captioning funded by cbs and ford. we go further, so you can. ( ticking ) >> a steady stream of plasma donors has been rolling up to dr. dinato's clinic. a machine that spins their blood "plasmapheresis." what's left is this gold-colored liquid, plasma. it's mostly water, and in this case millions of antibodies. how quickly do you expect patients to respond to this therapy? >> a few days. >> a few days? >> three, ( ticking ) >> this is where the tiajuana river crosses the border into the united states. this cement structure was built to contain flooding from rain

flow, t thin't jst rainwater, ia toxic mix raw sewage from neighboring tiajuana, draining into southern california on lower ground, eventually emptying into the pacific ocean. >> so it effectively it's like a toilet flushing straight into ( ticking ) >> has anyone ever brought back something from mars? >> no. it will be the first round-trip adventure to any other planet. >> four previous mars rovers have paved the way for this mission. the last rover, named "curiosity," has been exploring and sending back images like this for eight years, but "perseverance" is the first rover that will be able to look for evidence of ancient life and collect samples that nasa plans to bring back to earth. that does not sound possible. ( ticking ) >> i'm lesley stahl. >> i'm bill whitaker.

>> i'm anderson cooper. >> i'm sharyn alfonsi. >> i'm scott pelley. those stories, tonight, on "60 minutes." ( ticking ) >> this portion of "60 minutes" is sponsored by progressive insurance. save when you bundle auto, home, or motorcycle insurance. visit progressive.com. >> i'm scott pelley. those stories tonight on "60 minutes." >> this portion of "60 minutes" is sponsored we progressive insurance. save when you bundle auto, home, or motorcycle insurance. visit progressive.com.

>> bill whitaker: this past week, america passed a grim marker.av now died of covid-19. until there are new drugs available to treat it, experimental therapies remain the only option. one currently being tested at numerous hospitals is actually very old; more than 100 years old. it's called convalescent plasma

therapy: it relies on blood plasma from people who have recovered from disease, whose immune systems have produced virus-killing antibodies. the plasma is given to ill patients and has been shown to speed their recovery. at the peak of the covid-19 pandemic in new jersey, hackensack university medical center, rushed to stand up a distinct plasma study of its own, zeroing in on donors with the most potent antibodies. it began april 4th, and we joined them just days later to witness their breakneck battle against this deadly disease with the promise of plasma. it's early evening inhack, neeya 30 minute drive from midtown manhattan. medical oncologist michele donato, the principal investigator of the therapeutic study is armed with an arsenal of donated blood plasma loaded

with potent antibodies. >> michele donato: this is convalescent for, sars cov-2. >> whitaker: doctor donato is engaged in an all-out battle to save patients, who have been flooding the hospital for two months now, from the relentless onslaught of the killer virus. this is what hope looks like in the depths of despair. you're watching this unfold in real time. >> donato: yeah. >> whitaker: what's-- what's that like for you? >> donato: it's really terrible. i mean, we want to get out of this. and maybe there's fewer patients coming into the hospital. but they're still suffering. they're still dying. we have to find a solution. i think we're just a piece of that puzzle. >> david perlin: until we have an effective vaccine we're going to take the position that we need drugs. pati andhosew, our best drug isf individual

frs >> whitaker: david perlin is a biomedical researcher and chief scientific officer at hackensack meridian health center for discovery and innovation. he has traveled to hot zones around the world responding to infectious disease outbreaks, including sars-one and pandemic flus. he's also dr. donato's partner in this search for something to fight this virus. there are other therapies being tested out there. why did you decide to focus on plasma therapy? >> perlin: if you're looking for something that you know is antiviral, antibodies we know are antiviral. it's just a question of how do we identify those individuals who are producing high quality antibodies that either kill or neutralize the virus. >> whitaker: in early april, david perlin and doctor donato got expedited approval from the

