46 votes
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Huygens Lander: Why The Short Battery Life?

The Huygens was not capable of transmitting data directly to the Earth, instead Cassini relayed all communication. Therefore mission lifetime was limited by possible communication window from Titan ...
Martin's user avatar
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42 votes
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Can a spaceship land on an icy body using retropropulsion? wouldn't the ice melt?

Sorry for the length of this, but it brings up some interesting facts and possibilities. The moons you mention, Titan, Europa, and Enceladus, are three very different places. Titan has a relatively ...
Tom Spilker's user avatar
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34 votes
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Why are we interested in visiting the giant planets' icy moons?

The icy moons are of interest for exploration as part of the overall "follow the water" strategy of exploration that NASA (and others) have been exploring for some time. The "where else can water be ...
astrosnapper's user avatar
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31 votes
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Why was Titan the first celestial body beyond Mars to be landed on?

Simple. It was the easiest to land on. Titan has an atmosphere, which makes landing there quite a bit easier than landing on Europa, which does not. In addition, Europa has only been known as an ...
PearsonArtPhoto's user avatar
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29 votes
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How does Titan have hydrogen in its atmosphere?

How does Titan have Hydrogen in it's atmopshere? Hydrogen is a trace gas in Titan's atmosphere (0.099% per the wikipedia article on Titan's atmosphere). Titan's scant amount of hydrogen in its ...
David Hammen's user avatar
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27 votes
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How could a hot lander enter Titan's atmosphere without setting its hydrocarbons ablaze?

In order for a combustion process to happen, you do not only need fuel, you also need an oxidizer. On Earth, that is usually the oxygen in the air. In Titan's atmosphere, there is no oxygen. This ...
SE - stop firing the good guys's user avatar
24 votes
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How do I dress for a hike on a hot summer day on Titan?

The ESA Huygens probe very accurately characterized the conditions at its landing site on Titan's surface and verified measurements made by the Voyager 1 Radio Science (VRS) investigation nearly 25 ...
Tom Spilker's user avatar
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23 votes

How do I dress for a hike on a hot summer day on Titan?

A -183 C nitrogene-methane mix doesn't make you an icecube on the spot, but it still causes quickly frozen wounds. Your only way to avoid it if your whole body is protected, no $cm^2$ may remain open. ...
peterh's user avatar
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22 votes

Why does Titan have an atmosphere?

The mass of Titan is 1,345 · 1023 kg, but the mass of the Moon is 7,349 · 1022 kg. The gravity at the surface is 1,35 m/s² for Titan and 1,62 m/s² for the the Moon. But the surface temperatures are ...
Uwe's user avatar
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21 votes

Huygens Lander: Why The Short Battery Life?

This book has a table with the energy budget for Huygens: Data relay system: 214 Wh Computer: 246 Wh Electric power system: 5 Wh Payload: 325 Wh Losses: 132 Wh Pre-separation checks: 50 Wh Total: ...
Hobbes's user avatar
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19 votes

Can a spaceship land on an icy body using retropropulsion? wouldn't the ice melt?

It's probably going to be less of a concern than you'd guess. The icy worlds of our solar system have essentially no atmosphere, so the surface materials will sublimate directly to vapor and be ...
Russell Borogove's user avatar
19 votes

How does Titan have hydrogen in its atmosphere?

The chemistry of Titan's atmosphere is actually quite complex. Different reactions occur at different altitudes and there are a wide range of minor constituents in the atmosphere. One of those ...
Slarty's user avatar
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16 votes

Why are we interested in visiting the giant planets' icy moons?

The motivation is the growing understanding, from the Voyager, Galileo and Cassini probes, that these icy moons (I'd throw in Enceladus) are geologically active with sub-surface oceans of liquid water,...
antlersoft's user avatar
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14 votes
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Why are Titan's lakes "black" in radar images rather than transparent?

This article suggests that the radar can penetrate the lakes and reports them to be hundreds of meters deep. The space.com article referenced seems to be sourced from a Geophysical Research Letters ...
Steve Linton's user avatar
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12 votes
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Can Dragonfly make it to one of Titan's Lakes?

Can Dragonfly make it to one of Titan's Lakes? tl;dr: Yes! It could be doable in 2-3 years. According to your linked document Dragonfly will use a Multi-mission radioisotope thermoelectric generator ...
uhoh's user avatar
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11 votes
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What is the pop-up circular disk with spiral pattern in this NASA animation of the Dragonfly helicopter for Titan? Antenna? Kind, band, target?

