SpaceX stepped back up to the launch pad Saturday to take another crack at making history — not by what goes up, but by how it comes back down.
Its rocket lifted off early Saturday from Cape Canaveral, Florida.
The company hopes that, while the rest of the rocket continues on, the first stage, which is 14 stories tall, will land back down gingerly and on its feet on Earth.
Normally, once it has vaulted the rest of the rocket into space, the huge booster falls back into the ocean as, basically, garbage. That has been compared to throwing away a Boeing 747 passenger jet after it makes one transatlantic flight.
Don’t lose it; reuse it
But SpaceX is determined to change the practice to save millions in costs. Instead of losing the rocket, the company aims to reuse it.
After the launch, then the separation from the second stage of the rocket, the Falcon 9 rocket’s booster was set to turn around to head back down to a platform floating in the ocean.
The company logo “X” marks the spot in the middle of a bull’s eye on the black landing pad of the “spaceport drone ship” that autonomously plows through the water.
The originally planned launch on Tuesday was scrubbed due to technical issues that turned up in the rocket’s second stage. The Falcon 9 is a two-stage rocket.
Scratching a launch time is routine for the space industry — sometimes due to weather, sometimes for technical reasons.
As Space X founder Elon Musk said when a different model rocket self-detonated as a safety measure during a soft-landing test in August: “Rockets are tricky.”
The official mission
Though the landing is a test, the launch is not. Spearheading the Falcon 9, the capsule called the “Dragon” will carry a payload up to about 5,000 pounds to the International Space Station.
With five previous trips, the resupply missions have become somewhat routine.
The Dragon usually picks up a return load from the ISS to bring back down to Earth. It is to land four and a half weeks later, plopping into ocean water, after roaring back through Earth’s atmosphere with red-hot heat shields glowing at up to 3,000 degrees Fahrenheit.
Almost been there before
The Falcon 9’s towering booster has gone through all of the motions before — except for one last one. If it pulls it off, that will be historic.
First, as it falls back to Earth, it will reach a speed of about a mile a minute. Then its boosters will fire three times in sequence, which Space X describes in colorful terms.
The first boost, called the “boostback burn” will turn the bottom of the stage downward, then the “supersonic retro propulsion burn” will cut the fall speed to about 800 feet per second. Then comes the “landing burn,” when the landing gear legs also push out for a set-down.
It will then descend at a speed of about seven feet per second.
Falcon 9 boosters have done this successfully twice before, Space X says. In those tests, the rockets tipped sideways and crashed into the ocean, causing damage that made them, basically, garbage.
That was according to plan, SpaceX said.
What’s historic?
Setting down with its landing legs onto the platform is the last history-making step and will preserve the booster, paving the way for its reuse.
But SpaceX doesn’t expect it to be easy.
“Stabilizing the Falcon 9 first stage for reentry is like trying to balance a rubber broomstick on your hand in the middle of a wind storm,” the company said in a statement.
And the floating landing pad may look large when standing on it, but its a small target for a big rocket to set down in a single attempt.
The reason for the floating platform — despite the complications of landing on a moving target — is to prevent properties on Earth from being damaged if the landing goes wrong, said Keith Smith of Britain’s Royal Astronomical Society.
This is just the first try of many hopefully to come, it said. Space X puts the odds of success of this first try at 50% — at best.