Hi, long time lurker firt time poster here. I've just had a random thought and maybe you can let me know if I'm on to something or if and how my idea is flawed. So, I was thinking about how terribly inefficient rockets are when used to get to space. I mean, all that thrust that's needed to get that thing airborne, let alone e into space from a complete stand still is mind boggling. What if we were to use jet propulsion up to the maximum altitude for it to be effective then switch to a much smaller jet engine for the remainder of the ascent. Tye amount of fuel needed would be dramatically less leaving room for more supplies and other cargo. We already have passenger jetliner that reach pretty staggering altitudes on the regular. So what if we were to design. A jet that would take off normally from a runway, ascend to say 600000 ft., shut off the jets, engage a secondary rocket, with a comparably smaller burst of the rocket, blast off into orbit. Of course it would need have heat shielding for reentry among other things. But I feel like it would be a lot less expensive and more efficient than what we have going on now. And after seeing Virgins space craft succesfully make it into orbit after being dropped from a jet and engaging its rockets for the last leg of the journey up. I don't see why we can't build an interorbital jet that can make round trips to the ISS or make satellite drops. Or am I just totally wrong here