/sci/ - Science & Math

>>15072118
>>15072125
In the early 90’s, McDonnel was looking for a replacement for the even brand new Delta II. They decided to investigate using a hydrogen oxygen upper stage on a Delta II core to boost payload. There was a moment where they considered importing the cryogenic upper stage of a JAXA H-I rocket (which used the same diameter as the Delta tank already) and using it for their Delta II replacement

In our world, this never happened; Douglas built the gigantic hydrogen oxygen Delta III upper stage, which was adapted for the Delta IV after Boeing bought them. But there is an alternate world out there where “Delta III” as we know it never happened, and instead America used Japanese cryogenic engines instead of RL10s

>>15072128
Chinese rockets are indeed interesting. The basic naming scheme is:
>Long March 1
Dead end, ICBM derived design
>Long March 2, 3, and 4
All use the same hypergolic ICBM as a core, but surrounded with 0,2,or 4 boosters. 2 has no third stage, 3 has a hydrogen third stage, and 4 has a hypergolic third stag

>Long March 5-8
All use the closed cycle kerosene YF-100 engine

>Long March 5
Uses 4 dual YF-100 boosters around a 5 meter hydrogen oxygen core.

>Long March 6
Uses a single YF-100 to power a core stage. Smallsat launcher

>Long March 7 and 8
Both use a YF-100 powered core surrounded by boosters with the same engine