Last week, NASA announced the formation of the Mars Program Planning Group, which — as its title would suggest — is aimed at getting us back to Mars. The hope is to get another robotic rover on the surface of the Red Planet by as early as 2018, all with the ultimate goal of sending a human to the planet sometime in the 2030s.
But what will NASA’s future rovers look like? I decided to ask Richard Volpe, manager of the mobility and robotic systems section of NASA’s Jet Propulsion Laboratory (JPL). For future Mars missions, the trick is getting more bang for the buck. “Right now we’re assuming that power is limited,” says Volpe. “The question is, What can we do with that power?”
Unable to simply stick a nuclear reactor onboard each of its rovers, NASA is pretty much limited to using solar power for its Mars missions, which is less effective than it is on Earth because Mars is farther away from the sun.
That means that rovers have about 100 watts to work with, a figure that’s not expected to change anytime soon. That isn’t a lot of juice, especially considering it has to power absolutely everything. The JPL engineer’s job, then, is to make the rovers get the most out of those 100 watts. Why is that so important? A lot of it has to do with how rovers move around Mars.
Opportunity — the rover that outlived its predicted stay on the planet by more than seven and a half years — moves by driving around one meter, stopping to snap a photo, analyzing that data and then finally making its next move.
It’s a painstakingly slow way to get around. Volpe is hoping that things like field-programmable gate arrays (circuits that can be programmed after being manufactured) can make the whole moving process more efficient, freeing up power for what’s really important: taking samples of Mars’ environment.
The problem with designing rovers is that you don’t have a lot of test cases to work with. Take Opportunity. NASA thought it would die after three months because all its simulations showed dust blanketing the solar panels and cutting off power. What scientists didn’t predict was huge wind events periodically wiping the panels clean, giving Opportunity a new lease on life.
(PHOTOS: Roving the Red Planet)
“If we built 1,000 rovers, we would have a better sense of how each incremental change affects their lifetime,” says Volpe. “But because we can only build a few, we have to err on the side of being conservative.”
That’s why whatever launches next probably won’t look too different from what the public has already seen. You only get so many chances to test out a rover on Mars, not to mention taking risks with a piece of tax-funded equipment that costs hundreds of millions of dollars is generally frowned upon.
So if the next rover is basically going to be just a more efficient version of Opportunity or Curiosity — which, according to NASA’s online countdown clock, is going to touch down on Mars in 110 days — is there anything in the works that might give science-fiction nerds like myself a reason to be excited?
Definitely. One of the technologies being considered is a “marsupial-style system” consisting of a small rover connected to a larger rover by a tether. The small rover could then be lowered like a robotic spelunker down steep cliffs on Mars or Jupiter’s moon Europa, take samples, and then be hoisted back up to its big brother.
The coolest piece of tech, however, just might be Athlete. Normally, biomimetic robots — which mimic biological creatures — are off limits as rovers. Yes, legs are great for climbing over obstacles, but they also require too much power.
Athlete (short for All-Terrain Hex-Limbed Extra-Terrestrial Explorer) runs on wheels like most rovers. The difference is that when it encounters rough terrain, it can lock its wheels and use its six legs for walking. It’s meant to one day ferry astronauts around the moon, but it could eventually have a higher purpose: landing on near-Earth objects such as asteroids and comets.
Athlete’s active suspension could theoretically allow it to gently land on a moving object without disturbing the surface below. In the case of comets, that means potentially sampling ice that would be, in Volpe’s words, “primordial, from the earliest days of the solar system.”
If that isn’t cool enough to make you want to up NASA’s budget to Neil deGrasse Tyson–approved levels, I don’t know what is.