Russia has postponed its next missions to the Moon and Venus by at least a year, pushing their launches to 2028 and 2036, respectively, the head of the Russian Academy of Sciences (RAS) said Friday.

The Luna-26 orbiter will search for suitable landing sites on the Moon, while the long-delayed Venera-D mission aims to study Venus’s extreme conditions and search for signs of simple life, RAS president Gennady Krasnikov told the pro-Kremlin newspaper Izvestia.

Russia’s state space agency Roscosmos has not yet confirmed the revised timeline.

Former Roscosmos chief Yury Borisov had earlier said Luna-26 would launch in 2027, with follow-up missions Luna-27 and Luna-28 slated for 2028 and 2030 or later. The Venus mission, previously rescheduled for the 2034-35 window, will now slip to 2036.

Krasnikov did not explain the delays, though RAS Space Research Institute director Lev Zeleny said in March that scientists were reluctant to “rush” aerospace firm NPO Lavochkina, which is designing the orbiter, lander and aerostats for the missions.