arollectndrug administration to test the most powerful antibodies against the virus. what makes what you're doing here unique? >> donato: so what we wanted to see is can we handpick the best donor? see, in transplant, we handpick the best donors for leukemia all the time. so let's do the same thing for plasma. so we select donors who appear to have had the best immune response. >> whitaker: as chief of stem cell transplantation and cellular immunotherapy at hackensack's john theurer cancer center, dr. michele donato has spent her career matching donors to recipients for stem cell transplants; years of experience fighting cancer she's now using to combat this novel coronavirus. who are the best donors? >> donato: it looks like about 20% of people have really, really an extraordinarily good immune rese. and what we're looking at is if giving a quantity ofishe

best way to approach it. but that's what this study will tell us. >> whitaker: so far, thousands of covid-19 survivors have offered to donate plasma for the hackensack university medical center's study, but fewer than one-third of them have qualified. each donor must meet the threshold of having no remaining trace of the virus and they must produce an extraordinary number of antibodies that kill the virus. it's like finding a needle in a haystack and david perlin is finding and testing those antibodies here, in a secure level 3 biocontainment lab designed to work with highly usrtagious pathogens.th covid-19? >> perlin: just covid-19 right now. >> whitaker: down the hall, we were able to see what the research scientists saw, but without having to don space

suits. in the first slide are healthy cells; in the second those cells have been ravaged by the coronavirus. the third shows what happens when the potent antibodies are introduced. the virus appears to be vanquished. so what does that tell you? >> perlin: this tells me i have an antiviral. antibodies that have the potential to be protective, this is what i want. i want these antibodies at a high level that we can then use for our therapy. >> whitaker: david perlin's lab delivers a list of potential donors to dr. donato's inbox. she huddles with staff to review possible recruits. >> donato: he's a four star! >> i know. pl donorhas been rollingre of up to dr. donato's clinic. one by one they're hooked up to a machine that spins and separates their blood cells in a process called plasmapheresis.

what's left is this gold colored liquid: plasma. it's mostly water, and in this case, millions of antibodies. donors are rated on a scale of one to four stars. the small number of recovered covid-19 patients, who produce antibodies 10, 30, even 50 times more than others, are called" super donors." >> dan walsh: no, breathing was not bad." >> whitaker: we watched, as dr. donato's team drew the precious fluid they call liquid gold from one super donor at a time. what was going through your mind? >> donato: "gosh, i hope his vein's good enough." >> whitaker: the basics. >> >> whitaker: we met some of her super donors. each had different covid-19 symptoms, but they all wanted the same thing: to help. dan walsh is a retired currency broker. >> walsh: oh, it's great. i think it's great.

like, it gives me bragging rights to my friends i say, "i saved a life. you didn't do anything today." (laughter) >> whitaker: rick loshiavo is an investment m life to have these antibodies, but the fact that i have them maybe i was blessed with them to help somebody. >> whitaker: christopher jordan is a civil engineer. >> chris jordan: i just feel like we should do this like we should be giving back during these kind of times. like if you can help your neighbor, help your neighbor. >> whitaker: walter dimatia is a fabricator. >> walter dimattia: it'd be a great feeling to know that i helped someone, absolutely. i hope it does. >> whitaker: each donor provides one half liter of plasma to go to one covid-19 patient. dr. donato is testing whether the best chance of recovery depends on timing: when the patient receives the powerful antibodies. she's focused on a crucial

window: the gap between infection and the virus taking over the body. >> donato: it's during that gap that the virus causes damage. the virus invades the cells. it invades the lungs, and it causes tissue damage. from tissue damage, there's a cascade of inflammation that then follows. and that's what makes the patient so sick. so by preventing the virus from invading the tissues, invading the lungs, you help prevent that second wave of inflammation. >> whitaker: how quickly do you expect patients to respond to this therapy? >> donato: a few days. >> whitaker: a few days? >> donato: three, four, five days. >> whitaker: the 15th patient in the study was a gravely ill 37 year old construction worker and father of five, segundo guaman. dr. donato told us she

