An X-51 ScramJet type thing

[katateochi]

I saw this

*wiki image*

And thought oooo, shiny, I need one in KSP and started attempting to make one.

Unfortunately, as far as I know, we don't have any ScramJet engines, so this thing is not technically a ScramJet, it's just been made to look (a bit) like the boeing X-51 and my aim was to get it up to the same speed of 6400kmph (1778m/s).

It's a pretty simple craft, basically a probe core on a big strut and several of those oh so versatile flat things (u know the ones I mean) to cover it. It has 6 of the lengthed roundified fuel tanks from the KSPX pack and a turbojet engine. Underneath it, about where the inlet on the X-51 is, there is a radial airScoop. What you can't see from the pics is there are 3 circular intakes and another airScoop inside it.

Then like the X-51 it has an SRB which starts it off once it is dropped from the plane. Here is it sitting on its trailer waiting for the plane.

Right, the plane, hmmmm, well yes, this actually proved much much harder than the actual ScramJet. I had a small test plane to take it up during testing, but I really wanted to drop it from something that was kinda like the B-52 that the real one is take up on. And that was kinda tricky.

After many many crashes this was the result; a kinda B-52(ish) plane (type thing). I say 'type thing' cos if it was actually a plane it would fly like one. This one flies like a swan, a swan with severe brain damage and both eyes poked out (it also flapps its wings rather alarmingly at times)

The plane is a probe based plane too, as it has to be ditched and I didn't want unnecessary kerbal casualties (although Jeb did ask if he could ride on the ScramJet).

Two ScramJets were then attached to the underside of the planes wings (with remarkable ease). The main one and one just to balance it.

After a very sketchy flight with me frantically fighting to keep the plane climbing it reached around 16km. I wanted to get up to 18km, but the plane, apparently a bit afraid of heights, said no and started to fall at this height. So the ScramJets were released;

One was then set on course and its SRB fired up. As the SRB burns the TurboJet engine is also started up, so it was already warmed up by the time the RSB burned out

It climbed to 26km and accelerated to about 1600ms pretty quickly

Then gradually and carefully its alt. was increased and it slowly continued to accelerate. It passed my first goal of 1700m/s at an alt of about 27km and continued to accelerate gradually.

At this point I was on the very edge of having a flame out and was gingerly increasing its alt a little at a time. I used MechJeb's SURF function to control the pitch and was making pitch alterations of 0.1 of a degree at a time (something that's only possible to do with MJ, but after all this is rocket science, precision is sometimes needed).

I eventually hit a max speed of 1765m/s before getting a flame out, 13m/s slower than the X-51's speed, drat. I'd climbed to 27700meters and apparently there wasn't much air up there, who knew.

I still had some fuel left and I think if I'd been more careful and kept it level at 27700m I would have made it to 1778m/s.

So I'll try again. My biggest problem with the whole mission is the plane. It took several attempts to fly the ScramJet up to a reasonable height to drop it. Basically I need to learn more about how to build large aircraft in KSP. Any suggestions are welcome!

So will actual ScramJets ever be a thing we might see in KSP? I wonder if any modders out there have got plans to make one.

Edited April 25, 2013 by katateochi
Several instances of 'scamjet' instead of scramjet! Lol, kinda true.

[AmpsterMan]

beautiful!

[reptile2001]

Great read! I've actually been contemplating building a B-52esque dropship of my own, if for no other reason than the fun of it.

[Vanamonde]

You are just incapable of doing anything simple, aren't you?

[SalmonellaDingDong]

The TV aerospace pack has Ramjet engines, which are perfect for this type of thing. You need to be going 1100m/s for them to generate enough thrust to accelerate, however.

[ROFLCopter64bit]

The TV aerospace pack has Ramjet engines, which are perfect for this type of thing. You need to be going 1100m/s for them to generate enough thrust to accelerate, however.

Seems like a very good option for SSTOs then.

[PaperLemon]

You might want to check out Taverio’s Pizza and Aerospace mod on the spaceport. His pack includes a couple of scramjets that actually function like real ones (i.e. you need to be going really fast for them to produce any appreciable thrust). I made an X-43 replica using his parts that flew pretty well, but you've got to bring along another propulsion system to get it up to speed first. I've managed well over 2000m/s using this combination.

[SalmonellaDingDong]

Seems like a very good option for SSTOs then.

They're tough to get good results with. The transition between engines can VERY easily throw you into a spin.

You might want to check out Taverio’s Pizza and Aerospace mod on the spaceport. His pack includes a couple of scramjets that actually function like real ones (i.e. you need to be going really fast for them to produce any appreciable thrust). I made an X-43 replica using his parts that flew pretty well, but you've got to bring along another propulsion system to get it up to speed first. I've managed well over 2000m/s using this combination.

Yeah, that's the full name that I couldn't remember!

Heres a system I was experimenting with to get up to speed:

[katateochi]

You are just incapable of doing anything simple, aren't you?

put simply; yes.

The TV aerospace pack has Ramjet engines, which are perfect for this type of thing. You need to be going 1100m/s for them to generate enough thrust to accelerate, however.

Ah cool, I'd not seen those. I'll have to check it out. That's nice and realistic that they don't work until you've got them up to speed.

You might want to check out Taverio’s Pizza and Aerospace mod on the spaceport. His pack includes a couple of scramjets that actually function like real ones (i.e. you need to be going really fast for them to produce any appreciable thrust). I made an X-43 replica using his parts that flew pretty well, but you've got to bring along another propulsion system to get it up to speed first. I've managed well over 2000m/s using this combination.

Any idea why its "pizza" and aerospace?

I'd like to see your X-43 replica. And why is the X-43 soooo much faster than the X-51? The X-43 can do 10,461 km/h (mach9) whereas the X-51 hit 6,400 km/h (mach6).

[drakesdoom]

The X-43 was how fast can we go and ran on hydrogen fuel, the x-51 was a test for feasibility for use and used special blend jet fuel.