Alternus Space Shuttle: An early shuttle design takes flight!

[Exothermos]

While cruising Google images for inspiration for SSTOs, I came across a design sheet showing a few early space shuttle mock-ups. The design that became the Alternus Space Shuttle (edit: the Lockheed Star Clipper) was one of the proposals, and it caught my eye as being the most plausible of the group (the Real Space Shuttle's bizarre design wasn't even considered at this point). So I set out to make it work under the time tested adage of "If it looks right, it flies right."

I would come to the slow realization that this design needed more than my usual seat-of-the-pants engineering. One can see why the design was not adopted as the real shuttle's configuration is more efficient, even if it is overly complex.

Every aspect of the build presented problems, but eventually dozens of flights ironed-out the kinks, and a reliable and docile alternative shuttle design is the result!

Ascent is a standard Kerbal Rocket profile. Light the fires and drop the clamps at full throttle. Begin a gentle gravity turn a little early (9k meters and 250 is fine). There is lots of lift and control.

Staging of the main tanks must be done with care! Throttle back and they will peel-away beautifully. Then punch it! Apoapsis and insertion is achieved on internal fuel. Center of Mass and Thrust are preserved, no need for complicated maneuvers.

Make sure to unlock the rearmost fuel tank before insertion. It is a niggling fuel flow bug that I just couldn't crack. Oh well, it's a simple thing to do.

The Alternus has a maximum payload of 32 tons, or one Jumbo 64 Orange tank. Plenty of Monopropellant is available for fine maneuvering and docking.

Reentry is standard. Here I am trying to shed speed in high altitude turns like the real shuttle.

Touch down is at only 50 m/s. The Alternus is a flying gas can, so when it is empty it is very light and has a huge lifting surface. This also means that it is "draggy" in the stock aerodynamic model, so come in 'Hot' and shed speed late in the approach, or you will run out of energy and land short.

If you decide to download, I hope you enjoy, and as always feel free to comment!

DOWNLOAD

Edited January 28, 2015 by Exothermos

[Wjolcz]

And thats why I added you to the friends list. To keep an eye on every marvel you post.

[Naito]

Well done!!! I've been meaning to try all the various early shuttle designs, this looks fantastic!

[Rune]

While cruising Google images for inspiration for SSTOs, I came across a design sheet showing a few early space shuttle mock-ups. The design that became the Alternus Space Shuttle was one of the proposals, and it caught my eye as being the most plausible of the group (the Real Space Shuttle's bizarre design wasn't even considered at this point). So I set out to make it work under the time tested adage of "If it looks right, it flies right."

I would come to the slow realization that this design needed more than my usual seat-of-the-pants engineering. One can see why the design was not adopted as the real shuttle's configuration is more efficient, even if it is overly complex.

Every aspect of the build presented problems, but eventually dozens of flights ironed-out the kinks, and a reliable and docile alternative shuttle design is the result!

http://i.imgur.com/uzHftnJ.png

Ascent is a standard Kerbal Rocket profile. Light the fires and drop the clamps at full throttle. Begin a gentle gravity turn a little early (9k meters and 250 is fine). There is lots of lift and control.

http://i.imgur.com/1fdXbWi.png

http://i.imgur.com/s4Ej1Xz.png

Staging of the main tanks must be done with care! Throttle back and they will peel-away beautifully. Then punch it! Apoapsis and insertion is achieved on internal fuel. Center of Mass and Thrust are preserved, no need for complicated maneuvers.

http://i.imgur.com/Ej0YUd6.png

Make sure to unlock the rearmost fuel tank before insertion. It is a niggling fuel flow bug that I just couldn't crack. Oh well, it's a simple thing to do.

http://i.imgur.com/8u2FAnB.png

The Alternus has a maximum payload of 32 tons, or one Jumbo 64 Orange tank. Plenty of Monopropellant is available for fine maneuvering and docking.

http://i.imgur.com/Q6YCXeK.png

Reentry is standard. Here I am trying to shed speed in high altitude turns like the real shuttle.

http://i.imgur.com/XQCmAbp.png

Touch down is at only 50 m/s. The Alternus is a flying gas can, so when it is empty it is very light and has a huge lifting surface. This also means that it is "draggy" in the stock aerodynamic model, so come in 'Hot' and shed speed late in the approach, or you will run out of energy and land short.

If you decide to download, I hope you enjoy, and as always feel free to comment!

DOWNLOAD

http://i.imgur.com/bdNQeoo.png

As awesome as I imagined when you first teased it! The alternative shuttle concepts are all pretty awesome (and most make more sense than the final design).

As to the fuel bug, I have a feeling it's the same thing that has been happening to me lately (well, it's been happening forever, but now I know how to detect and fix it!): parent part issues. When you drop a part in the editor, take care that the cursor is hovering above the part that you actually want to attach to, and not another one, because otherwise the game can build the connection from the other part. This is how you can "lose" connection nodes, too, the game assigns it to the bugged parent part, that shouldn't have it in the first place, and when you remove the one connected to it, it reverts it to its node-less natural state, taking the connection node out of the craft file entirely. I'm sure that's happened to you before. At least I think that's how it works. In any case, the solution is to remove and re-attach all the parts involved in the fuel routing, and taking more care in the future. The KER feature of popping a contextual name for the part you are highlighting helps a lot to know what you are dropping stuff into.

Rune. These are the kinds of bugs that you wouldn't expect to happen by the release date... but will, I'm afraid.

Edited January 26, 2015 by Rune

[Exothermos]

That's a really powerful hint, Rune. The cursor hovering over the wrong part very well could be the case as I've been relying on the 'alt' key for the snap-to-node function a lot, and this build transitioned from horizontal to vertical endless times. Who knows where that cursor was!

[Rune]

That's a really powerful hint, Rune. The cursor hovering over the wrong part very well could be the case as I've been relying on the 'alt' key for the snap-to-node function a lot, and this build transitioned from horizontal to vertical endless times. Who knows where that cursor was!

Glad to be of help! Tracking that bug is one of the very few things I'm very proud to say I did all by myself, but there is a ton of other stuff that I learned because some very nice people took the time to tell me about it here.

Rune. So just returning the favour, really.

[Josh Harris]

Oh wow a Lockheed Starclipper. Looks good!

[Mesklin]

Really great design

[Prof. Endwalker]

Sweet Jeb riding an SRB. This looks crazy cool. Interesting way of designing one, without the hassle of having to adjust thrust for a radially attached engine. Great job!

[eorin]

Just... Awesome!

[SpaceLaunchSystem]

Looks like the X-33 VentureStar. Anyway, very cool! Downloading right now...

[OscarWilde]

Those radial tanks look amazing.. getting them to peel off like that! I find I always need to cut my thrust off (or nearly off) to drop tanks like that in my designs. Is that always the case?

[Exothermos]

Thanks everyone!

Yeah, unless you put a silly amount of thrust on the separation engines, you need to throttle back on these kinds of designs. In this case, the separation happens at such a high altitude that there is not much penalty to throttling back momentarily. Infact, one can keep accelerating through the maneuver as long as it is at less than one gee.

- - - Updated - - -

Oh wow a Lockheed Starclipper. Looks good!

Oh hay! Thanks for giving me a name to the one cruddy image that I had. It's a cool proposal.

Edited January 28, 2015 by Exothermos