administered the plasma hoping to keep him off a ventor often the hospital's last tool. we agreed not to show the faces of ill patients. this footage was shot by the hospital staff photographer. >> donato: you hang in there, okay? >> whitaker: the next day, dr. donato delivered the promise of plasma to jose ramirez, a 49 year old father of three who manages a new jersey bagel factory. he had been in the covid unit for a week. >> donato: i'll come check on you tomorrow, okay? high five. >> whitaker: no one knows better what these patients are going through than robert robinson, a 44 year old nursing director in the hospital's emergency department. he described the virus washing over new jersey like a tsunami and patients flooding his er. >> rob robinson: in the beginning, they would trickle in. but it started to go to, like, ten, 20. there was one point we would get 25 in an hour that were coming in.

>> whitaker: he was felled by the virus in march and ended up in his own hospital. he told us he was close to death. >> robinson: they told me, you're lucky that we-- you were able to pull through. it was close. >> whitaker: before the plasma therapy study was up and running, robert robinson recovered and was welcomed back by his colleagues. he offered to donate his plasma because he believes in the value of this therapy. what do you hope to happen? >> robinson: i hope we start to get patients discharged sooner and healthier. i hope it works.s g early promise for many of dr. donato's patients. remember segundo guaman? >> donato: segundo, how are you? how are you feeling? i don't even recognize you! >> whitaker: he was one of doctor donato's critically ill patients, he was close to being put on a ventilator before he got an infusion of antibodies.

she was amazed at how he responded. >> donato: pain in your chest or no more? >> no. >> donato: you look good! >> whitaker: then we got to witness this-- jose ramirez, the bagel factory manager, spent 11 days in the covid unit. four days after receiving the antibodies, he was reunited with his daughter. >> jose ramirez: i feel much better. i can feel my lungs opening. >> whitaker: if you were to meet the donor, what would you say to him or her? >> ramirez: save my life. thank and god bless him. >> whitaker: so far, 31 of the 46 patients who received plasma in this study appear to have recovered more quickly than those who didn't. david perlin cautions the study is a first step, and more rigorous trials are needed, but he is encouraged by the early

results. you're not seeing that with the general population? >> perlin: oh, definitely not. i mean, to go from being critically ill to going home is pretty dramatic. we don't typically see that now. >> whitaker: based on what you have seen so far, what does your gut tell you? >> perlin: my gut says that this is going to work. the initial response of the patients is incredibly encouraging. but as a scientist, i'm trained to be cautious. and so right now this is our best approach, we are going to take it, we'll be aggressive with it but we'll see how patients respond. ( ticking ) >> for more on our coverage of the coronavirus, go to 60minutesovertime.com sponsored by pfizer.

>> lesley stahl: the term" crisis on the border" typically refers to immigration issues or drugs being smuggled into the country. but it has one more meaning, as we discovered, when we went to the border in early february: tens of millions of gallons of raw sewage that spill every year

into the tijuana river on the mexican side and flow across the border right into southern california, polluting the land, mexico and the united states each thinks the other should be doing more to clean it up, with no effective solution found on either side of the border, for decades. this is where the tijuana river crosses the border into the united states. this cement structure was built to contain flooding from rainfall. but this isn't just rain water, it's a toxic mix of raw sewage from neighboring tijuana, draining into southern california on lower ground, eventually emptying into the pacific ocean. >> amber craig: so it effectively, it's like a toilet flushing straight into this river valley. >> stahl: border patrol agent amber craig took us on a tour of the sewage infiltration, showing

us that what doesn't flush out to sea, washes up on land: mountains of plastic bottles, furniture, and tires. >> craig: and this is a concern for us, too, not just because it's debris and waste, but because the mosquitoes love to nest in it, so... >> stahl: it's a health concern, an eyesore, and it's hindering the border patrol's main mission. she took us to see president trump's newly erected wall along the border: just this six-mile stretch cost an estimated $50 million. what we found is that under the wall, there's a network of basins and tunnels built 30 years ago to try to capture the e red me, nt to agent amber craig, inside one of those concrete sewage collection basins. it's connected on either end to tunnels from mexico to california that were constructed

