Ever since the days of the Roman legionary, foot soldiers have struggled to carry all their gear, and have preferred that someone or something else give them a hand.
Arse-kicking Roman general Gaius Marius, trying to reduce the size and unwieldiness of the legions' baggage trains, made his new professional soldiers - the elite of the ancient world - carry most of their kit themselves, so that they were nicknamed "Marius' Mules". In modern armies, crack troops still tend to make much of their ability to march with heavy loads.
A recent American development contract suggests that the US military may be looking to move in the other direction, however. Boston Dynamics, Inc, a company spun off from MIT in 1992, last week won $10m of Pentagon cash. This was for the construction of "a dog-like robot with the capability to run fast, traverse trough [sic] terrain, jump over obstacles one metre tall or two metres wide, and operate for two hours without refueling.
"The goal of this effort," according to the contract announcement, "is to create legged robots that mimic animal structure, mechanics and control to achieve animal-like strength, speed and mobility. This 15-month contract includes three one-year options which, if exercised, would bring the cumulative potential value of this contract to $40,000,000."
Boston Dynamics will use its petrol-engined, hydraulic-limbed quadruped "BigDog" walker-bot in this role.
YouTube footage? But, of course:
(You'll need Flash and a chummy firewall to see it.)
The machine seems like a miniature, rather limp-wristed version of the Imperial AT-AT, a machine known to all who have seen The Empire Strikes Back (our Roman allusions seem at least as valid as George Lucas'). But the prancing mule-droid is apparently intended more as a beast of burden than a gigantic insurgent-stomping battle vehicle.
"BigDog is the size of a large dog or small mule, measuring one metre long, 0.7 metres tall and 75kg weight...so far, BigDog has trotted at 3.3 mph, climbed a 35 degree slope and carried a 120 lb load," says Boston Dynamics.
On the face of it that's not too bad. UK Commando troops in training, for instance, have to complete a 12-mile load-carrying march with only 69lb of kit in four hours forty minutes. BigDog can apparently perform at this level already, though it might struggle with some parts of the route. However, it might need refuelling a couple of times - and there's no word on the size of its petrol tank. One of the problems of ordinary mules is that they can eat up their entire loads very quickly, and it seems that this might also be the case with robo-mules.
Likewise, there could be tactical issues with BigDog. The robo-mule seems a bit noisy, a thing infantrymen hate to be. BigDog might well be popular in the role of checking for landmines, ambushes, or booby-traps. Even so, for most practical purposes, you'd probably prefer that BigDog's place in the transports and the budget was filled by a fit and well-trained human.
But fit, well-trained human infantry are often in short supply among today's Western armies. It's at least possible that modern American legionaries may soon have a robotic mule train in attendance on their foot marches - no matter what Gaius Marius or the Imperial stormtroopers would have thought of that. ®