Today is the fourth day since the Malaysian Beijing-bound flight disappeared off the radar. Although China and other countries have used satellites to survey possible areas where the plane might be found, there are still no solid clues as to where the mysteriously disappeared plane is. With each passing day, attention is focusing on why satellites cannot find the plane.

After the plane went missing, China calibrated 10 satellites to conduct the search mission. A US satellite firm has captured numerous related images over likely locations. These optical and radar images can be used to help in the search for the missing aircraft, offer full services in weather monitoring, communication and other aspects of the search. However, experts believe it is unwise to rely on remote-sensing satellite alone to find the plane - every relief effort must be put into service simultaneously.

Multinational efforts on satellite searching

According to the Xinhua agency, China's Xi'an Satellite Monitor and Control Cente launched an emergency response for the search and adjusted up to ten high-resolution satellites.[Read more]

For the same purpose, many satellites from other countries also focus on the possible locations of the missing plane. According to Reuter, a U.S. government source said that the United Sates has reviewed extensive imagery taken by spy satellites for evidence of a mid-air explosion, but found none. The source also stated that U.S. satellite coverage of the region is thorough.

The world's premier space agency NASA has also joined the search.

The US-based satellite company DigitalGlobe had sent its GeoEye1, one of the highest-resolution commercial satellites, to capture data around possible sea regions.

Vietnam has used a satellite to survey the seas around Tho Chu Island, one of the possible crash areas.