 As the years pass and our technology progresses, our interest in the big red planet grows stronger. And yes, while I admit we did cross a huge milestone in human history by finally putting a rover on Mars, we still have a long way to go before we decorate the surface of Mars with our footprints. So what exactly are the mountains we have to climb before we can finally plant our flags on Mars with our own hands? In our entire human history we have come across hundreds and thousands, if not millions of planets which have piqued our interests. But among them one stands out to us, Mars. There's something interesting about Mars which you can't help but be attracted to, which is pretty ironic considering Mars doesn't really have much of a magnetosphere anymore. So far the best we have done is put a rover on the Martian surface. So what exactly is holding us back from putting boots on the red planet? Well, for starters, distance. Obviously the distance between Earth and Mars is colossal. About 78 million kilometers or 48 million miles from my US friends. That's pretty far. So far it takes light about 24 minutes to get from Earth to Mars, which could pose a little problem. Let's say we finally managed to send a manned spacecraft to Mars and the team of the spacecraft runs into a pretty serious problem once they finally reach Mars. Well, let's also say that they decided to reach out to mission control back on Earth, who knows what to do. Since they have to send a signal via radio waves, which travel at light speed, it would take 24 minutes for their cries of help to reach mission control and 24 minutes for our signal containing the solution to go back to Mars, a grand total of about 48 minutes. By then our beloved astronaut crew on Mars would have perished. However, this is just the tip of the iceberg. Communication isn't the only problem that arises with a huge distance. You see, sending a spacecraft to another planet is pretty hard. It all starts with building a spacecraft which takes thousands of people, a lot of shipping and assembling, and long tiring hours of collaboration, a process which takes a couple of months. But hey, it's all over on launch day when we finally get to send our hard work to the big red planet, right? Well, not exactly. Curiosity, the most recent Martian rover sent by the United States, is fast. How fast are we talking? About 36,000 miles per hour, which is pretty fast, but due to the fact that Mars is millions of miles away, it took seven months for curiosity to reach, and during that time anything could have gone wrong. Like for example, the rover's instruments could have failed and since it takes quite some time for the signal to be sent back to mission control that something is wrong, by the time mission control tries to do anything it could be too late. But wait, there's more. You see, building and sending a rover to Mars is far more easier than sending humans to Mars for obvious reasons. For starters, rovers don't have to be fed or have to worry about disposing of fecal matter or stuff that humans are unfortunately constrained to. In order to understand this, let's use a hypothetical situation. In this hypothetical situation, we have a crew of six in the Orion spacecraft, which is calculated to take up to six months to get to Mars. Well, the average person needs to consume about 2200 to 2700 calories a day to survive, in addition to drinking an average of 2.5 liters of water per day as recommended for optimum health. And this is just a bare minimum. So if we were to multiply that by six crew members by an average of 30 days per month over the course of six months, that means the Orion spacecraft needs to carry about 2700 liters of water and about 2.4 million to 2.9 million calories worth of food. And that's just for the go-to journey. We still have to keep in mind that we need more food for the time astronauts spend on Mars, as well as for the six months to return. In addition to having to find a way to carry sufficient amounts of food and water, astronauts must also deal with the health consequences of living in a microgravity environment. While many of us relish at the idea of having fun while floating around in a spacecraft flying thousands of miles per hour, we often fail to consider that spending excessive amounts of times in a microgravity environment leads to decrease in bone density and muscle mass, thereby lowering muscle performance and strength and endurance. Additionally, microgravity weakens your cardiac muscle, thereby opening up the door to heart problems. It goes way beyond that though. Excessive time spent in a microgravity environment can even disrupt your sleep cycle, as well as cause other problems such as loss of blood volume and immunodeficiency. And to top it all off, Mars exploration comes with a huge price tag. How much you ask? Well, one estimate says that a man mission to Mars would cost NASA about 80 to 100 billion dollars. But fret not, for human space technology has skyrocketed within the last 50 years. In under one century we went from just dipping our feet into the pool of space exploration with the launch of Sputnik to immersing ourselves waist deep by putting a man on the moon. What exactly does this have to do with cost? Well, hopefully as technology advances, we may end up finding innovative ways to make space travel cheaper. Additionally, we're beginning to see the dawn of the privatization of the space industry with companies like SpaceX propping up and making some pretty remarkable achievements. At the end of the day, while we have many considerable scientific and technological progress to make before we put human boots on the surface of the big red planet, we can rest assured knowing that with the rate of human progress that we have currently, we have a good chance of planting our flag on Mars within the next century. If you enjoyed this video, be sure to leave a like and subscribe. Also, if you want to go an extra step further, be sure to leave your opinion on Mars exploration in the comments below. Additionally, if you wish to learn more about Mars or any other subject, be sure to tell me in the comments below. And don't forget to stay tuned for more science videos.