Japan plans to launch a $275 million mission toward Venus on Monday to obtain the most detailed views ever captured of the planet's blistering atmosphere, search for active volcanoes and snap pictures of elusive lightning strikes.

Artist's concept of Akatsuki orbiting Venus. Credit: Akihiro Ikeshita/JAXA

Japanese space officials call the Akatsuki spacecraft the first interplanetary weather satellite, and it carries a suite of five cameras each designed to study a specific slice of the Venusian atmosphere, according to the Japan Aerospace Exploration Agency, or JAXA.

With a runaway greenhouse effect driving surface temperatures to nearly 900 degrees Fahrenheit and whipping high-altitude winds reaching 225 mph, Venus is a planet like no other in the solar system.

"Although Venus is believed to have formed under similar conditions to Earth, it is a completely different world from our planet, with extremely high temperatures due to the greenhouse effect of carbon dioxide and a super-rotating atmosphere blanketed by thick clouds of sulfuric acid," said Takeshi Imamura, Akatsuki's project scientist.

Previously called Planet-C and Venus Climate Orbiter, the mission will observe the high-speed jet stream, study the source of sulfuric acid clouds, snap the first pictures of lightning at Venus, and search for active volcanoes.

Why is Venus important? Scientists say Venus formed much like Earth and probably enjoyed calmer times in its ancient past. But something went wrong long ago, leading a potentially once-temperate Venus on an evolutionary course much different than Earth.

Before researchers can pinpoint what caused Venus to become hellishly inhospitable, they must dispatch robotic missions to unravel the planet's conditions and how they link together.

"Using [Akatsuki] to investigate the atmosphere of Venus and comparing it with that of Earth, we hope to learn more about the factors determining planetary environments," Imamura said. "From this viewpoint, we will be able to understand more about the reason why Earth is as it is now, and how it might change in the future."

Akatsuki means dawn in Japanese, honoring the common position of Venus as the morning star in twilight skies.

The half-year journey to Venus is scheduled to begin with liftoff on an H-2A rocket at 2144:14 GMT (5:44:14 p.m. EDT) Monday from the Tanegashima Space Center in southern Japan. Launch will be at 6:44 a.m. Tuesday local time.

The 17-story rocket rolled 1,500 feet Sunday evening from the Tanegashima assembly building to Launch Pad No. 1 of the Yoshinobu launch complex. The half-hour transfer began around 2100 GMT (5 p.m. EDT) Sunday, or about 6 a.m. Japanese time Monday.

Workers were expected to connect fueling, electrical and data lines between the pad and mobile launch platform in the hours after the rollout.

Two 50-foot-long solid rocket boosters will provide extra oomph to propel the 650,000-pound launcher off the planet, guiding the H-2A rocket east of Tanegashima for a high-speed trans-Pacific ascent into space.

The motors will separate from the rocket about two minutes after liftoff, and the first stage's hydrogen-fueled LE-7A main engine will continue firing for another four-and-a-half minutes.

The H-2A upper stage will fire twice to place Akatsuki on the way to Venus. Credit: JAXA

After shedding the first stage, the rocket's upper stage LE-5B engine will take over for the first of two firings to place the vehicle in orbit, then accelerate the payloads into an escape trajectory.

Akatsuki should be released from the launch vehicle just south of Hawaii at T+Plus 27 minutes, 50 seconds.

See more details of the H-2A rocket's launch timeline here.

A group of secondary payloads will also ride aboard the rocket, headlined by a small craft designed to set sail on the nearly immeasurable pressure exerted by sunlight.

The square Ikaros solar sail will deploy an ultra-thin membrane, measuring about one-tenth the thickness of a human hair, approximately one month after launch. The sail, which stretches nearly 66 feet across, is lined with experimental solar cells to generate electricity.

But the focus of the $1.3 million mission will be harnessing light pressure from the sun.

Solar sails provide an inexpensive and efficient way to travel through the solar system and eventually to nearby stars. The concept involves large thin deployable structures that capture the energy of photons, particles of light that can gradually propel a spacecraft without conventional chemical fuels.

Ikaros stands for the Interplanetary Kite-craft Accelerated by Radiation Of the Sun. The name also harkens to the Greek mythological figure Icarus, who fashioned feathers and attempted to escape exile but flew too close to the sun.

Japan has led solar sail research in recent years. A small reflector was deployed from a suborbital sounding rocket in 2004 and a larger sail failed to open completely during an orbital test in 2006.

Ikaros will deploy a membrane-like solar sail for a demonstration mission in deep space. Credit: JAXA

If weather or technical issues prohibit an on-time launch, JAXA has until June 3 to launch Akatsuki while Earth and Venus are in the proper positions to permit the 1,100-pound probe to make the voyage. The H-2A rocket only has an instant to launch each day.

Assuming the booster puts Akatsuki on a good course toward Venus, only one post-launch burn of the spacecraft's main engine is planned to tweak its trajectory. That firing should occur Tuesday in view of a Japanese tracking station, according to Seiichi Sakamoto, a mission spokesperson at the Institute of Space and Astronautical Science.

If Akatsuki launches Monday, the probe is scheduled to reach Venus around Dec. 6, when it will again ignite its engine to enter an oval-shaped orbit around planet. Its 30-hour-long operational orbit will stretch from just above the Venusian atmosphere to a high point of nearly 50,000 miles.

Akatsuki and the European Space Agency's Venus Express orbiter, which is already circling the planet, will double-team on studies of the Venusian atmosphere using each probe's science instruments. Both missions are currently scheduled to conclude in late 2012.

Venus Express observes the planet from a polar orbit, while Akatsuki will enter an equatorial orbit upon arrival late this year.

Akatsuki's five cameras are designed to take readings at several infrared and ultraviolt wavelengths, allowing scientists to analyze different layers of the atmosphere.

"Planet-C has numerous unique Japanese technologies that we hope will gather data to help solve the mysteries of Venus and lead to exciting new discoveries for our world," said Nobuaki Ishii, a project engineer for the mission.

Two short-wavelength infrared imagers will observe low-altitude cloud patterns, chart the distribution of water vapor and carbon monoxide, and map the surface of Venus with a goal of finding active volcanoes. Thick clouds prevent visible cameras from seeing the surface.

Data from Venus Express recently showed evidence of fresh lava flows around three mountains, giving scientists new hope of catching a volcano in the act.

Akatsuki's suite of cameras will each see a different view of Venus. Credit: Akihiro Ikeshita/JAXA

A long-wavelength infrared camera and an ultraviolet instrument will look at the super-rotating cloud structures in the upper atmosphere. The ultraviolet camera will also track sulfur dioxide, a precursor to cloud formation at Venus.

Venus rotates on its axis once ever 243 days, remarkably slower than any other planet in the solar system.

"On most planets like Earth and Mars, the atmosphere usually rotates very slowly as compared to the planetary rotation," said Masato Nakamura, Akatsuki's project manager. "On Venus, however, the atmosphere rotates at a very fast rate approximately 60 times that of the planet's rotation. In fluid mechanics, this very unusual behavior is called super rotation."

Another camera will snap frames 30,000 times per second with a wide field-of-view to determine if theorized lightning exists at Venus.

Controllers will also direct radio waves from Akatsuki's antenna through the Venusian atmosphere to measure temperature profiles and concentrations of sulfuric acid. The variations will slightly bend the signals as they travel from the spacecraft to Earth, allowing scientists to decipher atmospheric conditions.

Akatsuki's launch will come one month before Japan's Hayabusa probe is expected to return to Earth, completing the first round-trip mission to an asteroid.

Hayabusa's homecoming is scheduled for June 13.