Tuesday, July 06, 2010
Here's a really interesting video from four days ago:
This is a prototype lander that was created to demonstrate the ability to land on lunar terrain without needing any guidance from mission control back home. If you go directly to the video's page here you can also read the transcript (or automatically translate it into another language) and the functions built into this lander are quite impressive: it is capable of...well, I'll let the transcript explain:
So, we've got 3 sensors on board. We have a GPS, which is our truth sensor. That's what we're going to use to compare the results from the rest of the, umm, system to. We won't have GPS at the moon, we get it for free here. We also have on the far side of the vehicle a laser altimeter. It fires a near infrared laser beam. It hits whatever's in front of it and comes back. A little clock measures the time difference between the firing and receiving, divides by the speed of light and it says that's how far away whatever in front of you is. So that's one of the things we will have on the moon. Then we also have in the middle of the GENIE, there's this thing that looks like a coffee can, and that's a inertial measurement unit. It measures accelerations in 3 axes, and it also measures rotations. So when we put the GENIE out on the pad, the first thing we did is we turned it on, the inertial measurement unit is sensitive enough that it can actually sense the rotation of the earth. So it knew which way the north pole was basically. It can also sense gravity.
Note how easy it is to land a craft on the Moon compared to a location like Mars, as the atmosphere introduces a whole new level of difficulty. In addition to this we still haven't figured out how to land a craft containing humans on the planet, given that 1) the atmosphere is thick enough that a heat shield is required, but 2) the atmosphere is still too thin to slow a craft down to the extent our atmosphere does, and 3) a craft containing humans can only be subjected to so many g's before they get smushed, a problem that doesn't exist with a rover or other robot.