jet propulsion

I find the concept quite interresting and given that i didn't find anything here i tought of posting about it. https://www.ycombinator.com/companies/astro-mechanica View: https://youtu.be/Bvk3Mi9Y8hQ?si=4CyoDEIn2rcTZrhO

Well i don't have mutch knowledge about it and there is not so mutch to find about. They have the potential to be very good tought as far as my small research goes bearings where the big problems. Maybe you guys know more about it. I will link the wiki page to it...

A couple new books are on pre-order at Amazon.co.uk: https://www.amazon.com/Fighters-1945-Secret-Projects-Luftwaffe/dp/1911658085/ref=sr_1_1?qid=1563554467&refinements=p_27%3ADan+Sharp&s=books&sr=1-1&text=Dan+Sharp...