Airships on Mars? Hell yes

Yesterday I looked at the possibility of using an air ship to get the orbit on Mars. I wondered if an airship could go at the hypersonic velocity necessary. It so happens that this is already been done. Perhaps I didn't make a mental note of it at the time , but the during the first time I read it, I should have noticed that this was accomplished already. In 1964 , a hypersonic balloon test was done, and the vehicle survived the test. According to book, said vehicle flew 5000 miles an hour and at the altitude of three hundred thousand feet. The top speed of this vehicle was over half the velocity necessary for orbit on Mars.