| Ariane is still somewhat competitive to geocentric orbits and when dual berthing. Falcon 9 and Heavy lose most of their performance advantage when going to higher orbits, IIRC because their first stages stage lower, and their upper stage has an ISP disadvantage vs. hydrogen rockets. To maximize payload percentage to both LEO and higher orbits the most optimal rocket configuration is a first stage burning a dense fuel like RP-1 or Methane to minimize your largest tankage size/weight, and use hydrogen on your upper stage to maximum ISP without incurring too large a cost in heavier tankage. That’s how the Saturn V could lift 150 metric tons to LEO and 50 to translunar injection. But instead SpaceX decided to use the same fuel and engines for both stages to get economies of scale in engine production, and dense fuels to save the most dry mass. They could have optimized the next generation Falcon platform with a cryogenic hydrogen upper, and increased their GEO payloads 10-20%, at the cost of dual engine designs with less economies of scale and increased fueling complexity and infrastructure. Instead they decided to brute force the same simple design architecture and build a 10x larger booster/second stage with Starship/SuperHeavy with 3x times the engines. One engine type, one fuel type and bigger rockets with enough brute lifting capacity that you can still put 100 metric tons in LEO while conserving enough to fly back your first stage and make your second stage out of heavy stainless steel so it can re-enter and be reused too. So probably two thirds the payload to orbit capacity as a Saturn V style rocket, but 1/100th the cost per launch. |