Sannadkan ka Royal Institution ee Christmas Khudbooyin eegto caqabad ku ah duulimaadka meel aadanaha iyo waxa ay qaadataa in ay ku Gannaa aadanuhu galay xuduudda final on fiicfiican ee sahaminta.
Sida dhakhtar ayaan dheeraad ah ku qaatay ka badan toban sano u safraya iyo dib u dhexeeya UK iyo Nasa ee Johnson Space Center Houston, shaqeeya cilmibaare u booqday mashaariic laga bilaabo barashada saamaynta deegaanka meel bannaan oo ku saabsan da 'jirka nidaamka cuf aan dabiici ahayn. Isla mar ahaantaana aan dhammaynayay aan tababar caafimaad yar ee daawada suuxinta iyo daryeelka degdegga ah. Waxa uu ahaa cajiib ah isku dayayaan in ay wada splice kuwa labada qof. Ka shaqeynta on qaybta daryeelka degdegga ah habeen, cinwaanka garoonka diyaaradaha dhamaadka shaqada, Boobka hurdo qaar ka mid ah diyaarad, ka dibna uu yimid maalintii dambe qolka shirarka ee Houston, halkaas oo qof ayaa ku wareegsan fadhiya hadalka ku saabsan sida dadka si Mars diro si nabad ah.
Laakiin wixii lala laba ahaa caqabad ku ah nolosha ee dhinacada ah. In cisbitaalka aan raadinayey ee dhinacada nolosha marka loolan by cudurka iyo dhaawac. At Nasa waxaa la ii eegaya khatarta si jirka aadanaha by ee dhinacada dunida jirka iyo caalamka.
Marka aan ka hadlo jawi aad u daran fikrad xunxunna ay gunti by xukumaya waxaan ka heli kartaa inta ay taageeri doonaa nolosha aadanaha galmo iyo aqlka. By meel qiyaas in uu yahay xad-dhaaf ah kama dambaysta ah: gaar ah cadowga ku ah jirka aadanaha, waxay bixisaa taageero u ah nolosha aadanaha wax alla wixii. The socotada meel galmo aan noolaan lahaa jawi in loo idmo dhowr ilbiriqsi.
Waad qiyaasi laga yaabaa in ay jiri doonto badan dhakhtar inay sameeyaan - taas oo ah marka ay timaado sahaminta meel aadanaha, Ciddi wax kasi oo isku dubaridi kara jirka aadanaha noqon lahaa safka hore ee dadaal in. Laakiin dhakhaatiir caafimaad ciyaari a keyd saboolka ah si ay waxa si aada waa dhaqan of injineernimada - iyo sabab wanaagsan.
duulimaadka Space waa mabda 'jirka disarmingly fudud. Sidaas fudud in xaqiiqda in Newton bilaabay in la fahmo dhaqdhaqaaqa in ay waxtara ku dhawaad 400 sano ka hor. Inuu ka tago Dhulka iyo galaan falagiisuu ku wareegsan, in aad marka hore u baahan tahay inay ku tuuraan shay ceshay si adag in ay dhabbihii ku koobnayn oo qura jahooyinka Earth ee - si adag in la samayn karaa si aan u dhaco sidan oo kale in mar dambe helo dhulka.
Oo sidaas daraaddeed in ay ku riday shay galay kastana falagiisuu dhex wareegsan dhulka aad leedahay si ay u siiyaan aad u weyn tamarta. In la eego ballaadhan si degdeg ah aad u tagto gacan guud ee falagiisuu aad loo gaaro; si aad u hesho gaari si ay u gaaraan kastana falagiisuu dhex balaadhan oo ku filan si aad u hesho in ay seegi labada Earth iyo lakabyada sare ee jawiga, si aad meel sare ee la mid ah sida ay International Space Station qaar ka mid ah 250 miles naga, aad u baahan tahay in ay u safraan qiyaastii 17,500mph.
