R.400 X-2

$62.8m.
Two hundred tons to orbit (with more d-v remaining than before).

People talk about inexpensive and efficient rockets, well, here's my definition. For me an acceptable rocket can lift 2x it's cost, if you swap the dollar sign to tons. A $30m LV should lift 60t. $50m should lift 100t. $10m should lift 20t. That 2xmoney=tons is the baseline ratio of something I'll tolerate. Most of my rockets far exceed that, and are recoverable for yet more savings. I'm fairly happy where this one is at. It's still experimental and probaly has a few kinks to work out, but I'm chuffed. It's not quite on a TWR knife-edge at 200t, but it's close to it.

Craft History:

I tinkered with the R.400. I wanted delta nozzles, but that meant downsizing the engines to fit them. I also wanted kerolox for more fuel density.

Those changes made the rocket much heavier, with worse TWR at launch. The money saved went into impulse SRBs. Yes, TWR on the X-1 drops as low as 0.84 when the SRBs burn out, but it was wildly better at pushing 200t to orbit. The kerolox and delta nozzle pixies made it a high altitude specialist. It was so good that it went from circularising with only 1km/s spare, to nearly being a SSTO.

So the penny dropped. I don't need the upper stage at all, and removing it entirely will only make the booster fly better. And here we are with the X-2. It's (almost) the R.400 booster with a fairing. It does the same job better.

Re-entry is still prograde.(It took multiple tests to get the re-entry phase sorted again. Weight distribution and aero all changed.) There's a fair bit of shielding, and it should survive a hot re-entry.

The parachutes are for a water landing. 20m/s on land won't end well.

Recovery ~$35m if you land close to DSC.

*Once in orbit, firing all 7 engines with massive TWR is too violent, so the outer engines are on Group 10. Toggle them on and off as needed.