Project XR2 Ravenstar - Mk II

[Scarecrow]

One thing I'd consider is something that DanSteph came up with for the DGIV: Ejection capability...the DGIV can blow off the canopy so the pilot and pax could bail out in an emergency. Just a thought..=)

While I personally agree with the Ejection concept, Doug Beachy has stated that ejection will not be a feature of XR vessels, since in most situations, ejection wouldn't do you any good anyway (in orbit, flying at mach 10). I personally disagree, and think it's a useful feature for times like when you've come up short on fuel and you have to ditch in the wilderness. I'd much prefer to hit the ground under a parachute at a few meters per second vertical velocity with very little lateral velocity, rather than with a very small vertical velocity and protected by a plane, but smashing into trees and hills at 300 miles/hour.

 

[dutchpirate]

One nit I hadn't noticed before until the last pic you posted Coolhand, is the texture of the skin. It looks totally wicked, but in 'real life' would cause a tremendous amount of parasitic drag. Unless there is some kind of a magical clearcoat on top of it all smoothing it out:rofl:

 

[Coolhand]

Unless there is some kind of a magical clearcoat on top of it all smoothing it out:rofl:

If it makes you feel better, then yes, it does.

you won't even get that effect in the sim because there's no bump mapping, though it will be reflected to a degree in the specular map, no pun intended.

RE: the ejection system, i'm with doug here, there's no precedent for it and not really any need. I can't think of one civilian aircraft that has ejection seats, so why should this be different? they even ripped em out of the space shuttle after the first few flights. If this was a military vessel then perhaps yes, as it is there won't be an ejection mechanism, just lightweight seats, sorry*.



*no i'm not sorry at all, so there

 

[dutchpirate]

If it makes you feel better, then yes, it does.

My kind of answer!!:rofl:

 

[Master of Blades]

If it makes you feel better, then yes, it does.

you won't even get that effect in the sim because there's no bump mapping, though it will be reflected to a degree in the specular map, no pun intended.

RE: the ejection system, i'm with doug here, there's no precedent for it and not really any need. I can't think of one civilian aircraft that has ejection seats, so why should this be different? they even ripped em out of the space shuttle after the first few flights. If this was a military vessel then perhaps yes, as it is there won't be an ejection mechanism, just lightweight seats, sorry*.



*no i'm not sorry at all, so there

Will the ship be using UMMU then?

IIRC, UMMU comes with a "bail out" command, wich causes all the onboard crewmembers to leave the ship... prhaps that could be used in emergenices, rather than a real ejection seat?

 

[Coolhand]

Its basically got all the features of the XR series, though for much of the flight envelope bailing out isn't really something you'd want to do. i guess if you were to bail then you'd do it through the top hatch, which swings up and forwards to protect you a bit from the airstream. A pretty hairy manuever.

 

[Cale]

Didn't realize that UMMU had a "bail-out" command...will try it out.

I understand your reasoning about not doing the ejection feature. Definitely not a deal-breaker for me, was just curious.

 

[Donamy]

Should go for it... I just need somebody who could do the meshes...

Does this do anything for ya ?

 

[Coolhand]

Y'know what i think would be really interesting for an XR-0, something thats as large as possible, but with foldup wings or some clever system so it can be packed away in as small a space as possible. If you were really designing something to fit into another ships bay i think that would be the way to go, so you're not wasting space in the bay. Maybe something stubbier as well, since if you're packing it into an XR5 then that vehicle is going to take it through the hypersonice range into orbit, so it should look more like a compact lifting body or something that can fly in space and re-enter and glide to a landing.

The Goblin was a craft designed to be carried and deployed from a bomber... basically a fighter stuffed into as small a space as possible.
http://en.wikipedia.org/wiki/XF-85_Goblin

compact lifting bodies

http://en.wikipedia.org/wiki/Lifting_body

 

[Urwumpe]

Coolhand: Folding wings had been one design path I investigated. I dropped them as they had added unneeded complexity. The wing surface I had initially had been more then enough for a space plane, and when the payload bay was large enough, I kept the wing surface if I remember correctly, it now has 40% of the mass of a XR1, but 50% of the thrust and ~60% of the effective wing surface. it will be very agile compared to the XR1.

