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Will Human Intergalactic Space Travel Ever Be Possible?

As a writer of educational articles with a Master of Science degree, I explore scientific research on fascinating subjects such as this.

Will intergalactic travel ever be possible? Read on to learn what the future holds! The photo above shows a model of Mission Space at Epcot, Orlando, Florida

Will intergalactic travel ever be possible? Read on to learn what the future holds! The photo above shows a model of Mission Space at Epcot, Orlando, Florida

For many years scientists have been studying the endurance of humans for long periods in space. This article is about the requirements for human survival to achieve distant intergalactic travel.

How It All Began

I was a pre-teen when John Glenn was the first American to orbit the Earth in 1962. He circled the Earth three times, and that was the first major achievement.

Things progressed beyond that in 1969 when Neil Armstrong left Earth’s orbit with the Apollo II space mission to land on the Moon.

Today NASA has realistic plans with Elon Musk's SpaceX to send people to Mars with the technologies we already have. With continued progress, the next step might not be so unrealistic.

First Step: Inhabit Mars

Our present robotic missions have found that there are resources on Mars to sustain human life, such as water beneath the surface. There are also other raw material resources necessary to construct the communities of the future on Mars without the need to send these raw materials from Earth.

Now that water has been discovered on Mars, even though only in frozen form, it has enticed scientists to consider a mission that may have humans traveling to Mars and eventually inhabiting the planet.

NASA is finalizing the experiments to assure the success of the long flight to Mars.1

Curiosity Rover Selfie in Bigsky Region of Mars

Curiosity Rover Selfie in Bigsky Region of Mars

Next Step: Travel to Other Galaxies

More futuristic thoughts involve reaching out to more distant worlds. These missions would require advanced technology that we don’t have today.

However, it’s possible that someday humans will figure out how to traverse considerable distances in a heartbeat. That would solve the problem with spending time in space, which takes a toll on the human body.

Scientists think big. They imagine the impossible only to work hard at trying to solve a dilemma that stands in the way of achieving those goals. If nothing else, it’s enjoyable to entertain the thoughts of someday going to a distant planet in another solar system, or maybe even farther out to another galaxy.

These things are unimaginable right now. Its only place is in science fiction, but just think for a moment—when you were young, did you imagine carrying a phone around with you wherever you go? Furthermore, did you think you’d be able to call anyone in the world from that phone?

Yes, technology is advancing, and we already can send intergalactic space probes to extreme locations in the universe.2

Voyager-1 had reached interstellar space 35 years after its 1977 launch.

Voyager-1 had reached interstellar space 35 years after its 1977 launch.

Can Humans Survive a Lengthy Trip to Another Galaxy?

This type of trip would require sending humans on a one-way trip that only their offspring would experience. But even considering the enormous length of such as trip, how would it affect the human body?

In February 2017, NASA announced they discovered seven Earth-like planets 39 light-years away in a solar system called Trappist-1. Any one of these planets might support life, as we know it. I'm not talking about finding intelligent life there, but they might support human life, if we could only get there.

Assuming that’s feasible, two issues come to mind:

  1. We would need to live with limited resources and recycle what we have on the spacecraft. That process is being studied right now with experiments conducted on the International Space Station.
  2. It would take many human lifetimes. The people leaving would not get to enjoy the destination. They will need to reproduce in space while in transit so that their future generations would carry on the human race.

Human Reproduction in the Weightlessness of Space

Giving birth to humans in space has never been tried yet. Scientists are conducting tests with lab rats and learning a lot from the results.

Successful human reproduction in space is dependent on how the weightless environment affects fertilization and growth of the fetus.3

The development of the fetus in a weightless condition may cause severe neurological problems. For example, our inner ear develops before birth to achieve a sense of balance. The normal tendency to move and kick while in the womb will change due to weightlessness. The side effects on humans are not known.

The delivery of a newborn would be entirely different without gravity. The amniotic fluids would just float out and become airborne. These fluids would need to be contained, probably similar to how the toilet works in the international space station, with suction.

The development of the baby's ability to survive starts from birth.

  • Without daylight, the brain doesn’t develop sight properly.
  • Without gravity, the brain will not be able to develop a sense of balance.

That will not be necessary while in space, but what about the final generation that makes it to a human-friendly planet.

They will have lots of trouble with balance. Their bones will not have adequately developed to support the weight of their bodies.

The following 13-minute video will give you all the remarkable details.

What if You Were Born in Space?

How Might Extra-Terrestrial Life Elsewhere in the Universe Be Different?

If humans were to populate another planet with a completely different environment, our bodies would surely need to adapt through evolution. To understand this, let's consider what extra-terrestrial life forms might be like. How would they be different if they were to exist?

