WEBVTT - Time to Kick Some Asteroid 0:00:04.240 --> 0:00:07.240 Welcome to tech Stuff, a production of I Heart Radios, 0:00:07.320 --> 0:00:13.800 How Stuff Works. Hey there, and welcome to tech Stuff. 0:00:13.840 --> 0:00:16.960 I'm your host Jonathan Strickland. I'm an executive producer with 0:00:17.000 --> 0:00:19.079 how Stuff Rex and I Heart Radio and I love 0:00:19.160 --> 0:00:23.600 all things tech. And On June twelve, two thousand nineteen, 0:00:24.040 --> 0:00:29.720 a small spacecraft called Osiris Rex set a new out 0:00:29.760 --> 0:00:33.479 of this world record. That record was for entering the 0:00:33.560 --> 0:00:39.120 closest orbit around a small planetary body, and the record 0:00:39.200 --> 0:00:44.600 was previously held by well Osirius Rex, but now it 0:00:44.760 --> 0:00:49.640 was really extra super close, like six d eight meters 0:00:49.760 --> 0:00:55.120 or less than unred feet close. The planetary body is 0:00:55.160 --> 0:00:59.840 the asteroid Bnu b e nn you. It will eventually 0:01:00.320 --> 0:01:03.040 get even closer to Benu. The plan is for the 0:01:03.080 --> 0:01:06.960 spacecraft to make contact with the asteroid for the purposes 0:01:07.000 --> 0:01:10.280 of collecting a sample, then it will begin its journey 0:01:10.280 --> 0:01:13.480 back to Earth. Right now, it's taking a series of 0:01:13.520 --> 0:01:16.479 images of the asteroid, partly so that a team back 0:01:16.480 --> 0:01:19.759 here on Earth can evaluate the best spot to make 0:01:19.840 --> 0:01:23.160 that point of contact. It turns out Benu is a 0:01:23.160 --> 0:01:27.440 bit more bumpy than we anticipated, so finding a spot 0:01:27.440 --> 0:01:30.080 that will be suitable for a Cyrus Rex and given 0:01:30.120 --> 0:01:33.000 the best chance for a successful mission is no small 0:01:33.040 --> 0:01:37.440 task in of itself. That's the short version of the story. 0:01:37.680 --> 0:01:40.120 But today I want to talk more about the mission, 0:01:40.480 --> 0:01:44.360 the technology, and the long term plan to mine asteroids 0:01:44.400 --> 0:01:47.840 as part of the overall strategy for deep space operations. 0:01:48.400 --> 0:01:52.000 And this isn't the first time I've talked about asteroid mining. 0:01:52.200 --> 0:01:55.240 Way back in June two thousand twelve, my co host 0:01:55.320 --> 0:01:58.840 Chris Palette and I talked about this idea, and we 0:01:58.960 --> 0:02:03.920 also replayed that episode in May two thousand nineteen. So 0:02:04.240 --> 0:02:07.160 some of this might sound a bit familiar since I'll 0:02:07.160 --> 0:02:10.919 be tackling a similar subject, but it's well overdue for 0:02:10.960 --> 0:02:14.200 a follow up, So let's begin with a high level 0:02:14.280 --> 0:02:17.520 view of what asteroid mining is all about. There are 0:02:17.520 --> 0:02:21.160 many different types of asteroids out there. They formed over 0:02:21.320 --> 0:02:25.480 billions of years from the same proto planetary dust that 0:02:25.680 --> 0:02:29.320 orbited the Sun and eventually formed the planets and moons 0:02:29.360 --> 0:02:32.919 of our Solar System. Some of those asteroids were formed 0:02:33.040 --> 0:02:35.760 just by particles of dust crashing into one another and 0:02:35.800 --> 0:02:40.000 forming larger particles eventually growing into small rocks, and then 0:02:40.680 --> 0:02:46.000 you know, less small rocks into big honking rocks. Some 0:02:46.160 --> 0:02:49.880 formed after other planetary bodies had collisions and ejected matter 0:02:50.040 --> 0:02:54.040 out into space as a result. But in general, you've 0:02:54.080 --> 0:02:57.520 got a bunch of rocky stuff floating around the Solar System. 0:02:57.560 --> 0:02:59.520 And I said there are many different types of asteroids, 0:03:00.040 --> 0:03:03.800 and that is true, but it's also a bit complicated, 0:03:04.280 --> 0:03:06.400 and that's because there's actually more than one way to 0:03:06.480 --> 0:03:11.560 classify asteroids. You could classify them by their location. For example, 0:03:12.120 --> 0:03:15.120 most of the asteroids we know about are in orbit 0:03:15.160 --> 0:03:18.799 in what we call the asteroid belt appropriately enough, and 0:03:18.919 --> 0:03:22.280 that's between the orbits of Mars and Jubiter. Now there 0:03:22.320 --> 0:03:26.600 are other asteroids called near Earth asteroids, which, as the 0:03:26.680 --> 0:03:30.200 name suggests, have orbits that take them close to the Earth. 