案例库 · 工程与运营 · 技术决策 · 2015
这条还没译成中文，下面是英文原文。
SpaceX landed a booster so it could fly again instead of being thrown away.
The Falcon 9 first stage returned to land upright, so the multi-million-dollar vehicle is reused instead of rebuilt, cutting the cost of every later launch.
SpaceX
那一手
Spaceflight was built on throwaway rockets: each launch spent a booster that had cost tens of millions to build and then dropped it into the sea, so access to space stayed expensive. The propellant that fuelled a launch, by contrast, cost a tiny fraction of the vehicle.
On December 21, 2015 the Falcon 9 first stage flew back to Cape Canaveral and landed upright after putting eleven satellites into orbit. Elon Musk estimated the booster cost about $60 million to build while its fuel cost around $200,000, and said that reusing rockets like aeroplanes could reduce the cost of access to space by as much as a factor of a hundred.
The booster had to relight its engines, flip to engines-first, steer with grid fins and settle onto landing legs from a fast supersonic descent. Musk put the odds at about sixty to seventy percent, so the landing was the milestone even though deploying the satellites was the stated mission.
为什么管用
- The stage is the expensive part and the propellant is not, so reusing the stage saves the most.
- Propulsive landing lets the vehicle return to where it was launched, not into the ocean.
- The same avionics that guide launch steer the descent, so no new guidance system is needed.
- Repeated reuse spreads the build cost across many flights instead of one.
可以搬走什么
If the value is in a reusable asset and the consumable is cheap, engineering the return path cuts the cost of every later flight.
后来呢
SpaceX went on to reuse first stages routinely and to land and refly them many times, driving launch prices down and making reusability the industry's default ambition. The 2015 landing turned a stunt into the basis of SpaceX's economics.
资料来源
- Successful landing of reusable rocket promises cheaper space travel
- With landed rocket safely back in its hangar, what's next for SpaceX?
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