The human body has evolved for survival on Earth. Life forms on other planets in the universe may be drastically different from anything we can imagine. Those who theorize about what aliens from outer space might look like usually imagine a human-like figure.

It’s easy to relate to our own form. We even have good reason for considering this. We’ve developed the way we have so that we can manipulate our environment.

All living animals on Earth have evolved in such a way for survival in their environment. The survival of the fittest is what guides evolution.

  • Bees have hundreds of lenses in each eye.
  • Deep-ocean fish have no eyes. They don’t need them.
  • Bats use radar to maneuver in the dark.
  • Cockroaches have an outer skeleton to provide protection.
  • Humans have an opposing thumb so we can manipulate our environment.

The point is that every life form on Earth has evolved with the "tools" needed for their survival.

As for alien life-forms, we have to imagine how the type of environment they may live in affects their development. Also, if they do exist, we have to think of what period in their evolution they are in. We may have evolved ahead of them, or they may be ahead of us.

Surviving on Spaceship Earth

If we do find solutions to make this journey feasible, how will our future generation survive once they settle?

One thing is for sure—we need to get our own house in order first. Rather than destroy our environment, we need to learn to survive on Spaceship Earth.

If we can't survive on our own planet and learn to live with nature, then we will never learn to continue anywhere else.


  1. "Journey to Mars."
  2. Gregory L. Matloff. (October 21, 2010). “Deep Space Probes: To the Outer Solar System and Beyond.” Springer Praxis Books. ISBN: 978-3540247722
  3. "Effect of Space Environment on Mammalian Reproduction.

Questions & Answers

Question: When humans arrive on another plant (e.g Jupiter's 2nd moon Callisto), how will they get around, aside from walking?

Answer: It’s noteworthy that you mention Callisto as an example. Jupiter’s moon Europa is closely related to the Earth as well. Callisto has gained interest recently. It’s heavily cratered, and it’s an icy moon similar to Europa. It may even have an underground ocean.

A significant fact about Callisto is that it’s tidally locked to Jupiter, so the same side always faces the planet, just as our moon is tidally locked to the Earth.

In the 1990s and 2000s, several flybys had taken some pictures of Callisto. A mission named JUICE (Jupiter Icy Moon Explorer) will arrive in 2030 to get more information about its environment.

As for humans walking on its surface, I doubt this will be planned in any foreseeable mission. The mean temperature on the surface of Callisto is minus 218.47 degrees Fahrenheit (that’s 139.2 Celsius).

However, having said that, as with any mission to another planet the proper equipment would always be included for mobility. Consider the moon rover for example.


Question: When will we go to the Trappist-1 system?

Answer: Even though Trappist-1 has several planets that may be in the habitable zone, it’s too far away to consider with our present technology. Mars will have to be the first step. Nevertheless, what I discussed in this article would be the method for humans getting there, over many generations of a crew. It’s not something that will be considered any time soon.

© 2017 Glenn Stok


Glenn Stok (author) from Long Island, NY on November 09, 2019:

Ken Burgess - Very good points Ken. I think humanity will take two paths:

Those who think in terms of the greater good are the ones involved with missions to become a multi-planet species.

While those who want their nation to dominate the world will continue with their fight. Unfortunately that’s been the theme for most humans for thousands of years.

The thing that separates us is the concept of instant gratification vs. focus on the future, as you touched upon in your comment.

Ken Burgess from Florida on November 08, 2019:

The importance of getting to Mars cannot be overstated.

Going beyond Mars would almost automatically become a goal once we have grown accustomed to our being a multi-planet species. But first we must get to Mars, and right now that seems an impossible task to many.

Reaching Mars could solve a great many problems, I believe it would help humanity turn the page from Nation states and individual wealth to something greater.

There are organizations and corporations that have as their goal, one world united, free of borders, free of squabbling nations. But first we have to grow beyond this planet for that to truly take hold in the minds of people... we have to be greater than one planet, then perhaps we could be one people on this planet united in becoming something more.

We as a society seem intent on so many frivolous things, individual wants and desires that contribute nothing to the greater good, nothing to move mankind forward, and so long as we continue to think that we should focus on here and now rather than the future, we will continue to squabble as nations and as individuals amongst ourselves.

We are fortunate that a few people do have a vision for a greater future, a better future for mankind, like Elon Musk. If he fails in his endeavors all of humanity fails, and another generation, another half century will be lost.

Neil Huff on September 01, 2019:

Yes, I am fully aware of these commercial initiatives. I may be elderly, but stay fairly up to date on these various enterprises. But I stick to my own opinion that these futuristic investments are interesting, but irrelevant over even the near term. Immediate, political issues and transmigration of the climate displaced will inevitably skew govt spending priorities as the crisis threatens civil order. I understand you have a certain position in these matters to protect. So best of luck and I'll bow out. Thank you for indulging me and my 'antiquated' view point. .

