New Mars Forums

Shades of the Year 2000 bug!

Here we are at Spirit's anniversary & I see that the Time on Mars pics for Spirit & Opportunity on JPLs]http://marsrovers.jpl.nasa.gov/home/index.html]JPL's Mars Rover Page have both reset themselves back to "Sol 0" and "Sol 20", while the cartoon animation is informing us (amongst other things) that "Spirit has survived -90 sols past its '90-sol warranty'"!

I guess those who wrote the scripts for those did not think the rovers (and their webpages) would still be around. 

The Malin Space Science Systems website http://www.msss.com/press_releases/msls … x.html]has some interesting additional details on the three camera systems Malin & co are producing for the MSL. One of those details: that movie-maker James Cameron will be a co-investigator of the MastCam one! (Do you suppose this is his way of making good on those Mars movies he said he'd make after Titanic?)

http://www.astrobio.net/news/modules.ph … trobiology Magazine has some info on a proposed JIMO-style Neptune Orbiter (with three Neptune atmospheric probes & two Triton landers). The catch: we may have to wait 30 years before it actually reaches Neptune! (Although it is "expected to launch between 2016 and 2018" it will not arrive until about 2035.)

IMHO it probably *will* be later now that the Europa Orbiter's been scrapped in favour of JIMO. If JIMO succeeds a Neptune Orbiter will probably use the same technology, which is good news in the sense that it would allow a big heavy probe with all sorts of bells & whistles (like Triton landers and Neptune atmospheric probes). The downside is that other outer solar system orbiter missions will probably be pushed back. I notice that JIMO itself will not be launched until]http://www.jpl.nasa.gov/jimo/mission_launch.cfm]"until 2015 or later". If future orbiter missions into the outer solar system do use the JIMO technology they are not going to be launched until at least until after JIMO launches; and maybe a long while after if that technology must first prove itself on the prototype.

Not necessarily.

Quite apart from the obvious power problem (out at Triton, solar cells are going to be pretty much useless), there is another more serious issue.

A few nights ago I was watching a video I'd taped years ago of an (excellent) British documentary of the Voyager 2 encounter with Neptune in 1989.  While I was watching that documentary it occurred to me that any machine from Earth which lands on Triton may have to deal with a major problem.

As the documentary explained, scientists believe that Triton is covered by a thin layer (a metre or so) of nitrogen ice, a layer that exists at a temperature only a handful of degrees above absolute zero.

Now imagine you landed a MER-type rover on top of that ice. The very wheels of that rover are going to be dozens if not hundreds of degrees warmer than that supercooled nitrogen. As a result they are going to start melting that ice like a hot knife into butter (to borrow a metaphor from the documentary). As it melts the ice, the rover as a whole will probably start sinking into the Tritonian surface. As it sinks, it going to find itself surrounded (if not overwhelming) by melting slush, which in turn is going to start cooling the rover. If it cools it far enough, the nitrogen is going to refreeze, trapping the vehicle.

The rover might  pump out more heat to try to prevent such a fate, but doing so would merely make the rover sink further, eventually reaching a point where all that frozen nitrogen is going to wind up cooling the rover to the point where it will "kill" it, much as too much Martian cold can kill Spirit & Opportunity.

In other words, landing on that nitrogen ice would in effect be like landing on a kind of quicksand.

As far as I can see the only real way to stop a vehicle getting caught by that kind of trap (apart from some kind of aerial vehicle) would be to try to keep to rocky surfaces or to have all parts of the rover which come into contact with Triton's surface supercooled to much the same temperature as the nitrogen ice they are standing on so as to prevent it sinking in the first place. In turn, those supercooled parts would (of course) have to be insulated in some fashion from the rest of the vehicle.

All that is likely to increase the weight, size, & complexity of such a machine.

(Not that it probably won't get worse. That layer of nitrogen may mean it may never be possible, for example, for a human astronaut to stand on the surface of Triton.)

On the one hand I wish they could have sent the Europa Orbiter. JIMO might send back more science, but the Europa Orbiter would have got there sooner, allowing results to get back sooner, which in turn might have allowed serious planning to begin on the next stage (and the one  I imagine many people would probably be more excited about): burrowing into the ice of Europa to investigate the putative ocean there. Now that the Europa Orbiter is dead and JIMO is the great white hope, I don't expect to see any such mission launch before 2020 at the earliest.

On the other hand, JIMO would certainly be a far more ambitious mission. I notice, for example, that the science definition team are pushing hard for it to carry a "Europa Surface Science Package", referring to it as a "critical element of the baseline mission", which I've been kinda hoping would be included. It would (hopefully) also open the way for similiar missions to the other gas giants.

Two other sites throw a little light on the matter:

(http://www.onlypunjab.com/fullstory904- … punjab.com)

(http://www.thespacereview.com/article/2 … review.com)

Whether Rutan is the one with the mistaken impression about New Horizons or merely a few reporters is unclear.

Just saw this microscopic image from Spirit's sol 240. I do hope that's not a http://marsrovers.jpl.nasa.gov/gallery/ … .JPG]piece of the rover lying there in the Martian dirt!

For those who are interested, the August 2004 edition of the journal _Science_ is out (albeit you probably won't find it on newstands). It is (largely) devoted to papers on Spirit's first 90 sols at Gusev crater.

For those with access (dunno how much can be viewed by those without), the issue is also available online at:

http://www.sciencemag.org]http://www.sciencemag.org

Here's a pic of a rather http://marsrovers.jpl.nasa.gov/gallery/ … ous-shaped rock half-buried in the dust of a fissure (a little above centre-left) at the Meridani site. From pic's angle looks almost like a half-tipped-over fried egg. (Or a toy flying saucer.  :-)

Having your own space agency is all very well, but how will that help unless the British government is not prepared to fund it properly and for the long-term?

Certainly "full blown manned missions" would require the expenditure of the sort of serious money Britain does not seem to want to spend on space (judging from the amount it was prepared to spend on Beagle 2).

If all such an agency mainly ends up does end up doing is participating in ESA projects and a funding a handful of low-cost studies and talk-shops then sooner or later somebody out to save a buck is going to ask why Britain needs its own separate space agency at all.

For a better look at the white thingy, check out http://marsrovers.jpl.nasa.gov/gallery/ … 1.JPG]this image. That could almost be a Martian tent! 

However, there is  http://marsrovers.jpl.nasa.gov/gallery/ … PG]another which is probably more revealing. This one makes the thing look more like a camera glitch. (The last time I saw something not unlike that was when the Galileo probe took a shot of an Io lava fountain that was too bright for the electronics of the probe's camera.)