WIP - Nighthawk SSTO Crew Transporter (if it will reach orbit)

[XOIIO]

Hey all, been a bit since I played KSP, and I decided to take a crack at making a spaceplane again, though with the aerodynamics changes I don't know if it will reach orbit.

Anyways after failing to make a decent looking mk3 plane with lots of cargo room I decided to try making an mk2 plane to ferry people around, however since I've made some functional, but not very good looking planes in the past, I decided instead this time, I would turn off the com and col indicators and design one based just on looks, and fuel capacity.

I think it turned out pretty good, and when I launched it, to my great surprise, it actually flies quite nicely. Turning left and right are a bit limited, due to my not wanting a vertical tailfin, but aside from that it's remarkably stable, I did check the com and col a couple times, but didn't really have to move anything to my surprise.

So, I thought I'd get some opinions from you guys, and maybe someone who knows how to fly ssto's (I've only ever gotten into orbit three times, in previous ksp versions, it's probably way worse now) could give it a whirl and see how she does.

So, I'd love to get some feedback on the design and the performance. Download the craft file here -> https://www.dropbox.com/s/w1sc1gwqb8cmjqn/Nighthawk.craft?dl=0
 

Future improvements will be some parachutes if you can't touch down somewhere flat, and an RTG for power once I unlock it.

 

Edited January 4, 2016 by XOIIO

[XOIIO]

Sorry about there being no images for a bit, couldn't embed them, then the imgur album wouldn't embed and I couldn't remove it, and now embedding works *shrugs*

[XOIIO]

A couple slight changes. Tried a couple times but couldn't make it to orbit.
 

Edited January 4, 2016 by XOIIO

[SpaceplaneAddict]

Slow down there partner!

 

I can't download the craft right now,, but might be able to help verbally? Where exactly are you having problems flying this beauty to orbit?

 

 

Also, one major gigantic very painful problem. 1.0.5 says even ONE of those box intakes can feed a Whiplash jet. Too many intakes there buddy

Edited January 4, 2016 by SpaceplaneAddict

[SpaceplaneAddict]

EDIT: Another glaring problem that may become impossible, is that the bike appears to give you a TWR of 0.19. Way to low for ascent. You may want to add some LF/O rockets somewhere, along with a bit of Oxidizer, you boost you out of the atmosphere. 

Edited January 4, 2016 by SpaceplaneAddict

[XOIIO]

Ah alright, so I guess now you really only need one intake per engine? Cool.

I totally hadn't noticed the thrust to weight ratio. I was thinking of adding in a couple more jet engines anyways for looks since I have the room (and just move the rcs tanks that are under those nosecones), I'm guessing that will make a big improvement.

I want to use the LV-N and pure LF tanks since I will have a lot more flexibility  when it comes to maneuvering in orbit, and maybe even making single trips to minimus and the like, so oxidizer engines won't work very well, I think the extra jets should help though. I beleive in that image I had forgotten to remove the oxidizer from the mk2 to 1 adapter which would help. I'll boot the game up again and make the changes, and probably remove some intakes.

edit: I removed the nosecones and placed them again and the thrust to weight ratio jumped to 1.65, I think that mechjeb just didn't update properly. I'm going to slap a couple engines on anyways though and see how she does then (which when removing the intakes from the side brings it up to 2.94

Edited January 4, 2016 by XOIIO

[XOIIO]

Alright so a couple things, mechjeb was set to manage the air intakes, meaning all but two were closed, I think that's because the jet engines used to have the highest thrust output with a low range of air, causing me to lose a lot of thrust, it was pretty easy to get up to 15km this time. I was able to get just under 30 peak, but don't think I was able to get up quite enough speed. I also wasn't able to go totally vertical, the cockpit just doesn't have enough torque to do it, and I don't think I was high enough. I usually stick an mk2 drone for the extra torque, but I'll add a couple sas modules hidden behind the engine and upload the new file (the link in the OP will work to get it) edit: It's much more stable and hold position better now, so I think the main issue is just me not knowing what sort of ascent profile I need. 900~m/s was my max)

The jet certainly does look better with two more engines though.

