Sunday, 18 August 2019

The Plan to Fly Drones on Titan


The Plan to Fly Drones on Titan


Some time back (early winter 2018), I blogged about NASA’s upcoming decision about whether to do a comet material return mission or explore Saturn’s moon Titan up-close.



Quickly recapping those choices, as presented at that time:

“Should we return to the comet visited earlier by NASA/ESA (comet 67-P/Churyumov-Gerasimenko), to collect some material and fly it back to Earth for study, or land drones on Saturn’s moon Titan to study that icy world in more depth?  Those appear to be the deep solar system projects (New Horizons) currently most likely to be given the green light by NASA, according to a number of news sources.  Since I have previously blogged about the Rosetta mission to a comet, and about some possibilities for a Titan mission, this seems like a nice opportunity to revisit and elaborate upon those subjects.”

1) Dragonfly to Titan

“The proposed mission to Titan has been named The Dragonfly Mission.  The idea is to land a drone on Titan, which could fly to different spots, and thereby return data from more than one location on the moon.

2) CAESAR to Comet 67-P

The other mission being considered involves a return to Comet 67-P, the comet visited by Rosetta in 2016.  This would involve not only a landing, but a return of a sample from the comet.  It would launch in the mid 2020s, and eventually bring back a small sample, in the range of a few hundred grams. This would involve capturing volatiles (off-gassing) and non-volatiles (comet nucleus material).  These could then be analysed in great detail in labs back on Earth.”

The Planned Return to Titan

It seems that now (summer 2019) that decision has been made, and Titan has won the contest. 

The Titan mission will include a drone, named Dragonfly, that will be able to fly to different locations on that moon.  Titan’s dense atmosphere (4 times denser than Earth) and low gravity (one-seventh that of Earth) would indicate that flying conditions should be good.  The seemingly tranquil seas of methane on Titan would also imply that flying should be good, as winds must be light in order to stir the seas up so little, as radar observations from orbit have indicated (wave heights appear to be only centimeters).

Artist’s Conception of the Seas of Titan

Dragonfly will be the second lander on Titan, after the Huygens Lander that was attached to the Cassini mission.  That lander only lasted a short time on the surface, but it sent back some tantalizing pictures.
Dragonfly will further the work that Huygens began, but it will have a much longer operational life, as well as being able to move to different locations.  It will be able to fly to dozens of locations on the moon, with its main mission to be searching for prebiotic chemistry, also known as the building blocks of life (i.e. carbon-based organic chemistry, of which life on Earth is composed).  Among those areas are organic dunes and the floor of an impact crater.  It is thought that these could be especially interesting areas to search for precursors to life, or even life of some kind – though as Spock might say “not as we know it”.

Dragonfly is supposed to launch in 2016, arriving at Saturn in 2034.  It seems like the timeframe for this mission has been moved up, as my earlier blog noted that it was expected to arrive in 2041 and have a mission lifetime of about two years.  The currently planned mission has a lifetime of 2.7 years, so that has been altered a bit too.  It is worth noting that rovers on Mars have tended to remain operational well past their planned lifetimes, so this could be true of the Dragonfly drone as well.

Since Dragonfly will be a flying machine, it will be able to cover much more area than any other landers have on other planets (e.g. Mars rovers and lunar rovers).  It is planned to do a series of leapfrog type flights, that will eventually allow it to travel nearly 200 kilometers.  In order to achieve these feats, the probe will have to include a radioactive power source, but that has been used on a number of missions now, such as Mars rovers (readers of “The Martian” may recall that being an essential plot devise in the novel).


The mission is part of the New Horizons series of missions, the most notable of these being the highly successful Pluto flyby.  Let’s hope this one goes as well as that one did.

Sources:

1 - Comet mission or Titan mission?
2 - Titan’s calm seas.
3 - NASA’s decision to go back to Titan
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Now that you have read some real science (astronomy and astrophysics), you should read some science fiction.  The Witch’s Stones series would be an excellent choice.  Alternatively, you could try the short story “The Magnetic Anomaly”, a SF story which includes plenty of interesting geophysics. 

The Witches’ Stones

Or, you might prefer, the trilogy of the Witches’ Stones (they’re psychic aliens, not actual witches), which follows the interactions of a future Earth confederation, an opposing galactic power, and the Witches of Kordea.  It features Sarah Mackenzie, another feisty young Earth woman (they’re the most interesting type – the novelist who wrote the books is pretty feisty, too).


The Magnetic Anomaly: A Science Fiction Story

“A geophysical crew went into the Canadian north. There were some regrettable accidents among a few ex-military who had become geophysical contractors after their service in the forces. A young man and young woman went temporarily mad from the stress of seeing that. They imagined things, terrible things. But both are known to have vivid imaginations; we have childhood records to verify that. It was all very sad. That’s the official story.”


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