0:00:02 > 0:00:03EXPLOSIVE BLAST
0:00:11 > 0:00:13Ignition.
0:00:22 > 0:00:25Mars, the Red Planet.
0:00:27 > 0:00:31We've long wondered if it's harboured life.
0:00:32 > 0:00:35Some have dreamt of walking on its surface.
0:00:40 > 0:00:44More than four decades after they landed on the Moon,
0:00:44 > 0:00:50NASA are now imagining a two-year ride across space...
0:00:52 > 0:00:53..to Mars.
0:00:57 > 0:01:00The scorecard of Mars is at best 50/50.
0:01:00 > 0:01:02It's tough to get there.
0:01:02 > 0:01:06If you think about putting humans in harm's way, it's a tough job.
0:01:08 > 0:01:12To do it, they need new rockets on a new scale...
0:01:15 > 0:01:18A new way of surviving in space...
0:01:22 > 0:01:24..and a new breed of astronauts...
0:01:27 > 0:01:30Think about a mission to Mars. What is it? Is it outdoor stuff,
0:01:30 > 0:01:32or is it confinement?
0:01:32 > 0:01:35And then I see somebody that says, "I have a stamp collection,
0:01:35 > 0:01:38"I do a lot of reading, I enjoy watching movies."
0:01:38 > 0:01:41And I'm thinking, "That might be good for confinement."
0:01:43 > 0:01:46To finally go to Mars would be the fulfilment
0:01:46 > 0:01:49of one of our grandest dreams.
0:01:49 > 0:01:53I long for a time when I can actually walk out of my back yard,
0:01:53 > 0:01:57stare at space, spot Mars, and actually think,
0:01:57 > 0:02:01"There are humans on Mars, right now, and we helped put them there."
0:02:02 > 0:02:07But is this ultimately a dream NASA can really deliver?
0:02:33 > 0:02:37Right now on Mars, there is an object the size of a car,
0:02:37 > 0:02:39roaming about on the surface.
0:02:49 > 0:02:52It was sent across vast voids of space
0:02:52 > 0:02:55to this harsh and rocky planet.
0:02:58 > 0:03:03And now, every day, it opens its eyes upon on another world,
0:03:03 > 0:03:07trawls the surface for signs of life
0:03:07 > 0:03:09and sends back images like these.
0:03:16 > 0:03:19Now NASA want to go a stage further
0:03:19 > 0:03:22and put a group of people up here with it.
0:03:29 > 0:03:33And so the man who masterminded the landing of this rover
0:03:33 > 0:03:35is now part of a team trying to work out
0:03:35 > 0:03:39if humans can safely be sent to join it on Mars.
0:03:41 > 0:03:43Mars is a tough place to get to.
0:03:43 > 0:03:48It's a scary, expensive and risky proposition for robots.
0:03:48 > 0:03:50When you think about putting a human in harm's way,
0:03:50 > 0:03:53you've got to double down on your engineering
0:03:53 > 0:03:55to make sure that everything goes right.
0:03:56 > 0:04:01The simple truth is that much of the technology they'll need doesn't yet exist.
0:04:03 > 0:04:07People get, I think, confused by the technologies on Star Trek.
0:04:07 > 0:04:09And perhaps in 400 or 500 years from now,
0:04:09 > 0:04:11we'll have those kinds of technologies available.
0:04:11 > 0:04:14But for the present time, if we want to do space exploration,
0:04:14 > 0:04:15there are risks.
0:04:15 > 0:04:19And the longer the mission, and the farther away we go,
0:04:19 > 0:04:21then the higher the risks are going to be.
0:04:21 > 0:04:25The history of previous, unmanned, missions provides little comfort.
0:04:27 > 0:04:30So Mars is a risky place to go.
0:04:30 > 0:04:33Early attempts - Mariner 3 and Mariner 8,
0:04:33 > 0:04:35almost everything the Soviets tried to put there,
0:04:35 > 0:04:39the Mars Polar Lander in '99 - all these missions have failed.
0:04:39 > 0:04:43The scorecard of Mars is at best 50/50.
0:04:43 > 0:04:48So as NASA set their sights on a manned mission to Mars,
0:04:48 > 0:04:49can they pull it off?
0:05:11 > 0:05:14The scientists and engineers at NASA are returning
0:05:14 > 0:05:16to the business they're famous for -
0:05:16 > 0:05:22transforming a fantastical idea into a precise set of engineering plans.
0:05:29 > 0:05:32These are the people who must face, and overcome,
0:05:32 > 0:05:35every problem involved in sending human beings
0:05:35 > 0:05:3856 million kilometres from Earth.
0:05:43 > 0:05:47Everything from stopping them from going mad with boredom,
0:05:47 > 0:05:50to dealing with years of human waste.
0:05:55 > 0:05:57It's quite a challenge.
0:05:57 > 0:06:02And the team must begin at the beginning, by escaping planet Earth.
0:06:18 > 0:06:22If anyone should ever ask you to build a spaceship to go to Mars,
0:06:22 > 0:06:24then, like any craftsman,
0:06:24 > 0:06:28you first have to find a space to work in.
0:06:29 > 0:06:33This vast hangar, once home to key parts of the Apollo rockets
0:06:33 > 0:06:37and Space Shuttle, is where a rocket that'll one day
0:06:37 > 0:06:39go to Mars will take shape.
0:06:51 > 0:06:54Ricardo Navarro is clearing the decks
0:06:54 > 0:06:56so that assembly of the rocket can begin.
0:07:01 > 0:07:05It's so much larger than what we did here before. So much taller.
0:07:05 > 0:07:09The best way to assemble something this complex and this big
0:07:09 > 0:07:10is to assemble it vertically.
0:07:16 > 0:07:18You generally want to build like you fly.
0:07:20 > 0:07:23So they start at the bottom, with the fuel tanks.
0:07:24 > 0:07:28This is as high as we can go using the elevator. The rest is on foot.
0:07:35 > 0:07:37It's hard to tell with this big of a space
0:07:37 > 0:07:40how big the actual vehicle's going to be, the rocket.
0:07:40 > 0:07:43But you can actually already see some signs emerging.
0:07:43 > 0:07:46You can see that blue circle forming.
0:07:46 > 0:07:49That is the actual diameter of the rocket.
0:07:51 > 0:07:54So you can imagine something of that diameter, all the way up
0:07:54 > 0:07:56to about ten feet below where we are right now,
0:07:56 > 0:07:59being the actual size of the hydrogen tank.
0:07:59 > 0:08:02Even at this height, we cannot contain the entire rocket.
0:08:04 > 0:08:09The rocket is called the Space Launch System, or SLS.
0:08:09 > 0:08:12And this building can only accommodate half of it.
0:08:18 > 0:08:24So far, very little of the SLS exists beyond the drawing boards,
0:08:24 > 0:08:27save for one part that's already under construction.
0:08:31 > 0:08:34Here, in New Orleans, they're building the first section
0:08:34 > 0:08:37of this monster rocket - the fuel tanks.
0:08:52 > 0:08:56Lead engineer Todd May has come to see the first completed section.
0:09:13 > 0:09:16And this is what it's like to be inside a rocket.
