"(NB: The space station is big, but not that big."
Er, 340km is the altitude, not the dimensions of the ISS.
Strong rumours are circulating regarding plans for a European manned spaceflight capability. A firm announcement is expected later this month, which would outline a scheme based on modifications to the existing "Jules Verne" automated cargo module used to supply the International Space Station. The 'Jules Verne' ATV seen from …
I can easily see how Jules Verne can be modified to carry humans to the space shuttle. The main complication would be fitting seats to protect them from the G-force at take-off.
But since the current model is designed to burn on re-entry, you need rather big modifications to get it to land safely.
Another thing I wondered about Jules Verne is: Since it is habitable, why not just add it permanently to the ISS, increasing its size every time a new Jules Verne module arrives? Sure, parts of it (e.g., the engine) has little use after arrival, but it would probably not be that hard to modify the Jules Verne so the engine can be detached and burn on reentry, leaving the rest a permanent part of the ISS.
You would, of course, need a new place to dock the next Jules Verne module (or move the previous module out of the way to attach permanently someplace else), but that should not be impossible to arrange.
..we should be led into space by our government !! Can we pack the whole NuLabour government into a shipping container and blast them off into orbit ?? Please, pretty please !! No need for re-entry procedures. They can stay as a reminder for posterity !!
@Torben Mogensen - re. docking issue - no problem !! Just dock them nose to arse each time in 4 (four) equidistant spokes and then join them up to make a space wheel !! Spin up that wheel, and you have some gravity (well, centrifugal force, anyway) too !!
Actually the engine has still useful functions. It can raise the ISS periodically - ISS is still subject to miniscule earth atmosphere effects, so is permanently being dragged to earth.
Second, once the ISS is decommissioned in a decade or so, the "truck" is used to ensure the ISS doesn't fall on someone's head.
The ATV Evolution study (esamultimedia.esa.int/docs/gsp/completed/C18303ExS.pdf) is a previous look at upgrading the ATV to a crew transfer vehicle as well as other capabilities.
It'd be nice not to a have to rely on the US and Russia now if only the UK would decide to build more than scalded up Big Traks...
Hmm people travelling in cargo containers... Has the ESA considered interviewing at Sangatte detention centre for potential Euronauts with previous experience and the 'right stuff'... Although the occupants of the ISS may get a shock when 30 people pile out.
Paris, is 177 miles from Sangatte.
I mean, a 100-ton-plus "airframe", several-thousand-miles-an-hour velocities and delta-vees, aerodynamic loads that make a trip across the Atlantic feel like a stroll in the park, a landing that is the equivalent of trying to spit a grape onto a postage stamp in Hyde Park from a wobbly chair atop Nelson's Column... why would they need computer assistance? Tsk, overpaid screenwatchers the lot of 'em.
What I want to know is why they haven't made any more Orbiters? Well, I know they've dismantled the jigs and lost all the skilled techs and mechs that built the originals, but it's gotta be cheaper to build new STS birds than to keep fannying around promising new vehicles that never actually get anywhere beyond semi-scale "development" models hasn't it?
Dead Duck, cos that's what manned spaceflight is in very real danger of becoming. Who was it said "I always knew I'd see the first man on the moon. I just didn't expect to see the last, too."
The engine in Jules Verne is already used to push the ISS, so its orbit won't degrade. Apparently, it is sufficient to give a little push every time a Jules Verne docks, so there is little need to accumulate a large number of engines over time.
You will need more push as the ISS grows, but that is more easily handled by firing one engine for a longer time than by using multiple engines.
...an idea: send up a rather large wheel-type thing that would sit somewhere further out than the ISS (or even further out than any artificial satellite), and once a JV is used, send it off and dock it to that. That way, you create a huge, mostly pointless but maybe somewhat useful in the future storage area.
Not "why?", but "why not?"
Man-rating is an obsolete concept nowadays. All American launchers are made as relaible as possible nowadays. You don't want to lose a crew, but you don't want to lose a £1billion payload either.
The idea dated from fifty years back when putting people on ICBMs.
This is Mike Griffin's opinion. http://www.thespacereview.com/article/339/1
Certainly you need an escape system, but that goes on top of the crew capsule. It's not part of the Ariane V launcher.
If you want to know why they did not build more shuttles, or why they need a computer to steer the shuttle, MIT have a complete set of 23 lectures, each 2-hours long.
The lectures are presented by the main people that built, designed and flew the thing. Every sessions covers a particular aspect, such as how the requirements were determined, aerodynamics, main engine engine, guidance control, etc.
.. short answer:
- the shuttle made economical sense because they figured they could do 50 launches per year. Maintenance turned out to be way more difficult, resulting longer turn-around (so less flights to spread the dev cost over) and higher maintenance costs.
- Whilst decending you go down from ~30.000 K/h (for a typical 300 km-high orbit) to 0 Km/h in 20 minutes. Apparently aerodynamics work differently at mach 25 than they do at mach 2 and different again at a few 100 Km/h. On top of that you pass different air densities, resulting in a change from reactive control -little rockets- to classical aerodynamic flight control surfaces. This change is not the same time for all axis since not all surfaces have the same exposure, e.g. yaw controls come online first, then pitch, etc (I forget the real order). Keeping track of all these "flight regimes" is just too much to take into account by a human pilot in real time.
Also, the shuttle is unpowered during decent and it has a very poor glide ratio. It has been described as "landing a falling brick". So there is no way to correct and make another pass if you "undershoot". One of the funny stories in those lectures is for example where they explain how they use a converted learjet to simulate landings. Basically, they turn on reverse-thrust to keep your airspeed down you while you do a nosedive to the runway.
.."Man-rating is an obsolete concept nowadays"
I suspect that parameters such as vibration load, and max G-load are quite different for goods and people.
Also, life support systems are not trivial and add weight (which is a huge issue in space tech).
Lastly, a piece of cargo is happy to use an economical way of achieving a certain orbit (only boosting at apogee) even if that takes weeks. Humans are less patient. More fuel is more weight again, which is a big no-no.
Say by the time you do all the extra fixes needed it would weigh another five tonnes so they may as well call it W. Von Braun or Herman Oberth instead , so to me it would be far cheaper and more logical to use the mostly older and usually reliable well proven working Russian SOYUZ design !
But since they are spending wads of taxpayers money to fund another fat turkey , obviously some extensive empire building within ESA is now being built by adherents to the "Peter Principle" within it's current management structure !
Now where do they hide the paper clip counters when you need them with their hidden from sight veto stamp , to kill these bad "It seemed like a good idea at the time" silliness ?
For it reminded me of the old old story , if it works keeping adding small changes till it is broken , where if it is broken you leave it alone and as usual your staff will then fix all your little problems you have caused from your own basic stupidity and incompetence for free , as they are forced to find ways to work through the mess you have self created . Thus leaving you to take the accolades for a fix you did not do and still don't understand , sweet !
Biting the hand that feeds IT © 1998–2019