right under the wall. so you think of the smugglers and the migrants building tunnels to go under the wall. but the u.s. government built this tunnel that goes under the wall. >> craig: yes, we built this so that the water would flow freely into the united states. >> stahl: it has to flow freely, because four decades ago the u.s. signed an agreement with mexico not to cause backup flooding at this area of the border. these metal grates at the ends of the tunnel let the water in while keeping the rubbish out. drher, not when ks fine during >>raig: the am of wa through like a torrent. it is very, very dangerous. it is a raging river when it rains. >> stahl: with the tires and the barrels and everything. >> craig: full of debris and garbage. that's correct. it's very dangerous. >> stahl: the debris and garbage can hurtle down here with such

force that border patrol agents have to open the grates to prevent the system from clogging. that means trash flows into california unobstructed. it's also an opening for migrants. the purpose of the wall is being totally defeated by this obligation of yours to lift the grates. >> craig: you-- well, yup. it does make it a little more challenging to have to have that open. of course, we don't want to have it open. >> stahl: if they go through that tunnel, they're in the united states. >> craig: if the grates have to be opened, then we have to have a personnel, an agent, on the other side, keeping-- >> stahl: so as they come out. >> craig: that's correct. >> stahl: how do the smugglers know that the grates are lifted? >> craig: they watch. >> stahl: they watch? >> craig: sure. there're smugglers watching us probably right now. >> stahl: migrants are routinely caught risking their lives crossing in the sewage: some need to be rescued and

decontaminated. let me read you a list that we found of stuff that is in this water: fecal coliforms, drug- resistant bacteria, benzene, cadmium, mercury, hexavalent chromium medical waste, and ddt, which has been banned for years in the united states. >> craig: yes, ma'am. >> stahl: i hear that sometimes the water turns funny colors? >> craig: it does. we've had bright, bright purple, a bright pink, neon green, dark black. >> stahl: so the migrants are going into this? >> craig: yes, ma'am. >> stahl: and the patrol agents are going into this. are they getting sick? >> craig: agents have reported various health injuries. rashes are very common. stomach issues. we've had one agent who had a flesh-eating bacteria. and he almost lost his arm. >> stahl: how angry are you and the other agents? >> craig: we're frustrated, very frustrated. agents know our job is

dangerous. we've signed up for a job where we could be shot at, where we could die in a car accident. and we accept that. nobody thought that they were gonna come here and be exposed to this, to the sewage, and the chemicals and the smell. >> stahl: congress just allocated $300 million to address the sewage issue all along the border, a fraction of what's needed. especially here, because of the rapidly growing population of tijuana. >> craig: it is a difficult situation. we're having to deal with another country. and the city of tijuana, it's just a huge city, it's overpopulated. their infrastructure isn't-- isn't prepared to handle this kind of flow. so it just comes right over the sewage authoritynvited us to in tijuait oen breaks doue to mechanical failures. so workers have to wade

underground in black sludge to repair the buckling facility. while we were there, one worker got so overwhelmed by toxic fumes he required medical attention. according to the mexican authority, the last line of defense keeping the sewage out of the u.s. here is a small crew of sanitation workers who unclog drains by hand along the border. we found one of them, a man named abel, clearing trash with a rake. get collected is pumped into these giant pools six miles south of the border, where the sewage is supposed to be treated and discharged through this massive pipe as clean water into the ocean. but the facility hasn't worked for years, so what you're looking at is untreated sewage emptying directly into the

pacific. we stood by the torrent with fay crevoshay, an environmentalist with wild coast, a watchdog group of concerned citizens from both sides ofthe border. how much sewage are we talking about? >> fay crevoshay: yeah. the local authorities say that it's 25 million gallons a day. we think it's 40 million gallons. >> stahl: and it's just gushing, gushing, gushing out. >> crevoshay: that's what we have here. >> stahl: making matters worse, entire shantytowns have popped up in tijuana's canyons along the border. many of these makeshift shacks were thrown-up by people who moved here for jobs, at factories created by the north american free trade agreement. these factories are dumping their chemicals? >> crevoshay: sure. we have laws, but there is no-- >> stahl: enforcement. >> crevoshay: control. so why spend money? the problem is these factories come here because it's cheap. they're gonna pay the workers

