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Saturn's largest moon, Titan, is thought to have seas of methane with a landscape and
atmosphere functioning much similar to our own.
Which is why NASA is developing a nuclear-powered rotorcraft-lander, deemed Dragonfly, to send
to Titan's surface.
This car-sized drone will investigate the organic-rich terrain like never before, revealing
whether or not this moon really is a “primordial earth”,
harboring the very beginnings of life.
The reason we know anything at all about the composition of Titan, is thanks to the European
Space Agency's Huygens probe and NASA's Cassini spacecraft.
After disembarking from Cassini, the Huygens probe had a hazardous two and a half-hour
descent to the moon's surface – collecting data as it went.
It was the first time scientists ever landed on a world in our outer solar system and the
details from this mission provided a few insights.
Titan has an atmosphere, winds, dry river beds and lakes, mysterious dunes, a possible
subsurface ocean, cryovolcanoes, and, most excitingly, key ingredients for life, like
methane, ethane propylene, nitrogen, and carbon.
It was these qualities that propelled the creation of the Dragonfly mission.
Dragonfly is led by a team out of John Hopkins University, but it was an international collaboration
to get the unique duel quadcopter design, and for good reason.
So why is everyone excited about this mission?
Well, traditional crafts, such as a lander or rover, are limited to their immediate location.
A rover couldn't quickly travel vast expanses and a lander doesn't move at all.
But scientists found that Titan's cold atmosphere, and predominantly nitrogen makeup provides
a lower molecular viscosity than Earth's.
This, paired with high densities means it's much easier to get heavier items off the ground,
like a car-sized drone.
Plus, decades worth of advancements of autonomous multirotor technology made a rotorcraft a
perfect deep space candidate.
Scientists estimate Dragonfly will fly or “hop” from one location to the next faster
than any Mars rover has driven in a decade.
Over the course of two years, Dragonfly will have accumulated over a hundred and seventy
kilometers of groundwork, and it's prepared to do so, with a robust suite of instruments.
Looking under the hood, the drone will be equipped with a Multi-Mission Radioisotope
Thermoelectric Generator, better known as its nuclear power.
This same system has been used before to power the Mars Curiosity rover.
MMRTG's work by converting heat from the natural decay of radioisotope materials, in
this case plutonium-238.
It then uses solid-state thermocouples to convert the heat energy from that decay into
electricity.
What makes this latest engineering design special is that it generates smaller increments
of electricity, about 110 watts at launch, which will help prolong its lifetime in space.
Plus, the MMRTG will power a battery that is roughly a quarter of the size of those
found in a Tesla electric vehicles.
And Dragonfly's innovations don't stop there.
The rest of the craft will be composed of highly-specialized instruments that will be
used to explore the complex terrain on Titan.
These will include, geophysical and meteorological sensors, cameras to look ahead at horizons
and pointed below to look at dunes. And when it lands, Dragonfly will have an underbelly
instrument that will fire neutrons at the surface and and look for any gamma rays released
to determine terrain types, like ammonia-rich ice or carbon-rich sand dunes.
With all that's ahead, it's almost no surprise that the Dragonfly team won NASA's
competition, the New Frontiers Program.
Previous winners of this program include innovations like OSIRIS-REx, JUNO, and the New Horizons
spacecraft.
NASA considers this competition to represent a critical step in the advancement of solar
system exploration.
Dragonfly plans to launch in 2026 and arrive at Titan in 2034, and once it does, we'll
be one step closer to answering the questions to if life is only unique to our planet.
If you haven't already noticed, Seeker's Countdown to Launch series has gotten a facelift!
And that's because we're committed to bringing you more launch coverage than ever
before.
And with all the exciting missions we've done in the past and have planned for the
future, we want to know which ones do you want to hear about?
Let us know in the comments below.
Also, check out our CTL playlist that features stories on the latest launches from SpaceX
and ISRO.
Don't forget to subscribe so you never miss an episode.
Thanks for watching and we'll see you next time on Seeker.
コツ:単語をクリックしてすぐ意味を調べられます!

読み込み中…

NASA’s Nuclear Drone Will Search for Life on Titan

28 タグ追加 保存
林宜悉 2019 年 9 月 18 日 に公開
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