Traveling to outer space - for the rest of us
I saw a recent story on the Internet about how space travel may soon be available for the general public.
This travel would not be through NASA, but through private companies (see http://www.spaceportamerica.com, for one example). Optimistic predictions are that this could occur as early as 2012.
I think I’m ready to plan my vacation for 2012.
I would board the spaceship with the other passengers and fasten my seat belt. They would seal the doors and begin the countdown.
At this point, the pilot would say, “Did everyone remember to go to the restroom?” (I would worry about this for the rest of the flight.)
The proposed design calls for a rocket-propelled craft to be carried by a more conventional aircraft to a high altitude and released. Its own rocket engine would then launch it into low-Earth orbit. So the first part of the trip would be like any other takeoff and ascent in a jet.
The rest of the trip would be anything but routine.
First, there would be the sudden drop as the spacecraft is released. This would be similar to an amusement park ride where the passengers are raised slowly to a height, then dropped.
This “falling” feeling would disappear quickly when the rocket engine ignites, which would slam me into the back of my chair. There isn’t a muscle car on the planet that will compare with this acceleration, although top-fuel dragsters might come close. The difference is that a dragster’s acceleration is over in a few seconds. The boost into orbit will last several minutes.
If I have a window seat (I hope), after a few minutes of this ride, I would begin to see the blue sky fade quickly into a nighttime black, only with more stars than are visible from anywhere on Earth.
The odd thing is that the sun would still be shining in a pitch-black sky. Oh, and the horizon has gone from flat to curved. Instead of seeing a solid surface immediately below me, I’m suddenly seeing a very large sphere below me, which seems to be getting farther away all the time.
Then the rocket is done. Another gut-wrenching change, like going from the lowest point on a roller coaster (when you are smashed into the bottom of your seat) to the next peak, where you float out of your chair.
Except that the “floating” feeling doesn’t end after a few seconds — it just keeps going.
The pilot now announces that I can unfasten my seat belt. What? My stomach tells me I’ve been falling thousands of feet, and the pilot says I can get out of my seat? And this is exactly why they call it “free fall” — it’s weightlessness.
So I unbuckle my seat belt and, sure enough, I float. An exuberant kick sends me flying to the other side of the cabin, where I learn a physics lesson as I bang my head into the cushioned wall. The physics lesson is this: Weight and mass are not the same thing.
In weightlessness, if I were hit by a ping pong ball and a bowling ball traveling the same speed, the bowling ball would still hurt when it hit, because its mass is greater.
But if you place bathroom scales under the bowling ball, the ping pong ball or me, none of us would register any weight on the scales at all. It is only when you put mass under the influence of gravity that you get the effect we call weight.
So I learn the lesson that just because I have no weight, I still retain my mass. (Unfortunately, this part of physics is confusing to most people because mass and weight are both measured in the same units — kilograms).
This trip sounds rather drastic.
For a more relaxed vacation, I may just wait until the space elevator is built (another dream of private sector space travel — see, for example, http://www.spaceelevator.com).
But that is a topic for another article.
Vincent King is a certified health physicist who has been involved in radiological sciences for more than 30 years. He is a volunteer at the Western Colorado Math and Science Center in Grand Junction.