0:09:20 > 0:09:23To keep it light, it's made out of aluminium,
0:09:23 > 0:09:26using a design inspired by nature.
0:09:29 > 0:09:32This is an iso-grid pattern. It looks a little like honeycombs.
0:09:32 > 0:09:34You know, bees are pretty smart.
0:09:34 > 0:09:38We make this this way to actually keep most of the strength
0:09:38 > 0:09:43of the material while being able to remove 90% of the weight.
0:09:43 > 0:09:45Keeping the weight down is imperative,
0:09:45 > 0:09:49because this seven-metre-high slab is just one of many
0:09:49 > 0:09:52which will make up the overall rocket.
0:09:52 > 0:09:54Now, to make a core of a rocket,
0:09:54 > 0:09:59you actually have to have the equivalent of ten of these tall.
0:09:59 > 0:10:02You have a hydrogen tank, which is the equivalent of five of these,
0:10:02 > 0:10:05plus a dome on either end. And then the liquid oxygen tank,
0:10:05 > 0:10:09which is two of these with a dome on either end.
0:10:09 > 0:10:12The core, when you're finished, is two thirds of a football field long.
0:10:12 > 0:10:15By the time you add the interim upper stage,
0:10:15 > 0:10:17it's taller than the Statue of Liberty.
0:10:17 > 0:10:20This giant piece of metal will be useful for just moments.
0:10:20 > 0:10:23So, to give you a sense of what's going on through launch,
0:10:23 > 0:10:26this section, which is filled with rocket fuel,
0:10:26 > 0:10:29is pouring it out through the engines very quickly.
0:10:29 > 0:10:33Just one section like this would empty in about a minute.
0:10:33 > 0:10:36This is the only piece of the rocket that exists right now.
0:10:36 > 0:10:40But before it can be tested in 2017,
0:10:40 > 0:10:43millions of other parts will be made to join it.
0:10:53 > 0:10:57July 1969. The launch of Apollo 11.
0:11:00 > 0:11:03The mission - to leave Earth and carry three men
0:11:03 > 0:11:05in a 30-ton capsule...
0:11:14 > 0:11:18..a distance of 385,000 kilometres...
0:11:26 > 0:11:30..and to be the first to step on the surface of a body other than Earth.
0:11:35 > 0:11:38It was a phenomenal feat.
0:11:38 > 0:11:41And the whole experience took little more than a week.
0:11:43 > 0:11:45CHEERING
0:11:49 > 0:11:54But Mars is a very different proposition to the Moon.
0:11:54 > 0:11:58Lying 56 million kilometres from Earth,
0:11:58 > 0:12:02Mars is over 140 times farther away.
0:12:02 > 0:12:05With current technology, a return journey
0:12:05 > 0:12:07would take around three years,
0:12:07 > 0:12:11and require a team of four to eight astronauts.
0:12:11 > 0:12:15Anyone who thinks this is Apollo with bigger rockets
0:12:15 > 0:12:16needs to think again.
0:12:18 > 0:12:22Because this is a mission that will take man, for the first time,
0:12:22 > 0:12:28out of Earth's orbit, leaving its protection far behind.
0:12:47 > 0:12:48Stennis, Mississippi.
0:12:50 > 0:12:52This is the place where every single rocket engine
0:12:52 > 0:12:56that NASA has ever built has been tested...
0:12:56 > 0:12:59from Saturn V to the Space Shuttle main engine.
0:13:02 > 0:13:06Today, Mission Control are setting up for a full-power burn
0:13:06 > 0:13:08of one of their latest models.
0:13:11 > 0:13:13Gary Benton, who's in charge of rocket testing,
0:13:13 > 0:13:15has come to oversee the burn.
0:13:19 > 0:13:21SIREN BLARES
0:13:21 > 0:13:23The one-minute siren. So we're within a minute now.
0:13:23 > 0:13:27We're getting close. My heart's beating pretty fast right now.
0:13:27 > 0:13:30I've got some adrenaline rushing through me.
0:13:30 > 0:13:32And there'll be more once it cranks up here in a few minutes.
0:13:42 > 0:13:43We're off!
0:14:05 > 0:14:07An engine like this will be just one of six
0:14:07 > 0:14:11which will help propel the SLS into orbit.
0:14:17 > 0:14:19Looks like a safe shutdown.
0:14:24 > 0:14:27So when the time comes to test the much bigger SLS rocket,
0:14:27 > 0:14:30it must be at the largest stand they have.
0:14:35 > 0:14:37Like so much in the mission to Mars,
0:14:37 > 0:14:41they'll be standing on the shoulders of NASA's previous missions,
0:14:41 > 0:14:45borrowing and re-purposing the best from Apollo and the Shuttle.
0:14:51 > 0:14:54- How's it going, man? - It's going good.- All right.
0:14:54 > 0:14:56B Stand was built over 50 years ago
0:14:56 > 0:15:01for the testing of the Saturn engines that carried the Apollo missions to space.
0:15:01 > 0:15:05- You can't walk round there, cos there's so many people.- Right.
0:15:06 > 0:15:11Gary and his team will be reshaping and upgrading this stand
0:15:11 > 0:15:14so that it can cope with the next generation of rockets.
0:15:18 > 0:15:21This is the same crane that we used to lift those Saturn V four-stages
0:15:21 > 0:15:26and we're going to use the very same crane to lift the SLS four-stage
0:15:26 > 0:15:29and place it in this facility, anchor it down really good.
0:15:29 > 0:15:31Firing off about two million pounds of thrust.
0:15:31 > 0:15:34And that's going to be the biggest test we've done out here
0:15:34 > 0:15:37since we did the Saturn V.
0:15:37 > 0:15:39There's a palpable sense of excitement here
0:15:39 > 0:15:42because for the first time in decades,
0:15:42 > 0:15:45they're thinking of using these rockets to send PEOPLE
0:15:45 > 0:15:47beyond Earth's orbit.
0:15:52 > 0:15:55For now, this is NASA's best vision of what a rocket
0:15:55 > 0:15:57bound for Mars would look like.
0:15:57 > 0:16:01'Eight, seven, six, five, four...'
0:16:01 > 0:16:03But if you're going all the way to Mars,
0:16:03 > 0:16:06a single rocket of this size is not enough.
0:16:07 > 0:16:11NASA estimates that they will need at least seven launches
0:16:11 > 0:16:14to get all the equipment they need up into space.
0:16:15 > 0:16:18The fuel, the food, the Mars Lander -
0:16:18 > 0:16:21all will need to be launched into Earth's orbit
0:16:21 > 0:16:25and then assembled in space, much as the Space Station has been.
0:16:28 > 0:16:32Only then will it be ready to leave Earth's orbit.
0:16:39 > 0:16:43But there's an uncomfortable truth about the journey ahead.
0:16:43 > 0:16:46Since they can't carry enough fuel for the full distance,
0:16:46 > 0:16:50they need to rely on Mars's gravity to pull them in.
0:16:50 > 0:16:56It's called the slingshot effect and it means that once they're off,
0:16:56 > 0:16:57there's no turning back.
0:16:59 > 0:17:03Anyone who's willing to leave the safety of Earth behind
0:17:03 > 0:17:06needs to be a very particular type of person.
