The ExoMars Spacecraft Approaches the Red Planet(nytimes.com)
nytimes.com
The ExoMars Spacecraft Approaches the Red Planet
http://www.nytimes.com/interactive/2016/10/16/science/space/mars-exomars-spacecraft-arrives.html?rref=collection%2Fsectioncollection%2Fscience&action=click&contentCollection=science®ion=rank&module=package&version=highlights&contentPlacement=1&pgtype=sectionfront
31 comments
Am I missing something here? My calculator has solar panels! Why doesn't this thing have them too?
System design derives from mission and project design. The lander is a demonstrator for a future rover, they had (for this particular mission) no intention to manage and support a lander for a substantial period of time. They basically bolted a few science instruments that fit the weight and power budget on the frame – but they are in no means essential to the mission.
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solar panels in mars did not turn out to be very efficient. After couple of days, all those panels get covered with dust, and you need a wiper to clean that up, which will again drain a lots of battery power.
False. Most probes on Mars are powered by solar. E.g. Opportunity is still going strong (https://en.wikipedia.org/wiki/Opportunity_(rover)). Other upcoming landers are also solar powered.
Mission design dictates whether solar power is enough to satisfy your requirements. For Curiosity, they wanted to go faster and longer with more power than solar would have given them considering the size of the rover (i.e. not much space to put solar panels on, which yields in lower power available).
Mission design dictates whether solar power is enough to satisfy your requirements. For Curiosity, they wanted to go faster and longer with more power than solar would have given them considering the size of the rover (i.e. not much space to put solar panels on, which yields in lower power available).
> The lander will attempt to touch down on Meridiani Planum, near the site where NASA’s Opportunity rover landed in 2004. It will study the local environment for several days before running out of battery power.
How sad.
How sad.
Well, the Europeans refuse to consider using RTGs (scary radiation!), which pretty much cripples any attempts to make a non-trivial rover.
The lander is Russian, this is a joint mission in preparation for the rover mission.
The Russians have never had good luck with Mars all their probes failed or crashed.
This one isn't a classical probe this is effectively as identical to the rover lander just without the rover as they could get, with a few experiments stuck to it since there was room and they were going there any how.
A good analogy would be if NASA would have sent a skycrane probe that would lower a curiosity rover sized weight onto the surface of mars to make sure that it works.
Since the final lander itself won't have a power source or unfolding solar panels there is no point of adding them to this demonstrator since you are increasing the complexity of the system which is counter productive to the goals of the mission.
The Russians have never had good luck with Mars all their probes failed or crashed.
This one isn't a classical probe this is effectively as identical to the rover lander just without the rover as they could get, with a few experiments stuck to it since there was room and they were going there any how.
A good analogy would be if NASA would have sent a skycrane probe that would lower a curiosity rover sized weight onto the surface of mars to make sure that it works.
Since the final lander itself won't have a power source or unfolding solar panels there is no point of adding them to this demonstrator since you are increasing the complexity of the system which is counter productive to the goals of the mission.
The lander is not Russian. It was designed by the good people at Thales Alenia Space. Russia provided launch services and a few experiments for the TGO.
The lander is Russian AFIAK https://en.wikipedia.org/wiki/ExoMars the rover is going to be built by ESA https://en.wikipedia.org/wiki/ExoMars_(rover)
The Schiaparelli lander landing imminently is not Russian, but the next ExoMars lander is supposed to be. See the same cited reference.
https://en.wikipedia.org/wiki/Schiaparelli_EDM_lander
"It was built in Italy"
https://en.wikipedia.org/wiki/Schiaparelli_EDM_lander
"It was built in Italy"
From what I heard around the Philae landing, it's not that ESA wouldn't like RTGs - it's that due to Cold War and all the politics around it, Europe never developed RTG technology, and it's still politics that block it. The issues are not about "scary radiation", but about "zomg nukes!".
The Ulysses probe was powered with an RTG and it was an ESA/NASA joint mission, same goes for the Cassini probe.
Philae didn't use an RTG because it was a tiny 21KG spacecraft and RTGs are heavy and big.
When the RTG is bigger than you spacecraft you can't really use it ;) https://upload.wikimedia.org/wikipedia/commons/4/46/New_Hori...
That said in general RTGs are not that common, they are really only used when solar is completely out of the question.
Philae didn't use an RTG because it was a tiny 21KG spacecraft and RTGs are heavy and big.
When the RTG is bigger than you spacecraft you can't really use it ;) https://upload.wikimedia.org/wikipedia/commons/4/46/New_Hori...
That said in general RTGs are not that common, they are really only used when solar is completely out of the question.
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The Spirit and Opportunity rovers are both solar powered and weigh 400 lbs, so I think they could have made it solar powered. That said, they really should allow RTGs.
