#astro

# lecture 2

thermal rockets
>laser
>solar
>nuclear
>chemical
>>solid
>>liquid
>>hybrid

electric
>electro-thermal
>>resistojet
>>arcjet
>electromagnetic
>electrostatic
>>ion drives

nuclear
>explosive
>nuclear thermal

an impulsive manoeuvre is one that has an instantaneous change in velocity

## types of propulsion
![[Pasted image 20221020132614.png]]
### primary propulsion 
provide the main $\Delta v$ in a mission
burn time of $100-500$ seconds
thrust levels of $400-10^6N$

These can be considered impulsive because compared to the length of an orbit it is basically nothing.

### secondary propulsion
primarily for attitude and orbit control
thrust levels of $10^{-3} - 10N$
burn durations of $10^{-2} -1 s$

## types of electric propulsion (rewatch from like 40 minutes)
### resistojet
uses an electric generator to pass current through a heating element, which then heats up propellent to $1600 - 2500 C$

### arcjet
passes a current through gas, causing heating
high current needed
high thrust, low lifetime



# recorded lecture