it muss be able to stand heat and stresses like those never experienced before. It will need to carry all the equipment it needs all on an untried mission,to an unknown place. And then it must return safely to Earth by re-entering the atmosphere at speeds of over 25,000 miles per hour,causing heat about half that of the temperature of the sun. We want to do all this. And we want to do it right. And do it first,before this decade is out.