Knutsop

https://www.youtube.com/watch?v=H-AcSucRBbw

Stanford students showing that it is possible. It was seen as a possible launch design back in the 40-50's (called a rockoon - rocket+balloon). That was without modern computing power. you could easily make a heavy lift blimp and add a pressure vessel so that you can pump out of the blimp to create negative buoyancy to return to earth.

Why is it that blimps are not used as launch platforms? If you were to build a Hindenburg size blimp potentially double hulled (exterior helium fully encapsulating an interior of hydrogen) made with modern materials. Would you be able to get a blimp up to the height where Baumgartner did his jump from (120,000 ft)? That would make it so you could launch a rocket in any weather (the blimp would float above inclement weather), drastically reduce fuel requirements (less distance to travel to NEO and reduces weight do to less gravity), which means you could increase payload size or reduce launch costs. not to mention, a 100% (minimal H, and He loss) reusable first stage.

I would love to know why this wouldn't work