Originally posted by Liberator
I wonder why they didn't use a radiological power source? Not nuclear, radiological, like all the deep space probes we've ever launched. The damn things were still providing power 10-15 years after they launched and they're safe enough you could put on in your car. The key, I guess, is amount, most radiological cells can only do a few hundred watts an hour.
Typical response.
...and typical lack of understanding of the velocities of the objects involved, how radio behaves, etc.
Huygens was designed to operate for as long as Cassini would be in range, and designed to do a whole lot of work in that short timeframe.
It will be *weeks* before Cassini does another close sweep to receive radio signals from Huygens for a few hours.
The velocities involved means that there's doppeler effects, which were underestimated and led to the deployment date being changed. These effects mean that the window of opportunity to receive data is even narrower than originally thought.
Pretty much, Huygen's powerplant is the way it is because the mission designers knew that receiving further data from the probe would be very iffy.
They were in a similar situation as the folks designing the Mariner landers.
Now, if Cassini was a mission that actually orbited Titan and not the whole Saturnian system then it'd be able to receive the data that a long term lander would have.
People seem to have a hard time grasping the distances involved, how slow the speed of light actually is, the adjustments needed, etc. to get something like this to work right. Especially in a situation such as a high speed orbit around a gas giant with a few passes and trying to get data from a lander on a fixed spot.
However, I'm sure Liberator complained that the probe launched from Galileo into Jupiter was a waste because it was designed to measure the atmosphere and find the crush depth. It's
obviously a waste of money if it doesn't last 12 years. Just like Huygens was designed for atmospheric tests and some perliminary looks at the surface to confirm readings taken from the flybys. Keep in mind, this probe was designed for a lot of worst-case scenarios of what Titan would be like. It wasn't custom-tailored for further exploration like the current crop of Mars landers.