KerbalX

Description

The Madi is an SSTO specifically built to carry a Rockomax Jumbo-64; commonly known as an Orange tank, to LKO with 900m/s dV left, separate itself and return to land.

KSC management requested a cheap method of bringing more orange tanks to orbit, as these were widely used on space stations. While SSTOs such as the Niyaama Lite were capable of doing so, they were rostered so frequently for larger payloads, that a new craft was required. To try and wow the general public (and also give Jeb a headache), the TOTALLY original idea of bringing a craft that could separate itself was brought up.

This design was particularly challenging as previous variants usually had to compromise on one of these aspects:

• Being able to lift off the runway without ski-jumping.
• Atmospheric flight characteristics.
• Have a reasonable range of CoM shift.
• Re-entry stability.
• Ease of landing.

The tandem-wing design lent itself to be a good starting point. Afterwards, each of these issues were individually addressed with some rather unorthodox solutions. The resulting design left everyone scratching their heads, with Werner Kerman leaving the press conference in shame. The designers assert that the nose-up attitude on ground was deliberate, so as to help taking-off with a payload. It also unintentionally helped with landing. Lateral stability was considered just acceptable.

Built in the SPH in KSP version 1.4.5

Launch Profile

• Hit space to activate the Rapiers, unlike my other craft, keep the elevators neutral (or you will not accelerate).
• At 90m/s, lift the nose off the runway, then maintain level flight at low altitude by tapping F.
• At 400m/s, smoothly raise the nose to 10 degrees and hold this.
• At 9km, drop nose to 5 degrees, then let it come back up on it’s own as the craft accelerates.
• Your goal is to reach 1400+ m/s at 20km, with a pitch of 10-15 degrees.
• At 20km, press 3 to engage NERVs. At 26km, press 1 & 2 for ClosedCycle mode and to close air intakes, and smoothly pitch up to 25 degrees.
• Maintain 25 degrees, when Ap reaches 55km, press 4 to shutoff Rapiers and immediately hit prograde on SAS. Let the nose drop and watch your speed.
• As soon as the speed starts increasing again, cancel prograde and slowly bring the nose up to 30 degrees while ensuring you keep slowly accelerating.
• Let the nose come up on it’s own to 35 degrees and hold. When your time to AP starts increasing, slowly start bringing the nose back down.
• When your Ap reaches 75km, pitch to prograde or down as required to maintain. When Pe reaches 70km or more, you can circularize.

Payload Separation and re-docking

Though this operation is not particularly challenging, it is HIGHLY recommended to quicksave before payload separation, in the event the tail section spins out during docking.

• Make sure the craft is mostly SAS-stabilized, and not moving or rolling.
• Press 9 to undock the fuel tank. A sepatron is included to move the tank out of the way.
• Do NOT touch any of the roll controls. Engage RCS, and tap N to start slowly moving back. You may need to adjust vertically too. Tap H if your approach is too fast.
• Let the magnets catch, as this will ensure mostly successful docking. Not touching the roll controls shall ensure you end up mostly straight while docked.

Re-entry from 75km LKO

Use this as a general guide for re-entry purposes

• Aim somewhere near the old-island airfield, and target to deorbit with a 130-ish m/s burn
• Pitch attitudes of 5-20 will increase your range, 25-50 will decrease it. The craft does have a tendency to pull to the right, so keep this in mind.
• Try and keep the nose relatively straight laterally, even if you do lose control, the craft will tend to tumble around prograde. SAS prograde hold will help you recover easily. Pitch is less worrying, and you can nose up to 60 degrees!
• Press 7 to toggle the rudder-airbrakes if needed (you’ll probably need this on final approach to land).
• This craft slows down easily with a nose-up attitude, and glides really well. This leaves you with many options to reach the runway without overshooting.
• You can either dive towards the runway, and then aggressively slow down, or just simply hold the nose up around 60 degrees and let aerodynamic drag do the rest.
• Aim to touch down around 35-50m/s on the main-wheels. The craft has a naturally high-nose attitude so you can expect all 3 wheels to touch down at the same time.
• Toggle the brakes and you should slow down rather quickly, carefully hold the nose up if needed.

Notes and known bug

• Sometimes during takeoff, the landing gear may start bouncing erratically. Fly the SSTO off the runway and you should continue with no problems. This issue is somewhat sporadic and only happens from time-to-time.
• To enable easier payload separation, a sepatron is added to the orange tank.
• You could try carry other 2.5m payloads under 36t as needed (untested, will void your warranty!)