The Convair Shuttle B - 'Aquila' HL -LAUNCHED!

[PR19_Kit]

Despite saying I'd give this GB a miss, Weaver's posting of the Atlantis Models Convair Shuttle kit intrigued me and I bought it.

Overall it's pretty small and nowhere near as large a the RW Shuttle, so I've called it a Shuttle-B and the backstory says it was primarily for personnel transfers between Earth and space stations or long range space vehicles holding position in orbit, thus not needing large cargo bays like the full size Shuttle.

To that end I dug out an Airfix 1/144 Saturn V from The Loft, and bought a part built Airfix 1/144 Shuttle form ebay, as below.





These will be used to supply the other bits and bobs that'll be added to the Atlantis kit, after I've figured out what to do with them of course.

Here's the original kit and the pile of bits that are now in it's box!





Let the chopping and gluing begin. 

[Weaver]

Personnel transport to and from orbiting ships/stations is actually one of the strongest use-cases for a spaceplane. The other is as an on-orbit "lifeboat". In both cases, the human cargo is precious, and the cross-range and runway landing capabilities of a spaceplane give the crew a much greater chance of survival if the craft is forced to re-enter and land in an unpredictable place. Note that ESA's cancelled Hermes spaceplane was roughly the size of the Convair Shuttle.

If saving the crew is the primary motivation for the Convair Shuttle, then it's design makes more sense. If the primary motivation is economic however, then dumping the orbiter's engines makes less sense, since bringing back those expensive items is one of the primary economic goals of reusable spacecraft. Given that the design dumps three-quarters of it's engines anyway, it might be reasonably inferred that economics was not the primary motivation behind the design.

[PR19_Kit]

Given that the design dumps three-quarters of it's engines anyway, it might be reasonably inferred that economics was not the primary motivation behind the design.

I'm not sure that ever WAS a consideration in the early days of the US space programme.   

[Weaver]

Given that the design dumps three-quarters of it's engines anyway, it might be reasonably inferred that economics was not the primary motivation behind the design.

I'm not sure that ever WAS a consideration in the early days of the US space programme.   

They were interested in reusability pretty early though. There were some awesome schemes both here and in America for turning the first stage of a Saturn 1B into a winged, recoverable, horizontal landing spaceplane-booster, and there was even a scheme by Piasacki for giving a Saturn V first stage parachuted and then plucking it out of the air with a giant helicopter...

Even if they had the money today, if they wanted the money tomorrow, they'd have to have an answer to politicians with an axe to grinds looking at the space programme and saying, "you're going to use that huge thing once to put that tiny thing into orbit?"

[kerick]

Here's a link to the X-38 test vehicle from NASA. It was proposed to be an escape vehicle for the ISS. The actual vehicle would have been much larger.

http://www.primeportal.net/space/kenneth_erickson/x-38/

[PR19_Kit]

The basic build went remarkably quickly, once I'd de-flashed a lot of the parts anyway.

It all fitted pretty well, apart from what they call the 2nd stage, which is a very short bit that nestles into the back of the 'glider', the uppermost part of the system. That needed some tape to hold it in position while the glue dried, but after that it was fine.

Here's the complete assembly, in all its glorious BLUE-ness!



When the first stage drops off, it looks like this...



And then the little 2nd stage is dropped...



And after that there's a THIRD stage nestled underneath the 'glider'!



And to cap it all, the 'canopy', which is solid, comes off too, so you can see the itty bitty crewmen in place. Except they're not there now as I have to paint that tiny five man cockpit yet.



In the case of my Shuttle-B there'll be at least one extra stage, maybe more, as mine is the 'Heavy Lift' version which can also carry a limited amount of cargo, but needs some complex and sophisticated manoeuvering on the part of the glider's crew to collect the cargo before its carrying vehicle plunges back to Earth. 

[Weaver]

Kit, if you look at the box art, it's the half-carrot shaped section under the spaceplane which is the second stage: you can see it firing next after separation from the first stage. The back part of the spaceplane with half the wings attached to it is the third stage that gets dropped before re-entry.

I presume that the pair of relatively small engines on the third stage are for orbital maneuvering and the de-orbit burn, analogous to the pair of smaller engines in the "bumps" on the back of the real Space Shuttle.

[PR19_Kit]

Sure H, that's the logical configuration, but it's not what it says in the instructions. That small section, the proper 3rd stage, doesn't fit into the back of the glider very well, and will need a bit of fettling to improve things.

I'm not sure about the vestigial fin on the 3rd stage either. If that part is dropped before re-entry it doesn't need a fin at all, and it'd look better without it too. My razor saw may come into use...............

