Saturday, April 11, 2015

NASA's Mission to Europa May Get More Interesting Still has published an article reporting that NASA officials have asked their European counterparts if they would like to propose contributing a small probe to NASA's Europa mission planned for the mid-2020s.  

If the Europeans are interested, the probe could carry out any of several possible missions.   Two mentioned in the article would be a small lander or a craft that could fly through and study any plumes found erupting from the moon's surface.  

Europa as imaged by NASA's Galileo spacecraft in the 1990s.  Credit: NASA
Another possibility, not discussed by the article might be a small spacecraft that could repeatedly flyby the moon to make magnetic field and gravity measurements.  Both studies are key to understanding the size of this moon's ocean and the structure of its rocky core.  The main Europa Clipper flyby craft will make these measurements during each of its flybys.  Both studies, however, improve with the number of passes by the moon, so a second craft would add substantially to these measurements.  I'm told that one or more of the CubeSat studies NASA is separately funding as possible augments to the mission would do this.

British scientists and engineers have studied small penetrator landers that would be shaped roughly like a cannon shell that would use the force of impact to dive a meter or two into the icy surface.  Penetrators have been used on the Earth to deploy probes from planes and have been proposed several times for planetary missions.  Penetrators avoid many of the complications involved in a soft landing. The penetrator would need an avionics module to keep its orientation and likely would need a retro rocket to reduce the approach speed, both of which add considerable complexity to the design.  (Penetrators have flown on two missions, the Russian Mars 96 spacecraft that failed to leave Earth orbit and the two failed DeepSpace 2 Mars penetrators that were never heard from after their release from their mothercraft.)

Penetrators would not be the only possible small lander design.  All approaches, though, would involve small probe that would carry one to a few small instruments such as a seismometer/geophone and one or more chemistry experiments.  Even simple measurements could provide information that would complement the measurements made by the main spacecraft.  (As a side note, the same would be true of a small lander for Ganymede added to Europe's JUICE mission that will orbit this moon of Jupiter in the early 2030's.  I don't know if that design would still be open to adding a small lander that might be a near duplicate of one carried on NASA's Europa craft.)

You can read more about possible small lander designs in this blog post, this Science News article, or from this presentation.

If the European Space Agency's managers decide they might like to participate, then European scientists could propose specific probe plans as part of a future Medium Class mission competition, where it would compete against other planetary and astrophysics proposals.

Note: My thanks to RL for informing that the Mars 96 mission also carried penetrators; the text has been corrected.  However, there has been no successful use of penetrators on any planetary mission to date.


  1. Mid-1990s? When is the mission really thinking of going?

  2. CLJ - Thank you. Was thinking of Europa when I wrote that line.

  3. Best Beta TradingApril 17, 2015 at 9:46 AM

    I'm interested in the "crystalline homogeneity" if the bulk ice, and the ringing behaviour and acoustic environment of the oceans, at least the ones we can melt our way into. Again, I'd like to use Ice Moons to detect neutrinos that we have sent through Earth, as a way of imaging Earth's interior. This if possible would reveal clandestine Earth WMD labs and advance terrestrial tectonic sciences.
    I tentatively asked if platinum/palladium would be useful for making AI, and got an answer: "of course it would help at least a bit..." before I chickened out and retracted.
    My basic strategy for now is to advance sensors and communications (in concert with good gvmt and the post-modern tax rates that come with it) and retard future computing. I'd guess platinum does more for promoting good than bad. They confirmed a global sensor network, probably just like Intelligence Agencies use to look for contraband nukes now, is the way to go for preventing AI.
    I was able to get a few questions off 8 years ago. They said JFK's murder was a politically motivated killing. That is a very informative answer. I suspect now it means his belief of Roddenberry's tales had nothing to do with the murder.
    So I'd like the 1st or the 2nd asteroid captured and redirected nearby to be high in platinum, so we can learn about mining it. I might be able to suggest specific asteroids or specific remote imaging R+D to pursue. I might change my mind entirely about platinum.

  4. For the purpose of a search for active ecosystems, I'd guess the older the "cave-lake", the better. I imaging for Europa, where the volcanic vents meet the bottom of a glacier, there will be water. I imagine the scouring activity will cause the assumed to be hydrologically isolated cave-lake (like Lake Vostok), to get progressively saltier. This may be possible to image from orbit. Saltier "cave-lake" will be older and have had more time to originate an ecosystem.

    I'm curious from how far away you can image platinum and other expensive metals. The papers I've rad so far are all using magnetometers and NVIR spectroscopes very close to an asteroid. Is it possible to image platinum on small asteroids from GEO with an expensive satellite?
    A captured asteroids doesn't need to contain economically recoverable platinum to be useful for mining R+D. But it does need to have enough platinum to allow the test of processes for later recovery. I'm annoyed lunar papers suggest filtering regolith is the best strategy for recovering platinum from the Moon. I figure the asteroid platinum recovery processes will port to Lunar mines pretty easily.
    I'm envisioning an asteroid coring process, followed by placing a core sample in a hot oven and getting enough platinum to return some jewellery to be auctioned off on Earth. I don't think it is economical to visit every potential asteroid and image for platinum, but a couple of dedicated observatories should eventually pay for themselves. India's middle class will want jewellery and air pollution filters for the foreseeable future...

  5. Best Beta TradingApril 24, 2015 at 9:20 AM

    sry for multipost; last preliminary asteroid retrieval report:
    An asteroid composition paper, with a UofW author, suggests spectrometer don't reveal much about metals (I guess they all look the same). It used Arecibo radar and said denser surface asteroid substrates are revealed as such. So if you want a platinum asteroid, you look for the densest surface you can find. Maybe a dedicated observatory for this. If you want the highest science value, I'm not sure, but different observation methods at a rotating asteroid might reveal different substrates. I'm not sure how fine-grained you get, but you might be able to image that there are individual granola components as whatever observation method you chose, is used on a rotating asteroid. More types of minerals and more varied types of minerals, is more science value.
    Ideally, there will be two successful missions.

  6. Best Beta TradingMay 7, 2015 at 3:15 PM

    I've been thinking of a way to get to the Mars gullies that might seasonally experience water flowing along their sides. The best I can envision is a spool of space wool from the top; unspooling it would trigger simple sensor to measure for water or CO2 signatures...I'm weak on what sensors to use.
    I was thinking about an idea to melt trhough particle detectors on an ice moon, to capture neutrino flavours and possible other neutrino data, from a beam we send from the other side of Earth to image Earth. My friend mentioned melting through the ice and letting it solidify on top of you will trigger a biologically inert environment. The idea being not to import microbes from Earth to a pristine ice moon sludgy ecosystem. But what they might really have been trying to jog my thinking towards is a planetary protection protocol space station. You could use an inert comet or an icy moon as the biolab and melted hollows inside of ice deposits could function as petri dishes.