MOSCOW, July 19. /TASS/. The launch of Russia’s lunar mission Luna 25 will most likely be pushed back to 2023 at the earliest because recent tests of its soft-landing device showed it failed to meet requirements, two sources in the space industry told TASS.

The Doppler speed and distance sensor made by the Vega Concern, part of the Rostech State Corporation, was tested in May and June and underperformed in terms of measurement precision, the sources said.

The current precision would give 80% probability of a successful landing while the desired specifications call for a higher probability, which means either the device or the landing plan will have to be reworked.

"In order to implement either of the options, a launch delay will be required until 2023 at the earliest," one of the sources said.

There’s been no final decision to postpone the launch. The other source confirmed the information.

Research equipment have passed tests successfully, the source said.

Roscosmos declined to comment on the landing device, saying the launch was still planned for some time before the end of September this year.

The spacecraft is designed for research of the lunar south pole and it’s planned it will land at the Boguslavsky crater.