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Sunday, 29 May 2016

A couple of really cool videos....

It's a pretty exciting time for fans of the newspace startups, and to show you what I mean here're three recent video clips.

First: SpaceX has landed a re-usable Falcon 9 rocket for the fourth time, the third time consecutively. It's no longer groundbreaking, and that's why it's brilliant: They're building up a record of success, which s what they really need to prove to the world that their re-usable rockets can be relied upon, and can genuinely bring the cost of reaching space down. Here's the mission as seen by the rockets onboard camera... 


Meanwhile, on the International Space Station, an new room has been installed: The BEAM module was designed and built by Bigelow Aerospace as a demonstrator for technology that they hope will kickstart a new age of in space building. The module is inflatable, held up by bladders filled with gas rather than solid struts. That means it can literally be launched folded up like a tent*, which means a huge saving in weight and space. Here's the time lapse video of it being installed...


After a nerve wracking false start on Thursday, when the module seemed to be stuck, on Saturday they were able to get it fully expanded.....


People are working - and succeeding - in bring down the cost of getting to space, and the cost of building in space... and now I can't wait to see what the future brings! 

Above: A graphic of Bigelow's proposed B330 space station.


* Not literally like a tent, because I'm a Scout leader and know  tents are often packed by shoving them brutally into backpacks and sitting on them, unless I stand there and make them do it properly. Ahem. I mean that the BEAM was folded up.

Friday, 27 May 2016

Homes in space, part 1: Space stations...

Apologies if you notice some issues with formatting ad spacing - I'm loosing to my own html at the moment, but I'm working on it!

It’s an exciting time for fans of expanding human presence into the soar system: Orbital ATK, who build cargo ships for the ISS, have announced preliminary plans to build a deep space station. Bigelow aerospace have their groundbreaking inflatable space habitat attached to the ISS undergoing testing. The ISS itself is no longer a half built techno turkey but a scrumptious techno roast dinner with all the trimmings: It has served as a launch site for miniature space satellites, a destination for space tourists, boasting its own gym, internet connections, cupola, and masses of experiments going on. Spacecraft from across the world dock regularly to bring fresh crew, supplies, and experiments.

Above: The International Space Station. Tastes great with gravy, mm-mmm.

But what about the future of humans in space? There’re no guarantees the spectacular visions folks like Robert Bigelow and Elon Musk have – of a solar system full of human presence - will come to pass… but they’re certainly hard at work trying to make it that way.

Let’s assume they succeed, and in the late 21st century/ early 22nd century an interplanetary traveller needs a place to rest their weary, space suited, head. What are the options likely to be?


Types of space stations:

We’ve had a pretty few of these over the years – Skylab, Almiraz, Salut, Mir, Chenzou, and the ISS. Recently people are trying to make them more affordable, widen access, and get more people living and working out there. It looks like there could be three main types of space station for the 21st century: Hard hulled (like the ISS), inflatables (like the BA330 module Bigelow Aerospace is working on), or a combination of both types.

Hard- hulled space stations:


Until recently all space stations have been of this type – Mir, Chenzou, ISS - basically a big tin can in space*. OK, a very strong tin can designed to survive for years in space and support a continuous crew, run experiments, house space telescopes, launch mini satellites etc etc. But, on some level, a can filled with air.

Soft hulled/ inflatable space stations:
 
 
Above: The BEAM module, depicted fully nflated. Which they haven't managed yet.

A new development, but based on an old NASA design called Transhab: These’re bouncy castles in space, albeit bouncy castles made of unbelievably tough material. The air pressure inside one keeps it inflated and rigid, and it’s launched folded up, saving a lot of launch volume. Using air pressure this way also saves on the weight of a traditional support structure.

Bigelow Aerospace has launched two prototype inflatable stations – Genesis 1 and Genesis 2, as well as its BEAM module on the ISS. Genesis 1 and 2 performed very well – in fact both are still in orbit and pressurised today. This looks like a real possibility for the next few decades or space exploration.


Above: Bigelow's Genesis 1 space habitat.

A combined design:

In theory a prototype of this, using both hard shelled and inflatable modules, already exists in the form of the ISS with BEAM attached – and until the inflatable designs have really proven themselves this is probably how they will be used...
 

That’s the technology available – what about the all important location? 

Above: The inside of a Genesis module, fully inflated, with people's photo's (and trinkets they sent into space) floating about.