[Weaver]

I actually don't know why it drops the third stage at all: it looks like a perfectly viable spaceplane, with the centres of lift and mass in approximately the right place, with it attached.

Another incongruous thing about that centre fin is that the first stage booster doesn't have one, so it would tend to make the stack weathercock in yaw immediately after launch. If you look at the modified booster for the X-20 Dyna-Soar spaceplane, it had three MASSIVE fins to keep it stable.

[PR19_Kit]

Another incongruous thing about that centre fin is that the first stage booster doesn't have one, so it would tend to make the stack weathercock in yaw immediately after launch. If you look at the modified booster for the X-20 Dyna-Soar spaceplane, it had three MASSIVE fins to keep it stable.

Yes, exactly! I may saw it off and add it to the First stage. Well, THEIR first stage anyway.............. 

[PR19_Kit]

I did saw the fin off the third stage, and was wondering how to fill in the triangular hole that was left as there was no way I could stop any bits of plastic falling inside, there's no access now I'd glued in the front & rear bulkheads. 



At least the blue is more true to life than last night's gloomy efforts!

But when I attached it to the glider I found there was a hefty step up to the 'canopy' part, just about 40 thou thickness, so out came the sheet styrene and the scalpel! I cut and glued a panel all over the top surface of the third stage and then filed and PSR'd it to suit both ends and then primered it, looking lots better now.



I've also been working on my First Stage, or PBS (Primary Boost Stage) as everything HAS to have a TLA, doesn't it? 

I wanted to have enough room in the top of it to hold smaller cargo items, but the internal tank pressure dome (ITPD?) almost reached the top of the cut down Saturn V S-IVB stage I was using. I started to cut out a flat circular bulkhead instead when I had an idea. I put the original bulkhead in upside down! it worked a treat, who cares if there's a stress raiser all the way round the edge?



The little 225000 lb thrust S-IVB engine in the original Saturn V configuration wouldn't have been anywhere NEAR large enough to get this monster off the ground, so I found a larger one........... the 1746000 bl thrust F-1 engine from the S-1C first stage of the Saturn V. This is on the basis of the old hot-rodder's theory of 'There  ain't no substitute for cubic inches!' 



Should be large enough I reckon, and there's still space above the fuel for some cargo.



Just now all of the blue bits have been primed, after the ritual first PSR session, but it'll need at least one more PSR before I apply any paint though.

[Old Wombat]

If you can get a couple of thin strips of styrene into that hole to make a couple of ledges (glued to the inner surface), you can cut one or more little triangles of styrene sheet to fill the hole, then PRS until flat.

Another option is 3 rods of styrene (preferably with little square bases glued to them, to help them stay upright) of suitable length glued to the inside, then the little triangle/s, etc., again.

[PR19_Kit]

Oh sure, but the slab of 40 thou over the whole thing was much simpler, and it worked. 

I've been building a 1/144 scale Lunar Module from the Airfix Saturn V kit this afternoon to go in the cargo bay of the ex-S-IVB PBS, and that was designed by a sadist!

The teeny-weeny thrust modules on each corner are about 3 mm x 3 mm, with bits sticking out all over them, just holding them is almost impossible. But the 'instructions don't tell you where they go, just showing an arrow pointing vaguely in the direction of the LEM! I had to find some pics of the real thing to figure out where they went!

[Weaver]

Oh sure, but the slab of 40 thou over the whole thing was much simpler, and it worked. 

I've been building a 1/144 scale Lunar Module from the Airfix Saturn V kit this afternoon to go in the cargo bay of the ex-S-IVB PBS, and that was designed by a sadist!

The teeny-weeny thrust modules on each corner are about 3 mm x 3 mm, with bits sticking out all over them, just holding them is almost impossible. But the 'instructions don't tell you where they go, just showing an arrow pointing vaguely in the direction of the LEM! I had to find some pics of the real thing to figure out where they went!

Did you accurize it by scratching the exhaust deflectors under the thruster quads that are missing from most "classic" Apollo LEM kits?     

[PR19_Kit]

Did you accurize it by scratching the exhaust deflectors under the thruster quads that are missing from most "classic" Apollo LEM kits?     

In 1/144 scale? NO way! 

Now it's all been PSR'd and primed it's looking pretty good. The tail end of the Convair 1st stage was a tad too large to fit into the top of the Airfix S-IVB stage, but a short scraping session with a scalpel on the inner edges of the S-IVB sorted that out and now the upper stages are a 'plug-in' fit. RESULT!



The whole thing is about 17" tall now, but it'll end up a bit taller as there's quite a bit more stuff to add yet. 

The other two kits provided quite a few 'greebly' options that will fit on somewhere.