Here’s a list of appropriate prepositions to fill in the gaps in your text:

1. **in**
2. **on**
3. **about**
4. **on**
5. **over**
6. **in**
7. **about**
8. **in**
9. **at**
10. **on**

So the filled text would read:

The exploration of deep space will undoubtedly transform our understanding of the universe **in** the coming decades. Scientists are currently working **on** projects that aim to send probes to the outer reaches of our solar system, and even **about** distant exoplanets. These missions will rely heavily **on** advanced technologies, and will be developed **over** years of careful research. We hope to discover evidence of life **in** other worlds, and learn more **about** the origins of the cosmos. Furthermore, advancements **in** propulsion systems will allow us to travel **at** speeds previously thought impossible, opening up the possibility of reaching stars that are light-years away. We are standing on the cusp of a new era, and the information we gather will have a profound impact **on** our understanding of our place in the universe.