https://redduck.tistory.com/m/entry/SPCE-%EB%B2%84%EC%A7%84%EA%B0%A4%EB%9F%AD%ED%8B%B1-Virgin-Galactic-VSS-%EC%9C%A0%EB%8B%88%ED%8B%B0-%EC%B5%9C%EC%A2%85-%EC%83%81%EC%9A%A9-%EC%B6%9C%EC%8B%9C