0:17:19 > 0:17:24Back in the days of Apollo 11, picking a crew was straightforward.
0:17:24 > 0:17:26It was clear who had the right stuff.
0:17:28 > 0:17:32Neil Armstrong, Buzz Aldrin and Michael Collins
0:17:32 > 0:17:35were the cream of US supersonic flight.
0:17:35 > 0:17:39They were drawn from the elite world of fighter and test pilots.
0:17:40 > 0:17:45And with that came supreme hand-eye co-ordination and physical daring.
0:17:56 > 0:18:01But these may not be the same skills you'd need to go to Mars.
0:18:04 > 0:18:07I noticed that a lot of the astronauts were of the old school.
0:18:07 > 0:18:10"I hunt, I fish, I ski,
0:18:10 > 0:18:13"I climb mountains, I climb trees..."
0:18:13 > 0:18:15You know, lots of outdoor stuff.
0:18:15 > 0:18:18But think about a mission to Mars. What is it?
0:18:18 > 0:18:21Is it outdoor stuff or is it confinement?
0:18:21 > 0:18:24And then I see somebody that says, "I have a stamp collection,
0:18:24 > 0:18:27"I do a lot of reading, I enjoy watching movies."
0:18:27 > 0:18:30And I'm thinking, "That might be good for confinement!"
0:18:32 > 0:18:36Dr David Dinges is interested in how you select a crew
0:18:36 > 0:18:39and safeguard their psychological welfare in space.
0:18:43 > 0:18:46And the key issue is really understanding who's going to develop
0:18:46 > 0:18:50a problem and when will it develop? Will all the crew develop it?
0:18:50 > 0:18:53How do we detect it? How do we prevent it to begin with?
0:18:56 > 0:19:00To date, the only answers come from a Russian study -
0:19:00 > 0:19:03an Earth-bound simulation of the approximately 520 days
0:19:03 > 0:19:07in isolation it would take for a return trip to the Red Planet.
0:19:10 > 0:19:15As the Russian study was gearing up, Dr Dinges set himself a challenge.
0:19:15 > 0:19:18Could he use his expert knowledge to anticipate
0:19:18 > 0:19:20who would fare best in confinement?
0:19:22 > 0:19:25In the Mars 520 mission I watched the crew intensively.
0:19:25 > 0:19:29I wanted to see them during the maelstrom of media attention
0:19:29 > 0:19:32before they went in to the chamber and how they interacted
0:19:32 > 0:19:33in that environment.
0:19:33 > 0:19:37And body posture, where they were looking, what they said.
0:19:37 > 0:19:39When they went in, he made his prediction.
0:19:41 > 0:19:45And I made notes and I wrote down a variety of things.
0:19:45 > 0:19:48I made predictions - and this is true - I sealed it up in an envelope
0:19:48 > 0:19:52and put it in the drawer and waited till the mission was over.
0:19:52 > 0:19:55In this footage, released by the European Space Agency,
0:19:55 > 0:19:57the astronauts look well.
0:19:57 > 0:20:00But by the end, deep troubles were brewing.
0:20:03 > 0:20:06The bottom line is that out of six people who went,
0:20:06 > 0:20:09only two didn't have significant behavioural problems
0:20:09 > 0:20:10of one kind or another.
0:20:13 > 0:20:14A couple of them experienced insomnia.
0:20:14 > 0:20:20One experienced some depression. Another was more socially isolated.
0:20:20 > 0:20:24But the two I predicted would make it just fine made it just fine.
0:20:25 > 0:20:29Like the Apollo missions, the Russian study was all-male.
0:20:29 > 0:20:33But what if NASA were to shake up this tradition?
0:20:33 > 0:20:35I suspect we're going to find there are some areas women have
0:20:35 > 0:20:39a slight advantage. In some areas men have a slight advantage.
0:20:39 > 0:20:44Bone loss or radiation. And so I think a mixed crew is likely.
0:20:48 > 0:20:53The agencies want to show that the astronauts represent humanity, right?
0:20:53 > 0:20:55And that's a reasonable thing to do.
0:20:58 > 0:21:01NASA hope to launch the mission in 2033.
0:21:01 > 0:21:05So the astronauts who'll get to go are probably still at school.
0:21:13 > 0:21:16If you were among those astronauts on board,
0:21:16 > 0:21:20you'd sense the major physical challenge immediately -
0:21:20 > 0:21:21a lack of gravity.
0:21:22 > 0:21:26It's a problem faced every day on the Space Station
0:21:26 > 0:21:30but, so far, no-one has spent more than 15 months in low gravity.
0:21:32 > 0:21:36But if you were on your way to Mars, you'd be away for twice that time.
0:21:40 > 0:21:44For the scientists the question is, how do you understand
0:21:44 > 0:21:47the long-term effects of weightlessness here on Earth?
0:21:48 > 0:21:52- Good afternoon! Time for lunch. - Lunch, already?
0:21:52 > 0:21:56- Yes. Isn't it amazing how time flies?- Let's eat!- Bon appetit!
0:21:56 > 0:22:02Welcome to the weird, horizontal world of Frank and Daniel.
0:22:03 > 0:22:08They've volunteered to spend 70 days in a row lying down,
0:22:08 > 0:22:12as part of an ongoing study on the effects of weightlessness.
0:22:12 > 0:22:15That's because the closest thing to zero-G conditions
0:22:15 > 0:22:17here on Earth is to lie in bed.
0:22:19 > 0:22:22But that's much harder work than it looks.
0:22:22 > 0:22:24The second morning waking up from the bed-rest,
0:22:24 > 0:22:28you kind of, you know, want to try to normally sit up like you normally do,
0:22:28 > 0:22:32but then you bring the lamp down to you to turn on your lights.
0:22:32 > 0:22:35You don't go up to the lamp. It's a little difficult.
0:22:35 > 0:22:38Yeah, taking a dump here's not too pleasant!
0:22:38 > 0:22:40But, you know, what can you do? You've got to do it.
0:22:40 > 0:22:42It's not too bad, you know.
0:22:42 > 0:22:46I guess I can finally say I know how to use one of our bedpans!
0:22:46 > 0:22:47HE LAUGHS
0:22:47 > 0:22:49You should try it. It's a good experience!
0:22:49 > 0:22:51HE LAUGHS
0:22:58 > 0:23:01- Hey, Frank, how is it going? - It's been pretty good, you know.
0:23:01 > 0:23:04- You're on bed-rest day 28! - That's correct.
0:23:04 > 0:23:07Yeah, so how was it when you first went head down?
0:23:07 > 0:23:09Dr Roni Cromwell is running the trial,
0:23:09 > 0:23:12which overall has 27 subjects.
0:23:14 > 0:23:16So we get people from all walks of life.
0:23:16 > 0:23:18We've had people who are between jobs,
0:23:18 > 0:23:21that are looking for something to do.
0:23:21 > 0:23:25We've had people that wish they had been able to be an astronaut
0:23:25 > 0:23:28and since that couldn't happen, they wanted to do the next best thing.
0:23:30 > 0:23:33Roni ensures that all the subjects are kept with their heads tilted
0:23:33 > 0:23:38six degrees down, which best emulates the effects of space.