0:03:30.760 --> 0:03:34.600 These can sometimes pose what is called a problem, And 0:03:34.639 --> 0:03:37.360 by a problem, I mean that a sufficiently large enough 0:03:37.360 --> 0:03:41.440 asteroid could cause global devastation should collide with Earth, you know, 0:03:41.720 --> 0:03:46.000 fun times. But we can also classify asteroids based on 0:03:46.080 --> 0:03:49.440 what they are made out of. There are three major 0:03:49.520 --> 0:03:53.160 classes of asteroids. The most common type that we know 0:03:53.200 --> 0:03:57.600 about is C type or chondrite asteroids. These are made 0:03:57.680 --> 0:04:01.400 up of silicate rocks and clay and have some carbonaceous 0:04:01.400 --> 0:04:04.280 material in them. They are in the outer regions of 0:04:04.320 --> 0:04:08.240 the asteroid belt. They are dark and thus hard to spot, 0:04:08.440 --> 0:04:13.080 but they make up about of all known asteroids. Then 0:04:13.120 --> 0:04:18.919 you've got S type or silicaceous asteroids or stony asteroids. 0:04:18.960 --> 0:04:23.320 They consist of nickel, iron, and silicate materials primarily, and 0:04:23.360 --> 0:04:26.200 they tend to be brighter than C type asteroids, and 0:04:26.240 --> 0:04:29.760 most of those inhabit the inner asteroid belt. Then you've 0:04:29.760 --> 0:04:34.320 got M type or metallic asteroids that are made primarily 0:04:34.360 --> 0:04:36.839 from nickel and iron. They make up about eight percent 0:04:37.000 --> 0:04:39.920 of all known asteroids, and they're mostly in the middle 0:04:40.040 --> 0:04:43.520 region of the asteroid belt, and they also are brighter 0:04:43.560 --> 0:04:46.599 than C type asteroids. Now those are the major types, 0:04:46.640 --> 0:04:51.080 but they're also A type asteroids, B type, D type asteroids, 0:04:51.080 --> 0:04:55.680 and so on. These represent rare or extremely rare types 0:04:55.720 --> 0:04:58.920 of asteroids, and some are considered subtypes of the more 0:04:58.960 --> 0:05:03.279 common variants. Some are kind of a split between different 0:05:03.320 --> 0:05:07.040 major types. They're different enough to justify a subclassification. There's 0:05:07.040 --> 0:05:11.719 somewhere in between the major versions. Benu, the asteroid that 0:05:11.800 --> 0:05:17.760 osiris rex orbits, is one of these smaller subclassifications. It's 0:05:17.800 --> 0:05:22.200 technically a B type asteroid. B type asteroids are a 0:05:22.200 --> 0:05:26.240 subcategory of C type asteroids, which, as I just mentioned, 0:05:26.279 --> 0:05:29.120 make up the vast majority of the known asteroids that 0:05:29.160 --> 0:05:32.159 we've observed so far. That's one of the reasons the 0:05:32.200 --> 0:05:35.520 Osiris REX team selected Benu, But I'll get back to that. 0:05:36.200 --> 0:05:41.480 So asteroid mining, that's the name suggests, involves harvesting resources 0:05:41.520 --> 0:05:46.520 from asteroids. Those resources could include volatile substances like trapped 0:05:46.560 --> 0:05:50.720 gases within the molecular structure of the asteroid. Metals are 0:05:50.720 --> 0:05:54.520 another possible resource, and asteroid mining could go after stuff 0:05:54.520 --> 0:05:58.400 like platinum. Water is another big resource as it could 0:05:58.400 --> 0:06:01.799 be used to produce rocket fuel, among other things. Most 0:06:01.880 --> 0:06:07.000 deep space exploration strategies include some sort of asteroid mining component, 0:06:07.360 --> 0:06:09.440 as it would mean making use of materials that are 0:06:09.480 --> 0:06:12.839 already out in space to support the mission, which reduces 0:06:12.880 --> 0:06:15.160 the need to carry more stuff with you when you're 0:06:15.240 --> 0:06:18.960 launching from Earth. In fact, the concept of asteroid mining 0:06:19.320 --> 0:06:21.640 is all about being able to leverage stuff out in 0:06:21.760 --> 0:06:26.400 space while we're exploring or colonizing space. It's not about 0:06:26.480 --> 0:06:30.680 bringing resources back to Earth, but rather limiting the resources 0:06:30.720 --> 0:06:34.279 we need need to bring from Earth out into space. 