Hi, i have some questions about the Delta 4: Why is it being retired instead of being evolved into a less costly rocket? Basically ULA has this great vehicle and are going to just throw it away! F9 had to evolve to meat the commercial market, why not D4?Gotta be cheaper than developing Vulcan from scratch^.^
Delta IV is not that great. You can't get Atlas V 431/531/541/551 performance with a single stick. The integration process is longer and more expensive. Also, it has less launch rate per pad. It needs two different upper stages and there's a reason that the Common Upper Stage is based on Centaur. Its avionics were replaced with Atlas'. It had a lot of different fairings. You need at least four different cores models to offer the full performance design. It's not human rated. And its engine is ablatively cooled and thus has no reuse potential. Also its manufacturer has a lot of overhead because it was designed to mount on the SSME infrastructure. And there are no equivalent engines in the world to replace it with like they are able to with the RD-180.
In this image of the WGS-9 launch you can see that the Delta IV boosters have different aft skirts.Why is that?https://twitter.com/johnkrausphotos/status/843299763747479553
Quote from: pippin on 03/19/2017 02:14 PMIn this image of the WGS-9 launch you can see that the Delta IV boosters have different aft skirts.Why is that?https://twitter.com/johnkrausphotos/status/843299763747479553One pair has a fixed nozzle, the other pair has a gimballed nozzle. I don't know which is which.
Has anyone ever published good, worked-out performance figures for a version of the single-stick with 8x GEM-60 solids, aluminum-lithium structures and the 5-meter D-IVH upper stage? And with a regenerative RS-68 prospect and all the above gear? I'm willing to bet performance closing in on the Delta IV-Heavy, even with the standard RS-68A engine, and cheaper than the Heavy to boot.
But with Vulcan on the horizon .... Delta IV tooling heritage will live on with Vulcan.