0:23:38 > 0:23:41And by tipping them six degrees head down tilt,
0:23:41 > 0:23:44we see the headward fluid shifts,
0:23:44 > 0:23:48that is similar to what astronauts experience in space as well.
0:23:48 > 0:23:52And by doing that we can then study the mechanism for these changes
0:23:52 > 0:23:56as well as develop countermeasures to mitigate these changes.
0:23:57 > 0:24:00A typical day starts with breakfast in bed...
0:24:06 > 0:24:09..and a shower...in bed.
0:24:15 > 0:24:19After lunch, tests...in bed.
0:24:21 > 0:24:23My favourite part!
0:24:23 > 0:24:26Today, they're investigating a mission-critical problem -
0:24:26 > 0:24:30why astronauts often lose their appetite in space.
0:24:30 > 0:24:34During weightlessness, body fluids flow into the head
0:24:34 > 0:24:38and scientists believe this may affect the airflow.
0:24:38 > 0:24:41So they're measuring the size of Frank's nasal cavity,
0:24:41 > 0:24:43to look for swelling which might restrict
0:24:43 > 0:24:45his sense of smell and taste.
0:24:50 > 0:24:52Daniel is slightly luckier.
0:24:53 > 0:24:56He's among the 50% of subjects who are selected
0:24:56 > 0:25:01to occasionally escape bed to study the effects of exercise.
0:25:04 > 0:25:06It can be a little bewildering.
0:25:12 > 0:25:16The reason for optimising the exercise programme
0:25:16 > 0:25:22is to find the best sort of recipe for the exercise that's needed
0:25:22 > 0:25:25to preserve muscle and bone in our astronauts.
0:25:27 > 0:25:30Exercise has long been known as a means of staving off
0:25:30 > 0:25:32loss of bone and muscle mass in space.
0:25:34 > 0:25:37Because the effects of this can be devastating.
0:25:48 > 0:25:52These astronauts, just landed from the Soyuz capsule in 2013,
0:25:52 > 0:25:56are too weak to even stand, let alone walk.
0:25:57 > 0:26:01On a mission to Mars, the effects would be even more pronounced.
0:26:01 > 0:26:03After all, it's a much longer journey.
0:26:05 > 0:26:08But there'll be no-one on Mars to carry them away.
0:26:09 > 0:26:12The astronauts must be able to step out of the capsule
0:26:12 > 0:26:16and onto the Martian surface by themselves.
0:26:21 > 0:26:25Scientists are realising that exercise alone, however optimised,
0:26:25 > 0:26:27is not enough.
0:26:27 > 0:26:30If humans are ever going to be strong enough to explore
0:26:30 > 0:26:33the Martian surface, they'll need some other help
0:26:33 > 0:26:35to keep them fit for the adventure ahead.
0:26:42 > 0:26:47You may never even notice it, but millions of years of evolution
0:26:47 > 0:26:53have finely tuned your body to conditions on planet Earth,
0:26:53 > 0:26:57so that cells in your muscle and your bone simply can't grow
0:26:57 > 0:27:01without the force of gravity acting on them.
0:27:11 > 0:27:14So Dr Randall Urban is looking for something that can stimulate
0:27:14 > 0:27:18muscle and bone growth, in the absence of gravity.
0:27:19 > 0:27:21And he's turned his attention to a chemical
0:27:21 > 0:27:24that's well known for building your body.
0:27:26 > 0:27:30Well, testosterone is a very interesting hormone
0:27:30 > 0:27:35and it seems to be primarily responsible for protection of bone
0:27:35 > 0:27:36and protection of muscle.
0:27:38 > 0:27:41Dr Urban is working with the bed-rest study.
0:27:41 > 0:27:44He's giving regular injections of testosterone
0:27:44 > 0:27:47to half of the subjects who are exercising.
0:27:47 > 0:27:49But it's a double-blind study,
0:27:49 > 0:27:53so no-one knows who's getting the testosterone and who isn't.
0:27:53 > 0:27:57We see that one of the exercise groups is doing much better
0:27:57 > 0:27:59than the other exercise group.
0:27:59 > 0:28:02In our minds, we think that may be the testosterone group
0:28:02 > 0:28:04which is showing that benefit.
0:28:07 > 0:28:11Daniel doesn't know whether he's received the testosterone or not.
0:28:11 > 0:28:13He'll just keep on running
0:28:13 > 0:28:18and having his bone and muscle mass monitored, until his 70 days are up.
0:28:18 > 0:28:21The results of the study will help determine whether astronauts
0:28:21 > 0:28:24travelling to Mars will take doses of testosterone
0:28:24 > 0:28:27to keep their bones and muscles strong.
0:28:29 > 0:28:32But that raises an interesting question.
0:28:32 > 0:28:34What if some of those astronauts are women?
0:28:35 > 0:28:38When we use testosterone in women we have to be very concerned
0:28:38 > 0:28:42about the side effects which actually will cause them
0:28:42 > 0:28:45to develop male characteristics.
0:28:45 > 0:28:49We would have to be figuring out ways to deliver testosterone
0:28:49 > 0:28:52in low enough doses that you wouldn't get
0:28:52 > 0:28:55any of those other characteristics in the women.
0:28:57 > 0:29:01It remains to be seen whether testosterone can be given to women,
0:29:01 > 0:29:05not to mention a group of competitive men in a confined space.
0:29:06 > 0:29:09But the health risks of travelling to Mars
0:29:09 > 0:29:11don't just threaten the body.
0:29:11 > 0:29:16Perhaps the greatest challenge of all is in the mind.
0:29:28 > 0:29:29Ignition.
0:29:36 > 0:29:39Imagine you're one of the astronauts and you've now been on board
0:29:39 > 0:29:41for several months, in the same small place,
0:29:41 > 0:29:44with the same few people.
0:29:44 > 0:29:46You've played all the games on your tablet
0:29:46 > 0:29:49and the view out of the window never changes.
0:29:49 > 0:29:54You may start to feel a little bored. Perhaps a little glum.
0:29:54 > 0:29:59And this is important, not just because it's nice to be happy.
0:29:59 > 0:30:02Having a functioning team on a spaceship
0:30:02 > 0:30:04can be a matter of life and death.
0:30:06 > 0:30:09If you become depressed in space flight,
0:30:09 > 0:30:12if you develop a poor interaction style or you become socially
0:30:12 > 0:30:16isolated because something's wrong and your brain can't cope
0:30:16 > 0:30:19or your behaviour's off, or you become cognitively impaired,
0:30:19 > 0:30:20then you pose a risk for yourself
0:30:20 > 0:30:22and the rest of the crew and the mission.
0:30:22 > 0:30:25These problems occurred in the past with Shackleton, with Nansen,
0:30:25 > 0:30:28with Amundsen, with all the great expeditions.
0:30:28 > 0:30:30They remain fundamental problems.
0:30:35 > 0:30:38One solution being tested by Dr Dinges and his team
0:30:38 > 0:30:41is to use the spacecraft's on-board cameras
0:30:41 > 0:30:45to watch over the astronauts day and night.
0:30:46 > 0:30:49I want to review, sort of, what we've got. OK, so get position.
0:30:49 > 0:30:50Centre yourself.
