In 1994, the latest B-52H modification program began, the Conventional Enhancement Modification (CEM) program. CEM was designed to give the B-52H a capability for conventional warfare that it had not previously possessed. During the early 1990s, the USAF had planned that the B-52G would perform the conventional and maritime mission, with the B-52H being restricted to the nuclear standoff role. However, the B-52Gs were retired and the B-52H had to be able to take over some of its conventional warfare duties. The first stage in the process was the addition of AGM-142A and Harpoon capability to the B-52H. This was made possible by adding the Heavy Stores Adapter Beam (HSAB) to the underwing weapons pylon, which made it possible to carry weapons that were too long or too heavy to be accommodated on the I-beam rack adapter. The HSAB, which was originally fitted to the B-52G, made it possible to carry up to nine large weapons on each pylon externally, the precise number depending on which weapon is being carried. Later, a Global Positioning System (GPS) navigation system was added, with receivers located at the offensive station. An AN/ARC-210 VHF/UHF radio with secure voice encryption capability was added, and Have Quick II anti-jam features were added to the UHF wavelengths available at the pilots' and offensive stations. SINCGARS anti-jam/secure capability was added for VHF communications. The Military Standard 1760 databus was added to prepare the B-52H for a new generation of weapons not yet in the inventory such as the Joint Direct Attack Munition (JDAM), the Joint Stand-Off Weapon (JSOW), and the Wind-Corrected Munitions Dispenser (WCMD).
Among the weapons that the HSAB modification now enables the B-52H to carry are the Rafael/Lockheed Martin AGM-142A Raptor inertial/TV guided missile, the AGM-84 Harpoon antiship missile, the AGM-84E SLAM, the GBU-10, the MK84 or Mk 60 CapTor mine, the GBU-12, Mk 55/56 mines or JDAM, Mk 40 DST mines, British 1000-lb or 2000-lb bombs, or any bomb that can be carried by the I-beam.
The version of the Harpoon that is carried currently by the B-52Hs is the AGM-84D Block 1C, but a Block 1D version with enhanced range is planned for the future. The B-52H carries the Harpoon only externally, and can carry up to 12 of these missiles on the underwing pylons. Currently, the 96th BS has all the Harpoon-modified aircraft. The first live Harpoon launch by a B-52H took place on July 25, 1996. Although the B-52H can self-target its own Harpoons, the usual practice is to use a Navy aircraft such as an S-3 Viking or a P-3 Orion as an external targeting platform. By 1997, the specialized HACLCS equipment that needs to be fitted to Harpoon-capable B-52Hs is scheduled to be replaced by a new Harpoon Stores Management Overlay (SMO) system, which will allow the B-52H's offensive team (radar navigator and navigator) to load Harpoon-specific weapons software in order to target and launch the weapons.
For stand-off missions, the B-52H can carry either 12 AGM-86C ALCMs, eight AGM-130A rocket-powered bombs, or three AGM-141 Raptor missiles with data link pods. For naval operations, the B-52H can carry either eight Mk 55/15 or Mk 60 mines internally or ten Mk 60 mines on wing pylons. Alternatively, eight AGM-84 Harpoon antiship missiles can be carried on the wing pylons.