Friday, September 01, 2006
The Moon Takes Its Lumps
On September 3, the unmanned ESA spacecraft SMART-1 will be deliberately crashed into the Moon. SMART-1 is the first European spacecraft to reach and orbit the Moon, and it's especially interesting because it did so with solar-electric power, using low-thrust ion engines. You can read more about the spacecraft and its successful mission here.
As is often the case, an Orbiter add-on builder has provided the means to simulate the spacecraft and mission. "BrianJ" released a model of the spacecraft along with a scenario that starts 7 hours before impact on September 3. Read more about it on the Orbiter forum.
This is cool, but even cooler in my opinion is the "accessory" he built for this mission, a 3D mesh and texture set for the entire surface of the Moon. Orbiter's default surface textures are basically paint, photographic images mapped onto a smooth sphere. These look great from a long distance, but are often not so convincing closer in (though it depends on various factors). You can use 3D "meshes" for surface relief as well as for spacecraft and bases, but surface relief is usually confined to a small detail area, such as Vallis Dao on Mars. In this case, Brian used height map data to create a 3D mesh that's draped over the whole surface, along with textures to properly paint the 3D mesh (these are big textures and he warns that older graphic cards may not handle the large amount of data).
I like the effect of this lumpy Moon - instead of a razor sharp horizon from low to medium lunar orbit, you see bumps due to craters and mountains, more reminiscent of Apollo photos from lunar orbit. There are a few minor problems (e.g., surface bases are under the mesh), but for a quick experimental effort, this is quite good. More pix on Flickr.
September 3 Update: News reports indicate that SMART-1 crashed into the Moon as planned at 1:42 pm EDT.