Cargo SSTO & VTOL SSTO [v0.25]

[GeneralDisorder]

Hi All,

Thought I'd share some of my creations in version .25

Firstly a pretty 'standard' cargo SSTO capable of lifting a decent amount of cargo (I'd say 3 to 4t). For kicks, I made Jeb an Ion Bike to cruise around on up in space.

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Craft file here (version with MechJeb here)

Next up is one I'm really happy with. I've been mucking about with VTOLS since .20 and I've always wanted to create a VTOL SSTO that still looks like a plane. I've seen some nice examples out there (levelord's in particular), but here's my own attempt. You can of course take of and land normally as well as vertically.

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Craft file here (version with MechJeb here)

For those of you who are wondering how to fly an SSTO, I'll try to give a quick overview specifically for these two craft, but the principles remain the same for others... There's probably a lot of guides out there, but I still see a lot of questions about it, so I'll give it a go along with a craft to guide you.

Action groups:

1 = Jet engine

2 = Rocket engines

3 = VTOL engines (obviously only for #2)

Simple.

First of all, I want to express to all who feel intimidated by SSTO's, that they are really quite easy to fly in KSP. With these two craft, after you take off (in whatever way) you want to keep your throttle at 100% and pull up your nose to about 30 - 35 degrees (Your heading obviously being 90°). Then you wait (or use time acceleration, but be careful for the 'bumps') until you get up to about 25 km. From about 25 km you will want to start to slow down your ascent a little. Drop your nose to 20 degrees and not long after you will hear your engine thrust drop off slowly. You should be going around 1000 m/s at this point. Don't worry if you're off a bit. Now you need to keep your eye at the top of your screen. More specifically at the vertical speed gauge to the right of the altimeter. It's probably pointing north at this point, indicating you are going upwards at about 100 m/s. Now we're going to start 'chasing our apoapsis'. This means we're going to want to get our vertical speed down to a more relaxed pace. Essentially bringing our apoapsis as close in front of the craft as possible. Drop your nose to about 10 degrees and you will start to see the vertical speed drop rather rapidly, so ease it down by occasionally pulling up a little, keeping your nose pointed between 10 and 20 degrees. You should be around 30 km at this point. Don't worry if you're lower, there's plenty of fuel, so practice increasing and decreasing your vertical speed. Also if your vertical speed drops below 0 for a bit that's OK. No worries, plenty of fuel... Just ease it back up without going into panic mode and pulling up at a ridiculous angle. Remember: "You're a leaf on the wind, watch how you soar..."

Now we accelerate... Keep your vertical speed somewhere at 10 m/s all the way up to 35 km. At this point you'll be going around 1900 m/s and your engine will produce a low whine right now (still giving about 70 kN of thrust). You will find that to keep the same steady 10 m/s ascent, you will need to start tipping your nose down. You're almost at orbital speed after all. So don't be surprised to see your nose go down to between 0 and 5 degrees.

At about 36 km your speed display will probably switch to orbital mode and you should be somewhere around 2300 m/s and rising. At approx. 37 km you will start to circularize your orbit and start to push up your apoapsis away from you, all the way to the other side of Kerbin.

For the last phase, we're going to squeeze every kN of thrust out of our engine and assist with RCS to push up our apoapsis above 150 km.

At this point, your nose will be below the 0 degrees in an effort to stay in the higher atmosphere for as long as possible. Mind you, you'll still go up at 10 m/s or more. At around 39 km, your engine will cut out for the first time because it fails to find enough air to keep it going full throttle. Now you need to throttle down until it fires up again and repeat this process as you go higher and higher. Ever reducing your throttle until you finally run out of air (can be as high as 50 km)

You're free to use RCS to push up even higher, but your apoapsis should be over 100 km even without RCS.

Now you just coast up to your apoapsis and fire up your rocket engines to circularize (which should take about 100 m/s dV)

On a final note, the Cargo SSTO needs some fuel redistribution before coming back down. I'd advise to put any remaining fuel and oxidizer in the tank directly behind the cargo hold.

Fuel balancer mod will help here... The VTOL always flies true.

So thank you for reading this, I hope it helps and I always appreciate constructive feedback.

Enjoy flying!

Edited November 1, 2014 by GeneralDisorder

[Overfloater]

Good engine setup, 1 jet & 2 little orange motors is perfect for small planes!

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[LABHOUSE]

Good craft, how far can it go without a payload?

[GeneralDisorder]

Thanks Overfloater! Edited.

@LABHOUSE: Both are designed for LKO, so dV is limited. The Cargo SSTO without payload has a dV budget of 1000 in vacuum. Should get you to the moon if you can time your take-off correctly. Don't think you'd still have enough to circularize there though...

[GeneralDisorder]

Out of interest, I plugged in an extra fuel cell in the cargo hold which almost doubled up the dV. Went to the Mun, circularized, returned to Kerbin and landed at KSC. No landing on the Mun though... yet. Another challenge! Back to the drawing board...