Hybrid pulse-jet/rocket motor for space application

[Tiah]

Hi,

Im currently working on a project to design a hybrid pulse-je/rocket motor for space applications. The Pulse jet is to lift a payload in the Earth's atmosphere then reverts to a rocket motor in space. The idea is to reduce the use of on-board oxygen during ascent since it initially breathes air.

Questions:
Does pulse jets have the capability to produce enough thrust for this application?
What considerations are needed to justify its feasibility?

 

[Travis_King]

You have to do a bit of research first...How do you plan to design a dual purpose engine (I imagine you only need to design its operating parameters and requirements, but still) if you don't want to look up the capabilities of the stages you are looking at...

 

[enigma]

You need to figure out how fast the pulse jet will be able to take the craft, and then do the math to figure out how much extra fuel your rocket will need to accelerate the mass of the extra motor.

Then, you need to figure out the cost savings for the fuel and find out if the cost of the extra motor plus complexity plus failure risk is worth it.

 

[Travis_King]

BTW, you are probably going to want to research the work that went into the SABRE engine:

http://en.wikipedia.org/wiki/SABRE_(rocket_engine )

 

[Tiah]

Thank you for the advice and replies! They are of great help!