Earlier this week in Bristol, England, a ''test inflation'' of the hot-air balloon The Russia was carried out.
Son and project manager Oscar Konyukhov said the balloon was 70m tall and had a volume of 100,000 cubic metres.
''It is the largest hot-air balloon on the planet.''
An aircraft hangar, previously used to build Concord aeroplanes, was leased for the test inflation.
Even in such a roomy hangar, the team only managed to fill half the balloon, he said.
''But it was enough to check the internal envelope connections, the correctness of sewing of all the elements and the controls of the parachute valve, and also to install a remote monitoring system for the balloon's temperature.''
He said it would carry a pressurised ''gondola'' which would protect his father from the outside environment, where temperatures would drop to -60degC and there would be no breathable atmosphere.
It would also contain an integrated burner system which would create lift by burning propane at lower levels and aviation kerosene at higher levels.
The first would take place in Australia in April next year, once his father had finished the first leg of his round-the-world row; and the second would take place in Russia, in September next year.
On Friday, Mr Konyukhov said his father was nearly 800km east of Dunedin on his rowing record bid.
Unfortunately, weather conditions were making the journey very difficult.
''So far, Fedor is behind schedule, and the whole of next week he will experience adverse weather conditions.
''Southerly winds will back more to the southeast [headwind] and the boat will drift in the opposite direction.''