/sci/ - Science & Math

>>8788929
The difference is: Falcon 9 isn't more expensive to build and launch than the expendable rockets that were on the market when it showed up.

What does Falcon 9 need for reusability that the expendable version doesn't? Legs, cold-gas thrusters, small fins, a place to land, software, and about 50% more vehicle. Reasonably affordable stuff, with the additional expense mitigated by using the latest technology to keep costs down relative to the aging competition.

This makes it very easy to benefit from reusability. Recovery can have a high failure rate. Refurbishment costs can be borne. Vehicles only have to be reflown once or twice on average to make reuse beneficial. The design can be evolved rapidly as problems are discovered through experience.

What did the space shuttle need for reusability that an equivalent expendable rocket wouldn't have? Parallel staging, parachutes, wings, control surfaces, OMS, RCS, heat shielding, landing gear, a crew cabin, a pilot, and about 400% more vehicle. Very expensive stuff.

This makes it very difficult to benefit from reusability. Recovery must be highly successful. There's very little tolerance for refurbishment costs. Vehicles need a long lifetime of many launches to make reuse beneficial. The design must be committed to early, without the benefit for experience.