Tuesday, December 11, 2007

Northrop Wargames a Laser Armed Bomber

Northrop Grumman turned up at an Air Force virtual exercise in late September with a new weapon: the high energy laser (HEL) bomber. Based on a B-2, the notional bomber design combined the stealth bomber's massive internal payload with a HEL that could shoot down incoming double-digit surface-to-air missiles (SAMs), rendering the jet invulnerable to missile attack.

The project leader is Robert Smerke, principal investigator for operations and simulation analysis for the company's Integrated Systems sector. Smerke acknowledges that the key laser technology doesn't exist yet, but says that the study was more than just an exercise in PowerPoint physics.

First, Smerke's team talked to operators - B-2 crews at the 509th Bomb Wing, other bomber crews, special operations teams, fighter pilots and many others - to find out what they could do with a HEL-armed bomber, before they defined the aircraft and weapons used in the simulation.

Also, apart from the HEL, the technology installed on the simulated bomber was off-the-shelf, under development or simply modified: the SDB II Small Diameter Bomb, the Massive Ordnance Penetrator, the Army Tactical Missile System (ATACMS) adapted for air launch were among them. The bomber wasn't necessarily a modified B-2, but that technology was used as a baseline.

As for the laser, Smerke says, Northrop Grumman was looking at systems that have a serious chance of working "and don't weigh 7,000 pounds". The crews, he says, "will give up a couple of JDAMs" for a defensive capability Smerke's team modeled with two lasers. The nearer-term liquid-cycle concept provided unlimited shots over the mission, but needed to shut down and dump heat after a certain number of firings; beyond 2020, solid-state technology was assessed to allow continuous fire. Neither used expendable chemical fuel, but drew electrical power from the engines. (Smerke does not mention specifics, but DARPA's laser programs described here, here and here are an indication of where technology might be headed.)

The study does reflect the fact that, if an airborne defensive HEL is ever practical, it will fit on a large bomber before it fits on a fighter. It's also worth remembering that defending a 600 mph target is not like protecting a land target or a ship. It's enough to make the incoming weapon miss by a few dozen yards, in most cases, and (unlike a ship target) the bomber won't be hit by an uncontrolled but intact weapon. Punch a hole in a SAM's radome, and the supersonic airflow through the hole will blow the radome off and the missile will become unstable and miss.

There's another point about lasers, too: they make tactical maneuver irrelevant because they engage at equal speed and effectiveness over the entire field of regard, which is a complete sphere in the case of a flying wing with upper and lower turrets. A B-2 can't pull 9g or perform a vertical scissors. And it does not matter.
Something that they don't talk about is that if the bomber can have the laser, so too can the ground troops. If you can pack an airplane killer in a FCS, there's gonna be trouble for the Blue Beanies big time. It also gets interesting for artillery shells, rockets, and missiles. The ideal would be to have reduced the HEL hardware down such that it could be standard equipment on all 'tanks.' Truthfully, that's probably 20 years away at the current rate of development.

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