I'm very skeptical of the market they're targeting. SpaceX used to cover that same payload capacity with the Falcon 1 [0] rocket, but discontinued it since no one bought any. Maybe things have changed in the past few years, but I seriously doubt it. The aerospike engine is interesting since none have been used commercially before, but if there isn't a market it might as well run on fairy dust.
Still, I wish them the best. We need more innovation in the space sector, and I would love to see those engines become more commonplace.
Still, I wish them the best. We need more innovation in the space sector, and I would love to see those engines become more commonplace.
[0] http://en.wikipedia.org/wiki/Falcon_1