0:30:52 > 0:30:56Dr Dinges and his team are using new facial recognition software,
0:30:56 > 0:30:59and its success hinges on identifying telltale signs
0:30:59 > 0:31:04in the face, which betray what the mind beyond is really thinking.
0:31:04 > 0:31:08Number one, for just tracking purposes, the jaw line really helps.
0:31:08 > 0:31:10You, know where the face is oriented.
0:31:10 > 0:31:14Number two, we need the lips because the lips tell a lot about frowns,
0:31:14 > 0:31:16smiles. And then we need the eyes.
0:31:16 > 0:31:19The eyes are hugely expressive in humans.
0:31:19 > 0:31:22Chris, give us just neutral here.
0:31:22 > 0:31:25And just, you know, think about just work
0:31:25 > 0:31:28or whatever you're doing, and nothing particularly important.
0:31:28 > 0:31:30Now give me a positive.
0:31:30 > 0:31:32OK? A small smile, nothing big.
0:31:32 > 0:31:36Just a small joke, there you go.
0:31:36 > 0:31:39And now don't be so dramatic with the negative but definitely show me
0:31:39 > 0:31:42something negative, like you're annoyed that somebody's...
0:31:42 > 0:31:45You don't have to show sadness. Try and give me some anger.
0:31:45 > 0:31:46There you go, bingo.
0:31:46 > 0:31:48It's not just emotion.
0:31:48 > 0:31:51Another important state of mind in space
0:31:51 > 0:31:54is how much concentration you have.
0:31:54 > 0:31:58We discovered that the most reliable measure, better than brainwave,
0:31:58 > 0:32:00was speed of the eyelid closure,
0:32:00 > 0:32:02the levator palpebrae muscle in the eyelid.
0:32:02 > 0:32:05And that's what these little green boxes are tracking,
0:32:05 > 0:32:09and as we get more tired, no matter what we're doing,
0:32:09 > 0:32:12the speed of the eyelid blink slows.
0:32:12 > 0:32:17Now, it's only slowing in 100, 200, 300 thousandths of a second
0:32:17 > 0:32:21so it's almost not visible to a human, but in this case
0:32:21 > 0:32:24the computer can measure it with a great deal of precision.
0:32:24 > 0:32:28And that means you're highly likely to have a lapse of attention,
0:32:28 > 0:32:31to have either a microsleep or fail to respond
0:32:31 > 0:32:33in a timely manner to something you're monitoring.
0:32:33 > 0:32:37And that's why this is so valuable, because now we know your emotion,
0:32:37 > 0:32:40and we know if you're tired or fatigued from inadequate sleep,
0:32:40 > 0:32:42sleep loss, circadian desynchrony on the spacecraft.
0:32:45 > 0:32:48But is it overkill to design a machine to do a job
0:32:48 > 0:32:51so instinctive for humans?
0:32:51 > 0:32:54You could argue, "Well, can't a human just do it, then?"
0:32:54 > 0:32:55Are you serious?
0:32:55 > 0:32:58Is a human going to actually look at, you know, every 30 seconds
0:32:58 > 0:33:04or a minute, a face constantly for a 17-month mission? It's not realistic.
0:33:04 > 0:33:07Better to have a machine do it, with an algorithm,
0:33:07 > 0:33:09then it feeds it back in aggregate. Then a human can say,
0:33:09 > 0:33:12"Give me that section of the mission right here,
0:33:12 > 0:33:13"and give me this astronaut,"
0:33:13 > 0:33:16"and what's going on here? Cos we saw a big spike here".
0:33:18 > 0:33:21But what this research cannot answer is the question that might
0:33:21 > 0:33:24keep a would-be Mars astronaut awake at night.
0:33:25 > 0:33:30What if you or one of your crew members DID break down?
0:33:30 > 0:33:32How would you deal with it?
0:33:32 > 0:33:35You can't step outside to calm down.
0:33:36 > 0:33:38It's a frightening thought.
0:33:39 > 0:33:41One we've never faced before.
0:33:45 > 0:33:50Thankfully, life in space is not all rumination and introspection.
0:33:50 > 0:33:54There are everyday, practical issues to attend to.
0:33:54 > 0:33:59How do you keep yourself clean? Tidy? Healthy?
0:33:59 > 0:34:01How do you cope with the barest necessities?
0:34:06 > 0:34:09Here we are at the throne!
0:34:09 > 0:34:10Number two, right here.
0:34:12 > 0:34:13I'll show you.
0:34:14 > 0:34:18But you see, it's pretty small so you have to have pretty good aim.
0:34:18 > 0:34:22And this guy right here... is for number one.
0:34:22 > 0:34:24People always ask about toilet paper.
0:34:24 > 0:34:27"What do you do with toilet paper? What kind of toilet paper do you have?"
0:34:27 > 0:34:30We have gloves, just because sometimes it does get messy.
0:34:30 > 0:34:33We have some Russian wipes, which are a little bit coarse
0:34:33 > 0:34:35if you like the coarse type of toilet paper.
0:34:35 > 0:34:38We have Huggies, erm, just for any clean-ups.
0:34:38 > 0:34:42You know, we were all babies once and this sort of helps.
0:34:42 > 0:34:45And, of course, you do have your privacy. There's a little door.
0:34:48 > 0:34:51But once you've closed that door and flushed the handle,
0:34:51 > 0:34:54what happens next?
0:34:54 > 0:34:59How do you deal with years of waste, with no plumbing and no sewers?
0:35:01 > 0:35:04Here in Tucson, Arizona, Taber McCallum,
0:35:04 > 0:35:07a specialist in space life-support systems,
0:35:07 > 0:35:10is dealing with the nitty-gritty of this question.
0:35:12 > 0:35:15And in space, he believes what comes out
0:35:15 > 0:35:19must be inextricably linked to what goes in.
0:35:21 > 0:35:24So one of the most important things we need to stay alive
0:35:24 > 0:35:26is drinking water.
0:35:26 > 0:35:31And people consume about two litres a day of drinking water,
0:35:31 > 0:35:36so for a 500-day mission, that's a ton of water. Four crew,
0:35:36 > 0:35:39that's four tonnes of water you'd have to bring with you,
0:35:39 > 0:35:43so we have to drink the same water over and over again.
0:35:47 > 0:35:50Taber is into recycling in a big way.
0:35:55 > 0:35:58What we have is a sample of today's urine
0:35:58 > 0:36:04and then we put that urine on one side of a special set of membranes.
0:36:04 > 0:36:07Similar to the way plants essentially treat water for us
0:36:07 > 0:36:11by transpiring the water through the membrane of the cell,
0:36:11 > 0:36:14the water then goes in on one side of the membrane,
0:36:14 > 0:36:17travels from molecule to molecule,
0:36:17 > 0:36:20and at the other side of the membrane, evaporates away.
0:36:20 > 0:36:23So it's a process of hydration and dehydration,
0:36:23 > 0:36:26and in that process of the membrane we selectively only get water.
0:36:29 > 0:36:33He's hoping to reclaim 98% of drinkable water
0:36:33 > 0:36:35from the crew's urine.
0:36:35 > 0:36:38That's a significant improvement from the 75%
0:36:38 > 0:36:40currently recycled on the Space Station.
