state online.
This crowdfunding aspect suggests the group's founders "don't have any real credible business plan", Professor Mosteshar said.
On the legal aspects, Dr Ashurbeiyli says he wants to create a "new judicial reality in space".
"The project is creating a new framework for ownership and nationhood in space, which will adapt current outer space laws governing responsibility, private ownership and enterprise so they are fit for purpose in the new era of space exploration," a statement said.