3. Contents
• physical principles
• Newton 3rd law of motion
• Newton 2nd law of motion
• Tsiolkovsky rocket equation
• Launch vehicle anatomy
• Multistage rocket vs single stage
to orbit
• Reusable launch systems
• Falcon-9
• Propulsion Technologies
• SABRE Engine
7. Newton’s second law
• From the Newton′s second law
Σ𝐹 =
𝑑𝑝
𝑑𝑡
• Rocket initial mass = m, velocity = v
• Rocket mass after ejecting mass = m + dm, velocity = v + dv
• Propellant particle mass = -dm, its velocity = v – ve
• P after contains both the rocket and the exhausted particle
Σ𝐹 =
𝑚 + 𝑑𝑚 𝑣 + 𝑑𝑣 + −𝑑𝑚 𝑣 − 𝑣𝑒 − (𝑚𝑣)
𝑑𝑡
=
𝑚𝑣 + 𝑚𝑑𝑣 + 𝑣𝑑𝑚 + 𝑑𝑚𝑑𝑣 − 𝑣𝑑𝑚 + 𝑣𝑒𝑑𝑚 − 𝑚𝑣
𝑑𝑡
Σ𝐹 = 𝑚
𝑑𝑣
𝑑𝑡
+ 𝑣𝑒
𝑑𝑚
𝑑𝑡
, Σ𝐹 = 0
𝑚
𝑑𝑣
𝑑𝑡
= −𝑣𝑒
𝑑𝑚
𝑑𝑡
12. Why single stage rocket is bad?
• Double the fuel doesn’t mean double the velocity
• Adding more fuel causes more weight that requires more
engine which will consume that fuel and so on.
13. Why single stage rocket is bad?
• Double the fuel doesn’t mean double the velocity
• Adding more fuel causes more weight that requires more
engine which will consume that fuel and so on.
14. Why single stage rocket is bad?
• Double the fuel doesn’t mean double the velocity
• Adding more fuel causes more weight that requires more
engine which will consume that fuel and so on.
18. Why multistage is
better?
• Getting rid of useless mass.
• Efficiency and cost.
• Building better rocket engines
for upper stages (that are well
prepared to work in vacuum).
19. Why multistage is better?
SSTO with double the
propellant and thrust
of each stage
second stage
