Was Voyager 2 Hijacked by Aliens? No.

The interstellar probes are still operational (NASA)

The Voyager 2 spacecraft has been speeding through the Solar System since 1977 and it’s seen a lot. Besides scooting past Jupiter, Saturn, Uranus and Neptune, the probe is now passing through the very limit of the heliosphere (called the heliopause) where it has begun to detect a magnetic field beyond the Solar System. The fact we have man-made objects exiting our star system is something that makes me goosebumpily.

For some perspective, Voyager 2 is so far away from Earth that it takes nearly 13 hours for commands sent from Earth to reach the probe.

After decades of travel, the NASA spacecraft continues to relay data back to us, making it one of the most profound and exciting space missions ever launched. Perhaps unsurprisingly, the aging explorer recently experienced a glitch and the data received by NASA was rather garbled.

Naturally, the conspiracy theorists were out in force quickly pointing their sticky fingers at a possible encounter of the 3rd kind. How these ‘aliens’ found the probe in the first place and reprogrammed the transmission for it to appear corrupt Earth-side is beyond me, but according to an ‘expert’ in Germany, aliens (with an aptitude for reprogramming 30 year old Earth hardware, presumably) were obviously to blame.

One of the alien implication articles came from yet another classic ‘science’ post thrown together by the UK’s Telegraph where they decided to take the word of a UFO expert (obviously a viable source) without any kind of counter-argument from a real expert of real science. (But this is the same publication that brought us other classics such as the skull on Mars and the Doomsday Turkey, so it’s not too surprising.)

As I discussed in a recent CRI English radio debate with Beyond Beijing hosts Chris Gelken and Xu Qinduo, the Voyager-alien implication is beyond funny; an entertaining sideline to poke fun at while NASA worked out what actually went wrong. But the big difference was that Chris and Xu had invited Seth Shostak (from the SETI Institute) and Douglas C. Lin (from the Kavli Institute for Astronomy and Astrophysics at Peking University) to join the fun. No UFO expert in sight, so the discussion was biased toward science and logic, not crazy talk.

(It was an awesome show by the way, and you can check out the recording via my Discovery News article.)

So what did happen to Voyager 2? It turns out that aliens are not required to answer this cosmic mystery.

On Tuesday, NASA announced that Voyager 2 had flipped one of its bits of memory the wrong way. “A value in a single memory location was changed from a 0 to a 1,” said JPL’s Veronia McGregor.

This glitch was thought to occur in the flight data system, which formats information for transmission to Earth. Should something go wonky in its memory allocation, the stuff it transmits can be turned into gibberish.

Although it isn’t known how this single bit was flipped (and we may never know, as Voyager 2 is an awful long way from home), it sounds very much like a cosmic ray event interfering with the onboard electronics. As cosmic rays are highly energetic charged particles, they can penetrate deep into computer systems, causing an error in calculations.

And this situation isn’t without precedent either. Recently, NASA’s Mars Reconnaissance Orbiter (MRO) was hit by a cosmic ray event, causing the onboard computer to switch to “safe mode.” Also, Voyager 2 is beginning to exit the Sun’s outermost sphere of influence, where turbulence and confused magnetic fields rule. If I had to guess, I’d say — statistically-speaking — the probe might have a greater chance of being hit by the most energetic cosmic rays from deep space.

Just because something “mysterious” happens in space doesn’t mean aliens, the Illuminati or some half-baked doomsday phenomenon caused it. Before jumping to conclusions it would be nice if certain newspapers and UFO experts alike could look at the most likely explanation before pulling the alien card.

Alas, I suspect that some things will never change.

Could Genetic Algorithms Boost Space Probe Intelligence?

Voyager carried out a gravitational slingshot manoeuvre past Jupiter (NASA)

Rocket science ain’t easy, but what about celestial navigation? Once you’ve launched your probe into space, surely the hard bit has been done, and we can sit back and relax, happy in the knowledge our technology is out of the Earth’s hefty gravitational well? The robot is coasting through the vacuum of space ready to accomplish some science. Job done. Easy.

As you may have guessed, it isn’t that easy, in fact sending a spaceship on the equivalent of a Solar System-scale game of gravitational ping-pong is highly problematic. What if your launch is delayed? What if the inter-planetary medium (the stuff between the planets) is of a higher density than you expected? Perhaps the Sun has pumped out more particles than you had calculated pre-launch, creating drag and slowing your spaceship down?

Unfortunately, once the spacecraft is on its way, apart from a few minor Earth-commanded corrections allowed by the ship’s thrusters (wasting valuable fuel), the spaceship is by itself, hoping your calculations are as complete as they can be.

When the spaceship in question has to use planetary gravity assists to accelerate or decelerate on its journey to a deep space destination, slight deviations in trajectory than what was calculated can result in inefficient sling-shots or even complete loss of the mission.

Now Ian Carnelli and colleagues from ESA in Noordwijk (Holland) have prepared a publication that details a possible solution using a genetic algorithm. Basically, the computer on board a next generation space probe could simulate multiple autopilots guiding a virtual version of the probe. Each autopilot executes its code and the computer will select which simulated autopilot performs the best (i.e. solutions that waste fuel or find the slowest route will be ignored).

Happy with the best group of simulated solutions, the computer will selectively “breed” them together to develop an optimized pilot, with no need to wait for instructions to be sent from Earth. “After hundreds of generations of the GA you obtain a ‘pilot’ that is an extremely good performer – able to fly the assist trajectory that uses the least propellant while reaching the next target planet faster,” Carnelli says.

Using simulations here on Earth, Carnelli has successfully used his genetic algorithm to optimize the trip of a virtual spaceship to Pluto via Jupiter and another to Mercury via Venus.

Although installing this system on missions in the near future may not be a possibility, it is a tantalizing look into how unnatural selection could be used to optimize, and therefore protecting, expensive pieces of kit in deep space.

Source: New Scientist

Sci-Fi Space Robots: Top Five

Update (Nov 18th): OK, it looks like this article just hit the front page of Digg. Whilst cool, I’ve made a very quick deduction that people from Digg must not read the text of an article before commenting. Please read the opening paragraph before shouting “OMFG! This guy should really understand what sci-fi means!.” Perhaps the title could be improved (read: “Top 5 Space Robots that Look Like Science Fiction“), but I think all this can be remedied by simply reading the text and not just looking at the pictures. Thanks!

I love science fiction, I always have. In fact, it was the main motivational factor for me to begin to study science in the early 90’s. Although sci-fi is outlandish, futuristic and seemingly impossible, there is actually a high degree of science fact behind the TV shows, movies and video games. So when I was young, sci-fi fuelled my enthusiasm for physics; more specifically, astrophysics.

Many years after these first forays into trying to understand how the Universe really worked, I now find myself drawn to real space missions doing real science only to find the divide between sci-fi and sci-fact is getting smaller and smaller. However, to ignite the imagination and build an enthusiasm for the “futuristic” science being carried out right now, it helps if the robotic embodiment of the satellite, rover, probe or lander looks futuristic itself (possibly even a bit “sci-fi”). This way we not only do great science, but we ignite the imaginations of men, women and children who would have otherwise ignored the science behind space exploration.

So, here are my top five missions to ignite the imagination, past and future…
Continue reading “Sci-Fi Space Robots: Top Five”