NASA made its much anticipated announcement of the winner of the next Solar system exploration mission today at 4:00 p.m. EDT. And the winner is (drumroll please) … the DragonFly mission to Titan, the largest moon of Saturn.
Dragonfly is a mobile robotic rotorcraft lander (a Quad Octocopter), that will hop around on the surface of Titan to study its prebiotic chemistry and extraterrestrial habitability. The Dragonfly mission was proposed in April 2017 to NASA's New Frontiers program by the Johns Hopkins Applied Physics Laboratory, and it was selected as one of two finalists (out of twelve proposals) in December 2017. The other finalist was CAESAR (Comet Astrobiology Exploration Sample Return) — a sample-return mission to comet 67P/Churyumov–Gerasimenko, the same comet visited by the the Rosetta mission.
Dragonfly
Dragonfly will launch in 2026 and arrive at Titan 8 years later in 2034. Dragonfly will be the first multi-rotor vehicle to fly on another planet for science; it has eight rotors and flies like a large drone, taking advantage of Titan’s low gravity and dense atmosphere, which is four times denser than Earth’s.
During its 2.7-year baseline mission, Dragonfly will explore diverse environments from organic dunes to the floor of an impact crater where liquid water and complex organic materials key to life once existed together for possibly tens of thousands of years. Its instruments will study how far prebiotic chemistry may have progressed. They also will investigate the moon’s atmospheric and surface properties and its subsurface ocean and liquid reservoirs. Additionally, instruments will search for chemical evidence of past or extant life.
The development cost cap is approximately $1 billion.
Dragonfly will land at Titan’s vast Shangri-La dune fields, the same region where ESA’s Huygens probe landed in 2005, a region relatively flat and safer for landing. Dragonfly will be able to travel much larger distances — 175 km during its 2.7-year baseline mission - compared to Curiosity, which has traveled 21 km on Mars in about 7 years and spend relatively more time doing science. Dragonfly will touch down almost precisely one Saturn year after Huygens’ historic descent, meaning that Huygens’ experience provides a direct test of the environment through which Dragonfly will enter.
Each of the eight rotors of Dragonfly will be about 1 m in diameter. The aircraft will travel at about 36 km/h and climb up to 4 km altitude, as it hops from site to site. The spacecraft will powered by a plutonium-238 powered Radioisotope Thermoelectric Generator (RTG), which will charge its batteries at night for flights during daytime.
The Dragonfly will weigh a hefty 450 kg (on Earth).
From dragonfly.jhuapl.edu/… — The Dragonfly configuration for atmospheric flight, with the gray circular HGA (high Gain Antenna) stowed flat. The cylinder at rear is the Multi-Mission Radioisotope Thermoelectric Generator (MMRTG). A sampling drill mechanism is visible in the nearside skid leg, and forward-looking cameras are recessed into the tan insulating foam forming the rounded nose of the vehicle. Dragonfly will communicate directly with Earth, without the aid of an orbiter.
Credit: JHU-APL
Why Titan?
From www.nasa.gov/… —
Titan has a nitrogen-based atmosphere like Earth. Unlike Earth, Titan has clouds and rain of methane. Other organics are formed in the atmosphere and fall like light snow. The moon’s weather and surface processes have combined complex organics, energy, and water similar to those that may have sparked life on our planet.
Titan is larger than the planet Mercury and is the second largest moon in our solar system. As it orbits Saturn, it is about 1.4 billion km away from the Sun, about 10 times farther than Earth. Because it is so far from the Sun, its surface temperature is around -179 degrees Celsius. Its surface pressure is also 50 percent higher than Earth’s.
The climate of Titan — including wind and rain — creates surface features similar to those of Earth, such as dunes, rivers, lakes, seas (probably of liquid methane and ethane), and deltas, and is dominated by seasonal weather patterns as on Earth.
Titan is thought to be a prebiotic environment rich in complex organic chemistry with a possible subsurface liquid ocean serving as a biotic environment.
All of which point to the tantalizing possibility of life - now, in the past or in the future.
Here is a beautiful image of Titan, Saturn and Saturn’s rings taken by Cassini. The hazy atmosphere of Titan is clearly visible.
Here are some infra-red images of Titan, taken by Cassini -
Cutting through the haze. Credit: NASA/JPL-Caltech/University of Nantes/University of Arizona
NASA’s New Frontiers program
This is the fourth mission funded through NASA’s New Frontiers program. The earlier three missions are the Juno mission to Jupiter, the New Horizons mission to Pluto and beyond and OSIRIS-REX, the asteroid-sampling spacecraft currently in orbit around the asteroid Bennu.
Tweets and Videos
Here are some tweets, videos and links to articles about the mission. Enjoy them before and during a break from the Democratic debate tonight.
Here is the webcast from NASA today, with NASA scientists and mission investigators explaining the mission, its importance and its technology.
Here is a video taken by ESA's Huygens probe which made a 2.5 hour descent to the surface of Titan in 2015. This was part of NASA's Cassini mission.
Epilogue
Frankly, science and this mission are more exciting and satisfying than the debates. We know our candidates very well already and not much new will emerge tonight except how well the candidates fend each other off and handle the gotcha questions in the glare of the television camera lights. Wish there was a question about science or space exploration. But, nevertheless, we need to keep working on all fronts; lord knows there will be no science under republican rule.
Further Reading
- JHU-APL Dragonfly site — dragonfly.jhuapl.edu/…
- Dragonfly — en.wikipedia.org/...
- NASA Announcement — www.nasa.gov/...
- Dragonfly: A Rotorcraft Lander Concept forScientific Exploration at Titan — dragonfly.jhuapl.edu/...
- Titan — en.wikipedia.org/...