The Japanese Aerospace Exploration Agency (JAXA) is poised to launch a probe on a two-year mission to study the weather and explore the enigmatic surface of cloud-shrouded Venus.
The Akatsuki ("Dawn”) climate orbiter will be lofted into space on an H-IIA rocket, along with a small solar power sail demonstrator known as Ikaros that will accompany the orbiter to Venus.
Once in space, the 677-pound (307-kilogram) Ikaros is expected to separate from the rocket and unfurl a 46-foot-wide (14-meter-wide) solar sail.
"First proposed in the 1920s, solar sails are large reflective membranes that allow a spacecraft to be pushed by radiation pressure from sunlight, negating the need for heavy onboard fuel," explained National Geographic’s Julian Ryall.
"[But] Ikaros is considered a hybrid, because the sail's membrane—itself just 0.0075 millimeters thick—sports thin-film solar cells for generating electricity, which will power Ikaros's high-efficiency ion-propulsion engines."
Meanwhile, project scientist Takeshi Imamura told Space News that Akatsuki was the "world's first" interplanetary probe which deserved to be called a meteorological satellite.
"Once we can explain the structure of Venus, we will be able to better understand Earth," noted Imamura.
"For example, we may discover the reasons that only Earth has been able to sustain oceans, and why only Earth is abundant in life."
The probe is equipped with five different cameras to study Venus' clouds, map the planet's weather and peek through its thick atmosphere to view the surface.
"Venus somehow transformed from a more Earth-like place to the alien place it is today, and what's fascinating about the world is figuring out how it diverges from the Earth and the history behind why that happened," said David Grinspoon, curator of astrobiology at the Denver Museum of Nature and Science and an interdisciplinary scientist on the Venus Express mission.
"It could help us understand how things here [on Earth] might change."