# Could electricity propel Curiosity on Venus?

To-date the humans have dispatched surface missions to

Mars has a thin atmosphere. Luna lacks one. Venus has a soup-thick atmosphere. Landing a static craft on Venus is one thing. Exploration, rather mobile exploration would be a different cup of tea altogether given the alien (pardon the pun!) atmosphere - high pressure, high wind force.

On Mars, and Luna electricity serves as the motive power - generated either by an RTG, or by PV arrays, or some form of batteries.

Assuming the Curiosity rover is capable of surviving the Venerean atmosphere, could electricity serve as it's motive power at 93 bar? [ (+: Or a rover equaling Curiosity in terms of mass, and payload. ]

Not a good assumption. Curiosity would die a very quick thermal death on the surface of Venus.

But to answer your question, Curiosity's MMRTG would work on Venus and provide power. The smaller temperature delta reduces the efficiency of conversion, but its not too bad. See this paper.

The atmospheric density and wind are not a factor at all for rover speeds and Venus wind speeds. The wind at the surface is $0.1$ to $1\,\mathrm{m\over s}$. The density is $67\,\mathrm{kg\over m^3}$. So maybe $100\,\mathrm{N}$ over $3\,\mathrm{m}^2$ in a $1\,\mathrm{m\over s}$ wind. The torque of the wheels is enormous, and wouldn't even notice that. Each of the six wheels of Curiosity generates almost $3000\,\mathrm{N}$ of force when fully engaged. $100\,\mathrm{N}$ at $0.05\,\mathrm{m\over s}$ is just $5\,\mathrm{W}$ of motive power.

You'd need to be careful to protect your soil samples so they don't blow away on the way from the ground to the instrument. I'd worry more about the viscous drag when your wheels melt ...

• I'm sorry the question wasn't clear. More than the temperature I'm concerned about the effort involved in motion under 93 Bar. Would 300W be adequate? – Everyone Dec 4 '13 at 18:45
• The start of this answer should be modified to match the edited question. – James Jenkins Jan 20 '14 at 13:35

The equation for aerodynamic drag is: $$P_d = \mathbf{F}_d \cdot \mathbf{v} = \tfrac12 \rho v^3 A C_d$$ Curiosity has a max. speed of 5 cm/s (0.18 km/h). Air density $\rho$ of Venus is 67 $kg/m^3$, where on Earth it's 1.2 $kg/m^3$.
I'll guesstimate frontal area A = 4 $m^2$ and $C_d$ = 1, then at 5 cm/s the drag force due to the rover's own speed is 0.016 N. The drag from wind speed (as @Mark calculated) is much higher, but still nothing to worry about.
Curiosity has up to 4000 Nm of torque available, or 16 kN of force. That's with 110 W per wheel.