0:36:45 > 0:36:48But Taber has also set his sights on solid waste.
0:36:51 > 0:36:53There's two issues with solid waste.
0:36:53 > 0:36:57One is there is water in that solid waste that we'd like to extract,
0:36:57 > 0:37:00but even if you didn't bother to extract that water out, what
0:37:00 > 0:37:05am I going to do with bags of solid human waste for a year and a half?
0:37:05 > 0:37:09You've got to stabilise it somehow, that it won't produce
0:37:09 > 0:37:13lots of gases and smell bad and ferment and who knows!
0:37:13 > 0:37:14So some people keep suggesting,
0:37:14 > 0:37:17"Why don't you just blast this waste into outer space?"
0:37:17 > 0:37:21One of the more interesting reasons not to is that we'd end up
0:37:21 > 0:37:24at Mars with a cloud of waste around the spaceship.
0:37:24 > 0:37:29It's not going anywhere. It's already on the trajectory that we're on.
0:37:29 > 0:37:31So you really want to keep all that stuff away from the spacecraft
0:37:31 > 0:37:34and make good use of this material.
0:37:34 > 0:37:37It's good material - we just have to figure out how to use it.
0:37:39 > 0:37:43For some reason I can't get any of the lab techs interested in this project!
0:37:44 > 0:37:48It may seem trivial, but a mission to Mars will only become
0:37:48 > 0:37:50a practical reality if these problems,
0:37:50 > 0:37:54that all of us take for granted in our Earthly lives, can be solved.
0:37:59 > 0:38:03But imagine the recycling of waste was sorted.
0:38:03 > 0:38:07And imagine your body and mind could be kept strong.
0:38:07 > 0:38:10If you were on the way to Mars,
0:38:10 > 0:38:13there would still remain one powerful threat to your survival.
0:38:15 > 0:38:17Radiation.
0:38:22 > 0:38:26Just how much radiation you, as an astronaut, would be exposed to
0:38:26 > 0:38:29was quantified by the recent Curiosity mission.
0:38:30 > 0:38:33And they found it to be several hundred times more intense
0:38:33 > 0:38:35than on Earth.
0:38:35 > 0:38:36And that's a problem.
0:38:39 > 0:38:44So one important factor of, actually, life on Earth
0:38:44 > 0:38:46and how we were able to evolve is that we're protected
0:38:46 > 0:38:48from the radiation of galactic cosmic rays
0:38:48 > 0:38:51and from the radiation of the sun by the magnetic field of the Earth,
0:38:51 > 0:38:53which is caused by the iron core of the Earth.
0:38:56 > 0:38:59That magnetic field creates a protective shield around
0:38:59 > 0:39:04our planet called the magnetosphere, which deflects radiation.
0:39:05 > 0:39:08The more dangerous solar particles don't get through
0:39:08 > 0:39:12so that we, mostly, receive only life-giving sunshine.
0:39:21 > 0:39:24But out in space, everything is different.
0:39:26 > 0:39:31Out here, the bubbling surface of the sun occasionally builds
0:39:31 > 0:39:34to a huge explosion.
0:39:34 > 0:39:39These solar flares throw out massive bursts of radiation
0:39:39 > 0:39:43and high-energy protons, which might damage your DNA,
0:39:43 > 0:39:46causing mutations and cancer later on.
0:39:51 > 0:39:56Fortunately, there's a way of dealing with this - shielding.
0:39:56 > 0:40:00Jeff Cerro is investigating the best materials to absorb radiation.
0:40:02 > 0:40:06So we're looking at taking a garment and filling it with water,
0:40:06 > 0:40:09which you see a first concept of here.
0:40:09 > 0:40:15This astronaut with a water wall built into his wearable garment.
0:40:15 > 0:40:20So this is something that you fill for an event and you're not really
0:40:20 > 0:40:23charging the system the penalty of carrying all this mass.
0:40:23 > 0:40:27You need the water anyways for drinking, for contingency water.
0:40:27 > 0:40:31So it gets protection. It may be a different form
0:40:31 > 0:40:33but with a lot less mass penalty to it.
0:40:35 > 0:40:38Doubling up on function using materials that would be
0:40:38 > 0:40:42on board anyway is an idea that Jeff is enthusiastic about.
0:40:45 > 0:40:49We're trying to look at protecting astronauts using the logistics
0:40:49 > 0:40:52which we already have on hand, so there's food,
0:40:52 > 0:40:56items that we have in these bags that unfold to form a wall.
0:40:56 > 0:41:00If you put a wall against the outside surface, you're trying to place
0:41:00 > 0:41:05all these items between the astronaut and radiation you've got outside.
0:41:05 > 0:41:07So the more items you can put between him and that,
0:41:07 > 0:41:09you know, you attenuate the radiation,
0:41:09 > 0:41:13the safer he'll be during this 36-hour solar particle event.
0:41:13 > 0:41:17So, we've tried with food, we're trying to use water
0:41:17 > 0:41:21but we're trying to use items that you're going to have on board the station anyways.
0:41:24 > 0:41:26But there's an even bigger problem...
0:41:27 > 0:41:32Another source of radiation that's even more damaging -
0:41:32 > 0:41:34galactic cosmic rays.
0:41:37 > 0:41:40Galactic cosmic rays are high-energy particles
0:41:40 > 0:41:44spewed out from supernovae - exploding stars.
0:41:46 > 0:41:48Their effects are pernicious.
0:41:48 > 0:41:52By affecting the growth of brain cells, they can induce memory loss
0:41:52 > 0:41:55in an astronaut after just six months in space.
0:41:57 > 0:41:59But to shield a crew from radiation such as this
0:41:59 > 0:42:04is currently impossible, so they have to look for other answers.
0:42:06 > 0:42:09The best solution is to have people who are less
0:42:09 > 0:42:13susceptible to their effects, or get there more quickly, so the lower
0:42:13 > 0:42:18time in exposure is going to result in a lower risk to the crew members.
0:42:20 > 0:42:25So the "right stuff" for a Mars astronaut might not just be defined
0:42:25 > 0:42:29physically and psychologically, but also genetically.
0:42:31 > 0:42:35There's a theoretical possibility as well that we could find some
0:42:35 > 0:42:38genetic markers of people who are less susceptible to
0:42:38 > 0:42:40the kinds of damage that occur during radiation.
0:42:40 > 0:42:44It's too early in any of our research programmes to be able to
0:42:44 > 0:42:47speculate on that, but it's certainly a theoretical possibility,
0:42:47 > 0:42:51and it's one that we'll be investigating over the next few years of our programme.
0:42:51 > 0:42:55But, for now, the stark reality is there is no obvious solution
0:42:55 > 0:42:58to the problem of surviving space radiation.
0:42:58 > 0:43:03At the moment, this is one of the great unknowns of a mission to Mars.
0:43:14 > 0:43:17But assume you've escaped the radiation
0:43:17 > 0:43:19and the mission is on track.
0:43:23 > 0:43:26After being launched in the world's biggest rocket,
0:43:26 > 0:43:29you've staved off the weakening effects of zero gravity...
0:43:32 > 0:43:35..you've kept yourself sane...
0:43:35 > 0:43:37you've managed to recycle everything...
