In January, we had an exclusive interview with Elon Musk, in which he explained for the first time his thinking – and the complex technical issues – behind his decision to build the SpaceX rocket and its stainless steel thruster. The previous design of the rocket (known at the time as the BFR) advocated carbon fiber, but Musk recalculated and used steel because of its durability, cost-effectiveness and ductility .
In the rest of this interview, Musk explains in detail what needs to be done to actually travel beyond the orbit and into space. In addition, it seems that Mars will have a beautiful park.
Ryan D'Agostino: What most potential future space tourists do not understand about the convenience of traveling in space?
Elon Musk: Some basic concepts of orbit and gravity are counterintuitive because they are not what we live. For example, many people think that if you go high enough, gravity stops. This is not true. The gravitational reach of the Earth is infinite. You could be on the other side of the universe. If you have enough time, if you do not have relative speed in relation to the Earth, you return immediately to Earth.
The simple Newtonian formula for gravity is GMM on R squared – you know, gravitational constant multiplied by two masses divided by distance to centroids. So if you have to travel 100 miles, you will not change the distance between you and the center of the Earth much. The attraction of gravity would seem the same to you. The reason we call this thing called zero gravity or microgravity – it's really due to the very fast zoom around the Earth. A rocket does not climb directly. He makes this bow. It goes only briefly vertically then turns and accelerates horizontally to the surface of the Earth.
The reason it is horizontal is that it is trying to further accelerate its radial acceleration. Its acceleration to the outside. If you swing a ball on a string – like a ball – you can make it essentially horizontal by rotating it very fast. This radial acceleration towards the outside is what maintains it. So you try to make sure that the radial acceleration to the outside is equal to the acceleration towards the inside of the gravity. So you have zero net acceleration, and that sounds like weightlessness. But in reality, you are like a support ball.