1 00:00:07,220 --> 00:00:05,660 my name is Shaun Hegarty 2 00:00:08,930 --> 00:00:07,230 a little bill the engineer on the Mars 3 00:00:10,190 --> 00:00:08,940 Science Laboratory so as you can see 4 00:00:12,350 --> 00:00:10,200 down there we just recently completed 5 00:00:14,539 --> 00:00:12,360 two testing the wheels and suspension 6 00:00:16,670 --> 00:00:14,549 system on the flight rover now the 7 00:00:18,170 --> 00:00:16,680 mobility system might look familiar 8 00:00:20,599 --> 00:00:18,180 it's a classic rocker-bogie suspension 9 00:00:22,790 --> 00:00:20,609 system we've used the last two 10 00:00:24,320 --> 00:00:22,800 generations of mars rovers and it does a 11 00:00:26,330 --> 00:00:24,330 lot of thing that actually the mobility 12 00:00:28,070 --> 00:00:26,340 system hasn't done in the past so for 13 00:00:30,320 --> 00:00:28,080 this mission mobility system not only 14 00:00:32,030 --> 00:00:30,330 drives the rover around it's also the 15 00:00:33,410 --> 00:00:32,040 landing gear the wheels are actually the 16 00:00:36,530 --> 00:00:33,420 first thing that make contact with the 17 00:00:37,700 --> 00:00:36,540 surface of Mars now just about 18 00:00:40,130 --> 00:00:37,710 everything you see on the mobility 19 00:00:42,080 --> 00:00:40,140 system looks black but that doesn't mean 20 00:00:43,369 --> 00:00:42,090 it's all the same material the tubes the 21 00:00:45,500 --> 00:00:43,379 suspension arms coming down to the 22 00:00:48,020 --> 00:00:45,510 wheels those are all titanium the tires 23 00:00:50,150 --> 00:00:48,030 themselves those are aluminum the shell 24 00:00:51,889 --> 00:00:50,160 on those tires is actually a piece of 25 00:00:53,420 --> 00:00:51,899 machined aluminum as about 30 26 00:00:55,010 --> 00:00:53,430 thousandths of an inch thick that's 27 00:00:57,439 --> 00:00:55,020 about the thickness of seven pieces of 28 00:00:59,869 --> 00:00:57,449 paper and when they're that thin 29 00:01:01,790 --> 00:00:59,879 it makes them actually soft so they 30 00:01:03,680 --> 00:01:01,800 behave in much the way that a rubber 31 00:01:06,440 --> 00:01:03,690 tire would behave and give you that 32 00:01:08,300 --> 00:01:06,450 springy load for it for landing for 33 00:01:10,130 --> 00:01:08,310 driving over rocks this test was sort of 34 00:01:11,570 --> 00:01:10,140 an obstacle course for the rover is we 35 00:01:13,520 --> 00:01:11,580 have to drive over obstacles with 36 00:01:15,080 --> 00:01:13,530 certain Heights and those correspond to 37 00:01:16,100 --> 00:01:15,090 rocks of certain Heights that we expect 38 00:01:18,020 --> 00:01:16,110 to see on the surface of Mars 39 00:01:19,670 --> 00:01:18,030 so those ramps were mimicking those 40 00:01:21,140 --> 00:01:19,680 rocks to make sure that we can actually 41 00:01:22,999 --> 00:01:21,150 drive over them and get to assignments 42 00:01:25,580 --> 00:01:23,009 now you notice that it's six wheel drive 43 00:01:27,830 --> 00:01:25,590 and all four corner wheels steer now 44 00:01:29,690 --> 00:01:27,840 those wheels can steer plus or minus 90 45 00:01:31,819 --> 00:01:29,700 degrees and what that allows you to do 46 00:01:34,760 --> 00:01:31,829 is actually position the wheels kind of 47 00:01:36,649 --> 00:01:34,770 toe in and turn the rover in place and 48 00:01:39,050 --> 00:01:36,659 it makes it a very maneuverable platform 49 00:01:40,760 --> 00:01:39,060 the position itself for science now 50 00:01:43,460 --> 00:01:40,770 Hawaii what you saw in that test was 51 00:01:45,410 --> 00:01:43,470 actually top speed of the rover about 4 52 00:01:47,539 --> 00:01:45,420 centimeters per second or to put another 53 00:01:49,580 --> 00:01:47,549 way it takes about 40 minutes to go the 54 00:01:51,830 --> 00:01:49,590 length of a football field we want to go 55 00:01:52,999 --> 00:01:51,840 slow because when you are 50 million 56 00:01:55,100 --> 00:01:53,009 miles away from the nearest service 57 00:01:56,899 --> 00:01:55,110 station it's ok to go a little slow and 58 00:01:58,160 --> 00:01:56,909 be a little careful my name is Shaun