Science is trying to explain how the universe is made. The beginning of the universe explains the Big Bang theory. But what happened before Big Bang? Science cannot go before that. So, does this mean that always there be space for religion and philosophy to explain things that science cannot?
Science is a method. The scientific method gives us tools to hypothesize and theorize models to fit what we currently observe about our universe. Science is not an absolute truth; our body of scientific knowledge is a collection of the best models we currently have. Many models are extremely strong, some are works in progress, and some are just starting to develop. We don't yet have models to fit absolutely everything that we observe, and there are also many things that we have not yet observed, could never observe directly, or have not yet even contemplated. We are inside of a complex system, doing our best to make models that explain the system.
Physics is the primary tool that we use to explore models for the mechanics of the universe. We use our current theoretical models of the universe and extrapolate backwards in order to hypothesize what came before what we currently observe.
The strongest theory I have ever read for the initial inciting force is the necessity for the existence of an "unmoved mover" (also called "prime mover").
It is philosophy that illuminated the unmoved mover. I would recommend reading about it. I will try to find a better link that Wikipedia, but it is a great start.
Nothing from astrophysicists that I have read has presented a convincing-enough argument for what comes before the Big Bang. Many refer to a singularity, but the force that initiated the expansion of the universe has not been successfully modeled.
This suggests that it is indeed philosophy that so far has been capable of going beyond the current scientific models proposed. (I consider religion as being an aspect of philosophy.)
There are various proposed scenarios for the very early universe, most of which differ radically from one another.
A discussion of some of them can be found in the Wikipedia entry on the Chronology of the Universe:
All ideas concerning the very early universe (cosmogony) are speculative. No accelerator experiments have yet probed energies of sufficient magnitude to provide any experimental insight into the behavior of matter at the energy levels that prevailed during this period. Proposed scenarios differ radically.... Some of these are mutually compatible, while others are not.
Science has limits. We use tools developed inside of a complex system to try to measure and model the system itself. It is likely impossible that we, as component parts of the system, could ever build a cohesive scientific model to accurately define the entire system. Science can only expand by extrapolating from our current models and rulesets. Philosophy is a different type of tool which can explore many things that the scientific method cannot. As such, it is essential.
Lastly, philosophy has throughout history originated a good percentage of the concepts that science has explored and tested to construct these models.