Protecting a rover from hackers

Cybersecurity is a serious issue not just for computers on Earth, but also for those in space.

Last month, JAXA (Japan’s space agency) announced that hackers had broken in to gain access to information about the Kibo Space Station module. The information consisted of Kibo “operation preparations” and mailing lists. In September, a 16-year-old was sentenced to six months in jail for hacking into NASA (and other) computers. In early 2012, NASA’s Inspector General Paul Martin testified to Congress about the state of NASA’s cybersecurity defenses and woes. “In 2010 and 2011, NASA reported 5,408 computer security incidents that resulted in the installation of malicious software on or unauthorized access to its systems,” he said. This goes beyond hacking into an employee’s PC: “The March 2011 theft of an unencrypted NASA notebook computer resulted in the loss of the algorithms used to command and control the International Space Station.”

Naturally, the same concerns apply for our rovers on Mars.

On Tuesday, I attended a talk titled “MSL Cyber-security implementation status report” by Bryan Johnson and Glen Elliott of JPL. You can view the slides from a similar conference talk. They reported on the long list of actions the team has taken to increase the security of operations and commanding for the Mars Science Laboratory (MSL) rover. These include the implementation of Two-Factor Authentication for access to mission systems and applications, consolidating computers into a single virtual LAN, implementing and testing an “incident response process,” and taking obvious (but time-consuming and easy-to-overlook) steps like pruning the list of people with access to the MSL network.

These steps all aim to improve security here on the ground. I asked whether they would discuss measures being taken to prevent unauthorized access to the rover itself, such as encryption or authentication prior to the rover accepting commands. Unfortunately, they declined to discuss it, but the unofficial word is that there is little or no security on the rover side. Conceivably, anyone with a powerful enough antenna and the right pointing information could send the same kind of signals currently being transmitted by the Deep Space Network to all of our remote assets (rovers, orbiters, and other spacecraft). And as we know, security through obscurity only gets you so far. MSL has had a sufficiently high profile that a rumor began circulating last August that the hacker group Anonymous was trying to gain access to the rover:

MarsCuriosity: “Anyone in Madrid, Spain or Canbarra who can help isolate the huge control signal used for the Mars Odyssey / Curiosity system please? The cypher and hopping is a standard mode, just need base frequency and recordings/feed of the huge signal going out. (yes we can spoof it both directions!)”

A group dedicated to “Space Asset Protection” is looking into this side of the problem. Unfortunately, there is some reluctance to adopt encryption, which carries its own overhead in complexity and bandwidth consumption for the often severely limited data links available for spacecraft communication.

And as for authentication, there’s always the chance that the rover might suddenly say, “I’m sorry, Dave, I’m afraid I can’t do that.”

What is Io’s lava made of?

Jupiter’s moon Io is very active volcanically:

“A Giant plume from Io’s Tvashtar volcano composed of a sequence of five images taken by NASA’s New Horizons probe on March 1st 2007, over the course of eight minutes from 23:50 UT. The plume is 330 km high, though only its uppermost half is visible in this image, as its source lies over the moon’s limb on its far side.” (Robert Wright and Mary C. Bourke)

But what is that lava made of? What materials lie inside the moon that are being spewed out? We can’t (yet) land on Io and test its lava directly. But we can make some inferences based on remote sensing observations of the lava’s temperature. The temperature carries information about how mafic (magnesium and iron-rich) or felsic (silicon-rich) the lava may be.

The best way to test our ability to deduce composition from orbit is to do it here on Earth, where we do have the opportunity to determine the true composition by sampling the lava on the ground. Scientists Robert Wright, Lori Glaze, and Stephen M. Baloga recently reported a positive correlation between temperature observations from Earth orbit (using the Hyperion spectrometer) and ground composition observations of 13 volcanoes: “Constraints on determining the eruption style and composition of terrestrial lavas from space”. The conclusion for Io is that the lava is so hot that it is likely ultramafic: very high magnesium/iron content.

You can read more about this endeavor (and view more pictures).

Did Viking find life on Mars?

