The Falcon 9 touches down on the launchpad. (Credit: SpaceX) A month after Jeff Bezos’ aeronautics company Blue Origin successfully landed a rocket back on earth after reaching the edge of space, Elon Musk's SpaceX pulled off an even more impressive feat with its own rocket design. The spaceflight company launched its Falcon 9 from Cape Canaveral Air Force Station Monday evening, delivering a payload of 11 Orbcomm satellites into orbit. But the real achievement occurred roughly ten minutes later when the craft descended from the heavens to touch down safely on a launch pad several miles away. [embed]https://youtu.be/O5bTbVbe4e4[/embed]
Success at Last
The successful launch and subsequent landing proved that persistence yields rewards: The company's previous flight in June ended in flames after a strut failed shortly after launch, causing the rocket to explode. If successful, the ill-fated Falcon 9 would have delivered supplies to the International Space Station. Monday's launch, initially scheduled for Dec. 18, was postponed twice, once because of an engine anomaly during a preflight check and a second time due to weather. After several modifications, the 23-story rocket lit up the night sky Monday without a hitch. And this time, the rocket returned to earth unscathed, checking off another milestone for reuseable rockets. Launching and landing a rocket upright, as opposed to allowing it to crash into the ocean, will exponentially lower the cost of spaceflight. Although SpaceX plans to use its technology to land reusable rockets in the future, this particular rocket was not designed to fly again.
How it Happened
Modifying Falcon 9's fuel was one of SpaceX's primary changes. The Falcon 9 is now loaded with oxidizer cooled to minus 340 degrees Fahrenheit to make it more dense, packing additional energy into the same volume. The upgraded fuel mix propelled the 500-ton rocket to a height of 124 miles above the Earth’s surface, where a capsule containing the satellite payload broke off and continued into orbit.
An illustration of Falcon 9's journey. (Credit: SpaceX) The rocket’s journey was from over, however. In a daring maneuver at the top of its arc, nitrogen thrusters flipped the rocket around to point its tail earthward, readying it for descent. Just 10 minutes after launch the Falcon 9 fell toward earth at supersonic speeds, reignited its thrusters to slow its descent, and finally touched down on a target a few miles from the original launch pad. This is the first successful landing for the Falcon 9. SpaceX twice this year failed to land the rocket on a barge in the Atlantic Ocean. The rockets tipped over on the landing pad and exploded in both attempts.
A time-lapse exposure showing the rocket's path during both liftoff and landing. (Credit: SpaceX)Much More Difficult Falcon 9’s landing looked similar to what Blue Origin accomplished with its New Shepard rocket, but what SpaceX did was significantly more difficult. As a rocket designed to deliver heavy payloads into orbit, the Falcon 9 is bigger, flies higher, and is more top-heavy than the New Shepard, which means forces involved in bringing it to a soft landing are orders of magnitude higher. In terms of the rockets' raw power, it isn't even close: Falcon 9 puts out 1.5 million pounds of thrust at sea level, compared to New Shepard's 110,000 pounds. Additionally, New Shepard traveled to the edge of space, about 62 miles up, while the Falcon 9 doubled that. The Falcon 9 must also deal with horizontal as well as vertical velocity, caused by Earth's rotation. Simply put, Falcon 9 contended with forces far greater than experienced by the New Shepard. Still, landing a rocket is exciting news no matter how high it traveled. Now that two separate companies have achieved what was only recently thought of as impossible, the dawn of a new space race appears imminent. But instead of putting men on the moon, the goal of this race is to achieve safe, cost-effective spaceflight. With the huge advancements in aeronautics made this year, the next space race is off to a heck of a start.