$8.00 a day. and this is the result. this is where the workers live. these houses have no services, no electricity. >> stahl: no plumbing. >> crevoshay: no plumbing, nothing. >> stahl: this stream, this entire stream, is just raw sewage. >> crevoshay: sewage. >> stahl: when it rains, what happens to this stream? >> crevoshay: it grows. they have a whole river! you see all the lying garbage, all around it? >> stahl: yeah. that-- >> crevoshay: it takes it with! >> stahl: we saw tires everywhere: a lot of them from california that were sold to mexican car owners second-hand. when the tires wear out, many are used to prop up homes on the hillside, or just get dumped and then get swept by the sewage right back to southern california. we wondered where all the untreated sewage that emptied into the ocean goes. well, we learned that it can flow right by a u.s. military training base.

rd to e e s ni right in the of you-- have gone swimming in that? >> all of us. >> stahl: retired naval officer mark west and four retired seals, alex lopez, kyle buckett, bill lyman, and steve viola, told us how the sewage impacts those training here. >> steve viola: it wreaks havoc on your system. stomach aches, throwing up, i mean, coming out both ends, fever. and you just have to suck it up and keep going. >> kyle buckett: we've had classes of, you know, 38 to 42 guys contract it during their training cycle. and it's a very, it's a big challenge for us to deal with that. >> alex lopez: i contracted cellulitis. which is-- >> stahl: what's that? >> lopez: a bacterial, like, saph infection. it just took off, and it started eating, you know, flesh on both my legs. >> stahl: they say that the most vulnerable are seal buds, those

trying out to be seals, especially during "hell week": five and a half days immersed in the ocean, testing their endurance. have you heard that during hell week the buds now take prophylactic antibiotics? >> viola: yes, i have heard that. >> stahl: you were a trainer. do you ever say, "these kids can't go in this today. i can smell it, i can see it." >> buckett: yeah, absolutely. yeah, we have. >> stahl: you do-- you do. >> buckett: we have, we have. and then we have to transition to the bay or to a pool. >> bill lyman: there's no waves in the bay and there's no waves in the pool. >> stahl: are you seeing any reason for us to worry about your readiness? >> mark: i think, i think that our readiness is being impacted. and you know-- >> stahl: it is being im-- >> mark: yeah, it .>> stahl: th, is monitoring the water quality. so we found it odd that it is spending a billion dollars to expand the seals' training base much closer to the source of the pollution.

>> steve: well we had outgrown the capacity of the buildings that we had. so that's why we moved down there. >> stahl: but were they taking the pollution into account? >> bill: no. >> stahl: the navy did do an environmental impact study. >> yes. >> kyle: the navy's main focus was to see how much we were going to impact the environment. it wasn't focused on what the environment was going to impact on the navy seal community. >> stahl: the navy turned down our request for an interview, but recently told congress in this report that the run-off is a concern, yet its impact has been "infrequent and short term," concluding that it is easily mitigated. serge dedina, mayor of imperial beach, the city on the south edge of the new base, doesn't buy it. >> serge dedina: they've ignored the health and safety of their own national security staff, and that's absolutely unacceptable. >> stahl: did you ever get any health problems from the water? >> dedina: yeah. i have a tube in my ear because

i had so many ear infections. my kids have gotten sick. our lifeguards have gotten sick. pretty much every one of our council members have gotten sick. so it's-- it's devastated our >> stahl: in more ways than one. imperial beach is a surfing town, but its beaches are closed a third of the year or more due to the toxic sludge. >> dedina: i've got to spend my time hammering people in power to make sure they understand that dumping toxic waste on navy seals and border patrol agents is a bad idea, and getting them to acknowledge that it's actually happening. >> stahl: if the navy weighed in do you think things would begin to happen? >> dedina: i think if the navy brass weighed in, this would be fixed tomorrow. >> stahl: meanwhile, the niagra of sewage keeps gushing, the grates keep opening, and abel keeps at it with his rake. ( ticking )

>> cbs money watch sponsored by capital one. what's in your wallet? >> good evening. the may jobs report is expected to show unemployment nearing 20%. zoom is among tech companies reporting earnings this week. and spacex celebrates a new corporate era in space flight after launching astronauts into orbit. i'm steve savard, cbs news.

