One of the things we’re working on with our global Mars atmosphere model (MarsWRF) is predicting martian dust storms. Dust storms on Mars can range anywhere in size from small local events a few kilometers in scale to events that fill the entire global atmosphere. In modeling them, we’re hoping to understand how they develop. The processes we consider in the model are: 1) dust lifting, 2) dust transport and mixing by the winds, 3) dust settling to the surface under gravity, and 4) the heating of the atmosphere as dust absorbs sunlight and interacts with thermal infrared radiation from the planet and atmosphere.
We just published a paper in the journal Icarus (Sept-Oct 2012 edition) on the influence of resolution on global modeling of the Martian atmosphere. The study uses a general circulation model – or global climate model (GCM – take your pick on what the acronym stands for, the definition seems to have changed over time and no one can now agree! ) – this is the same kind of model used to look at things like the large scale atmospheric circulation and climate change on the Earth. In this study, we took a look at how the simulation of the Martian atmosphere changes as the grid spacing (effectively the resolution) changes from about 5 degrees (about 300 km) down to 0.5 degrees (about 30 km). There were a number of interesting findings, including significant changes in the middle and upper atmosphere circulation. In the figure below, surface wind patterns and wind stresses are shown for a 2 degree and a 0.5 degree case. Wind stress is the lateral force (per unit area) felt by the surface due to wind blowing across it. When this stress becomes high enough, sand can get kicked around on the surface and dust lifted. Being a desert planet, dust storms of all sizes play across the Martian surface. A major science question revolves around how these storms form and grow. The resolution test was designed to examine whether there were significant changes in total wind stress with resolution (no) and whether the patterns changed significantly (yes – peak stresses became much sharper and more focused on topography). The paper can be found here in our (Ashima Research’s) publications section.
Here’s a quick image of our miniQuad test article during a static test of the vehicle thrust. We don’t consider the miniQuad a real flight vehicle – it’s a testbed that uses our new modular and integrated ESC / battery / motor (“wing”) boards we showed a couple of months ago; and it drives them with the old centre board from the bigger quad that you can see flying in several of our prior posts. The rest of the structure on this “Franken-vehicle” is the harness needed to couple the old and the new for this temporary test system. The testbed is being used to conduct functional tests and thrust measurements using the new “wing” boards. The next step in the vehicle development will be the new centre boards.
Today we took delivery of our new 3D printer. Bigger print volume, two nozzles. Here come some ESC / battery holders and a hexcopter cover…
So far we had been using a nice little CMOS low-light camera on the quad. However, we also wanted to test and demonstrate the system with a popular off-the-shelf camera. The advantage in this case being that we ought to be able to obtain a live feed at moderate quality over a wifi link (as with the prior system) but also an HD video when we landed and popped out an SD card. Voilà: a quad flight demonstration with a GoPro Hero2. We’ve embedded snippets from our filming from the ground (including some shots of our live feed monitor) on the HD video we recovered from the GoPro after flight. Make sure to crank this sucker to 1080p on the youtube settings and run fullscreen else it won’t seem any different from the earlier videos! (on the flip side, the sound is from the on board, might want to crank that down – these motors really aren’t *that* loud… unless you’re like 10cm from them)
We are updating our Mars panorama WebGL tool to include the latest Mars Science Laboratory (MSL) “Curiosity” panoramas as they get created at JPL. The display system demonstrates some capabilities of WebGL – an API that allows browser-based systems, via HTML5, to directly exploit the power of your system’s graphics card.
Ashima Arts is developing a range of technologies to allow developers to use WebGL more effectively and efficiently. Check out our upcoming presentation at the 2012 OCaml Users and Developers Workshop (Sept. 14, 2012 in Copenhagen, Denmark). The usual caveat is in place that the display tool will not work for some combinations of browsers and graphics cards (and as usual, friends don’t ever let friends use Internet Explorer). In case this doesn’t work on your machine, here’s a youtube video showing the demo running on one of our Mac laptops.
This is a flight test from today with the copter flight system maintaining a “true north” control setting while spinning. The idea is the vehicle may likely need to spin for scanning a scene – yet still needs to properly respond to flight commands such as “fly north.” This is from a sequence of flight software tests of this nature:
Real short blog post. We’re on Mars!
Today will bring the moment of truth for the Mars Science Laboratory, aka Curiosity – at about 10:30pm Pacific time. Ashima Research is a part of the science team for the Rover Environmental Monitoring Station (REMS) – the rover’s weather station. You can follow along with what’s happening via Ashima Research’s Mars Weather website. Fingers crossed!
Our first prototype printed boards for the hex flier motor controllers / vehicle legs just came in. This is the first batch of printed hardware we’ve had in a while – a much more common experience several years ago when we were working on a prototype Mars weather station. More about these when they get populated and tested…