The reason they give is as follows:
Schiaparelli is primarily designed as an entry, descent and landing technology demonstrator, and therefore does not carry solar panels or radioisotope thermal generators to supply power over an extended period. It is only intended to survive on the surface for a few days powered by batteries.
http://m.esa.int/Our_Activities/Space_Science/ExoMars/ExoMar...
The reason they give is as follows:
Schiaparelli is primarily designed as an entry, descent and landing technology demonstrator, and therefore does not carry solar panels or radioisotope thermal generators to supply power over an extended period. It is only intended to survive on the surface for a few days powered by batteries.
http://m.esa.int/Our_Activities/Space_Science/ExoMars/ExoMar...
> In addition, a simple camera (DECA) will take 15 monochrome images during the descent of Schiaparelli to provide engineering insight into the landing process and to identify help the actual landing location. However, it is not designed to take images from the surface.
Well, if they're not even going to try to take pictures from the surface, I guess it doesn't make much sense to bother with solar panels or an RTG...
Well, if they're not even going to try to take pictures from the surface, I guess it doesn't make much sense to bother with solar panels or an RTG...
From what I've read, that's not true - esa doesn't have a suitable supply of plutonium 238, and is developing equipment using an alternative radioactive source (americium).
https://www.quora.com/How-does-ESA-plan-to-power-its-future-...
http://www.space.com/692-esa-chief-europe-space-nuclear-powe...
https://www.quora.com/How-does-ESA-plan-to-power-its-future-...
http://www.space.com/692-esa-chief-europe-space-nuclear-powe...
> esa doesn't have a suitable supply of plutonium 238
In fact, the link you give explicitly mentions safety and political risks in addition to availability.
> not only are there sourcing issues with Pu-238 (reserves are running low and production is not high enough), there are safety concerns and political issues related with its use in RTGs.
Furthermore, it's not an accident they don't have any Pu-238. The lack of it is deeply connected to the general fear of doing anything radioactive, and hence no effort to develop production capability.
It's clear ESA is being forced to consider nuclear power sources simply because it's almost impossible to fulfill certain missions without them. But the fact that they are willing to consider it when absolutely necessary does not mean they haven't seriously scaled down mission potential in the past by using solar power.
In fact, the link you give explicitly mentions safety and political risks in addition to availability.
> not only are there sourcing issues with Pu-238 (reserves are running low and production is not high enough), there are safety concerns and political issues related with its use in RTGs.
Furthermore, it's not an accident they don't have any Pu-238. The lack of it is deeply connected to the general fear of doing anything radioactive, and hence no effort to develop production capability.
It's clear ESA is being forced to consider nuclear power sources simply because it's almost impossible to fulfill certain missions without them. But the fact that they are willing to consider it when absolutely necessary does not mean they haven't seriously scaled down mission potential in the past by using solar power.
No one but the Russians really does, the US now started production of P238 again.
Europe can produce P238 if it wanted too, it has one of the highest nuclear material production capabilities globally.
Europe can produce P238 if it wanted too, it has one of the highest nuclear material production capabilities globally.
As far as I know even the US only has a very limited supply.
True, and production has been restarted. [1]
[1] http://www.space.com/32890-nuclear-fuel-spacecraft-productio...
[1] http://www.space.com/32890-nuclear-fuel-spacecraft-productio...
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There's an especially interesting picture in the article:
https://static01.nyt.com/newsgraphics/2016/10/16/exomars-lan...
Obviously anything about Mars is interesting, but this picture has a peculiar property. Look at the picture and imagine that the light is coming from the upper right -- when you do that, the crater becomes a dome. If instead you imagine that the light is coming from the lower left, it becomes a crater again.
I've seen this in other ambiguous terrain photographs, but this picture easily supports the ambiguity.
https://static01.nyt.com/newsgraphics/2016/10/16/exomars-lan...
Obviously anything about Mars is interesting, but this picture has a peculiar property. Look at the picture and imagine that the light is coming from the upper right -- when you do that, the crater becomes a dome. If instead you imagine that the light is coming from the lower left, it becomes a crater again.
I've seen this in other ambiguous terrain photographs, but this picture easily supports the ambiguity.
I can't get it to look like a crater, no matter where I pretend the light's coming from. It's always a dome for me.
Try flipping the image. Or turning off the light: if you have actual light coming from above you can't imagine it is coming from below.
I don't see what's peculiar about that. I've experienced this phenomenon with objects right in front of me when I wasn't sure what I was looking at. One time while riding a motorbike on a wet sand dune a colour gradient appear to be a slight decline, but it was actually a sharp incline, resulting in a rather sudden change of velocity and me headbutting the handlebars.
There are countless other illusions we could talk about too, none of which seem all that peculiar to me, even if they were to be observed on another plant.
There are countless other illusions we could talk about too, none of which seem all that peculiar to me, even if they were to be observed on another plant.
there is brittle base underneath the lander, when it drops that base breaks into pieces to absorb the shock, interesting.