[music] [music] especially in times like these, strong public schools make a better california for all of us. strong public schools make a better california here's what we want everyone to do. count all the hugs you haven't given. all the hands you haven't held. all the dinners you didn't share with friends. the trips you haven't taken. keep track of them. each one means one less person vulnerable, one less person exposed, and one step closer to a healthier community. so for now, keep your distance. but don't lose count. we'll have some catching up to do.

>> anderson cooper: if you're >> anderson cooper: if you're tired of being cooped up and yearning for a get-away, have we got an adventure for you. it's a new mission to mars, nasa's most ambitious one yet. the goal is to land a new vehicle, a high-tech rover, to search for signs of ancient life on the red planet and, eventually, bring that evidence back to earth. unmanned space craft have been exploring and photographing mars for decades. but no one's ever discovered clear signs of life there, or anywhere else in the universe. nasa scientists now believe they've found a perfect place to look. coronavirus could have derailed the whole mission, but so far the launch is still on schedule. blast off is less than two months away. given all that's already

happened, this new rover's name seems particularly appropriate: "perseverance". it'll take seven months and a journey of hundreds of millions of miles for "perseverance" to get to mars, the planet whose reddish hue, caused by rust particles in the rocks and soil, led the romans to name it after their god of war. today, the surface of mars is a radiation-filled desert. it's freezing-- minus 80 degrees fahrenheit on average. there are windswept sand dunes and outcroppings of rock that could easily be mistaken for parts of arizona. some of those rocks hold clues that suggest mars may have been years ago, with lakes and rivers of water and the building blocks of life. >> bobby braun: "perseverance" is really our ast iotrrsloobgy actually searching not just for environments that may have once been habitable but for evidence of the life that may have

exted there in the past. >> cooper: bobby braun, the director of solar system exploration at nasa's jet propulsion laboratory, says "perseverance" is designed to be the first of three missions that will be required in order to bring samples from mars back to earth. has anyone ever brought back something from mars? >> braun: no. it'll be the first round-trip adventure to any other planet. >> cooper: nearly eight years and $2.5 billion have been spent building "perseverance." bobby braun told us that if nasa misses a narrow three-week window to launch that begins on july 17th, it could cost half a billion dollars more and years of work. >> braun: because of the motion of the earth and mars about the sun, you can only send a spacecraft from earth to mars once every 26 months. and if we miss that window we would have to wait 'till 2022 to try it again. >> cooper: you'd have to wait that long. wow. i mean, there's not only a lot of time, a lot of money, a lot of, very smart people dedicating their lives to this, there's

also a lot of eyes on this. >> braun: yeah, the stakes are high from a number of vantage points. >> cooper: four previous mars rovers have paved the way for this mission. the last rover named curiosity has been on mars for eight years, sending back images like these while exploring an area known as the gale crater. but "perseverance" is the first rover specifically outfitted to collect retrievable samples. in early january, before there were any known cases of coronavirus in the u.s., nasa invited us to the jet propulsion laboratory in california, where ernce" and theehicles that will bring it to mars. they were in what's called a clean room, to keep them free of any dust particles or other contaminants that might jeopardize their mission. >> matt wallace: you can feel a little bit of a metallic wire along the top. >> cooper: deputy project manager matt wallace showed us how to put on the layers of protective equipment required before entering the clean room. our cameras were wiped down