Edited January 4, 2016 by XOIIO

[selfish_meme]

The LV-N can only get a few tonnes into orbit, I would think you have too much weight with all the engines and wings, you probably need to reduce rather than add, less engines and wings, more wings than you need for lift = more drag than you can push through the air, higher speed 1000m/s+ by 10km

[eddiew]

I'd suggest swapping the nerva for a T45 or T30, as selfish_meme says above. Jets fizzle at a lower altitude now than they used to, and the LV-N's thrust is pitiful. It is very hard to make a jet/nerva combo without some sort of LFO rocket in there.

The other biggie is aerodynamics. Keeping things smooth has really mattered since 1.0 and all those intakes are just drag without any benefit. The double wing is probably not required either; I suspect you could remove one of them and it'd still have plenty of lift.

Overall, if you're returning after a long break, start simple!   Two jets and a T45 will fly, if you keep the accessories down and the wing area sensible. I do like the look you're going for, but you're adding a lot of complexity to the job ^^

[XOIIO]

3 minutes ago, eddiew said:

I'd suggest swapping the nerva for a T45 or T30, as selfish_meme says above. Jets fizzle at a lower altitude now than they used to, and the LV-N's thrust is pitiful. It is very hard to make a jet/nerva combo without some sort of LFO rocket in there.

The other biggie is aerodynamics. Keeping things smooth has really mattered since 1.0 and all those intakes are just drag without any benefit. The double wing is probably not required either; I suspect you could remove one of them and it'd still have plenty of lift.

Overall, if you're returning after a long break, start simple!   Two jets and a T45 will fly, if you keep the accessories down and the wing area sensible. I do like the look you're going for, but you're adding a lot of complexity to the job ^^

Yeah, that double wing is just for looks lol, I'm considering changing to an aerospike if I can't nail it with the nerv, but I really want to be able to pull this design off.

[eddiew]

I suspect you're just plain too heavy for the LFO engine you have. Not even sure that two would be enough. Nervas just aren't meant for orbital ascent, usually they'll even struggle to circularise before you dip back into the atmo :S

[Rune]

On 4/1/2016 at 1:31 PM, XOIIO said:

Yeah, that double wing is just for looks lol, I'm considering changing to an aerospike if I can't nail it with the nerv, but I really want to be able to pull this design off.

Actually, change the jets. Put RAPIERs in there, and all your troubles will be gone. RAPIERs have thehighest cutoff speed, meaning the less work to be done by rockets, and you can use their in-built LFO mode to give you the 500~700m/s kick into high suborbital trajectory where Nervs will be able to circularize. All you need is a bit of oxidizer somewhere... an I'm pretty sure you already have enough tankage in adaptors and such.

 

Rune. Pure LF SSTOs can be done, but they look like flying wings, have tons of Nervs, and horrible payload fractions.

[SpaceplaneAddict]

I suggest maybe removing entirely some intakes, shove some LF/O tamks and fuel lines in somewhere, and maybe add like two of those "Thud" engines. Those probably have enough ISP and thrust you push you out of the atmosphere, running with the nuke. Just pack enough Oxidizer to punch some extra speed in.

 

 

Amazing SSTO you've built though, because you're the one in a while that I've seen use TurboJets for main atmo thrust, instead of RAPIERS. 

[XOIIO]

3 hours ago, SpaceplaneAddict said:

I suggest maybe removing entirely some intakes, shove some LF/O tamks and fuel lines in somewhere, and maybe add like two of those "Thud" engines. Those probably have enough ISP and thrust you push you out of the atmosphere, running with the nuke. Just pack enough Oxidizer to punch some extra speed in.

 

 

Amazing SSTO you've built though, because you're the one in a while that I've seen use TurboJets for main atmo thrust, instead of RAPIERS. 

Yeah, I picked them at random, and then turned them on, and excrements I fell in love with the look lol. Rapiers sound and look worse, and also blow up the control surfaces.

I didn't know those thud engines were strictly liquid fuel, they might work well in between the wintips, I thought that they needed some filler. Those might be just what I need.