0:06:35.240 --> 0:06:38.320 And that's a big deal. The more massive the payload 0:06:38.680 --> 0:06:41.719 of your spacecraft, the more fuel you need to get 0:06:41.760 --> 0:06:44.919 off the ground, and that could necessitate the design of 0:06:44.960 --> 0:06:48.160 new launch vehicles if the payload you're looking at is 0:06:48.200 --> 0:06:51.360 heavy enough and the fuel itself is really expensive. So 0:06:51.560 --> 0:06:53.640 if you can reduce the amount of fuel you need, 0:06:54.000 --> 0:06:56.920 then you bring down the complexity and the cost of 0:06:56.960 --> 0:07:01.359 a launch. And it's absolutely necessary to do something like 0:07:01.440 --> 0:07:04.200 asteroid mining if we want to send people to places 0:07:04.240 --> 0:07:06.640 like Mars and have them be able to get back again. 0:07:07.279 --> 0:07:09.200 If those who travel to Mars can make use of 0:07:09.240 --> 0:07:12.480 the resources that are actually on the Red planet using 0:07:13.040 --> 0:07:16.280 techniques that we've perfected through asteroid mining, then they can 0:07:16.280 --> 0:07:19.160 do that to produce their own rocket fuel. They can 0:07:19.240 --> 0:07:21.680 manufacture their own fuel they need to return to Earth. 0:07:21.720 --> 0:07:23.560 There would be no need to carry twice as much 0:07:23.560 --> 0:07:28.000 fuel on board to make a round trip. Moreover, harvesting 0:07:28.040 --> 0:07:31.800 resources from asteroids could yield us the materials we need 0:07:31.920 --> 0:07:34.920 to build structures out in space in the first place. 0:07:35.160 --> 0:07:38.720 So instead of launching spacecraft that are carrying components and 0:07:38.840 --> 0:07:42.320 modules that then have to be assemboled in orbit or 0:07:42.360 --> 0:07:45.840 in deep space, we could get the raw materials in 0:07:45.920 --> 0:07:50.720 space itself and establish orbiting manufacturing facilities. Again, we wouldn't 0:07:50.720 --> 0:07:53.200 have to take stuff from Earth incident on into space, 0:07:53.240 --> 0:07:56.120 because we'd be harvesting all that raw materials from other 0:07:56.200 --> 0:07:59.720 bodies in space. Of course, all of this is easy 0:07:59.760 --> 0:08:03.920 to talk about in the hypothetical. Actually building the equipment 0:08:04.120 --> 0:08:07.760 that can make this possible is another matter entirely, and 0:08:07.800 --> 0:08:11.800 while we can be theoretical about it, being practical requires 0:08:11.920 --> 0:08:15.360 a whole lot more work. Oh, cyrus Rex and other 0:08:15.400 --> 0:08:19.320 projects are building the foundation upon which we can actually 0:08:19.360 --> 0:08:24.000 construct this asteroid mining future. So let's talk more about 0:08:24.040 --> 0:08:27.360 that mission and the spacecraft. One thing the team had 0:08:27.400 --> 0:08:30.480 to do must figure out which asteroid to select for 0:08:30.520 --> 0:08:32.560 a mission in the first place. I mean, there are 0:08:32.559 --> 0:08:36.240 millions of them. So how did they settle on Benu 0:08:36.360 --> 0:08:40.400 metaphorically speaking, since the spacecraft has not, as the recording 0:08:40.440 --> 0:08:44.800 of this podcast, literally settled on the asteroid. There are 0:08:44.840 --> 0:08:48.960 more than half a million identified asteroids in the Solar System. 0:08:49.040 --> 0:08:53.160 So why did the team choose Benu? Well, first, they 0:08:53.200 --> 0:08:56.200 decided the asteroid couldn't be too far away that would 0:08:56.240 --> 0:08:59.360 make it impractical to journey there. So the further way 0:08:59.400 --> 0:09:01.520 the asteroid, the harder it is to get there, and 0:09:01.559 --> 0:09:06.000 the potential for failure increases as distance increases. For that reason, 0:09:06.040 --> 0:09:08.520 the team wanted to focus on asteroids that fall into 0:09:08.520 --> 0:09:12.960 the category of near Earth objects or an EOS. Near 0:09:13.200 --> 0:09:16.839 is a relative term, mind you, they're not just a 0:09:16.920 --> 0:09:20.920 quick jaunt away. To be classified as an n EO, 0:09:21.120 --> 0:09:24.400 the