Why humans as opposed to robotic missions?
First of all, let me say, after working on a half a dozen robotic missions, we’ve learned a tremendous amount. Robotic missions have been excellent. We have learned much about Mars atmosphere surface, but they have their limitations.
And one of the limitations is that everything that we do on a robotic mission has to be preprogrammed, and preprogramming assumes that we understand the environment. The human explorer has a whole bunch of qualities that are not in machine probes at this point, like: intelligence, ingenuity, adaptability, agility, dexterity, mobility, and speed and efficiency.
A very well-known Mars scientist said that he can do in two hours what it takes a rover to do in six months, because he’s on the scene, he can understand the geology, he can figure things out that we didn’t know before, whereas a robotic mission – we assume we know the environment, and in a lot of cases, we don’t.
Let me talk about mobility. The National Research Council Space Studies Board, which oversees NASA by law, has said, “Mobility on a planet is the most important single parameter.”
We just completed the first Mars marathon, about a week ago NASA’s Mars exploration rover, “Opportunity”, traveled 262 miles. It completed a marathon run on Mars. Unfortunately, it took 11 years.
With what we’re planning to send to Mars, for human exploration, we can do that in a day or less. So we have great mobility.
Why send humans to Mars? Why become a two planet species? Well, there are threats to humanity, there are threats to planet Earth. I don’t want to spend much time at it other than to say there’s catastrophic climate change. We know that the climate is changing.
We don’t understand where we’ll end up at this point. We know Mars experienced catastrophic climate change.
The second point I want to make: synthetic biology experiments and natural pandemics. You know, we’ve recreated, humans have recreated the poliovirus in recent years. Finally, perhaps the most likely, are cosmic impacts.
There are things circling the Solar System that can impact with Earth; I’m talking about asteroids, comets and meteors. There’s an example, earlier this year, a large asteroid passed within 3 times the distance of the Earth to the Moon, 31 times that distance, and that’s a near miss. There are many, many asteroids and objects in the Solar System, as you’ll see in a second.
Well, what we’re looking at is the asteroid belt. The yellow thing in the middle is called the Sun, then there are four circles – Mercury, Venus, Earth, and Mars – and then on the right side you see Jupiter.
But you see those hundreds and hundreds of green things? They are asteroids. They’re chunks of material that range from 10 feet to several hundred miles across. One of them actually came in over Russia. How would you feel if you’re in your car and all of a sudden – This is a cam recorder in someone’s car.
This object that hit the Earth in 2013 had the energy of 30 nuclear weapons. Thirty nuclear weapons. It destroyed many hundreds of buildings and injured many thousands of people. So, there is a dream.
Now I will speculate. Once we send humans to Mars, the next likely step is to take plan of Mars and terraform it. Terraform is a bad word; planetary engineer it to look like planet Earth. This is our oddest conception of Mars becoming a second Earth, and I’ll talk to you about that in a second.
Once it’s terraformed or planetary engineered, there’s a potential second home for the human race. You know, dinosaurs were the major form of life on Earth for many millions of years, until about 65 million years ago, Yucatán Peninsula, a large asteroid hit, now, that was a Wednesday, and the rest is history.
The dinosaurs became extinct. The dominant form of life on planet Earth for millions of years became extinct.
How do you make Mars habitable?
I’m going to tell you a simple way. There are several other ways. The first is: we know there’s a lot of frozen water and a lot of frozen carbon dioxide below the surface of Mars, and if we can get a large solar reflector heat up the surface, it will cause that carbon dioxide and water vapor to enter the atmosphere.
It turns out that those are two of the most efficient greenhouse gases that we know about. So we release the frozen water and the frozen carbon dioxide, put it in the atmosphere. Once that happens, we seed the surface of Mars with photosynthetic plants.
The photosynthetic plants convert carbon dioxide, which is the major gas on Mars. We’ll convert it to a gas called oxygen, and gas called oxygen is useful because humans breathe oxygen on a regular basis.
Once we have oxygen from these photosynthetic plants, oxygen is broken up by solar radiation, – a small amount – and it forms a gas called ozone. Ozone shields the surface of the Earth from biologically-lethal radiation that comes from the Sun, called ultraviolet radiation.
So we form an ozone layer once we have oxygen in the atmosphere. Once we have oxygen in the atmosphere and ozone, the atmosphere is thick enough because we outcast a lot of the carbon dioxide and water vapor, and liquid water can form on the planet and be stable over geological time spans. This is an artist’s conception of Mars today.