June 18, 2014
Four questions on the LRS-B
Part One—How survivable will today’s bomber be a decade on?
By James Hasik
Relatively fast and relatively cheap, at least by the standards of past programs, but should the United States buy it? Since the 1950s, justifications for the US Air Force’s long-range bomber programs have had to grapple with four thorny issues:
- If the bomber is to have a conventional capability, how it is going to penetrate serious air defenses?
- If the bomber is to have a conventional capability, why is a shorter-ranged aircraft inadequate?
- If the bomber is to have a nuclear capability, why are ballistic missiles are inadequate for nuclear attack?
- Can the performance requested be provided within the cost and schedule advertised?
In the next few days, I will deal with each of these issues in turn, posing the question that policymakers should want addressed if the LRS-B is to proceed as a program.
Let’s start with the question of penetrating air defenses. This has been a salient vexation for every bomber program, at least until that of the B-2. Michael Brown thoroughly covered the USAF’s long-standing approach in his 1992 book Flying Blind: The Politics of the US Strategic Bomber Program (Cornell University Press). The damage inflicted in nuclear attacks could justify high loss rates, but sustained conventional campaigns can’t be conducted that way. Eventually, even the B-52 lost its tail guns, when the USAF realized that they couldn’t match the range of even early versions of heat-seeking missiles. So, the service just insisted that every succeeding bomber fly higher and faster than the preceding, whether that was technically possible at the time or not. By pouring enough money into development, and waiting long enough, that approach mostly worked, and for decades. But faster-higher-further met its limits in the programmatic disaster of the B-70 Valkyrie, and the switch to low-level penetration with the terrain-following B-1.
The B-2’s approach was novel, though it really only works at night. And as the loss of that F-117 in the 1999 Kosovo War reminds us, it’s not even guaranteed to work then. In the long run, stealth characteristics are built into an aircraft in the design phase, and retrofitted later only on the margins (take Boeing’s Silent Eagle as an example of what can be accomplished). Presuming (as I wondered some time back) that Moore’s Law still has some life in it, the technical capabilities of air defense sensors may keep improving for some time. Stealth may not be going the way of the castle-as-defensive-fortification, but any new bomber’s free ride will be limited, and eventually it will require escort by fighters, jammers, and radar-attack aircraft.
So, here’s the first question to ask any Air Force general darkening your door with a briefing on the LRS-B: what's the long-term plan to keep the big bomber relevant, to the extent that we can expect Russian and Chinese air defenses to improve over time? Is the architecture sufficiently flexible to admit injections of new technology a decade hence? And if so, what are the limits of weight and power growth?
Tomorrow, I’ll be back with the next question.
James Hasik is a senior fellow in the Brent Scowcroft Center on International Security.