object has to be within one point three astronomical 0:09:24.559 --> 0:09:28.880 units from the Sun in their orbits. A single astronomical 0:09:28.960 --> 0:09:31.120 unit is the distance between the Earth and the Sun. 0:09:31.640 --> 0:09:35.079 That means it's about ninety three million miles or around 0:09:35.120 --> 0:09:39.160 a hundred fifty million kilometers. That makes one point three 0:09:39.400 --> 0:09:44.040 astronomical units at around a hundred twenty million, eight hundred 0:09:44.080 --> 0:09:50.079 thousand miles or one four million, five hundred thousand kilometers. So, 0:09:50.480 --> 0:09:53.880 as I said, near is relative, but that's because space 0:09:54.000 --> 0:09:58.920 is really big. An EOS can sometimes pose a potential 0:09:59.000 --> 0:10:02.959 hazard to Earth. These asteroids are in a subcategory called 0:10:03.080 --> 0:10:07.880 potentially hazardous asteroids or p h a's, and ben Wu 0:10:08.040 --> 0:10:12.320 happens to be one of those. There is a small 0:10:12.480 --> 0:10:15.760 chance that the asteroid could collide with Earth late in 0:10:15.800 --> 0:10:19.679 the twenty second century, and by small chance, I mean 0:10:19.720 --> 0:10:22.160 we currently estimate the odds of it happening are less 0:10:22.160 --> 0:10:25.920 than point zero four percent. But still, when you're looking 0:10:25.960 --> 0:10:31.720 at the potential for devastation. Any chance isn't you know great? 0:10:32.480 --> 0:10:35.960 But back to choosing Benu. So Benu was one of 0:10:36.000 --> 0:10:39.000 just a d two asteroids that had an earth like 0:10:39.280 --> 0:10:43.240 orbit with low eccentricity, so it's got a nice stable 0:10:43.320 --> 0:10:47.360 orbit that's pretty similar to Earth's. Out of all the 0:10:48.080 --> 0:10:51.640 thousands there are more than seven thousand year Earth objects 0:10:51.679 --> 0:10:56.359 that they were looking at, only two met that criteria, 0:10:56.520 --> 0:11:00.160 and ben Wu was one of those two. Next, the 0:11:00.200 --> 0:11:03.640 team looked at the size of the remaining candidates, because 0:11:03.800 --> 0:11:08.760 smaller asteroids rotate faster than larger ones, and fast rotating 0:11:08.760 --> 0:11:12.120 asteroids can eject material out into space and that could 0:11:12.200 --> 0:11:15.960 pose a problem for any spacecraft that is flying nearby 0:11:16.080 --> 0:11:18.800 or trying to make contact with that asteroid. So the 0:11:18.840 --> 0:11:21.319 team needed to rule out any asteroids that had a 0:11:21.360 --> 0:11:24.319 diameter smaller than two hundreds because they would probably be 0:11:24.360 --> 0:11:28.600 spinning too quickly. That eliminated all but twenty six of 0:11:28.640 --> 0:11:31.800 the candidates ben who's diameter, by the way, is approximately 0:11:31.880 --> 0:11:35.480 five and we have to use approximations in part because 0:11:35.520 --> 0:11:37.920 Benu is a big, lumpy rock, so it all depends 0:11:38.000 --> 0:11:41.680 upon where you're doing the measuring. Then there's the asteroids composition. 0:11:42.120 --> 0:11:44.760 Out of the twenty six remaining in NEOs that were 0:11:44.840 --> 0:11:48.240 under consideration, not much was known about fourteen of them, 0:11:48.320 --> 0:11:52.120 so those were out. Out of the twelve remaining in eos, 0:11:52.160 --> 0:11:54.760 only five are known to be rich in carbon and 0:11:54.800 --> 0:11:58.760 other materials like volatiles, and therefore they have the potential 0:11:58.840 --> 0:12:02.040 to have or anic materials sort of the building blocks 0:12:02.080 --> 0:12:06.840 of life, not necessarily any proof of life forms on 0:12:06.880 --> 0:12:10.960 the asteroid itself, but rather the basic components that together 0:12:11.200 --> 0:12:15.800 could form a life. And so Benu and four other 0:12:16.240 --> 0:12:18.880 asteroids were left on the list, and the team eventually 0:12:18.960 --> 0:12:22.080 chose Benu from those few remaining and eos that were 0:12:22.120 --> 0:12:26.200 under consideration. To complete a full orbit, it takes Bnu 0:12:26.280 --> 0:12:29.760 about four hundred thirty six Earth days to go around 0:12:29.760 --> 0:12:33.839 the Sun. Every half dozen years, Benu gets fairly