Possible Locations:

Earth orbit: 


Being sited near Earth has it’s advantage… and it’s perils. On the pro side:

  • A station in Earth orbit can be powered by solar panels.
  • Should anything bad happen it’s short journey back to the safety of Earth – the ISS and most other stations have at least one man rated space craft docked at all times, to act as a life boat should aliens attack, someone crash into the station**, or a storm of space debris threaten to tear the place to splinters.
  • Being close to Earth also means that the station can take advantage of the Earth’s magnetic field. Cosmic radiation can seriously ly increase a persons risk of cancer. Earth’s magnetic bubble diverts the worst of this.

On the con side…

  • Have you seen that movie about the storm of space debris that chews up everything in orbit? Well, that’s not the far fetched nightmare scenario you might hope it is, although such a chain reaction wouldn’t happen that fast: Near Earth space is pretty crowded these days, and what it’s crowded with dead satellits and pieces of satellites, whizzing along at 11 km/sec. Satellites have been blown apart by it, the ISS has had it’s reinforced windows damaged.  
Space agencies track the larger pieces, and space stations often have to manoeuvre to avoid anything that’s going to come too close.

Above: The cracked ISS window that probaby caused Tim Peake to change his sace underwear.


    Space stations between the Earth and Moon:


    Above: A Cygnus freight ship, the proposed base unitfor Orbital ATK's space station.

    An idea that is being seriously looked at, and might well get built. The two most often proposed sites are at a Lagrange point between Earth and the Moon, and in orbit about the Moon. A Lagrange point is a place where the gravitational pull of two objects cancel out, creating a zone where objects can sit without needing to orbit anything. That makes navigating and docking to a station sited there a lot simpler, and also makes the station a convenient point to store fuel and other supplies for missions deeper into space. Orbital ATK is proposing to build such a station from two of it’s Cygnus freighters, which would be loaded with goods as they left Earth. Such a space station could also be used to conduct better microgravity experiments, and as a safe refuge if a Lunar mission ran into trouble a-la Apollo 13.

    A graphic of Orbitals proposed lunar station. Courtesy of Orbital ATK.

    But the big question mark over a Lagrange point or lunar orbit space station is the cosmic radiation problem we mentioned befpre. Protecting such a station tried before, and while there are a few potential technologies that could do it – from simply lining the walls with water tanks to a magnetic field around the station that would imitate Earth’s- none of them has ever been tested against a real storm.

    Space stations around other planets:

    If we look a bit further ahead, at space stations around Mars, Venus or other worlds, we need to deal with all of the above and new kinds of challenges: A station orbiting Venus or Mercury would need a beefed up thermal regulation system, to shed the heat from the intensified sunlight. Go much further out than Mars and your station can no longer collect enough sunlight without an unrealistically huge set of solar panels, so you’ll need a nuclear generator, or other more complex power source... but it will probably be a very long time before we have manned stations that far out...


    Next: Bases on other worlds...

    *Let me be clear: It is definitely  lot more complicated than that – lest some ESA engineer come to my hose tonight and slap me.

    ** This has happened- link here
    *** I couldn’t resist, sorry.

    Wednesday, 25 May 2016

    Bernie Sanders and Donald Trump on space exploration...

    Hi everyone, family commitments and a shifting work schedule is making posting a bit harder for me this week and next, but I’ve found something a bit interesting to share...



    Space traditionally plays very little role n the election campaigns of American presidents - to the point where they usually show little interest in space policy until they’re almost at the White house.
    So it’s not a surprise that, when Aerospace America magazine sent around a list of ten questions on space policy to each of the presidential campaigns, only two bothered to respond. What has surprised me a little is who responded: Bernie Sanders, and Donald Trump – Sanders has seemed much more focused on social policy, and Trump has simply said whatever would please his audience. Their replies are here.

    Have a read: As always it’s sad to see that America’s space use and exploration are at the mercy of politics – look at what happened between the start of George Bush Junior's administration and now - but that’s the way it is.

    Sanders gives far more in depth answers, showing a lot more interest in space exploration itself - the impression I get is that this is a topic he really cares about. Trump’s answers are much more hurried, and mainly are trying to divert attention to economics – but he voices support for commercial spaceflight. Trump is far and away the republican frontrunner, and space fans can take some hope from the fact that he responded, and showed some awareness of the issues.



    Sunday, 22 May 2016

    Vacuum - a survival guide

    So you're in an airlock, sans spacesuit, and in a few moments the outer hatch will open and ... well we've seen the films, and the TV shows: The moment that door opens you'll explode, or possibly flash freeze solid. Either way.. you're a gonner.

