Delta IV Heavy Upgrade 40 t

American orbital launch vehicle. Proposed upgrade to Delta IV Heavy by adding 4 GEM-60 solid rocket boosters, RS-68 Regen upgraded engines with regeneratively-cooled nozzles to the core vehicles, and cryogenic propellant densification. 6.5 m diameter payload fairing. Introduction would require modifications to existing launch pads.

LEO Payload: 36,000 kg (79,000 lb) to a 407 km orbit at 28.50 degrees. Payload: 14,000 kg (30,000 lb) to a earth escape.