close 0:12:33.880 --> 0:12:37.120 to Earth, as the respective orbits of Benu and our 0:12:37.200 --> 0:12:40.920 planet bring the two bodies within point zero zero two 0:12:41.040 --> 0:12:44.600 astronomical units of each other. And as I said late 0:12:44.600 --> 0:12:47.760 in the twenty second century, that's going to happen about 0:12:47.800 --> 0:12:53.120 eight times, really fairly close to one another. But the 0:12:53.200 --> 0:12:56.680 chance of a collision is is fairly really small, not 0:12:56.760 --> 0:12:59.839 fairly small, less than point zero four percent. Still it's 0:12:59.840 --> 0:13:03.080 a possibility. Now when we come back, I'll talk more 0:13:03.160 --> 0:13:05.920 about the spacecraft itself before moving on to talk of 0:13:05.960 --> 0:13:09.359 other technology and development. They'll bring us close to mining asteroids. 0:13:09.360 --> 0:13:19.680 But first let's take a quick break. So let's talk 0:13:19.760 --> 0:13:23.400 about o Cyrus Rex. First, let's talk about the name. Now, 0:13:23.440 --> 0:13:26.000 I'm pretty confident that the name was one of those 0:13:26.000 --> 0:13:28.800 where they came up with the name first and then 0:13:28.880 --> 0:13:33.920 retroactively worked to turn that name into an acronym. Osirius 0:13:34.440 --> 0:13:37.400 is the name of the ancient Egyptian god of the 0:13:37.480 --> 0:13:42.800 afterlife and rebirth. Benu, the asteroid, happens to also have 0:13:42.840 --> 0:13:45.760 an Egyptian name, is named after a mythical bird in 0:13:45.880 --> 0:13:49.400 ancient Egyptian lore, which played a part in creating the 0:13:49.440 --> 0:13:53.120 world itself. So my guess is that the team was 0:13:53.160 --> 0:13:57.240 working on this spacecraft, they selected Benu as the asteroid 0:13:57.240 --> 0:14:00.000 they were going to visit, and Benu was named back 0:14:00.040 --> 0:14:02.520 in two thousand twelve, so this is probably all happening 0:14:02.520 --> 0:14:04.800 around the same time, and then they decided to go 0:14:04.880 --> 0:14:08.319 with a similar theme and they chose an Egyptian reference 0:14:08.800 --> 0:14:11.920 when they named their own spacecraft. That's a guess on 0:14:11.960 --> 0:14:18.840 my part. Now, officially, the acronym stands for Origins, Spectral Interpretation, 0:14:19.000 --> 0:14:25.960 Resource Identification, Security, Regular Leath, Explorer Cyrus REX, and the 0:14:26.200 --> 0:14:30.040 X is in lower case because explorer all the other 0:14:30.120 --> 0:14:32.800 letters are upper case. Now, I think my guess that 0:14:32.920 --> 0:14:35.840 it was a retroactive acronym, as a fair one with 0:14:35.920 --> 0:14:38.200 a name like that doesn't just roll off the tongue. 0:14:38.240 --> 0:14:40.640 But hey, I could be totally wrong. This is again 0:14:40.760 --> 0:14:43.240 just a guess on my part. Maybe they came up 0:14:43.240 --> 0:14:45.440 with the long name and then someone looked at the 0:14:45.520 --> 0:14:51.320 initials and said hang on, and it was just gissemn. Well, 0:14:51.360 --> 0:14:53.560 I'll talk about the equipment on O Cyrus REX in 0:14:53.600 --> 0:14:55.880 a second, but first I want to talk about the 0:14:55.960 --> 0:14:59.680 overall mission. The spacecraft launched as part of the payload 0:14:59.760 --> 0:15:04.800 on a Atlas five rocket on September eight, two thousand sixteen. 0:15:05.440 --> 0:15:08.520 About a year later, the Earth gave Osiris REX an 0:15:08.520 --> 0:15:12.960 assist by way of a gravity boost. So Osiris kind 0:15:12.960 --> 0:15:15.520 of entered into an orbit, and then in order to 0:15:15.640 --> 0:15:20.280 put it on a intercept trajectory with Benu. As it 0:15:20.360 --> 0:15:23.440 was completing this orbit and getting close to the Earth, 0:15:23.920 --> 0:15:26.920 it passed near the Earth so it would get pulled 0:15:27.000 --> 0:15:32.480 by Earth's gravity then used a deflection strategy to put 0:15:32.520 --> 0:15:36.680 itself on it's its intercept trajectory with Benu and was 0:15:36.720 --> 0:15:39.800 able to get a little speed boost that way. Another 0:15:39.920 --> 0:15:45.320 year later, in August two eighteen, the spacecraft transitioned into 0:15:45.360 --> 0:15:49.400 the approach