If something goes wrong on the way, it will be blamed on engineering failure. It has been forecast that the Great Questions of Science will nearly all be answered in the next twenty years. A scientist knows, for example, that mixing hydrogen and oxygen and striking a match is likely to prove noisy. It certainly cannot be proved as a fact or a truth- though any amount of evidence might be found to support it. And who knows, it might even be true.
Scientists delight in propounding laws.
These laws, however, are just rules of thumb. Voltage is proportional to current - over a limited range. The stretch of a spring is proportional to the tension - but the 'law' runs out of steam long before the spring is pulled into a straight piece of wire. And these laws are very convenient within their limitations, allowing measurements to be predicted and experiments to be second-guessed. It is when the law takes on the flavour of a universal truth that the scientist is transformed into a credulist.