TOKYO -- Video feed issues halted on Tuesday the mission of a robot trying to retrieve the first sample of melted fuel debris from inside one of the damaged reactors at the tsunami-hit Fukushima Daiichi nuclear power plant , the managing company said.

This marks the second time in less than a month that the mission has been suspended. The operation was initially scheduled to begin on Aug. 22, but a misconfiguration of a set of pipes designed to guide the robot into the reactor's primary containment vessel delayed the effort for nearly three weeks. The extendable robot, known as “ Telesco ,” requires a full week to reach its designated location and another week to be retracted, as it must navigate around various obstacles. Any errors in its movement come at the cost of valuable time.

Fukushima's cooling system was damaged during the 2011 earthquake and tsunami, causing meltdowns in its three reactors. An estimated 880 tons of fatally radioactive molten fuel remains in them, and the Tokyo Electric Power Holdings Co. has been trying to access the reactors to figure out how to decommission the plant.

Telesco was scheduled to collect a fragment weighing less than 3 grams (0.1 ounce) on Tuesday from within the Unit 2 primary containment vessel, following a successful rehearsal over the weekend, according to TEPCO. However, the transmission of images from two of its four cameras, designed to capture the clippers' movements and their surroundings, failed to reach a monitor in the remote control room. This resulted in the suspension of the mission as sampling could not proceed without the crucial visual data.

TEPCO attributed the issue to ongoing investigations, citing potential camera or power cable malfunctions, possibly stemming from high radiation levels that have previously caused equipment disruptions during internal probes. Despite technicians' efforts to restore camera functionality and reconnect cables, these attempts were unsuccessful.

It remains unknown when the mission would resume.

Telesco is slated to approach the area directly beneath the Unit 2 reactor core, the site of significant melted fuel deposits during the meltdown 13 years ago.

The government and TEPCO have established a 30-to-40-year timeframe for the cleanup, which experts deem overly optimistic and recommend revising.

No definitive plans exist for the complete removal of the fuel debris or its final disposal.