phase. At this point, Osiris Rex was still 0:15:49.440 --> 0:15:53.160 about two million kilometers or one point two million miles 0:15:53.240 --> 0:15:57.440 away from Benu. This phase actually lasted several months and 0:15:57.480 --> 0:16:00.680 would end on December third, two thousand eight team when 0:16:00.720 --> 0:16:03.000 no Cyrus Rex was able to get a visual on 0:16:03.120 --> 0:16:05.880 Benu and was starting to create a sort of map 0:16:06.120 --> 0:16:11.120 for the team on Earth to study. Starting on December third, ten, 0:16:11.200 --> 0:16:15.240 the spacecraft entered into the next phase, the preliminary survey phase. 0:16:15.840 --> 0:16:19.080 At a distance of about seven kilometers or four point 0:16:19.120 --> 0:16:22.520 three miles, a Cirrus Rex passed over the north pole, 0:16:22.600 --> 0:16:26.640 equator and south pole of Benu a total of five times, 0:16:26.760 --> 0:16:28.520 and the data was sent back to Earth so that 0:16:28.560 --> 0:16:32.240 scientists could estimate things like the asteroids mass and get 0:16:32.280 --> 0:16:35.000 a better idea for the shape of the asteroids, also 0:16:35.040 --> 0:16:38.400 to learn how the asteroid was spinning in orbit, which 0:16:38.440 --> 0:16:42.280 is all valuable information for planning the upcoming phases that 0:16:42.320 --> 0:16:46.360 would follow next, on December thirty first, two thousand eighteen, 0:16:46.400 --> 0:16:49.560 the spacecraft entered into a very close orbit with Benu, 0:16:50.080 --> 0:16:53.480 which ranged from about one point six to two point 0:16:53.520 --> 0:16:57.040 one kilometers in altitude above the asteroid or about point 0:16:57.160 --> 0:17:00.920 nine nine to one point three miles not at the time, 0:17:01.480 --> 0:17:05.119 this was the closest spacecraft had ever orbited a small 0:17:05.160 --> 0:17:08.879 body in space, so this was the first time Osiris 0:17:08.920 --> 0:17:11.720 REX set a record for that. And it was in 0:17:11.760 --> 0:17:15.520 this phase that the navigation technique switched from being star 0:17:15.720 --> 0:17:18.439 based in other words, it was using the stars to 0:17:18.560 --> 0:17:22.240 navigate where it was going to becoming a landmarked based 0:17:22.359 --> 0:17:26.440 navigation system, so now it's in respect to the asteroid itself. 0:17:26.840 --> 0:17:29.679 During this phase, the navigation team on Earth could practice 0:17:29.720 --> 0:17:32.920 maneuvering the spacecraft near the asteroid, which would be important 0:17:32.960 --> 0:17:35.840 for the later phases as well. So each phase kind 0:17:35.840 --> 0:17:39.479 of set the ground for the next phase, and that 0:17:39.560 --> 0:17:43.520 next phase began on February two thousand nineteen. This one 0:17:43.600 --> 0:17:48.239 was called the Detailed Survey Baseball Diamond phase and had 0:17:48.240 --> 0:17:51.200 gotten that name early in the mission design process because 0:17:51.200 --> 0:17:54.920 originally the plan was to have Osiris REX move around 0:17:54.920 --> 0:17:58.480 in orbit in a shape reminiscent of a baseball diamond, 0:17:58.880 --> 0:18:02.960 and the actual pattern changed during the mission design phase, 0:18:03.000 --> 0:18:06.160 but the name stuck. Now. The purpose of those movements 0:18:06.640 --> 0:18:09.800 is to produce a bunch of viewing angles of Benu's 0:18:09.880 --> 0:18:12.240 surface to get a better idea not just of where 0:18:12.280 --> 0:18:16.000 Osiris Rex might eventually make contact, but also teach us 0:18:16.040 --> 0:18:18.480 more about what the asteroid is actually made out of. 0:18:19.280 --> 0:18:24.239 Next was the detailed Survey Equatorial Stations phase, and that 0:18:24.280 --> 0:18:28.320 phase was much more about finding an appropriate collection site 0:18:28.480 --> 0:18:31.680 for the Osiris REX to take samples from the asteroid. 