Taasi waxay u baahan tahay gaari laga gano by matoorada iyo Haamaha Shiidaalka leh awooda qarxa of a hub nuclear yar. safarkan, lagana rujiyey dhulka galay kastana falagiisuu dhex Earth hooseeyo - saarnaa pride Soyuz ah - qaadataa wax yar ka badan sideed daqiiqo. Oo sidaas daraaddeed sabab ah in dhaqanka ee Nasa, iyo meel hay'adaha dunida oo dhan, waxaa si xeeldheer in baahidii of injineernimada halkii kuwa bayoolajiga aadanaha waxaa ugu wacan in mudadaas kooban laakiin dulmiga badan waxaa jira ku dhawaad waxba daawo casri ah siin karaan jidka ilaalinta. Inta lagu jiro la bilaabay, labada injineernimada u shaqeeyo iyo qof kasta oo ku nool, ama ma aha in qof walba oo ka luntaa;.
ilaalinta ee nolosha aadanaha bilaabay dhan waxay ku xiran tahay ma ku dul hababka caafimaad laakiin on layers-gashan ilaalinta macmal ah in injineerada design iyo in la dhiso iyo tuujin, shaqaalaha cir ee.
matoorada gantaal waa in si fiican dab, delivering just the right thrust at just the right time, directed in precisely the right way. The tremendous force of that propulsion mustn’t be allowed to shake the vehicle, its systems or its fragile cargo of passengers apart. It is the job of engineering teams to make sure that the launcher and the vehicle are designed to perform in the face of forces that are trying to destroy them.
And perched atop that tower of kerosene and oxygen is a tiny capsule, with the volume of a handful of telephone boxes, and a couple of tonnes of supplies and three passengers crammed in among them. That capsule is a tiny bubble of life support, pinched off from the Earth and maintained artificially. Inside, still more machines provide a breathable atmosphere with enough pressure and warmth to support life in the void of space. If you survive the launch, your problems are really only just beginning.
International Space Station
It’s tempting to think of the International Space Station as a hi‑tech Big Brother house, floating high above the Earth. In some senses that is true: living conditions are harsh by any normal standard. There are few creature comforts and precious little privacy. It is a living arrangement bristling with the potential for huge social conflict. But remarkably that is largely avoided and in 15 years of operation there have been no evictions.
But the ISS is much more than an accommodation block. When crews go to live there they are taking up residence inside a machine upon which their lives depend every second of the day. They electrolyse water to produce oxygen, employ molecular sieves to scrub waste gases out of the air that they breathe, run heating systems from vast solar arrays that can pump out 80kW of power. That solar energy also drives four huge gyroscopes, which steady and steer the station, preventing it from tumbling out of control.
The International Space Station is far from tranquil: it hums and whines perpetually; fans are running all the time. Without gravity hot air doesn’t rise and cold air doesn’t sink. Waxaa jira, as a consequence, no convection and without that it’s hard to get air to move or mix. That in turn causes problems, leaving astronauts prone to headaches in poorly ventilated areas, where exhaled carbon dioxide can build up. Hence the constant drum of motors churning air. The draughts on the ISS, like almost everything else that the crews depend upon for healthy living, are artificial. All of this effort just to maintain that bubble of life support in an outpost just 250 miles above our heads. The challenges involved are legion and we haven’t even started to talk about leaving low Earth orbit yet.
Back to the moon
There is unfinished business on the moon. It is nearly half a century since the Apollo programme landed a dozen men on its surface. And while it represents a treasure trove of scientific discovery, nobody has been back since. Low Earth orbit is 250 miles away and can be reached in minutes. The moon is about 250,000 mile, takes days to get to and, in addition to isolation and the added complexity of the rocket science required, leaves crews extremely vulnerable to radiation. On Earth we’re protected from some types of radiation by the thick blanket of atmosphere above, which absorbs gamma rays, x-rays and ultraviolet radiation that would otherwise be harmful. But there’s another layer of protection that also keeps us safe: Earth’s magnetic field.
The magnetosphere filters out a particularly harmful species of radiation, which comes in the form of charged, high-energy particles – atomic nuclei spat out as a by-product of thermonuclear reactions in stars including our own. This type of radiation is particularly harmful and, during solar flares, can increase in intensity by many thousands of times. Presently we have little in the way of effective protection from the radiation that comes with the worst solar flares.
