now, earlier in the programme, we'd met back up with gav, from the slow mo guys, to film a rocket engine test at 80 times slow motion. that's 2,000 frames per second. and here's how we got on. we're in a nice, flat part of texas. seems a sensible place to do a rocket test, doesn't it? and as you walk along, you start to get hints that, yeah, there's something going on here. lots of compressed nitrogen in canisters. then you get to this shed. there's a massive canister of something there, some more serious and complicated—looking pipes, some dials. and you start to get the impression, yeah, the engine must be quite close by now. and then, oh, actually, no. this is actually the engine that we've been walking past. they've attached it to a building, so at least it's not going to go anywhere. and what's also interesting is how we have to film this test. we have to put our cameras