    
    Let's be clear: This. Doesn't. Happen.

    Nope.
    First, lets look at the 'you'll explode' idea: By itself that's not completely crazy - in fact there was a tragic, and very, very messy incident involving a group of deep sea divers going from nine atmospheres to one -  but you're only going to get a one atmosphere drop, not nine*: You won't explode, because your organs and skin are too tough.

    That doesn't mean the next bit will be any fun but it might just be survivable...

    The airlock decompresses: Any air you're holding in will be pulled instantly out through your throat - so to avoid tissue damage vent everything gassy from yourself. And I mean everything: Any gasses in your stomach and bowels will also exit the premesis, carrying stomach and bowel contents with them at high speed.

    So burp and fart as much as you can before that hatch pops, unless you're wearing brown trousers and like the taste of stomach acid.

    All that means the only oxygen you'll have out there is what's already dissolved in your blood. If you're in really good shape you might get fifteen seconds of full consciousness, and maybe a few of total disorientation, before your pass out (link to NASA article on the subject). Maybe enough to save yourself**.

    How will you do that, when you'll be floating in space? Actually... most airlocks decompress before the outer hatch opens. If the hatch does just 'blow' then, unless the airlock you're in is huge with a tiny door, the air will empty in much less than a second - not enough time for the gale to transfer much force to your body. Tying yourself to the handle of the inner hatch with your shirt should keep you anchored in place.

    Sorry, you can't really get rid of the xenomorphs that way either...

    So, you're in the airlock, the outer door is open and you've got eighteen seconds. But won't the cryogenic cold of space instantly freeze you solid?

    This also doesn't happen.

    Lucky you, no it wont: Space is a big nothingness - there's no conduction or convection to carry heat away, and you'll radiate heat no faster than you would on Earth.

    Damn...this is getting both dull and smelly: You won't explode, be sucked into the void, or freeze. You may poo yourself. Will anything happen like in the movies?

    Well...you'll swell up, although not so much you can't move. Some animals go temporarily blind but there're no reports I've found of that happening to humans. After your fifteen or so seconds you'll pass out - but that's not the point you die: Your heart will carry on beating for about three minutes: Animal experiments*** suggest you'll recover if you get repressurised before your heart stops.

    What should you do once the hatch is open?

    Astronauts agree : Wearing a space suit is the key factor.
    Airlocks without a mechanism to let the occupant shut the outer hatch and re-pressurise them wouldn't make sense: An inbound traveller couldn't get in. So...
    • If you've gotten spaced by accident I'd thoroughly recommend just shutting the airlock hatch and pressing the re-pressurising control. 
    • If your airlock is broken you've got fifteen to twenty seconds to get out and reach another. Incidentally, Dave Bowman from the film 2001 pulls this off somwhat realistically, as he's hunted by HAL the insane computer.
      Above: Time it with a stopwatch - he actually would have pulled this off (as far as my research can tell)

    • If you've been spaced deliberately, and your would-be assassin got his knowledge from movies.... I suggest just re-pressurising the airlock and kicking his teeth down his throat.
    • If you're being spaced by someone who can override all the ships airlocks... then, frankly, I'm out of ideas. Float to the window nearest to them and use your last few seconds to shove your bum against it?

    On the whole I suggest putting ' get exposed to vacuum' on your list of things not to let happen. But, should you make that particular mistake^... Stay calm, brace up, be ready to shut that hatch and hit that re-pressurise control - you should make it.



    * Even so, it won't be fun and it could be very messy in... other ways.

    ** I've heard it suggested that forcing yourself to hyperventillate and load your blood stream with O2 just beforte you exhale might help (although, as far as I know, that's never been tested). Slowing your heartbeat probably would, as it would slow the passage of de-oxygenated blood to your brain.

    *** Yes that's a mean thing to do to an animal - please don't write to me telling me that, I never said I approved.

    **** Unless the airlock is just for throwing people out of.

    ^ HOW have you managed to make that particular mistake?

    Thursday, 19 May 2016

    Juno - cracking the mysteries of Jupiter

    Above: The planet Jupiter, as seen through a small telescope. Courtesy of mikesastrophotos.

    In less than two months the Juno space probe arrives at Jupiter (July 4th), the first mission to the king of the giant planets since the Galileo probe. Closer to the time there'll be a big ol' media circus from NASA, so I thought I'd get in there first...


