Exemption for International Space Station co-operation highlights American dependence on Russia in space

After insisting that space relations would not be altered by earthly politics, Nasa on Wednesday said it was severing ties with Russia over the Ukraine crisis, except for the International Space Station.

Nasa employees cannot travel to Russia or host visitors until further notice. They are also barred from emailing or holding teleconferences with their Russian counterparts because of Russia's actions in Ukraine, according to a memo sent to workers.

• The first Russian motherboard based on ARM-processor Baikal-M