thoroughly, and we got what's called an "air shower." so that's the rover right there. >> wallace: it's bigger than you think it's going to be. >> cooper: yeah. >> wallace: usually when you get close. it's the heaviest. it's the most sophisticated, most capable vehicle that we've ever actually put on the surface of mars. yeah. >> cooper: "perseverance" is equipped with 25 cameras, two audio mics, and seven scientific instruments, many of them specifically designed to detect faint traces of ancient life on the surface of mars. but the rover will also be testing out new technologies that astronauts may some day need to explore mars and return baea right inside this vehicle. it actually makes oxygen on mars from the atmosphere for life support obviously, but also that oxygen is useful as an oxidizer for fuel for the return trip for those astronauts. >> cooper: do you know that it is possible to make oxygen on mars? >> wallace: we know that it is theoretically possible. we have simulated the conditions

here. but we're going to take it to mars and show that we can do it. >> cooper: i know this isn't the most important thing, but the hubcaps are really cool. >> wallace: thank you, yeah. >> cooper: the rover also has this small helicopter which it can drop on the surface of mars. if it works, it would be the first vehicle ever to fly in the atmosphere of another planet. one of the most important parts of the rover is its powerful robotic arm, seen here in time- lapse video taken during a test. as this nasa animation shows, if "perseverance" finds fossils or other signs of ancient life, that robotic arm will be able to drill into the rock, cct core samples, and place them in specially designed, super- sterilized tubes. >> wallace: and this is what the tube looks like actually. it's a titanium tube. and we're hoping to bring back 20, 30 samples. we're able to keep the sample very clean because this is really the only part of the spacecraft that the sample will touch, which is very important for the science of the mission.

>> cooper: so you don't want any dirt or anything that would compromise the sample. >> wallace: that's exactly right. >> cooper: for that reason, the actual tubes that will go to mars were being kept in restricted areas nearby. these are even cleaner clean rooms, where workers wearing double layers of protective gear were repeatedly sterilizing the tubes with heat and chemicals. the insides of those tubes, nasa says, are some of the cleanest things on earth. a team of nasa scientists will decide where "perseverance" goes and what kind of rock samples it'll collect. you only have 20 or 30 samples that you'll be able to get. i mean, you've got to pick some good ones. >> katie stack morgan: that's right. >> cooper: is that scary? >> morgan: no, it's exciting. >> cooper: katie stack morgan worked as a geologist on the curiosity rover mission and is a deputy project scientist for "perseverance". if there was life on mars, how long ago was it? >> morgan: so we think it was probably at least three billio agon the surface. >> cooper: you're talking about not actual martians, but organisms.

>> morgan: we're thinking microbial life, very simple, single cell organisms-- that kind of thing. >> cooper: what would that look like? >> morgan: well, they can take all kinds of forms, you know, small tubes and little circular fossils, micro-fossils. you know, we have examples of this-- from earth-- most rocks are layers, very flat, horizontal layers. but sometimes we get very interesting shapes like this, and that these microbes were responsible for the interesting shapes that we think formed that rock. >> cooper: so something like this, you wouldn't be surprised to actually see. >> morgan: we would be absolutely delighted to discover finding signs of life on mars. it's called the jezero crater. no rover has ever been there before. it doesn't look like much today, but three and a half billion years ago scientists believe it had the makings of a microbialvr flowing out, and a rich river

delta. >> morgan: to know that in this particular spot on mars we had water here, enough water, and for long enough to fill this 30- mile diameter crater, is a big deal for us and says that this is a special place. >> cooper: if all goes according to plan, "perseverance" will arrive at the jezero crater in february 2021. it'll explore the area for at least two years. as this nasa animation shows, the rock samples "perseverance" collects will most likely be left on the surface of mars. but that's just the beginning of what one nasa official has described as "probably the most complex" scientific mission the agency has ever undertaken. years later, a new rover will arrive to fetch the tubes, put them on a small rocketship, and launch them into orbit around the red planet. another spacecraft wil already be waiting there in orbit, and the samples will be passed to it in a container the size of a soccer ball. the samples will then be

