Its future is far from clear, however, and dependent on decisions that will be made this year.

Around 75 percent of ISS's costs are borne by the U.S. at an annual cost of $3 billion to 4 billion. Russia launched ISS's first components in 1998, and by 2010, ISS became fully operational. The plan was for ISS to last 15 to 20 years, by which time it would be replaced. Such was not to be.

The ISS cost over $150 billion, five times the combined budgets of NASA and Roscosmos, so replacing it would be an enormous undertaking, probably choking funding for Earth observation, human visits to the Moon or Mars or deep space exploration. The Trump administration's "Artemis" response was to transfer Earth-orbiting space stations from government to the private sector and focus government spending instead on a lunar-orbiting space station and a human Moon landing. With several countries already agreeing to invest in America's lunar space station, it's difficult to see how these countries would also invest in a $100 billion replacement ISS. So, unless the Artemis program is delayed, the financial burden of a new ISS would fall on the U.S.