Last week, the world lost a pioneer in the exploration of the final frontier. John Glenn, the first American to orbit the Earth, died at the age of 95.

Glenn was hailed as a national hero for his successful orbit around the Earth aboard the spacecraft known as Friendship 7 on February 20, 1962. This success came at a crucial time in world history. The U.S. and the then Soviet Union were engaged in the Cold War and were racing to make progress in exploring space through artificial and manned spacecraft, famously known as the Space Race. The U.S.S.R had beaten the U.S. by mere weeks to send a human being into space. Glenn’s flight helped restore confidence among the American people and reaffirm the importance of sending people to the moon.

Despite lacking a science-based degree and nearing the fourth decade of his life, Glenn was chosen by NASA through its astronaut recruitment program. Glenn had experience through being a military pilot in World War II and the Korean War, and as serving as a test pilot for the U.S. Naval Test Pilot School. Years later, he and the Friendship 7 successfully completed their mission.

Despite retiring from NASA in 1964, Glenn wasn’t done with space just yet. He went back aboard the Space Shuttle Discovery in 1998, becoming the oldest person in space at age 77.

Glenn died on December 8, and as of this writing the cause of death has not been revealed yet.

Those who became the faces of and inspired future generations to continue space exploration are slowly being taken from the world. First man on the moon Neil Armstrong died five years ago, and less than a week before Glenn’s death, Buzz Aldrin, the second man to walk on the moon, was medically evacuated from Antarctica after feeling short of breath.

While our millennial generation knows of Glenn’s accomplishment, we absolutely cannot feel the same feeling that those who watched and waited had back in the 1960’s. However, that does not mean we will never be able to feel that same feeling.

Our next frontier: Mars.

Interest in exploring the red planet has arisen among several parties. NASA wants to send humans to Mars by 2030 (but first, humans to an asteroid by 2025). Entrepreneur Elon Musk and his company SpaceX has developed plans to reach Mars as well. An organization called Mars One wants to create a permanent human colony on Mars by 2032 and are accepting applications for people that want to be part of the program.

Interest in sending people back into space hasn’t waned either. Though the Space Shuttle program sadly flew its last flight in 2011, there exists companies that want to provide commercial space flights. Virgin Galactic is testing spaceplanes for its goal to turn regular human beings into astronauts, or rather, “space tourists.”

With the old generation of space exploration fading, a new ambitious generation is taking over, and it's exciting. Just think, we may be able to send regular people into space without all that serious training. We might find another planet similar to ours that we can inhabit if the Earth cannot sustain life anymore. It sounds like science fiction, but how much farther can it run away from us with the advancements the human race is making?

However, we cannot forget the contributions of those before us, those that pioneered the early adventures into space and inspired our generation’s interest in the future of spaceflight. Because of them, the sky’s not the limit. In fact, there is no limit; space is an infinite frontier with infinite possibilities, and we’re merely scratching the surface of what we can do with it.