0:43:39 > 0:43:41..and you've survived solar flares.
0:43:46 > 0:43:50So now, after travelling for over eight months
0:43:50 > 0:43:54and across 56 million kilometres of space,
0:43:54 > 0:43:57you're finally arriving
0:43:57 > 0:43:58at the planet Mars.
0:44:02 > 0:44:07Now comes the greatest engineering challenge of the whole mission -
0:44:07 > 0:44:08landing.
0:44:11 > 0:44:14Dr Adam Steltzner has been set the task of working out
0:44:14 > 0:44:15how it'll be done.
0:44:18 > 0:44:24He masterminded the audacious landing of the Curiosity rover on Mars in 2012.
0:44:29 > 0:44:35I have tried to describe that many times and I fall short.
0:44:35 > 0:44:41And I fall short because it pegged my emotion level, you know,
0:44:41 > 0:44:44I have a meter... It just buried the needle.
0:44:49 > 0:44:53But my career's not over. I'm going try and make something better.
0:44:54 > 0:44:58But landing a human crew is a different matter entirely.
0:45:03 > 0:45:05So landing Curiosity, a ton,
0:45:05 > 0:45:09biggest thing we've landed on Mars to date, a challenge.
0:45:09 > 0:45:14But not nearly as much of a challenge as landing humans.
0:45:16 > 0:45:19Humans are sensitive, they're delicate, they don't
0:45:19 > 0:45:23like a lot of Gs, they like to carry water with them, they're heavy.
0:45:23 > 0:45:28So we think that landing humans might be something like
0:45:28 > 0:45:3240 metric tonnes, or maybe more.
0:45:33 > 0:45:37Once again, with a spacecraft carrying humans,
0:45:37 > 0:45:40it's the bigger size that raises challenges.
0:45:40 > 0:45:43There's this interesting bit of physics that occurs
0:45:43 > 0:45:46as you scale up things.
0:45:46 > 0:45:50Imagine scaling up a drop of water.
0:45:50 > 0:45:53As it gets small or big,
0:45:53 > 0:45:58its weight goes up with the size of it...
0:46:00 > 0:46:03Cubed, raised to the third power.
0:46:03 > 0:46:08But its aerodynamic drag gets larger
0:46:08 > 0:46:14based on its area, which is its diameter squared.
0:46:14 > 0:46:19What that means is, the bigger this self-similar thing gets,
0:46:19 > 0:46:21the more easily it falls.
0:46:21 > 0:46:23Same thing happens with spacecraft.
0:46:23 > 0:46:26So if you think about Curiosity,
0:46:26 > 0:46:31she came in going very, very fast, slowing down, slowing down,
0:46:31 > 0:46:34and eventually making contact with the surface.
0:46:35 > 0:46:39The smaller size of Curiosity meant that it was successfully
0:46:39 > 0:46:42slowed by aerodynamic drag as it fell.
0:46:42 > 0:46:46But scaling up the size for a human lander changes
0:46:46 > 0:46:49the physics of landing, radically.
0:46:49 > 0:46:51I've got this self-similar shape.
0:46:51 > 0:46:54I'm going to not put Curiosity on the surface,
0:46:54 > 0:46:57but I'm going to put two Curiositys.
0:46:57 > 0:47:01OK, three, four, five, getting a little challenging.
0:47:01 > 0:47:0240.
0:47:02 > 0:47:05Now, all of a sudden I can't fly that shape. It's the same shape
0:47:05 > 0:47:09it was before, it's packed at the same densities of spacecraft,
0:47:09 > 0:47:13but now it ends up flying a trajectory
0:47:13 > 0:47:18that intercepts the surface of Mars when its moving Mach 20.
0:47:18 > 0:47:20Not good.
0:47:21 > 0:47:24Perhaps to get really big things to the surface of Mars,
0:47:24 > 0:47:27what we need to do is...
0:47:30 > 0:47:34..we need to make our shape like this,
0:47:34 > 0:47:36which regular rockets look like,
0:47:36 > 0:47:39but when we come flying in, we don't put the pointy end in
0:47:39 > 0:47:42or the back end in, we come in sideways.
0:47:43 > 0:47:47By coming in sideways, the drag on the spacecraft is increased
0:47:47 > 0:47:53significantly, slowing the rocket from hypersonic to supersonic.
0:47:53 > 0:47:55To slow it down further,
0:47:55 > 0:48:00you need something else to push against the gravity of Mars.
0:48:00 > 0:48:03It's called supersonic retro-propulsion.
0:48:03 > 0:48:06Imagine motorbiking with your mouth open at 60mph.
0:48:06 > 0:48:09It's, "Whoa!" It fills your mouth with air
0:48:09 > 0:48:12and it's actually sometimes hard to breathe out against it.
0:48:12 > 0:48:14Well, that is the challenge of supersonic retro-repulsion.
0:48:14 > 0:48:17You're going to light a rocket off into the flow,
0:48:17 > 0:48:20but it's going to be supersonic flow.
0:48:20 > 0:48:22Well, NASA's working on that.
0:48:22 > 0:48:26And it's likely to take those rockets from a supersonic condition
0:48:26 > 0:48:28all the way down to the surface.
0:48:28 > 0:48:31It's an inventive and daring idea.
0:48:31 > 0:48:34But to carry out this manoeuvre calls once more on one
0:48:34 > 0:48:38of the sticking points that bedevils this entire mission -
0:48:38 > 0:48:39fuel.
0:48:40 > 0:48:43Retro-rockets will need a lot of it.
0:48:43 > 0:48:48And where that fuel comes from is something NASA will have to solve
0:48:48 > 0:48:50if they are ever to reach Mars.
0:49:02 > 0:49:05To stand on the planet Mars.
0:49:07 > 0:49:11What would be the reality of this centuries-old dream?
0:49:13 > 0:49:17Well, the good news is, not a lot of weather on Mars.
0:49:17 > 0:49:20It's very dry, it's windy, it can be dusty.
0:49:21 > 0:49:23But the bad news is
0:49:23 > 0:49:26that when the little weather there does stir the dust,
0:49:26 > 0:49:29it can create scenes like this.
0:49:30 > 0:49:34These are real images of a dust storm on Mars,
0:49:34 > 0:49:36captured by a NASA rover.
0:49:36 > 0:49:38When these storms do kick up,
0:49:38 > 0:49:42they can go on for months and envelop the whole planet.
0:49:46 > 0:49:50It's likely to be a far harsher situation than any astronaut faced
0:49:50 > 0:49:52on the lunar landings.
0:49:56 > 0:49:59Even on the Moon, conditions weren't easy.
0:50:00 > 0:50:04Lunar soil is clingy and caustic - its particles were small enough
0:50:04 > 0:50:08to cause a kind of lunar dust hay fever in the astronauts,
0:50:08 > 0:50:11and sharp enough to wear though their Kevlar boots.
0:50:13 > 0:50:17But no Apollo mission stayed on the Moon for longer than four days,
0:50:17 > 0:50:19and they all used their lander as a base.
0:50:21 > 0:50:23On Mars, life will be harder.
0:50:23 > 0:50:28The dust whipping around in the wind is known to contain carcinogens
0:50:28 > 0:50:31and other damaging chemicals called perchlorates.