0:18:31.880 --> 0:18:34.840 I'll cover that actual process in just a second, and 0:18:35.280 --> 0:18:38.920 it's super cool, but before that can happen, the team 0:18:38.960 --> 0:18:42.320 has to determine the right spot for it. The goal 0:18:42.359 --> 0:18:45.000 of the phase was to select up to twelve potential 0:18:45.040 --> 0:18:48.600 collection sites on the surface of Benu. This has proven 0:18:48.880 --> 0:18:51.560 to be trickier than you think. As I mentioned earlier, 0:18:51.640 --> 0:18:55.840 Benu is a bumpy little sucker, so finding spots that 0:18:56.119 --> 0:19:01.679 are smooth and flat enough has been really challenging. The 0:19:01.720 --> 0:19:04.440 team also has looked for evidence of loose regulars on 0:19:04.520 --> 0:19:08.440 the surface of the asteroid. That's the loose soil. Essentially, 0:19:08.800 --> 0:19:11.800 it's the stuff that the spacecraft will ultimately try to 0:19:11.840 --> 0:19:15.840 collect on its sampling mission. The current phase that it's 0:19:15.880 --> 0:19:19.280 in is orbital B. That's what broke the record that 0:19:19.320 --> 0:19:22.679 Osiris REX had set during the orbital A phase by 0:19:22.720 --> 0:19:26.240 getting even closer to Benu. Right now, Osiris REX is 0:19:26.280 --> 0:19:29.360 gathering information that will be used to create as accurate 0:19:29.480 --> 0:19:32.000 a three D model for the asteroids shape as we 0:19:32.040 --> 0:19:35.720 can manage. It will also conduct a radio science experiment 0:19:35.800 --> 0:19:38.879 during this phase, and the result of this phase is 0:19:39.480 --> 0:19:42.320 meant to help the team determine which of those up 0:19:42.359 --> 0:19:45.480 to twelve candidates would be best to focus on to 0:19:45.600 --> 0:19:50.199 really eliminate ten of those twelve. So they're looking at 0:19:50.240 --> 0:19:55.200 three criteria to select two potential landing spots. Those three 0:19:55.240 --> 0:20:01.000 criteria are safety, sample ability, and science value. So it 0:20:01.119 --> 0:20:03.920 needs to be able to score high on all three 0:20:03.920 --> 0:20:08.600 of those to be considered a potential collection site. And 0:20:08.680 --> 0:20:11.479 as I said, they will select two of them. One 0:20:11.520 --> 0:20:14.600 of them will be the prime target, their number one choice, 0:20:14.920 --> 0:20:18.040 and the second is their backup. Now, at the conclusion 0:20:18.200 --> 0:20:21.040 of this phase of Cyrus REX will then enter a 0:20:21.160 --> 0:20:24.560 third orbit, orbit See, but this one will actually be 0:20:24.640 --> 0:20:27.840 further out than orbit will be, so orbit will See 0:20:27.920 --> 0:20:30.240 will move o Cyrus Rex to about one point three 0:20:30.320 --> 0:20:33.680 kilometers above the surface of the asteroid as it examines 0:20:33.760 --> 0:20:38.240 particles on and around venue. Next, o Cirius Rex will 0:20:38.320 --> 0:20:41.199 enter into a recon phase where it will take a 0:20:41.359 --> 0:20:45.560 very close look at those two potential collection sites, and 0:20:45.600 --> 0:20:47.880 it's going to pass at an altitude of around two 0:20:48.280 --> 0:20:53.400 d or seven hundred thirty eight feet above benus surface. 0:20:54.080 --> 0:20:57.640 At that distance, the cameras aboard the Osiris Rex can 0:20:57.680 --> 0:21:01.440 focus on objects as small as two meters in size. 0:21:01.760 --> 0:21:04.199 The team can then determine if their initial site or 0:21:04.240 --> 0:21:06.679 the backup site would be the best bet for the 0:21:06.720 --> 0:21:10.040 actual collection, so they can narrow their choices down to 0:21:10.280 --> 0:21:15.560 their actual you know end target. Before committing to that course, 0:21:16.040 --> 0:21:19.119 the team will hold a couple of rehearsal events. They 0:21:19.119 --> 0:21:21.800 will practice moving the spacecraft out of its orbit to 0:21:21.880 --> 0:21:25.639 fly above the landing site, initially at an altitude of 0:21:25.680 --> 0:21:30.240 about four hundred ten feet or one ms above the 0:21:30.280 --> 0:21:34.800 collection site. Then they will maneuver the Osiris Rex back 0:21:34.800 --> 0:21:39.119 into orbit. On the second rehearsal, the Osiris Rex will 0:21:39.119 --> 0:21:44.160 actually descend further and hover over the collection site, well 0:21:44.240 --> 0:21:47.359 over it, but still over it, before returning to orbit again. 