Today's OneWord: Necessity

"Is it really that big of a necessity to make this rocket fly?"

"Yes."

"To Jupiter?"

"Yes."

"Where there is absolutely no landing dock?"

"Yes."

"And no way to travel on foot, because it's a freaking gas giant?"

"Yes."

The physicist calmly eyed the gleeful newcomer. "And yet you still want to be the first man to walk on Jupiter?"

"Yes, sir," said the newcomer. "I defy physics!"