    The mission: 
     
    Jupiter is often outshone in the media by its potentially life bearing moon Europa, and the ever violent and changeable Io, but JUNO is actually a mission to Jupiter itself: Jupiter is easily one of the most complex worlds we know of, and has plenty of unsolved mysteries - from simple ones like 'why is the Great Red Spot red', to what makes its storm belts fade away and re-appear, to what causes it's internal heat and how exactly it formed. Juno carries a suite of instruments designed to study deep layers of Jupiter not visible to the naked eye.

    Above:The Great Red Spot, a storm the size of Earth - what powers it, why it's red... Juno w try to answer these questions. Courtesy of NASA/JPL.

    The giant worlds internal structure, and whether or not it has a rocky core, carries information on how the solar system formed, like a huge 4.5 billion year old fossil.  Jupiter's huge mass and fast rate of spin are expected to warp space-time in a specific way too, letting Juno use it to test general relativity.  The probe will also get the first really good look at the giant planets poles, and hugely powerful aurora.

    But to do all this Juno has to survive long enough - Jupiter puts out enough radiation to cook a probe. Once it reaches Jupiter Juno will go into an orbit that will take it to within 5000km of Jupiter's cloud tops and then out over 2 million km. The planned orbit ducks under Jupiter's radiation belts, sparing the craft from the worst effects.

    Above: Jupiter, seen by Hubble in infra red light. That heat-glow isn't reflected from the Sun: Something inside Jupiter is still producing energy..... Courtesy of hubblesite.org,
    The mission will last for one Earth year, and will take in 32 polar orbits of old Jove - a time limit not based on money, but on how, even with the radiation belts avoided and it's main computer shielded, the probe will slowly be eaten away by the radiation.  
    Then Juno will be crashed into Jupiter's atmosphere, meeting its end as a flash of plasma. To leave it floating out there would pose a risk of contaminating one of Jupiter's moons with Earth life - a viking funeral for an armoured spacecraft.

    The Science:

    JUNO's official science objectives are...
    • Measuring the abundance of water in Jupiter, which will help distinguish among prevailing theories linking the gas giant's formation to the Solar System.
    • Measure Jupiter's core mass, which will also help distinguish among prevailing theories linking the gas giant's formation to the Solar System.
    • Map Jupiter's gravitational field to assess the distribution of mass in Jupiter's interior.
    • Precisely map Jupiter's magnetic field to assess the origin and structure of the field and help scientists understand the fundamental physics of dynamo theory.
    • Map the variation in atmospheric composition, temperature, structure, cloud opacity and dynamics to pressures far greater than 100 bars at all latitudes.
    • Explore the three-dimensional structure of Jupiter's polar magnetosphere and its auroras.
    • Measure the orbital frame-dragging, known also as Lense–Thirring precession caused by the angular momentum of Jupiter, and test general relativity effects connected with the Jovian rotation.

    The ship:

    Above: Double click to see this full sized infographic of Juno, courtesy of NASA.
    Juno is built around a radiation hardened hexagonal core, which houses the craft's brain - even though the orbit has been chosen to avoid Jupiter's radiation belts there's  still a lot of high energy particles in Jovian space. Surrounding the core are the sensors and three sets of solar panels -  50% more efficient and radiation resistant than old silicon based designs, which has allowed Juno to break the record for furthest solar powered spacecraft from the Sun. The fore face of the core has the main antenna, which also performs gravity science experiments.
    The probes odd shape is partly because Juno is spin stabilised, so it needs to be highly symmetrical along the axis of the spin. The sensors this huge (each solar panel alone is over eight meters long) probe carries are:
    • A gravity/radio science system (Gravity Science)
    • A six-wavelength microwave radiometer for atmospheric sounding and composition (MWR)
    • A vector magnetometer (MAG)
    • Plasma and energetic particle detectors (JADE and JEDI)
    • A radio/plasma wave experiment (Waves)
    • An ultraviolet imager/spectrometer (UVS)
    • An infrared imager/spectrometer (JIRAM)
    • A color camera, called JunoCam, to provide the public with the first detailed glimpse of Jupiter's poles
    Juno's engines are simple chemical rockets, and a set of hydrazine RCS navigation thrusters - it's all designed to be simple, robust, and work in one of the most dangerous stretches of space in our solar system

    I think that covers the basics - so all that remains is to say: Good luck JUNO, and good luck to her ground control team!