0:21:48.400 --> 0:21:50.879 After all of that, if assuing all of it goes 0:21:50.880 --> 0:21:55.520 well at showtime. The critical phase is called TAG, and 0:21:55.640 --> 0:22:00.360 TAG stands for touch and go, which should happen in Also, 0:22:00.720 --> 0:22:05.320 i've heard people erroneously say that the game tag stands 0:22:05.359 --> 0:22:08.720 for touch and go. That does not appear to be true. 0:22:08.800 --> 0:22:12.200 The etymology of the word is older than that particular 0:22:13.040 --> 0:22:17.200 phrase has been, so I don't think that that really 0:22:17.920 --> 0:22:20.800 applies to the game tag, but it certainly applies to 0:22:20.920 --> 0:22:26.000 this process with os Cyrus Rex. I'll explain what the 0:22:26.040 --> 0:22:29.320 collection process is in just a moment. But after that phase, 0:22:29.640 --> 0:22:32.600 the spacecraft's thrusters will push it back from Beneu to 0:22:32.680 --> 0:22:35.280 a safe distance and it will kind of chill out 0:22:35.520 --> 0:22:40.240 at that safe distance until March one. At that time 0:22:40.520 --> 0:22:45.000 it will enter into the return cruise phase, and that's 0:22:45.080 --> 0:22:47.920 what's supposed to bring Osiris Rex home. So why is 0:22:47.960 --> 0:22:50.960 it waiting. It's waiting because, just as I've talked about, 0:22:51.480 --> 0:22:54.199 when it comes to going from Earth to Mars, you 0:22:54.200 --> 0:22:57.000 have to wait for the orbits of the different bodies 0:22:57.240 --> 0:23:00.440 to aligne up properly to make the trip up as 0:23:00.440 --> 0:23:06.399 efficiently as possible. So that won't happen until March one. Uh, 0:23:06.520 --> 0:23:11.080 and that's when Osiris REX can start its intercept trajectory 0:23:11.119 --> 0:23:15.560 to Earth anyway onto the spacecraft itself with its solar 0:23:15.600 --> 0:23:19.720 panels deployed. It measures six point two meters or twenty 0:23:19.800 --> 0:23:23.640 point to five feet in length. It's two point four 0:23:23.760 --> 0:23:29.360 meters wide. Uh, that's essentially eight feet, and it's sort 0:23:29.359 --> 0:23:32.440 of like a rectangular prism, so the width measured either 0:23:32.600 --> 0:23:35.399 left right or up down with respect to its length 0:23:35.520 --> 0:23:40.480 is the same. It weighs two thousand rams when full 0:23:40.480 --> 0:23:44.240 of fuel. That's about four thousand, six hundred fifty pounds, 0:23:44.240 --> 0:23:47.280 so it's hefty when it's fully fuelled. The spacecraft is 0:23:47.320 --> 0:23:51.160 home to five science instruments as well as the system 0:23:51.240 --> 0:23:55.080 called tag SAM. Tag SAM stands for Touch and Goes 0:23:55.119 --> 0:23:59.320 Sample Acquisition Mechanism, so this is the actual device that's 0:23:59.359 --> 0:24:03.680 going to do the collecting. The tag SAM is part 0:24:03.760 --> 0:24:09.040 of the Osiris REX that will actually make contact with Benu, 0:24:09.080 --> 0:24:11.800 and it looks kind of like a pogo stick that 0:24:11.920 --> 0:24:15.040 extends out from one side of the spacecraft, but this 0:24:15.119 --> 0:24:18.480 is a pretty powerful pogo stick. Inside of the tag 0:24:18.520 --> 0:24:21.000 SAM is a mechanism that will direct a jet of 0:24:21.080 --> 0:24:25.119 nitrogen gas to quote fluid ize regular to allow the 0:24:25.200 --> 0:24:29.080 sample head to capture granular material, while contact pads capture 0:24:29.160 --> 0:24:34.119 fine material end quote. So it's blasting the surface with 0:24:34.200 --> 0:24:37.000 this jet of gas and then collecting what ends up 0:24:37.040 --> 0:24:41.760 flying out. The whole process should last about five seconds. 0:24:42.280 --> 0:24:45.959 Then springs in the tag SAM will actually expand, pushing 0:24:46.000 --> 0:24:49.040 Osiris rex off the surface of Benu, so you could 0:24:49.119 --> 0:24:51.440 argue it really is like a high tech pogo stick. 0:24:52.040 --> 0:24:54.639 The team on Earth will initiate commands to make Osiris 0:24:54.680 --> 0:24:58.080 rex spin, and the purpose for that is to figure 0:24:58.119 --> 0:25:01.280 out how much stuff did it actually collect. They will 0:25:01.320 --> 0:25:05.200 monitor the change in the spacecraft's inertia, and by looking 0:25:05.200 --> 0:25:08.199 at the difference in inertia between when the spacecraft was 0:25:08.920 --> 0:25:11.200 had before it had taken the sample and after it 0:25:11.200 --> 0:25:14.640