Spectators at the Cocoa Beach became witness to the third attempt by NASA to launch the dual-spacecraft mission finally as it lifted off from Cape Canaveral.

The mission is aimed at studying closely the gravitational field of the earth's only natural satellite- Moon.

The Delta II rocket carrying the GRAIL mission spacecraft was scheduled to be launched earlier on Thursday and then on Friday. But it had to be rescheduled due to weather and a data glitch, respectively.

The Gravity Recovery and Interior Laboratory or the GRAIL mission spacecraft is of the size of a washing machine, and lifted off into the sky at 9:08 a.m.

A conformation was given out by NASA, 90 minutes after the GRAIL-A and the GRAIL-B had separated from the rocket, unfurled their solar panels and begun a 31/2-month trip to the moon, reported LA Times.

Our GRAIL twins have Earth in their rear-view mirrors, said David Lehman, GRAIL project manager at the Jet Propulsion Laboratory in La Cañada Flintridge, which is responsible for the $496-million mission.

According to Maria Zuber, GRAIL's prime investigator, the experience was an emotional one. It was nothing less than watching a child practice for years at music or sports, then watching them perform in extraordinary fashion, the report said.

The spacecraft is sent for three months and is expected to give out a map of the lunar gravitational field, the data that will help scientists understand the moon's crust, mantle and core.

There are a lot many significant lingering unanswered questions, which scientists are seeking answer for. An understanding of the thermal history of the moon would help scientists under the evolution of rocky planets better, including Earth.

GRAIL is the first technique known as precision formation flying to be studying the same object using multiple, coordinated spacecraft - will be used beyond Earth's orbit, the report said.

According to some scientists, GRAIL will mark the revolution is the study of planetary science. This technology could pave the way for various spacecrafts to create  a single technology platforms that can see deeper and get more details.