Mars and beyond
In recent years the idea of putting human crews on the surface of something other than the moon or Mars has found its way into the strategy documents of the international space agencies. This mission is less science fiction than you might think. The European Space Agenecy’s Rosetta mission, which so spectacularly landed the Philae lander on the surface of a comet last year, showed us that we could find and intercept a tiny target hurtling through space hundreds of billions of miles away. This has given agencies confidence that their idea of landing a human crew on an asteroid might be realisable.
But for now it is Mars that lies at the edge of possibility, and surviving that journey presents a challenge on a different scale. With Mars, the problem is distance and time. To get to the red planet you have to traverse hundreds of millions of interplanetary miles; in ka badan 1,000 times the distance Apollo crews travelled to the moon. With existing technology it would take between six and nine months to travel from Earth to Mars and the same again on the return leg.
That’s a lot of time spent without any gravitational load on your body. Weightlessness may look like fun, but like everything else, too much of it can be a bad thing. When physiologists first considered what effect the space environment might have on the human body, before anybody had even been into space, they correctly predicted that muscle and bone would waste. Those systems are sculpted by gravity and as anyone who has ever so much as looked at a gym knows, if you don’t use it you lose it. Taas aawadeed, crews aboard the International Space Station must subject themselves to a daily programme of resistive exercise to try and prevent some of that bone and muscle loss.
Weightlessness wreaks havoc with other systems. It upsets your senses of balance and co-ordination, making it more difficult for crew members to track moving targets, creating illusions of motion and, for the first few days of flight, generally making them feel pretty queasy. With the exception of the nausea, all of these problems tend to get worse the longer you spend weightless.
More dhawaan, new – and potentially more worrying – problems have cropped up. For reasons that are not yet entirely clear the pressure in some astronauts’ brains appears to rise as a consequence of space flight, and this has been linked to alterations in their eyesight that sometimes persist for many years after their return to Earth. This phenomenon has only been noticed after long duration missions, which highlights the message: spending a lot of time in space isn’t great for your health.
But time also creates problems for life support systems. If you imagine the amount of food, biyaha, oxygen and power a single person might consume in a mission set to last up to three years (if you include the surface stay), that demands quite a sizable larder. Now multiply that by a crew of four or six and it looks like you need an impossibly huge spacecraft just to keep you fed and watered.
And that does become impossible unless you are able to recycle and reuse everything you can. Already aboard the space station astronauts recycle most of their waste water, including their urine. They scrub carbon dioxide out of their exhaled air and rebreathe the remaining oxygen. You might be able to go further still, by growing crops hydroponically, as a source of food and a mechanism of removing carbon dioxide and renewing the oxygen supply. If you choose the right plants you might even recycle the nitrogen in human solid waste. Which of course is a scientific way of saying that maybe you could use your own poo to fertilise your life-supporting crops.
A system as sophisticated as that is extremely difficult to assemble, manage and maintain, and it’s likely to be a while before we see greenhouses flying through deep space. For now life support engineers will content themselves with finding ways to recycle more and more of the resources they can, and in so doing reducing the amount of payload that crews have to set aside for the things that keep them alive.
There is a simple lesson from all of this: space is hard. All frontier endeavours are. But there is plenty to celebrate here. Since the start of the 21st century there has been a permanent human presence in space. What started as a surrogate battlefield for nuclear war has become a multinational programme of science, exploration and collaboration. This is not the place to get into a discussion of why we should explore space at all. There are many benefits that derive from human space exploration but one is more important than all the rest. Human space exploration inspires children to study and pursue careers in science, technology and engineering. It does so by showing them that within the limits of human imagination anything might be possible. I know this because it inspired me and throughout the whole of my life has continued to hold my fascination.
It is an enormous honour to give the Royal Institution’s Christmas Lectures. And yes, the take-home message is that space is hard. But the real lesson for this year’s audience is that this has been my adventure and it can be yours too.
How to Survive in Space will be shown on BBC4 in three parts on 28, 29 iyo 30 December at 8pm. Find out more on the Royal Institution’s website and join the conversation on Twitter and Instagram by following @ri_science or searching for #xmaslectures
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