On Friday, at 1:21 a.m. ET, exactly on schedule, SpaceX’s Falcon 9 lifted off for a mission that would be one of its most impressive to date.
After launching a communications and TV broadcasting satellite toward an extremely high orbit, the rocket beat the odds and landed its first stage safely on target on the “Of Course I Still Love You” drone ship in the Atlantic Ocean.
SpaceX’s CEO, Elon Musk, didn’t even think they’d make it. He gave the landing a 50/50 shot:
Rocket reentry is a lot faster and hotter than last time, so odds of making it are maybe even, but we should learn a lot either way
— Elon Musk (@elonmusk) May 6, 2016
But they did. Musk was ecstatic:
The landing wasn’t the only impressive goal SpaceX achieved.
It also successfully delivered a satellite called JCSAT-14 – which will deliver HD TV to folks in the Asia-Pacific region and help boats and airplanes communicate – into geosynchronous transfer orbit (GTO).
GTO is a highly elliptical orbit that puts the satellite in position to move around the Earth about 22,000 miles above sea level. To put this in perspective, the first stage of the rocket from SpaceX’s first successful Falcon 9 landing at sea (on April 8, 2016) was returning from low Earth orbit (LEO), which is only 1,000 miles above sea level.
Friday’s target is 90 times further from Earth than the International Space Station, where some of SpaceX’s previous rockets have launched payloads. To reach it, the rocket had to travel roughly 23,000 miles per hour, 13.5 times faster than a speeding bullet.
After turning 180 degrees and reentering into Earth’s atmosphere, Friday’s rocket also:
- Traveled more than a mile per second Used 4 times as much energy as the last SpaceX rocket Withstood 8 times as much heat as the last SpaceX rocket
Thetech behind SpaceX’s most impressive rocket landing
Shortly after it launches, the first stage burns through its propellant, then separates and heads to the drone ship. This is to prevent it from dragging the rocket down with excess mass on its way to orbit. Next, the second stage, carrying the satellite, continues to its first burn, bringing it to circle Earth in what the SpaceX engineers call “parking orbit.” Then the second burn begins, raising the orbit to geostationary distance about 22,000 miles above sea level – geosynchronous transfer orbit (GTO). Here, the satellite is in position to achieve its desired orbit. Next, the second stage deploys the satellite. When the satellite reaches its highest point of orbit, it uses its thrusters to prevent getting to close to Earth.
Launches to extremely high orbits like this require more fuel, which is where landing on a drone ship comes in handy: They require less fuel than traditional launch pad landings on land.
This landing was a perfect opportunity for SpaceX to prove its reusable rocket technology, which will significantly decrease the cost of space travel. It will allow companies to salvage and reuse rockets instead of discarding them after just one use, potentially saving them tens of millions of dollars.