0:50:33 > 0:50:38What's more, Mars astronauts will be expected to stay for a whole year
0:50:38 > 0:50:41before the planets line up for them to take the shortest journey
0:50:41 > 0:50:42back to Earth.
0:50:44 > 0:50:48So for these astronauts to live and work comfortably on the Martian
0:50:48 > 0:50:52surface, they're going to need a new form of protection.
0:51:11 > 0:51:15In charge of developing the next-generation spacesuit
0:51:15 > 0:51:16is Dr Amy Ross.
0:51:21 > 0:51:25So, one of the videos that we watch a lot is the Charlie Duke
0:51:25 > 0:51:27dropping the hammer on Apollo 16 video.
0:51:28 > 0:51:30He's trying to take a core sample,
0:51:30 > 0:51:35he's hitting that core with his hammer, and he just loses the hammer.
0:51:44 > 0:51:48He has real trouble retrieving the hammer,
0:51:48 > 0:51:51so he just resorts basically to falling on it.
0:51:54 > 0:51:56You can see we've progressed quite a ways,
0:51:56 > 0:51:59and so our crew members now and our subjects now
0:51:59 > 0:52:02can do all of those functional, realistic tasks that you need to do
0:52:02 > 0:52:07in a much more normal fashion that didn't scare spacesuit engineers
0:52:07 > 0:52:09like Charlie did on Apollo.
0:52:11 > 0:52:15Remarkably, spacesuits have changed little since the Apollo days,
0:52:15 > 0:52:19and those worn on the Space Station are just as bulky.
0:52:19 > 0:52:21So Amy is looking to slim down
0:52:21 > 0:52:24and add flexibility in every way she can.
0:52:25 > 0:52:30So we have a side bearing which allows you to rotate your shoulder.
0:52:30 > 0:52:32And then we have an upper-arm bearing, which you can see here,
0:52:32 > 0:52:34that lets you rotate your arm.
0:52:38 > 0:52:40Now, in the waist area,
0:52:40 > 0:52:44this suit was built so it can allow flexion extension joint,
0:52:44 > 0:52:48a waist bearing, and allows them some pretty wide range of motion,
0:52:48 > 0:52:51very natural, and you move your waist a lot when you walk
0:52:51 > 0:52:55and you don't realise that, so that's a very important joint to have.
0:52:55 > 0:52:56And then we can watch him squat...
0:53:02 > 0:53:05He can get down to his boots. So he can adjust his boots
0:53:05 > 0:53:07when the suit's pressurised.
0:53:12 > 0:53:14Can you touch the ground?
0:53:23 > 0:53:27And you can see the joints work as he's doing these functional tasks.
0:53:29 > 0:53:33Seemingly small developments like this take NASA ever closer
0:53:33 > 0:53:35to the prospect of sending humans to Mars.
0:53:40 > 0:53:43But from setting up a home on Mars
0:53:43 > 0:53:47to knowing how they'll generate enough food and oxygen,
0:53:47 > 0:53:50there are many thousands of these steps left to conquer.
0:53:52 > 0:53:54And the final unknown is this.
0:53:55 > 0:53:59Will the Mars astronauts be able to get home?
0:54:12 > 0:54:16When the Apollo astronauts returned, it was to a heroes' welcome.
0:54:31 > 0:54:33But for the astronauts going to Mars,
0:54:33 > 0:54:36there's rather more uncertainty about their homecoming.
0:54:41 > 0:54:46And that's because, as yet, no-one's worked out a way to get them home.
0:54:53 > 0:54:57For now, this is a problem that NASA is trying to solve.
0:55:01 > 0:55:03I would expect that they would come back.
0:55:03 > 0:55:06We wouldn't design a mission unless we were pretty certain
0:55:06 > 0:55:09they were going to be able to get back safely. That's one of our objectives.
0:55:09 > 0:55:12We want to explore, which means getting there and coming back
0:55:12 > 0:55:14and telling us what happened.
0:55:14 > 0:55:20We value, in our modern society, life too greatly
0:55:20 > 0:55:24to send astronauts on a one-way trip to the surface of Mars,
0:55:24 > 0:55:27intentionally, certainly. There are tremendous risks.
0:55:27 > 0:55:32The brave men and women who go into the astronaut corp...
0:55:32 > 0:55:34take on those risks knowingly.
0:55:35 > 0:55:37And sometimes astronauts perish.
0:55:39 > 0:55:42Part of planning the mission will be about the risks
0:55:42 > 0:55:44NASA are willing to accept.
0:55:45 > 0:55:47But that's a delicate balance.
0:55:48 > 0:55:51Because the more they aim to protect the astronauts,
0:55:51 > 0:55:55the higher the cost and the further into the future
0:55:55 > 0:55:57the dream will be pushed.
0:56:04 > 0:56:09A momentum is starting to build around a manned mission to Mars.
0:56:09 > 0:56:13Not just at NASA, but within other privately owned companies
0:56:13 > 0:56:16who may work alongside them or even in competition.
0:56:17 > 0:56:21Here at NASA, the scientists and engineers are doing what
0:56:21 > 0:56:24they love doing - starting to grapple with problems which,
0:56:24 > 0:56:27at first sight, seem unsolvable.
0:56:28 > 0:56:31If we committed ourselves to getting to Mars,
0:56:31 > 0:56:34we'd BE on Mars. Certainly within a decade.
0:56:34 > 0:56:37I believe that we could get there within a decade.
0:56:37 > 0:56:41The question is, are we willing to spend the efforts, the resources,
0:56:41 > 0:56:43the capital to do that?
0:56:43 > 0:56:46And I think the answer is, right now, no.
0:56:46 > 0:56:49But maybe sometime in the future.
0:56:49 > 0:56:52One reality is dawning.
0:56:52 > 0:56:54Given the scale of this challenge,
0:56:54 > 0:56:57it's one that no country can tackle on its own.
0:56:58 > 0:57:04More likely than not, a Mars mission will be a multi-national mission,
0:57:04 > 0:57:09so one political person in one country isn't going to drive the whole thing.
0:57:09 > 0:57:14It's going to require a lot of cooperation from countries around the globe.
0:57:14 > 0:57:16So this becomes a very interesting challenge,
0:57:16 > 0:57:19but one that Earthlings will take on
0:57:19 > 0:57:21and not just people from one country.
0:57:21 > 0:57:26So the greatest challenge of this mission to put Earthlings on Mars
0:57:26 > 0:57:29may not be a scientific or engineering one.
0:57:29 > 0:57:33Whichever countries or companies join the undertaking,
0:57:33 > 0:57:37it will be ambitious, risky and expensive.
0:57:38 > 0:57:43But, above all, their challenge is to re-kindle the dream
0:57:43 > 0:57:44of manned space travel...
0:57:46 > 0:57:47..beyond our own planet.
0:57:49 > 0:57:53What are we doing when we are exploring other worlds,
0:57:53 > 0:57:56other planets, our solar system, our universe?
0:57:56 > 0:58:02We are engaging in one of the most fundamentally human acts.
0:58:02 > 0:58:05We are following our curiosity.
0:58:05 > 0:58:08We are more curious than any other creature on this planet.