The US National Aeronautics and Space Administration (Nasa) began its Mars exploration programme in 2003 with the sending of two surface rovers – Spirit and Opportunity – to explore the Martian surface.

The mission’s scientific objective was to characterise a wide range of rocks and soils that hold clues to past water activity on Mars.

The total cost of building, launching, landing and operating the rovers on the surface for the initial 90-Martian-day mission was $820-million.

The rovers are six wheeled vehicles, each about 1.8 m high. They were designed to last for a 90-day mission but have managed to do much more than that. Opportunity is still travelling and communicating, while Spirit stopped working in 2011. They are interesting vehicles but, I am afraid, clearly show all the attributes of something designed by a committee. This article is about these vehicles, what their defects are, how they are similar to what is often wrong with engineering design today. Now I know that the guys down at the Jet Propulsion Lab (who have done much of the operating of the rovers) will never talk to me again, but, hey ho, thus is life.

So, what is wrong (or right) with the rovers? Here it is: the rover vehicle has six wheels. The top speed is about 30 mm/s, which is not very much. However, radio waves take ten minutes to get to Mars from the earth and ten minutes back. Thus, you would rather not send a ‘go-ahead full-speed’ signal to the rover and find out that, in the interim, a rock had loomed up which your rover had charged and damaged. So, slow as you go is good. But that slow? It is appropriate since the rover wheels are about the same size as the surface rocks, so you have to miss them but, heck, I would add a second, even a third gear.

The rovers have solar panels for power. Since Mars is further away from the sun than the earth, the panels do not get as much power as they could on earth (about 56% less). So, design wise, it would make sense for the panels to be able to tilt to get optimum sunlight. This feature is not fitted to the rovers. Perhaps there is a good Nasa reason for it but I cannot see it.

Further, the surface of Mars like Saldanha Bay, where the Transnet iron-ore terminal is located, is covered in red dust. Thus, the solar panels get covered, in, uh, red dust, which makes them less effective. It should be possible to fit some sort of shaker or tilter to stop this from happening but, nope, the rovers do not have it. They have to relay on the occasional Martian wind storm to clear the panels. Wind storm? Yes, the Martian atmosphere is about 96% carbon dioxide, 2.1% argon and 1.9% nitrogen, but its pressure is very low – about 0.6% of earth mean sea-level atmos- pheric pressure.

Now let us go back to the six wheels: they can articulate separately, swivel and all sorts of stuff. But, if more than one of them become stuck in Mars quicksand, the rover is stuck. As was Spirit. Forever. Hold that thought. Now there was a programme on BBC called Robot Wars, in which small (rover-sized, sort of) robots fought each other. The robots were hand built and I can tell you if any of those robot builders got to design a rover, it would never get stuck in the sand without having a way out.

Okay, one says, not bad. The rovers did okay! For $820-million? They could have done better. At some point, you can see the budget stopped the engineers from doing what was right. So the result (far longer mission than planned) is good but not great. Why? Why? Why? Surely, they could have got one of the “Robot Wars” people to give an opinion? How on earth did they not come up with a way to clean and tilt the solar panels? I can see why. Whenever the design was vetted, there was some sort of review committee that, in reaching common consensus, agreed on the lowest common denominator. Which is a pity.