Quick answer, bit short of time atm: What is the pop-up circular disk with spiral pattern in this NASA animation of the Dragonfly helicopter for Titan? Is it a high gain antenna? If so, what kind, ...
blobbymcblobby's user avatar
10 votes
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What is the solar flux on Titan?

The solar flux at 1 AU (Earth's distance from the sun) is ~1361 W/m2. Flux falls off as the square of distance. Saturn, on average -- and thus Titan, on average -- is about 9.58 AU from the sun, so ...
Russell Borogove's user avatar
10 votes
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Could a Nuclear-Thermal turbine keep a winged craft aloft on Titan at 5000m ASL?

It's absolutely impractical. Source: https://en.wikipedia.org/wiki/Kilopower Current designs: 1 kWe Kilopower reactor weighs 134 kg 10 kWe Kilopower is expected to mass 1500 kg The Artemis nuclear ...
Antzi's user avatar
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10 votes

Could a Nuclear-Thermal turbine keep a winged craft aloft on Titan at 5000m ASL?

As Antzi correctly identifies, doing this via nuclear decay->heat->boiling fluid->turbine->electricity->electric motors->propellers is pretty marginal. In terms of serious ...
GremlinWranger's user avatar
9 votes

Maximum survivable atmospheric pressure

The maximum pressure for long term survival in an atmosphere of 79 % nitrogen and 21 % oxygen is limited by oxygen toxicity. The limit of the partial pressure of oxygen is about 0.5 bar, the maximum ...
Uwe's user avatar
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9 votes
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What are the technical challenges in building a Titan rover that didn't need heating?

I think we should break this down in two parts: Operation at low temperature and impact of a "hot" rover on the environment. Most semi-conductor based electronics as we have them today don't have an ...
asdfex's user avatar
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9 votes
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Could SpaceX's Starship's landing and restart process work on Titan?

Getting There: In general there is "the quick way" and "the efficient way" to get to the outer planets. The trade-off is between the capability of the launch vehicle and the time-...
BrendanLuke15's user avatar
9 votes

Could a helicopter escape Titan?

Good luck getting a helicopter hypersonic. You need more than 2,600 m/s to escape Titan. The speed of sound on Titan is 194 m/s.
Loren Pechtel's user avatar
8 votes

How much methane to push Titan into Saturn?

Let's turn the question on its head and see what exhaust velocity we need to if Titan's entire (mostly nitrogen) atmosphere were used as a propellant. $\Delta v = v_e log(m_i / m_f)$ Wikipedia tells ...
user25972's user avatar
  • 431
8 votes
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How will Dragonfly (mission to Titan) keep from flipping over?

They plan to use some form of "site evaluation" to prevent tipping over: However, technology developments in the last two decades, notably the revolution in availability of multi- rotor ...
Hobbes's user avatar
  • 128k
8 votes

How can they be so sure that Dragonfly will "freeze to death" as opposed to simply (and eventually) running out of RTG power? (238Pu decay)

The RTG makes heat, which is used in two ways in missions to cold places: Through thermocouples to generate electricity, and through waste heat. Some of the waste heat is cycled through coolant loops ...
Wayne Conrad's user avatar
7 votes

What is the process to produce a chemical composition spectrum of a celestial body?

The spectrum you show from Titan was taken using the IRIS spectrometer aboard Voyager 1. Of course Voyager 2 had one as well. A huge amount of work went into developing and optimizing the design in ...
uhoh's user avatar
  • 149k
7 votes

What type of information can be gathered from a plot of brightness against wavelength?

In general, a spectrum can tell us about the composition of the source of the radiation, or of any substance between the source and the detector. Each material has its own fingerprint and ...
gerrit's user avatar
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7 votes
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What would a "water" landing on Titan be like? How viscous is the liquid?

According to NASA's article "Rainbows on Titan": The density of liquid methane is only about half the density of water. This is something, say, a boat builder on Titan would need to take ...
Russell Borogove's user avatar
7 votes

Why Never-EVER Land?

As noted before, landing gear, especially for soft or relatively rough surfaces, tends to be heavy, and mass is at a premium. More on that later. But there is another good reason to stay aloft, ...
Tom Spilker's user avatar
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