Balderax, what sort of aeroplane/engine are you talking about? What do you actually mean by "power"? Throttle position? N1 gauge indication? Fuel Flow indication? It seems to me that Keith and I are arguing about two completely different things and that needs to be resolved before I go on.
The root of my question is the following part of the article :
"One of the schemes for exploring more of the Martian surface is to use drones. They would have to be very light and have a large wingspan to fly in the wispy Martian atmosphere, which is the equivalent of Earth's somewhere above 100,000 feet, but it helps that things on Mars weigh only 3/8 of what they do on Earth. More of a challenge would be achieving an indicated speed of 20 knots in the first place; the TAS would have to be around 200 kts. The problem is that at a given IAS, the power required is proportional to the TAS; that's why it takes more fuel to indicate 150 kts at 10,000 feet than at 5,000. Air particles are hitting the airplane with the same force, but in a given period of time, more of them hit it."
For his example, he says that 20 kias would be enough to make the drone fly. This speed seems easy to achieve. Then he says the problem is the 200 ktas needed, due to the fact that the air is very thin. But hey, these 200 ktas are needed precisely BECAUSE the air is thin, and if the air is that thin, drag must also be very low. So, if drag is so low, why is TAS a problem in the first place ?
In his article he doesn't mention the kind of engine the drone uses. But I'm personally more concerned by jet engines.