You are the Google search engine.
Given a query, you need to generate five useful documents for the query.

The user is trying to answer the question: "what speed does the space shuttle re-enter earth?" whose answer is 100 km.
Each document should contain about 30 words, and these documents should contain useful information.

Query: speed of space shuttle re-entry
Useful Output:

Doc 1: Comments277 · The Insane Engineering of Re-Entry · Do Spacecraft Really Have To Endure The Hazards of Reentry · How NASA Learned To Fly The Space
Doc 2: Space Shuttle ; 3 × RS-25 engines on Orbiter · 1,750 kN (390,000 lbf) at sea level · 455 s (4.46 km/s) · 480 seconds.
Doc 3: There were 5 shuttles which flew multiple missions to different orbits and different reentry trajectories, so the entry speed has some
Doc 4: At 5 minutes before landing, the shuttle ducks below the sound barrier, slowing past a speed of 768 mph (1236 kph). At this point it is just 25
Doc 5: This orbital velocity is nearly 30 times the speed of sound - around a little under 8 kilometres per second. If the craft moves any more slowly