transported back to our atmosphere, and dropped off on earth. that does not sound possible. >> braun: totally possible. i guarantee you. so listen many of these pieces we've done in piece part before. >> cooper: the return part of the mission is conceived as a joint venture with the european space agency and has yet to be fully approved or funded. is there an estimate of the cost? >> braun: we're working on that. but there's not a final, you know, number today. >> cooper: we're in the midst of a pandemic-- obviously an economic crisis, is sending a rover to mars, is that a good idea at this time? >> braun: i would say this is precisely the right time to make that investment. if there's anything that this pandemic has taught us is the importance of science and technology. >> cooper: in march, as "perseverance" was being prepared for launch at the kennedy space center in florida, nasa went into lockdown along with much of the rest of the country because of coronavirus. was there a time where you thought maybe you'd have to

cancel the launch? >> braun: well, certainly you know, when it was first starting up here in the u.s., we were all rally oncernrs and foremostbout the safety our team. so we took time to kind of regroup and put up-- put forward a new plan. >> cooper: under that new plan, 90% of nasa employees are working from home, including matt gildner, who's driving the curiosity rover on mars right now from his apartment in los angeles. is it a little weird driving the rover from your one-bedroom apartment? >> matt gildner: oh yeah, it's definitely weird. i mean, normally i'm used to being inside a room with about 25 people and we're all, you know-- we have kind of the work hats on. and you don't hav the distraction like a, you know, dump truck picking up trash outside or your dog barking. >> cooper: can i see your dog? >> gildner: yeah, where's-- where's kiley at? oh she's sleeping on the couch right now.

>> cooper: if kiley, like, jumped on your lap or hit one of the keys, would the rover fly off a cliff? >> gildner: no. our process involves developing a plan throughout the whole day. after everything is complete and integrated and checked, we will bundle it up and send it to the spacecraft. so that's the point in time where we will be able to catch any-- you know, paw prints on our commands. >> cooper: correct me if i'm wrong, but i would imagine you-- you're spending a good amount of your mind every day on mars. and not in this pandemic. in a sense, every day you're journeying to mars. >> gildner: that's true. yeah, we get to have our own little escape on another planet. >> cooper: the team working on "perseverance" is persevering as well. about 80 people are on site at the kennedy space center in florida, getting the rover ready for launch. the competition, though, is heating up. the u.s. isn't the only country getting ready to go to mars this summer.

china is preparing to send its first orbiter and rover, and the united arab emirates plans to send an orbiter as well. the european and russian space agencies have created this rover that they plan to launch in two years. do you see this as a race to find evidence of life? >> morgan: i see it more as-- we're all working together to answer this question. and we're doing it in slightly different ways. i think it really is a human endeavor. it's a human question that we're after. >> cooper: if in fact ultimately it turns out that there was microbial life on mars billions of years ago, i mean, it's cool. but why does it actually matter? >> morgan: the idea that we would find evidence of life that wasn't on our own planet, alien life would show that you know, it can occur in other places and that there are other forms of life. >> cooper: if there's microbial life, there's no reason there couldn't be a higher form of life or a different form of life. >> morr how life could have evolved elsewhere in the universe. and it may take us some time beforere but if we find life on another planet, we'll know that it can happen elsewhere.

it's not just here. i think it'd be a real paradigm shift in terms of how we think about our place in the universe. ( ticking )

>> bill whitaker: this past week, americans made their first, tentative steps from beneath the shadow of the covid- 19 pandemic, only to be confronted by a much older toxic threat to life in this country: racial injustice. this time it began with the death of george floyd while in the custody of minneapolis police officers. the image of a man begging for breath as an officer presses a knee to his neck, and the life out of him, is indelible.as he w t sparked by monday's death on a minnesota street ignited protests and in some cases violence in cities across the country. this virus of racism and injustice has threatened and infected america for 400 years. there is no antidote, but we desperately need to heal from

it. i'm bill whitaker. we'll be back next week with another edition of "60 minutes." ( ticking )

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