The 1976 Viking landers conducted a handful of experiments that involved injecting a nutrient-laden solution into Martian soil, then measuring gases given off in response. Indeed, gases were observed from the regular soil, but not from soil that was first heated to 160 C (sterilized). That seemed intriguing to many scientists—but others noted that the same result could be obtained through (abiotic) chemical oxidation triggered by the application of water. If I understand the arguments, heating the soil would break down the presumed oxidizer in the soil so it would then react less or not at all to a new injection of moisture.

But lo and behold, the scientists who (still) insist that Viking found life have published a new paper: “Complexity Analysis of the Viking Labeled Release Experiments” by Bianciardi, Miller, Straat, and Levin. They’ve used “complexity variables” to characterize the time series data, then clustered them (with k-means clustering, k=2). Indeed, they found that presumed “active” samples (including some examples from Earth) clustered together while presumed “inactive” samples (including some controls from Earth) clustered in a different group.

Since my dissertation was on clustering, I thought I should take a look and see how this machine learning method was being used in this setting. And, well, I’m just not convinced. Yes, they do seem to have gotten two distinct populations. But they only used 15 samples (11 from Mars, 4 from Earth) and that hardly seems sufficient to characterize the range of behavior, nor are they all obviously comparable (one time series consists of “core temperature readings taken every minute from a rat in constant darkness”; how is this related to possible bacterial activity in soil? Is darkness relevant? What about a rat in daylight, or a diurnal cycle?). The authors have agreed that more data would be better. I think more data, and thoughtfully chosen, would be essential.

My other reservation is about the “complexity variables” that were used. These are presented with no justification or discussion:

  • LZ complexity
  • Hurst exponent
  • Largest Lyapunov exponent
  • Correlation dimension
  • Entropy
  • BDS statistic
  • Correlation time

Especially since these generated the 7D space in which the clustering happened, it’d be nice to have some intuition about why these might relate to life. There are some brief comments about life being “ordered” and of “high complexity” (and I’ve worked on this subject myself!) but I’m not convinced that the distinction they found is truly meaningful.

I don’t want to be unscientifically biased or negative. The results as presented in the paper do seem to show a quantitative separation between active and inactive samples. But this should be conducted with hundreds or thousands of samples from the Earth at the very least, where we have tons of examples of life-bearing soils as well as artificial or sterilized samples. These could fill out the feature space and properly position the Viking observations in more context.

Of course, it would also be useful to get more Martian samples!

Probing the interior of Mars

Most of what we know about Mars only goes skin deep. We’ve had several orbiters studying the planet with a variety of remote sensing instruments (cameras, lasers, radar, etc.) and several rovers running around on the surface. The Phoenix lander dug around in the soil a little.

But so far, we haven’t been able to look beneath that skin. No drills, no cores, no subsurface probes. We haven’t even gotten a seismometer to the planet, which could be used to learn about the composition of the planet’s interior, and help answer the question of whether Mars still has a molten core. (The Apollo astronauts put seismometers on the Moon to help answer similar questions.)

The InSight mission to Mars seeks to change that. InSight is a lander that will use a seismometer and a heat flow probe to learn about the planet’s interior. (It will also have a surface camera, of course!) The plan is for InSight to launch in early 2016 and land on Mars later that year.

We’ve studied Mars from the outside for decades now… it’s time to look under the hood!

InSight is competing with two other concepts to be the next Discovery mission to Mars. (The others are the Titan Mare Explorer and Comet Hopper.) One of the three will be selected in late 2012. Stay tuned!

The penultimate Shuttle flight

The Space Shuttle program is coming to an end. The next flight, STS-134, is currently scheduled for April 29, 2011. The goals of this mission are to deliver the Alpha Magnetic Spectrometer (AMS) and some communication antennas and other parts to the International Space Station. The flight readiness review will be on April 19, at which point they’ll determine the final launch date for Space Shuttle Endeavor.

Not an astronaut? You can still send your face to space at (no joke) Face in Space. NASA wants to literally UP-LOAD your digital image, along with the Space Shuttle, to the Space Station. Sure, it’d be faster to just send it on the comm link, but hey! This is outreach. So far, 315,048 people have participated. Your face won’t actually go up with STS-134, but instead with STS-135 — the final Shuttle flight. Last chance!

If you’d like the latest news from NASA, consider subscribing to one of the NASA RSS feeds. As we near the end of the Shuttle era, it will be interesting to see what next steps the agency takes.

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