MOSCOW (AP) _ Soviet cosmonaut Yuri Romanenko said Wednesday his record 326-day mission in orbit brought human beings closer to interplanetary travel.

The 43-year-old flight commander returned to earth Tuesday with two other cosmonauts after spending nearly 11 months aboard the Mir space station.

Doctors and scientists will examine the results of Romanenko's medical checkups to gauge the effects of prolonged weightlessness on the human body and the possibility of space missions to the planets.

Scientists say a trip to Mars and back will take about three years. Romanenko's trip will help them determine whether a spacecraft traveling to Mars will have to produce its own gravity or whether humans can live that long in zero gravity.

Soviet evening television news showed Romanenko walking arm-in-arm with his wife along a snowy sidewalk and moving stiffly in sneakers and a brown flight suit before a news conference at the Baikonur Space Center in Kazakhstan, near where the space capsule landed Tuesday.

''After such a long flight as 326 days, I feel well, but of course it's not that simple,'' Romanenko said in a soft voice. ''It's a success of our Soviet national medicine.''

He said he was certain that two cosmonauts now aboard the space station would break his endurance record, but added that his lengthy flight would aid scientists and doctors plan travel to the planets.

''We talk a lot about Mars, but for us, Mars is getting closer and closer to Earth,'' Romanenko said.

The television report said that one of the cosmonauts who returned with Romanenko, test pilot Anatoly Levchenko, had flown to Moscow from Baikonur and back within a day of his return to earth.

Levchenko rocketed into orbit Dec. 23 aboard the Soyuz TM-4 capsule with fellow spacemen Vladimir Titov and Musa Manarov. The third cosmonaut who returned to earth Tuesday, Alexander Alexandrov, had arrived at the Mir as part of a joint Soviet-Syrian mission in July.

Titov and Manarov remain aboard the orbital platform for what the official Soviet news agency Tass has said will be a yearlong mission.

On Wednesday, Titov and Manarov moved the TM-4 capsule to a new docking port at the Mir to clear the way for unmanned shuttle rockets that will bring them supplies, Tass said.

The two cosmonauts are expected to host a joint Soviet-Bulgarian mission this summer and will carry out scientific studies.