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H2M, as well as the entire H2 family series, follows the Soviet-style approach, different from the American system where the space shuttle and rocket boosters function as a complete system for orbit insertion. The H2 series is fully launched as a payload.
The conventional methane version replaced three A100 nuclear engines with three 50-ton liquid oxygen and methane engines, with nozzles especially optimized for vacuum and thus immensely huge.
The empty weight of the spacecraft is 78 tons, lighter than the nuclear-powered version. It carries about 14 tons of oxidizer and fuel, with a launch mass of about 95 tons, and a maximum takeoff weight of 132 tons. The cargo bay can accommodate up to 37 tons of cargo.
What does that mean? The C919 has an empty weight of 42 tons and its maximum takeoff weight is just over 70 tons.
