"We (NASA) want to do something bold and take measured risks."
Ars Technica said:On Thursday, NASA announced its next medium-class mission to explore the Solar System—a lander named Dragonfly that will fly like a drone over the surface of Titan, Saturn's largest Moon. Titan has a fascinating environment, with a hydrocarbon atmosphere much thicker than Earth's atmosphere. NASA intends to spend a couple of years exploring its complex chemistry.
NASA scientists were deciding between this Titan explorer and another mission that would have flown to a comet named 67P/Churyumov–Gerasimenko. The comet had been previously visited by Europe's Rosetta spacecraft, which returned a sample of cometary material to Earth.
Of the two missions, the Titan explorer—with an unprecedented design that would fly a vehicle the size of a larger Mars rover over the moon—carried the higher risk. But, half a century after the Apollo lunar landings, NASA decided to go boldly. "A great nation does great things," said NASA administrator Jim Bridenstine.
In 2004, a small spacecraft built by the European Space Agency detached from NASA's Cassini probe in the Saturn system and descended through Titan's thick atmosphere. It only survived about 90 minutes on the surface, but it returned tantalizing information about the complexity of a cold, exotic world that nonetheless has familiar features such as lakes and rivers filled with liquid methane.
"[Dragonfly] has so much potential for fundamental science," said Elizabeth Turtle, a planetary scientist at the Johns Hopkins Applied Physical Laboratory who is the principal investigator for the mission. Scientists believe the complex organic chemistry in the atmosphere of Titan and on its surface may look something like the chemistry on Earth before life developed. "Titan is just a perfect chemical laboratory to understand pre-biotic chemistry," Turtle said.
Cost capped at $1 billion
As a New Frontiers mission in NASA's portfolio, Dragonfly will be cost-capped at $1 billion. It is the fourth mission in this medium classification, following the New Horizons Pluto flyby mission, the Juno spacecraft now at Jupiter, and the OSIRIS-REx mission exploring the Bennu asteroid. It is expected to launch in 2026, aboard an unspecified rocket, before reaching Titan in 2034.
Once there, Dragonfly will land in the equatorial region of the moon, which is covered by large sand dunes. A radioisotope thermoelectric generator will recharge a battery, which in turn will power Dragonfly's rotorcraft flight system for a couple dozen flights across the surface of Titan during a period of 2.5 years. Over that time, Dragonfly will cover about 180km, a sizable chunk of a Moon that is 5,149km in diameter—about 1.5 times the size of Earth's Moon.
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