So... what do you think of the RAPIER engines?

[Joshington]

I made an SSTO that got into an almost completely stable orbit (67k at the lowest point) on my first try, with no working SSTOs in the past. So yeah, I think I like it.

[Eric S]

I have not yet test the jet in 0.23. If what you said is true, it would be a great improvement. Thanks for the information, I will test the jet ASAP.

It most certainly is, I had a spaceplane I designed in 0.22 that was just enough to get to orbit, play around a little bit, and then head home. No chance of having enough delta-v to go to the Mun or Minmus. That same spaceplane shocked me in 0.23 when at about 30 km altitude, 2300 m/s velocity, it was still both climbing and accelerating. It was in a 122 km x 20 km orbit when the engine finally died, and only needed 60 delta-v from the rockets to circularize at 122 km (I was still low enough in the atmosphere that drag ate a little bit of the apoapsis). It was originally designed as a bit of an airhogger, five ram intakes for one turbojet engine.

[maccollo]

Well, you can make a very small SSTO with a 4.5 meter tank, a rapier engine, a ram intake and a lander can.

This configuration of just 4 parts is easily capable of doing a mun flyby, so I would say this thing probably has it's uses.

Other than that, the design of the engine is very boring and uninspiring.

[tntristan12]

I did a retread of Brotoro's SSTO crew transfer shuttle and got it to work with just RAPIERs. That freed up some space in the middle for a heat shield if and when I ever decide to dabble in deadly re-entry, and it's fewer engines but looking at the cost I'd say the only true benefit is that it's an absolute joy to fly! I can see the appeal of RAPIERs for smaller craft that aren't trying to lift too much. It's also nice to cut back on the number of action groups you need. I'd say it's pretty well balanced.