A new spacecraft dedicated to studying the Earth's oceans was shot into orbit aboard an Indian rocket early Wednesday, marking the country's 20th successful satellite delivery mission.

The Polar Satellite Launch Vehicle, flying in a core configuration stripped of its six strap-on boosters, lifted off at 0621 GMT (2:21 a.m. EDT) from the Satish Dhawan Space Center on India's east coast. Launch occurred at 11:51 a.m. local time in India.

The Indian Space Research Organization declared the launch a success on its Web site early Wednesday.

The four-stage rocket was propelled off the launch pad by a powerful solid-fueled motor during the first two minutes of flight. The second and third stages burned liquid hydrazine and solid propellant, respectively.

The PSLV's fourth stage was loaded with extra hydrazine fuel during Wednesday's flight to increase the rocket's lift capacity to orbit.

A new avionics system was also used aboard the PSLV, according to ISRO

The 146-foot-tall launcher deployed the 2,112-pound Oceansat 2 satellite about 17 minutes after liftoff. Four more tiny CubeSat payloads were set free moments later.

The PSLV also carried two attached Rubin demonstration payloads for the Automatic Identification System, a communications network used to track and identify shipping vessels.

ISRO confirmed the first signals from Oceansat 2 were received after launch.

The PSLV delivered the spacecraft to the expected orbit about 447 miles high with an inclination of 98 degrees, according to ISRO.

Circling Earth on a path designed to maximize the potential of science returns, Oceansat 2 will spend the next five years using its three instruments to observe the planet's oceans and atmosphere.

Oceansat 2 will ensure continuity of data now provided by the Oceansat 1 satellite, which was launched in 1999 and is nearing the end of its life.

The satellite's Ocean Color Monitor, a wide-angle visible and near-infrared imager, will take pictures with a resolution of up to 1,200 feet and across a swath of around 882 miles, according to ISRO.

Scientists say the camera will keep tabs on water pollution, fish populations, sediment distribution and algae.

A scatterometer will measure wind direction and speed over the ocean's surface. This information will give forecasters insight into weather patterns and tropical cyclones.

Oceansat 2's third instrument is an Italian experiment devoted to probing the atmosphere. The sensor will observe distortions in GPS radio signals traveling through the upper atmosphere to derive up to 500 temperature, pressure and humidity profiles each day.

Data from Oceansat 2 will be used by Indian and foreign scientists, according to ISRO.

Four CubeSat payloads, each about the size of the palm of a hand, were also sent into space during Wednesday's launch.

Two German CubeSats, BEESAT and UWE 2, were built by student teams to test new attitude control systems.

ITUpSAT 1 was developed by Istanbul Technical University in Turkey to examine the performance of a new stability system and take pictures of the Earth.

Another CubeSat, SwissCube, is Switzerland's first satellite and will try to detect a phenomenon known as airglow using an off-the-shelf sensor.

Innovative Solutions in Space, based in the Netherlands, provided the launch opportunity for the CubeSat missions. The company said ground stations received signals from all four spacecraft shortly after launch, verifying they were healthy after arriving in orbit.