War of the worlds II (Mission to Mars)

My apologies to H. G. Wells and the brilliant folks at NASA

H. G. Wells got it wrong
When he said to Earth would throng
Sinister invaders from Mars.
In their metal capsules they'd come
And us Earthlings would be too dumb
To resist their machines of war.

Wells' Martians were beaten
When their insides were eaten
By bacteria which they had not encountered.
Such a silly blunder
Sent all their plans asunder
And thus the Martians were countered.

With roles now reversed,
Earth's rovers will traverse
On Mars to collect soil samples.
Our goals are noble and fine
And scientific and benign
For there are no Martians to trample.

Our science is sound
And no Martians abound,
Success will surely be ours.
But yet, we were beat
Converting from meters to feet
Stalling our Mission to Mars.

Please quote if you wish, but don't forget to cite the source as Ranjit Nair's limericks.