Flying to Titan

Decadal surveys and other prioritizations of potential NASA exploration missions often rank one thing very highly: a sample-return mission from Mars. However, I think there are some much more scientifically interesting, technologically challenging, and engaging to the public mission proposals out there. This is one: a Titanian UAV!

The idea is to send an airborne vehicle to Saturn’s moon Titan which would fly around the moon, observing surface features from its high vantage point. A powered flyer, as opposed to a balloon, has the advantage of being able to travel to a specific location: such as the moon’s liquid lakes!

The proposal team uses some clever mission planning approaches to handle the limitations of the aircraft: for example, using glide phases to hoard power for downlink sessions. Their nominal mission duration is one year: a year of exploring another planet from the air, a year of images and science data depicting a world of lakes, rivers, ice, and rain. The full proposal is online here.

I find the idea exciting, and I hope that NASA’s governing councils soon prioritize exploration of those extraterrestrial locations most likely to harbor life – like Europa, Enceladus, and Titan.

2 thoughts on “Flying to Titan”

  1. Even on Mars, there are probably better ways to spend our short planetary mission dollars than a sample return mission. The assignments I did for the NASA NCAS program last spring called for us to design a sample return mission. I, and many others in the program, all wrote reasons why it was a bad idea and we weren’t going to wast money on it. I estimated that adding a sample return capability would either more than double my mission cost, or seriously reduce the on planet scientific capability of the mission while still nearly doubling the cost.

    Personally, I’d like to see more MER class rovers, or even larger numbers of rovers between Sojourner and MER class. One fairly simple instrument that’s gotten the short shrift multiple missions in a row is the Raman spectrometer. One was part of the initial Athena proposal for MER and then I think one was proposed for MSL. I’m not sure if that ended up flying; I know they included the LIBS and that often goes hand in hand with Raman, but I haven’t found anything definitive. The Mars Astrobiology Explorer-Cacher was also supposed to include Raman, but that entire rover was cut.

    I harp on Raman because of its speed, simplicity, and compound detection capability. Raman works by looking at color shifts from molecular bond vibrations. Much of what we’ve sent to Mars is pretty good at element identification, but lousy at compound detection. Take the recent announcement at possible evidence of for minerals deposited by water
    With the Alpha Particle X-ray Spectrometer, they can tell you that calcium and sulfur are present. With a Raman spectrometer, they could definitively tell you that sulfate was present. What’s better is that the Raman result would take seconds or minutes, rather than the hours needed for the APXS scan. The Raman could be used for quick characterization of potential sulfate (or other minerals, such as olivine) that are then confirmed with the APXS. APXS tells you what elements are there (though apparently not oxygen, I never see it mentioned in these articles), Raman tells you how they are bonded together.

    I don’t think I am exaggerating on the capability of Raman spectroscopy. I use a fairly inexpensive unit ($40,000 range with a laboratory microscope that can be used with the spectrometer) almost every day. Sulfate is one of the compounds I test for on a near daily basis. I know exactly what vibration to use for it. In fact, I found that vibration in literature on the potential of using Raman spectroscopy on Mars! Whenever these articles come out on “potential” or “possible” mineral finds, it drives me bonkers with how quickly Raman would give them a definitive result.

    OK, this all came out a lot longer than I meant it to, but I am really passionate about the potential of Raman on Mars. I’d also love to see it on Titan, Europa, and Enceladus. Raman has been well demonstrated to quickly identify compounds that are indicators of life. It handles liquid as well as solid samples with ease, and probably can do gas and atmosphere (I haven’t done that myself, but I do liquids and solids daily with the same instrument). It’s non-destructive, allowing for later re-analysis, but can be coupled with destructive techniques such as LIBS or drills. Basically, it’s just a laser and some optics that allows for detecting the scattered laser light, and measuring the change in color.

    My ideal future mission to Mars would be half a dozen rovers in a sub-MER class with an APXS, a Raman spectrometer with both macro and micro modes, an MER Pancam, and maybe a drill, all on a chassis with the necessary nav/power/comm/control capability. Two spectrometers, a camera, and a drill. The drill is optional. Build as many of these and send them to as diverse a set of locations on Mars as possible and you would have such a quickly expanding picture of Martian geochemistry and possible biological history that you would not believe it. Hell, I’ve seen articles where Raman was used to identify biomolecules in 500 million year old fossils.

    This is where faster, better, cheaper can still yield amazing results.

  2. I remember doing Raman labs in physics class with a dye laser. It kind of blew my mind that the whole big organic molecule could lase!

    I can see one good reason to do a Martian sample return mission, and that’s as a technology demonstrator for in-situ return stage fuel production. That would be a capability that could feed directly directly into both robotic and human exploration throughout the Solar System. Mars rocks themselves are probably less interesting, especially because the samples we return are likely to be much smaller than the rocks from Mars that we already have.

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