Skylon

Question 1

What does SABRE stand for?

Answer 1

Synthetic Air-Breathing Rocket Engine

Question 2

What are the performance parameters of the Skylon?

Answer 2

200 reuses
6100 m/s exhaust velocity
6100 Ns/kg specific impulse
1% mission abort rate
48 hour turnaround
22% mass ratio (still double what is allowable)

Question 3

What are the main challenges with Skylon?

Answer 3

1. To be able to trim during aerodynamic flight
2. To achieve mass fractions resulting in orbital speed with a useable payload
3. Using an engine that is realisable with available technology

All of this is to be done while having aircraft-like reusability.

Question 4

How does it work?

Answer 4

Engine uses pre-cooled and compressed air as the oxidiser. Switches to liquid oxygen once the momentum limit is reached.

The same engine can be used as an air breather and a pure rocket, which saves weight, reduces drag and is simpler.