The three-man crew aboard the space station Mir will have to stay in space an extra month, reportedly because of a shortage of funds to build the rocket transporting a replacement crew.

Russian space officials confirmed Thursday that they plan to keep the two Russian cosmonauts and a German astronaut in orbit 39 days longer than their original four-month mission.

The delay was caused by funding problems that prevented the booster rocket for the crew’s replacements from being ready on time, the ITAR-Tass and Interfax news agencies said.

Russian Space Agency spokesman Anatoly Tkachev would say only that construction of the Progress booster for the Soyuz-22 spacecraft was taking longer than planned.