14 DAY TRIAL // Big disappointment for ESA officials, as last week's scheduled launch was prevented because of certain glitches in the fuel gauges of the liquid fuel external tank. With just a few hours before the liftoff, which should have taken place on December 6th, technicians verified the last details and realized that three of the four fuel gauges, indicating the levels of fuel in the liquid fuel external tank, were giving false readings.
After a quick fix of the problem, NASA also decided to modify the protocol related to the liftoff, for security reasons, thus preventing the space shuttle Atlantis to launch if just one of the fuel gauges failed. Said and done. However, the second attempt to launch Atlantis into space had to be aborted as well, because of similar glitches in the sensors indications.
It seems that NASA engineers will try to fix the problem with the shuttle still on the launchpad, so that it would be ready for another launch attempt on January 2nd, next year. A fill up of the large liquid fuel external tank will be conducted, in order to run several tests on the problematic fuel gauge indicators.
According to the Atlantis' program flight manager, the problem could be in the wiring of the gauges, stretching more than 30 meters, from the lower part of the fuel tank to the shuttle, or possibly in the sensors inside the tank. While the wiring will be inspected with a reflectometer that will find any possible problems, another team of investigators will study the effects of ultra-cool liquids on the sensors, in order to simulate the exact conditions inside the fuel tank, as they only seem to fail as the tank is being filled.
The sensors inside the tank are part of a safety system that ensures the shutdown of the engines, when the fuel tank is empty. The exact same problem has been occurring for over two years since the space shuttle program was resumed, after the tragedy of the Columbia. However, NASA hasn't given much thought to the problem all these years.
During this time, the astronauts on board the International Space Station have a scheduled spacewalk, in order to inspect the faulty rotary joint which controls the movement of one of the solar panel. Although it only had four months since it was installed, at the time when the malfunction occurred, during the inspection made by the crew of the space shuttle Discovery, metal grindings have been found throughout the whole mechanism.