One major trade-off: the design is optimized for Earth reentries and ascents. The fuel budget should allow landing also on the moon (and on mars as well), but require refueling on the ground in both cases for returning. The flight time on SCRAMs will be longer as on the XR1, but the design can't even reach the moon without refueling in LEO. It is no true general purpose craft, like the XR1 or possibly your XR2, but capable of cruising in the upper atmosphere for quite a long time. Which for example would allow transporting small amounts of cargo (or a passenger) from a low inclination orbit to a high-latitude airport. Or you could do atmospheric science with it, using its better aerodynamics compared to the XR5.

If you plan flying to bodies without atmosphere, a design without wings or aerodynamics would IMHO be more effective. But such a device would not be able to spent any time in the atmosphere and so far all released XR vessels have a pretty limited cross range for reaching distant targets on Earth. But still, I would like somebody making a vacuum optimized XRx vessel, similar to the Dragonfly. It would just be a good complement of the series.

 

[Coolhand]

See, i don't see what the point would be if it's capable of ascent by itself really, you may as well use an XR1 or 2. I don't see why folding wings would be impractical, its a fictional / futuristic vessel, and the shuttle orbiter shows us that you can have doors in your heatsheild so there's a precedent for heat-proof seams, presumably a folding wing would not be difficult, it would just add a bit of extra weight. Many naval combat aircraft have folding wings, if wingfolding wasn't practical then i don't think navies would have used it for so long. So, in fact folding wings would only increase its practicality from the POV of fitting into a bay.

You've come up with a fine design, a cool spaceplane in it's own right, but the wrong direction i think for that type of vehicle. Of course you're welcome to tell me to get ****ed.

I think a compact as possible folding wing or lifting body design that can carry out orbital manuvers, lunar transfers and atmospheric return would be the way to go. either that, or as you suggested a totaly space only vehicle that is recovered and returned to earth by the xr5, i've had some ideas for both types of vehicle myself, and a smaller vehicle that would fit in the XR2 but would have fairly limited capabilities, but i don't know if i'll have the time to realise them or if doug would even be interested.

 

[Urwumpe]

See, i don't see what the point would be if it's capable of ascent by itself really, you may as well use an XR1 or 2. I don't see why folding wings would be impractical, its a fictional / futuristic vessel, and the shuttle orbiter shows us that you can have doors in your heatsheild so there's a precedent for heat-proof seams, presumably a folding wing would not be difficult, it would just add a bit of extra weight. Many naval combat aircraft have folding wings, if wingfolding wasn't practical then i don't think navies would have used it for so long. So, in fact folding wings would only increase its practicality from the POV of fitting into a bay.

You've come up with a fine design, a cool spaceplane in it's own right, but the wrong direction i think for that type of vehicle. Of course you're welcome to tell me to get ****ed.

I think a compact as possible folding wing or lifting body design that can carry out orbital manuvers, lunar transfers and atmospheric return would be the way to go. either that, or as you suggested a totaly space only vehicle that is recovered and returned to earth by the xr5, i've had some ideas for both types of vehicle myself, and a smaller vehicle that would fit in the XR2 but would have fairly limited capabilities, but i don't know if i'll have the time to realise them or if doug would even be interested.

Well, feel free to disagree. :lol:

I don't leave the folding wings out, because they are technically unthinkable - we have even doors in the nose of vessels. I just noticed, that the extra wing area by allowing folding wings would not be needed. Call the decision economic, I think that describes it best.

The plane would have a wing loading which is 66.6% of the XR1 - or you can say, at the same flight conditions, it could have 50% more lift per kg vessel. The XR1 can easily create 3G turns, so I decided that 4.5G+ is a good design limit for a rather stratospheric craft.

It is not a fancy luxury yacht... I think that is something the XR2 can do much better. I designed it more as affordable auxiliary craft. For example, in the current design, it has no deployable radiators, as I have more wing surface available for a fixed radiator (like on the SR-71, which was the main inspiration) than the XR-1 has for deployment. So, even if the performance of such a radiator will be worse as a deployable radiator, it should be more than enough for the ECLSS of a smaller craft.

But people complain already about these missing deployable radiators.

When a XR0 by my design would cost around 25% of a XR1, I have met my economic design goals. :beach:

 

[Coolhand]

Well if you went with a lifting body then you don't need the folding at all since your actual wing area is so small. but i think a wing fold with your current design would be essential, since your taking up so much payload bay space with the wings, the XR5 would be kind of wasted hauling such a design up into space. And if you had wing folds you could perhaps haul more of these vessels up at once. I could really see the military doing something like that, lifting multiple, cheap, manned orbital interceptors into orbit from a larger carrier, if that would be practical at all. Other than that, if you just wanted to see how small and cheap you could make a spaceplane that can make it into orbit by itself and the ability to fit into the 5's payload bay is just a bonus, then i don't see whats wrong with the design

 

[TSPenguin]

I think you guys are taking this into the completely wrong direction. We need a ship that can lift multiple XR5s into orbit, not the other way around.

