Yogi's builds - to boldy glue, where ...

[Retired_for_now]

Dropped off the space station set and shuttles with the Planetarium. I should probably re-shoot the display as the director has reorganized, etc.

Quick project sparked by the X-37's successful return. Justin's version is nice, but there are a lot more photos out now. Biggest revision is the fuselage cross section - circular barrel set into the aerodynamics for most of the length, aft RCS section is a very subtle bulge on the lower sides only.


Center is Justin's design, right is first complete prototype, left is final (?).

Yogi

[Paper Kosmonaut]

That's a nicely done shape-up you did there, Yogi. I like the un-bulged backside a lot. It does the craft good. it gives it a sleeker appearance, though less feminine. Just two things: Aren't the leading edges a bit more blackish? And I thought the X37b had just one engine. (But I might be wrong, of course!)

[Retired_for_now]

Well - shades of black are always tough. The X-37B does not use reinforced carbon-carbon for the hottest sections like the shuttle. It uses a fiber reinforced variant on the thermal tiles for the hot sections, shuttle type tiles for the bottom, and the thermal blankets seen on the latest shuttle mods for the rest of the airframe. The bottom/leading edge tiles are black, I just didn't go with a 100% black shade ...
Engine designs included one large hydrogen-peroxide rocket, but the version launched used hydrazine (nitrogen-tetroxide/monomethyl hydrazine) rockets - a proven, storable, and restartable system. Likely the switch to two motors reflects re-use of an existing design.
Found directions to a very dense NASA treatise on the propulsion system on a space-engineering blog.
Yogi

[Retired_for_now]

Re the profile: the post landing pictures released seem to clearly show the airframe as a 4-foot (or so) cylinder embedded in the aerodynamic "sled." Head-on shots don't show a drastically wider aft end - likely the pre-launch photo has some camera distortion that makes it look fatter than it is. So, I figured it would be engineered as a constant section fuselage with a nose section and the RCS "pods" scabbed on and faired in aft.


Shape can be seen in this shot of one of the prototypes.

Yogi

Still refining - at this rate I'll have a fleet of prototypes for give-aways ...

[jparenti]

Looking good! I noticed that the landing photos gave a little more detail regarding the profile of the vehicle, and you've added that very well so far. (If only they'd just give us blueprints. :D)
I attempted to put the original together a few days ago, but I did something wrong, because I couldn't get the rear part holding the engine in correctly. :(

[Paper Kosmonaut]

Thanks for the explanation, Yogi. The engine story does make a lot of sense.

[Retired_for_now]

So, recycling some bits from a previous effort (LCROSS booster) we have:



Second try to get the rescaling factor correct to make the OTV 1:48 to match. Still need the (big) launch shroud - on the Atlas V stack the shroud covers both the Centaur and the X-37 payload. Plus, all the cool logos are on the outside of the shroud ...

Yogi

BTW: that's three plain paper boilerplates and six prototypes so far with a shroud and landing gear still to go (just info for other not-so-professional-or-talented designers); talent is best but you can get by on persistence ...

[silveroxide]

Hello Yogi, I thought that this might interest you as a reference material. It is plastic but the details make up for it. Saturn V - F1 Engine Replica - Resin Illuminati

[Retired_for_now]

Originally Posted by silveroxide

Hello Yogi, I thought that this might interest you as a reference material.

Some neat stuff there. Thanks.

Yogi

[jparenti]

I like the idea of adding the Centaur and shroud. I thought it was kind of unusual to shroud the craft while launching instead of just leaving it exposed, X-20-style. Apparently they were concerned about aerodynamics during launch? It will make a great display to have the whole setup.