This is literally rocket science, it was, and forever will be, complicated. Of course there will be failures in space exploration because we just don't know a lot, and how are we supposed to learn without have failures along the rode?!?! I believe that this crash is one step closer to gaining even more knowledge in science, and if they stop now, then the accident was a total waste!
Failures are only opportunities to know a specific area well enough to take control. More failures in the prototype phase is far better than one in operations. Thanks to computer based simulations that today we can conduct large number of tests even before the prototype phase but still certain results need to be verified by subjecting the prototype to real life situation.
This kind of event is a huge disaster which should force them to identify and closely examine the causes before setting out into space again. Space flight is very early in it's development, and it is important to ensure this kind of disaster doesn't happen again in the future when more people's lives are at risk.
I don't think Virgin Galactic should take a break from space travel. Accidents will always happen. This was called a test flight for a reason, to check systems and ideas work perfectly. Also, after the Malaysian Airways crash, should we stop flying planes for a while? I think we all know the answer to this!
The purpose of testing is to see if something works properly. Now is not the time to take a break. Now is the time to push forward. Space travel will only be possible when the appropriate real life tests are complete so we shouldn't stop in the face of failure. We should learn and adjust and move forward.
Virgin Galactic are dreamers and visionaries and what they do is great. Their space travel plans have to become reality, so many people are looking forward to this.. The recent crash is a serious and dangerous matter that has to be tackled openly and thoughtfully. However I hope they continue working on the project with double efforts and make happen for everyone to travel in space one day.