When the 239 passengers and 12 crew members boarded Malaysian Airlines Flight MH370 from Kuala Lumpur at 12.41 am on March 8th, they probably had one thought in mind - To go to their respective homes or hotels and catch up on some well deserved rest when the flight landed in Beijing, at 6.30 am.

Unfortunately, that would never happen. Within two hours of the flight's departure, the Boeing 777-200ER lost all contact with the control tower and disappeared. Believing that the airplane had met with some mishap caused by engine failure or perhaps even a hijacking gone wrong, the Malaysian government immediately sent out a search team to look for debris. But after an intense six-hour search of the area revealed nothing, the officials had no choice but to tell the world and anxious relatives and friends that were waiting in Beijing, that Flight MH370 appeared to have simply disappeared into thin air.

That news sparked what has become the largest search and rescue effort in history. The initial search was restricted to the Gulf of Thailand and South China Sea, the areas that lay right under the airplane's flight path. But after some satellite data showed that the flight seemed to have veered off its path and continued for a few hours after the captain's last contact with the control tower, the search area was expanded extensively.

The big break came on March 16th and 18th, when two satellite images showed what appeared to be aircraft debris in the Southern Indian Ocean, southwest of Western Australia. However, while there have since been almost daily sightings of marine debris by the satellites in the area, there is still no confirmation that the objects actually belong to the aircraft. But given that these are the first reliable leads, search teams are hopeful that they may finally be able to put the mystery of the missing flight to rest.

Despite this news, relatives and friends had continued to believe that the airplane had landed safely at an unknown destination and that everybody on board was alive and well. But this optimism was dashed on March 28th, when the Malaysian government announced that despite the fact that no tangible evidence from the airplane had been recovered, they concurred with the data from British Air Accidents Investigation Branch and British Satellite telecommunications company, Inmarsat, that Flight MH370 had definitely crashed in the Southern Indian Ocean, leaving behind no survivors.

With all hope lost, there is only one thing everyone wants to know - What caused the crash? The only way to find out is by locating and retrieving the airplane's flight data recorder or what is popularly known the 'black box'. That however is proving to be difficult because there is no confirmed location of where the airplane crashed. To make things worse, the stormy weather in the area has meant that search missions have had to be abandoned, numerous times.

On Friday, April 4th, a total of 14 aircraft and nine ships began an intense search in what seems to be the most plausible crash site - a 217,000 square kilometers stretch of the remote Indian Ocean northwest of Perth. Among them is Australian naval supply ship Ocean Shield, which is carrying with it, TPL - 25, a giant underwater microphone that is trying to detect the 'ping' or pulse signal that the locator beacons of the flight recorders are designed to emit, following an airplane crash. If it is able to locate the black box, the crew will deploy US built robot - Bluefin-21.

Sent in by the US navy, the 21-foot-long robot can be lowered down up to 2.5 miles and kept submerged for 25 hours at a time. It is designed to hover over the seabed and take images of the ocean floor using sonar acoustics. Because of its slow and deliberate search method, it can only cover 40 square miles in each session. This means that until the search teams are able to pinpoint the exact area where the flight may have crashed, the robot is of no use.

The bigger problem however is that time is running out. That's because the batteries in the locator beacons have a maximum life of 30 days, which means that they could run out of power as early as April 8th. This gives the search crews just a few days to find and verify the debris and deploy Bluefin-21. If they are unable to do that, the fate of Malaysian Flight MH370 may go down as one of the world's biggest mysteries - One that may never be solved!

Resources: online.wsj.com, abcnews.go.com, cnn.com