A rotorcraft that could flit around the Saturnian moon Titan and a probe that could bring a sample back from an already-famous comet have emerged as top prospects for a future NASA mission.
Those two mission concepts were selected for further study from a list of 12 proposals that were submitted for NASA’s New Frontiers portfolio, aimed at space missions with a development cost cap of about $850 million.
Examples of existing New Frontiers projects include the Juno orbiter circling Jupiter, the OSIRIS-REx spacecraft that’s on its way to sample a near-Earth asteroid, and the New Horizons probe that flew past Pluto and is now heading toward another icy object on the edge of the solar system.
A showdown is expected to result in one of the two new mission concepts moving onward to its development phase in 2019, NASA said today.
Both concepts call for robotic probes to be launched in the 2020s and yield results in the 2030s.
Flying around Titan
The Dragonfly mission would launch a drone-type rotorcraft toward smog-covered Titan in 2025, with arrival set for 2034. Its multi-year mission would follow up on findings from the Huygens lander, which sent back a brief burst of data from Titan’s icy surface in 2005.
Readings from Huygens and its mothership, the Cassini orbiter, have shown that Titan has seas, lakes and rivers of liquid hydrocarbons such as methane and ethane. Titan’s environment may seem unworldly in comparison with Earth, but astrobiologists say it could conceivably support weird kinds of life.
“We will land on the surface of Titan, perform detailed compositional measurements and study Titan’s habitability,” Elizabeth Turtle, the planetary scientist from Johns Hopkins University’s Applied Physics Laboratory who’s leading the Dragonfly team, told reporters during a teleconference. “In this way, we can evaluate how far prebiotic chemistry has progressed in an environment that we know has the ingredients for life — for water-based life, or potentially even hydrocarbon-based life.”
She said Dragonfly’s instrument-laden drone would spend most of its time on the ground, but it’d be able to fly through Titan’s dense, nitrogen-rich atmosphere and survey other sites dozens of miles away.
Sampling a comet
The other mission selected for further study is known as Comet Astrobiology Exploration Sample Return, or CAESAR. It’s designed to return to Comet 67P/Churyumov-Gerasimenko, the duck-shaped chunk of ice that was studied up close by the European Space Agency’s Rosetta probe in 2014-2016.
CAESAR’s team leader, Cornell University planetary scientist Steve Squyres, said there’s an advantage in returning to a previously mapped comet. “By going to that comet, there’s an enormous amount of risk reduction that takes place,” he said.
The mission would also make use of technologies that were put to the test by the Japan Aerospace Exploration Agency for Hayabusa, its sample return mission to an asteroid.
“What the CAESAR mission will do is return the first samples from the surface of a comet nucleus,” Squyres said. (An earlier NASA mission, Stardust, brought back flecks of dust from the coma surrounding Comet Wild 2 in 2006).
CAESAR would collect at least 100 grams (3.5 ounces) of cometary material and bring it back to Earth in 2038.
Squyres noted that past studies have confirmed comets contain water as well as organic compounds that could serve as life’s building blocks. CAESAR’s sample material would be distributed to researchers worldwide to “produce groundbreaking science for decades to come,” he said.
Thomas Zurbuchen, NASA’s associate administrator for science, said in a news release that the two missions are “tantalizing investigations that seek to answer some of the biggest questions in our solar system today.”
“This is a giant leap forward in developing our next bold mission of science discovery,” he said.
Enceladus and Venus
In addition to Dragonfly and CAESAR, NASA said two other concepts would receive technology development funds to prepare them for future mission competitions:
- Enceladus Life Signatures and Habitability: The ELSAH team will receive support to develop cost-effective techniques that limit spacecraft contamination and enable life detection measurements.
- Venus In Situ Composition Investigations: The VICI team will conduct further development on the Venus Element and Mineralogy Camera to operate under Venus’ harsh conditions. The instrument would use lasers to measure the composition of rocks on the Venusian surface.