Delta IV - friznit/Unofficial-BDB-Wiki GitHub Wiki

Background

Delta IV was designed to launch payloads into orbit for the Evolved Expendable Launch Vehicle (EELV) program and for the commercial satellite business. Delta IV uses a Delta Cryogenic Secondary Stage on top of a 5m diameter Common Booster Core (CBC) powered by an RS-68 cryogenic engine. The Delta IV Small proposition would have used a single CBC, a Delta II second stage and an optional Star 48B third stage inside a Delta II payload fairing. Delta IV Medium (technically Delta 9040) has a modified Delta III second stage (DCSS) topped by a 4m or 5m fairing and adds 2, 4 or 8x GEM-60 SRBs on the Delta IV Medium+. Delta IV Heavy (Delta 9250H) uses 2 strap on CBC's in place of the SRB's.

Tags: Delta IV

Variants

Variants	First Stage	Boosters	Second Stage	Third Stage
Delta IV M	RS-68		DCSS-4 RL10B-2
Delta IV M+ (4,2)	RS-68A	2x GEM-60	DCSS-4 RL10B-2
Delta IV M+ (5,4)	RS-68A	4x GEM-60	DCSS-5 RL10B-2
Delta IV H	RS-68A	2x CBC	DCSS-5 RL10B-2	Star 48 (optional)

Basic Build Guide

Place the radial decouplers in 2x symmetry then add the CBC's individually so the raceways and pipes all face the same way. Switch on the side node on the Upper Liquid Fuel Tank to attach it to the decoupler. Delta IV M uses the 4m DCSS with the Delta IV config to give it slight tank extension. A 3.125m to 2.5m interstage variant is available on the Delta III interstage part to connect the 4m DCSS to the booster core.

Delta IV M, Delta IV M+ (5,2) & Delta IV H

Legacy Builds

Old kit bash builds for posterity. Delta IV M using BDB LDC parts and an alternative build using Restock.

BDB & Restock Delta IV M & Delta IV M+ (5,4)