Monday, August 4, 2008

Into Orbit - The Challenge

SpaceX's Falcon 1 Falters For a Third Time
Jeremy Hsu Sun Aug 3, 1:46 AM ET
A Falcon 1 rocket failed to reach orbit late Saturday, marking the third unsuccessful attempt for private spaceflight-firm SpaceX.

Two rocket stages failed to separate about two minutes and 20 seconds into launch from the U.S. Army's Reagan Test Site on Omelek Island in the Kwajalein Atoll, about 2,500 miles southwest of Hawaii in the central Pacific Ocean.

"It was obviously a big disappointment not to reach orbit on this Flight 3 of the Falcon 1," said Elon Musk, SpaceX chairman and CEO, in a short statement read to reporters by Diane Murphy, SpaceX vice president of marketing and communications. The problem is still under investigation by SpaceX.

It's really hard getting anything into orbit. Once we get there, it's relatively easy to get to the Moon or any place else in the solar system. It's easy to stay in orbit for long durations, but getting into orbit is really really fucking hard.
To get into a low Earth orbit (~125 miles up), you've got to acheive a speed of over 17.000 MPH. Considering the fastest speed ever attained by a conventional airplane was just over 2000MPH, you can see how daunting it is to reach orbital velocity of 17,000MPH. It takes really, really powerful rockets.
You see, when you throw a rock up in the air, it just crashes down to the Earth. Imagine you could throw the rock hard enough and fast enough that it flies out past the edge of the Earth and when it comes down, it misses the Earth. That's what getting into orbit is all about. You've got to fling that thing so hard and so fast that when it falls, it misses Earth and goes back out into space, then it falls and misses Earth again and swings back out into space. Orbit is all about doing that over and over again.
It took the most powerful machine ever constructed just to get the Apollo spacecraft stack into Earth orbit. The Saturn V rocket had 7.5 million lbs. of thrust in it's first stage along, 1.5million in it's second stage and 250,000 in it's third stage. The Apollo astronauts used a second burn of the third stage to take them from Earth orbit all the way to the Moon. As a reference, a single engine on a Boeing 747 has about 60,000lbs of thrust and it can carry one hell of a lot more cargo than a Saturn V can put into orbit. . . 150 tons vs. less than 50 tons.

So you see, acheiving Earth orbit is still the biggest task we have in space flight whether we're sending scientists to the International Space Station or spacecraft to Mars. Space flight at this stage of the game is all about getting into Earth orbit and breaking the bonds of Earth's gravity.

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