4 ms·

Thanks, but now I wonder. Mass is different from Weight (absolute and relative respectively). Are we comparing apples and oranges here?

• acqq 12y ago
  We compare correctly: we measure everything on Earth (that means, under the same gravity) and the proportionality holds, so it's still more than 20 times less mass to carry for the power source with the given solar panels vs. the RTG. The mass doesn't go away, the amount of stuff remains, the weight is how much something pulls down the spring in the spring scale and that depends on gravity, but we conveniently measure on Earth.