 

[Urwumpe]

Well if you went with a lifting body then you don't need the folding at all since your actual wing area is so small. but i think a wing fold with your current design would be essential, since your taking up so much payload bay space with the wings, the XR5 would be kind of wasted hauling such a design up into space. And if you had wing folds you could perhaps haul more of these vessels up at once. I could really see the military doing something like that, lifting multiple, cheap, manned orbital interceptors into orbit from a larger carrier, if that would be practical at all. Other than that, if you just wanted to see how small and cheap you could make a spaceplane that can make it into orbit by itself and the ability to fit into the 5's payload bay is just a bonus, then i don't see whats wrong with the design

It is sort of a lifting body - the chims of the fuselage produce a lot of lift. But other than a full lifting body, this compromise shape offers some maneuverability at lower Mach numbers.

A variable geometry lifting body would of course run better above Mach 4. And be more complex and more expensive. When the XR0 would cost more than the XR1, it would have to be extremely powerful, which it, by it's small size, could never become.

The chims also store payloads - they should have doors, which open to above for deployment or installation, and protected standard windows in the bottom for sensors.

 

[Coolhand]

I'd love to see a varible geometry spaceplane. maybe that could be included in later XR's, whether i end up building any more or not. For me, in the context of the XR series, i'd be more interested in seeing something (lifting body, folding wing, or non-aero) that uses one of the larger XR's to take it into orbit and is designed for that purpose and not capable of ascent to LEO by itself, though could takeoff from the moon. Though a standalone one or two person vehicle would also be neat, it's probably only practical in terms of a spacefighter/interceptor or something... I don't know what a company would do with it to make money or what practical use it would have - apart from being cool, which might be enough reason to build it for orbiter in the first place.

 

[Urwumpe]

Well, what about making a PB-XR, which is in the same scale as the Shuttle PB?

 

[Coolhand]

I think that would be cool, again though - and it's kind something that i think affects all these small ships no matter what shape - what would you do with it, whats its purpose? the XR1 carries passengers, maybe whatever small items you could stuff into the cabin... The XR2 carries even more passengers (i see that, like the XR1, as being almost like a learjet for space) and now has a payload bay which extends its capabilities, and the XR5 is just a beast of a machine that hauls tons of stuff. what would something even smaller than an XR1 do, whats its purpose? Whatever, it might be fun to fly, like the equivalent of a small sportscar for space, no real function, just for fun/showing off. like i say that might be enough reason to build something like that but i prefer designs that have some well defined purpose even if thats not totally utilised in the sim. Probably the 2001-esq workpod is the most practical - maybe something like the flying monkey that willy suggested, or the space only vehicle. Otherwise i think you're either looking at an escape vehicle, like the X33 lifting body or a military/espionage craft that would probably be better served by some sort of satellite or UAV drone.

Sorry to rain on your parade, man, i think it would be fun to fly so just ignore me

 

[Urwumpe]

No, you are right on the purpose side. It could with more realistic technology, do almost nothing. But a small work bee would be for example possible. Or a two person excursion vessel for moon/mars, similar to the proposed moon hopper.

Form always follows function a bit, unless you do abstract art.

 

[dbeachy1]

I really like the idea of an XR0, and I'm happy to see it being discussed again. I envision the XR0's primary role to be a one- or two-person landing craft that would travel to a plant or moon in the Vanguard. Then the Vanguard would stay in orbit while the XR0 would deorbit to the landing site, refuel, and then take off again to rendezvous with the Vanguard in orbit. I think that would be a lot of fun, particularly if the XR0's fuel level was set to realistic in its config file, requiring a skilled pilot to reach the Vanuard again after refueling.

It would also be fun to fly a SCRAM ascent to LEO and rendezvous with an orbiting Vanguard or dock with the ISS. Given its high maneuverability it would be fun to buzz around in the atmosphere, too.

In addition, I could add a config setting to make the radiators "marginal" so that the coolant would slowly rise even if the radiators were deployed. That would require the pilot to be efficient and either land or dock within a short time so that external cooling could be engaged before the internal systems overheat. This would reinforce the idea that the XR0 is a short-range craft, as well as adding additional challenge for veteran pilots. After all, challenge is what makes it fun! :beach: