Today, it’s best suited as a museum piece. The Kholod might be one of mankind’s most amazing feats of engineering, but it’s anything but practical. It’s estimated that the French engineers spent over $200,000 just on one launch, and that was 23 years ago. Plus, it’s designed to fly incredibly fast across a given trajectory, at which point it simply falls back to Earth at a horrifying rate. Still. Mach 6.5, you know?