Mullet Dyne Cross Wing SSTO - Feedback?

[Speeding Mullet]

I haven't made an SSTO in absolutely ages.  In fact I haven't made one since before the significant aero changes occurred as I simply lost the ability to do it.  That really had to change so I put my mind to it and over the last 3 days have designed and flown this mission in my spare time.  First some stats:

Name:  Mullet Dyne Cross Wing (Variant 5)

Parts: 86 (including payload)
Mass: 43.155t
Cost: 81,464 (including payload)
Power: 3 x CR-7, 2 LV-N

Mission Report - Click here

Craft File - Click here

So basically what I'm looking for is a bit of feedback if anyone wants to chip in.  Since this is my first foray into SSTO's since before the major aero changes (although the design went through 5 iterations before I was happy with it) I've no real idea (beyond being capable of Mun/Minus return) whether I've got the balance, look, design, efficiency right etc.  Feel free to download it and try it out, or just provide feedback based on what you see

 

Thanks everyone!

SM

Edited January 4, 2017 by Speeding Mullet
updated craft file link

[Samniss Arandeen]

It's a unique design, but you certainly went overkill with the engines and fuel. What's the dV on it after orbital insertion?

[Speeding Mullet]

1 minute ago, Samniss Arandeen said:

It's a unique design, but you certainly went overkill with the engines and fuel. What's the dV on it after orbital insertion?

Thanks!  I thought I might have gone overkill with the engines by 1 LV-N at any rate!  I maybe should have noted that LF starts at full with 3118 units, but oxygen only about 600 units to help with the boost before the LV-Ns take over.  I got to a 150km orbit and then transferred to dock to a 200km station and had 1160 units of LF left if that helps?  No idea on the dV on orbit unfortunately.

SM

[Samniss Arandeen]

That does not help, as delta V also depends on vessel mass (which I don't know from just looking at the picture). Having 1160 fuel left after docking to the station means you're lugging around quite a bit of dead weight, and you can omit some of those tanks if all you want is a crew shuttle/light utility craft.

[Speeding Mullet]

Just now, Samniss Arandeen said:

That does not help, as delta V also depends on vessel mass (which I don't know from just looking at the picture). Having 1160 fuel left after docking to the station means you're lugging around quite a bit of dead weight, and you can omit some of those tanks if all you want is a crew shuttle/light utility craft.

Ahha, I just went into the VAB and replicated the fuel conditions at 200km and got a weight of 29.875t and an empty weight of 23.925.  So the on orbit dV if I'm right from just learning how to do this is   800 * 9.8 * ln (29.875/23.925) or 1741.25 m/s.  Thanks for making me learn something .

I wasn't thinking about use really when I designed it, apart from wanting something to go as far as possible. Based on the dV figure it could do Minmus landing and return I reckon!  If I was going to employ it as an LKO Spaceplane for simple crew delivery tasks I think your are right that iterating the dead mass out would be a good idea, and then chucking a couple of engines too!

SM

[Thor Wotansen]

If all you want is a LKO light shuttle you don't need LV-Ns.  I recently made a Mk2 SSTO with 2 rapiers, the Mk2 by-coupler, the long LFO tank and a short LF tank.  It can put 6 kerbals or 1.5t of cargo into LKO.

[Speeding Mullet]

8 hours ago, Thor Wotansen said:

If all you want is a LKO light shuttle you don't need LV-Ns.  I recently made a Mk2 SSTO with 2 rapiers, the Mk2 by-coupler, the long LFO tank and a short LF tank.  It can put 6 kerbals or 1.5t of cargo into LKO.

One of the early iterations used CR-7s and a couple of sparks for LKO work, functioned fine as a light LKO shuttle, but I wanted to push out as far as I could with this one.  I want to see if I can iterate this one towards a Duna landing and return if possible.

SM

[Thor Wotansen]

Ah, I see, but if you can land on Minmus you can get to Duna.  I have a bunch of SSTOs that can do it, but I'm too lazy to get a transfer.