Glenn Stok (author) from Long Island, NY on September 01, 2019:

Neil Huff - I understand why you have those outdated opinions. A lot of private investment into space travel is occurring. If you are interested in catching up, I would recommend you do a Google search on Alan Stern, a planetary scientist. He is involved with many successful planetary space missions.

Also do research on Elon Musk, who is CEO of Tesla and is founder, CEO, and lead designer of SpaceX. He is testing an Interplanetary Transport System called the Starhopper, to be used for possible Mars colonization.

Neil Huff on August 31, 2019:

I assumed anyone reading my comment understood that it is was more intuitive than science based. I spent 30 yrs working in underdeveloped countries (13) and dealt with issues related to too many people chasing scarce resources. That experience and the migration of peoples into North America and Europe from climate affected peoples can hardly be dismissed. The problems associated with this struggle and the inevitable competition for every resource which certainly will include human capital is going to take precedence over such futuristic applications as interplanetary travel. Just keeping SETI alive and financed is indicative of such investment with no immediate return. Pubic financing has dried up. Again I confess I have only my own intuition and experience of human nature for this view. I am in my mid 80s.

Glenn Stok (author) from Long Island, NY on August 30, 2019:

Neil Huff - Please provide plausible resources to justify your claims.

Neil Huff on August 30, 2019:

I think this discussion is interesting, but moot, as our technological window will not remain open long enough for science to solve all the problems related to space travel and survival on a different planet. Within the life time of, say, my grand children the battles for resources on this planet will absorb the energy, technology and genius needed for each tribe to hold it's patch of earth and simply survive. The will and interest and organization required for space travel will be a distant fantasy of a bygone era in 75 years.

Glenn Stok (author) from Long Island, NY on June 23, 2019:

I published a related article last week for your continued research.

“Will We Ever Live on Mars? Q&A Dealing With This Topic”

Jim Beam on November 25, 2018:

We’ll need to be able to create and control some type of artificial gravity source so that we can we can live and function inside a space vessel without wasting away.

We’ll need to discover how to travel safely inside a vessel near the speed of light, or manipulate space and time to shorten the distances needed to travel to other star systems.

We’ll also need to learn how to protect ourselves against the radiation exposure of space.

We’ll need to create a space vessel that can continually and effectively repair itself, and we’ll need to be able to create breathable and sustainable oxygen.

We’ll also need renewable and sustainable food sources for journeys that could decades or centuries to complete.

If we can save our planet and ourselves, we may have the time needed to remove all of the barriers to interstellar travel.

Glenn Stok (author) from Long Island, NY on July 20, 2017:

Stella, Good point. I agree. We need to learn how to take care of our own planet. All the other animals do. Humans are the only creatures that destroy their environment.

Stella Kaye from UK on July 20, 2017:

Interesting article. I used to think humankind would eventually travel to the stars... I even wrote an article about it. Now I'm not so sure. Just as you've stated at the end of your article, I tend to think if we've messed up this planet which was about as perfect as you can get, then we're just going to recreate the same scenario elsewhere. Scientists should perhaps be spending their time trying to improve life on this planet before looking elsewhere.

Glenn Stok (author) from Long Island, NY on March 25, 2017:

MizBejabbers - Very good points you've made. In addition to the different chemical makeup of the atmosphere on Mars, the air pressure is also an issue as I mentioned in my last comment. Homes on Mars would require an airlock entryway, and people would need to wear spacesuits to go outside.

Doris James MizBejabbers from Beautiful South on March 25, 2017:

Very good article, Glenn. Like you say, first we have to see if we can survive on Mars. With an atmosphere of 93% nitrogen and .13% oxygen, not to mention the other gases, humans would have to exist in a contained atmosphere until the planet could be terraformed. It would take a special breed of human to be able to do that. As for galactic travel, you've made some good points about the survival of the human body. I don't think anyone can guess as to the condition of the human emotional body if humankind survived the trip.

Glenn Stok (author) from Long Island, NY on March 24, 2017:

"Mere mutants of our former selves." That's a good way to put it Mary. Your question about how they "maintain muscle quality" is something I discuss in my other article about "What It's Like to Be in Space on the International Space Station?" I've also included a video showing how astronauts exercise without gravity. Check it out. There's a link to it right before the 4th subtitle above.

Mary Wickison from USA on March 24, 2017:

Interesting idea about the potential problems not just of getting there but the hurdles to overcome during the journey.

For example, without exercise, the muscles will atrophy. In a gravity-free environment, how is muscle quality maintained? The humans who would leave Earth might be radically different than those who would eventually arrive after a long journey, mere mutants of our former selves.