You might also want to consider the thousands of troops "invited" to "witness" the British A-bomb tests in the 1950s......
That was little short of criminal behaviour.
Is experimenting on humans without their consent justified by "a small sacrifice for the greater good?" Take the Marshall Islands project 4.1 for example.
Experimenting on anyone without their permission is just unacceptable. No one has the right to determine whise life is more valuable than another's.
It depends on what the product of it is. If it causes more benefit to the greatest amount of people than the pain expirienced by those who were tested, then it is. If it doesn't cause more benefit than the harm (i.e, killing a few painfully to test out makeup) then you should not. If it is benefit to a few or one, then no. If the benefit it causes is still at the expense of others that aren't even in the test, or the research that comes out of it will be used negatively for society (for the benefit of a few) than still, it's not worth it. It's important to consider the end product. More happiness than pain=good, but too much pain that doesn't outweigh the result is bad.