SSTO to Low Minmus Orbit?

[lammatt]

is it possible to do that?

anyone who managed doing that mind giving some advice on how the SSTO vehicle is built?

my problem is... the nuclear engines cant produce a good thrust to counter act the drag+gravity at mid-stratosphere where the jet dies and the aerospike/ LT- engines are pretty fuel-hungry in Vacuum.

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the best i managed to do with an SSTO is flying the Aires 4A (modified: replacing the docking port with the Kerbal Attachment System plug) to a 100km kerbin orbitting station and flying to minmus after having refueled.

but what i actually wanted to do is to fly to minmus and do the refueling there instead of getting it done at kerbin since my kethane station is at minmus (whose isnt?) and refueling at kerbin means one day the kerbal station will run out of fuel and needs refueling too... and that would be pretty hard (well... docking a 30t full Rockmax tank at kerbin is not as easy as docking a full 8000unit Kethane tank at minmus)

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i am not using Ferram... i am playing with the stock aerodynamics

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my desire Minmus orbit is ~12km (with ~200m/s dV to spare for the inclination change maneuver)

Edited July 14, 2013 by lammatt

[ComradeGoat]

MOAR intakes. You can use an LV-N based SSTO, but you need to be at near orbital velocity above 30,000m when you switch the jets off. Also, arranging to have some substantial vertical speed when you cut out, so that your apoapsis is ahead of you by a minute or so and up beyond 40K will help.

It's not easy, but it can be done. Good luck!

[Scotius]

I've seen a YT clip of Ion-powered SSTO flying to Duna. So yes, it is possible (and hard apparently).

[joppiesaus]

I've seen a YT clip of Ion-powered SSTO flying to Duna. So yes, it is possible (and hard apparently).

I saw once a SSTO to Laythe and back. Everything is possible!

[geb]

Like ComradeGoat said, you need a lot of intakes. If you have a huge number of intakes, you can get up to very high speeds in the upper atmosphere, and need only a small velocity change to reach orbit.

Runway to Minmus surface and back again can be done with this design.

Craft file here if you want to play with it: http://mrp.ath.cx/stuff/Anisakis%20Mk5.craft

Action group 1 should disable jets and intakes.

[Amphiprion]

I made this SSTO that is currently In extreme low minimus orbit.

600 meters at some points.

Are you making sure you reach +-1800m/s in upper atmo, getting the most of the ISP in your turbines before you get into vacuum?

[lammatt]

so... it seems airhogging is the only way then....will try it later~

(while i dont think they should totally get rid of it; they should make the intake has a diminishing return... this exploit is kind of lame indeed)

[Sof]

Intake spam will die with the advent of real aerodynamics.

It is possible to build a SSTO plane that has jets->rockets->nuclear engine without intake spam. It just ends up being quite big.

[tavert]

It's possible to get to the surface of the Mun and back with a rocket-only SSTO, Minmus is easier. T30's and one or two LV-N's, possibly with some SRB's for takeoff (still an SSTO if you don't ditch them, and they don't weigh much empty), can do the trick. A jet makes life easier still, and tons of intakes the easiest. If you want to try a jet with a small number of intakes, you probably just need a couple T30's (or even the small orange radial Rockomax engine, which has lousy Isp but great TWR) to help you get out of the atmosphere. You can turn them off once you're in orbit if you have an LV-N to switch to, for the delta-V to make the Minmus trip.

Edited July 14, 2013 by tavert

[arq]

Airhogging is not necessary. I've done it with a intake/turbojet ratio of around 2.5. IIRC, my plane had 4 turbojets, 9 or 11 intakes, 2 aerospikes (though LV30's would have been better) and 1 LVN. It gets up to around 25km/1500m/s on jets, then kicks on all the rockets to get up a bit, uses the LVN to finish getting to orbit and circularizing, and really only uses the LVN from there (more than enough power to land on Minmus). Fuel goes further than you'd think with a LVN. Over half the rocket fuel gets burned getting into LKO, and the rest is plenty for a Minmus landing and return (getting back from Minmus is only maybe 300dV).

[ComradeGoat]

No stacked intakes here. Over 3000m/s delta V left on reaching orbit. I cut two of the jets at 25,000, riding to 30K on 2 jets. At 30K and 1,800m/s I switch over to the NERVA and have enough thrust to keep my apoapsis in front of me, which means I've won:

Just keep pushing your apoapsis, get as close to straight and level flight as possible while still having your apoapsis in front of you, and climbing away. Throttle back as the air gets thin. When the apoapsis isn't climbing away on near-idle jets any more, cut them and switch to the NERVA. Increase pitch to keep apoapsis running away if need be. I can get this to 35K, point straight at the horizon and leave it all the way to escape velocity.

Good luck!