[wolf550e]

The SpaceX comparison is bad because they don't do science missions. SpaceX do commercial launches for paying customers. Mission success is defined by whether the payload gets to its intended orbit, unharmed. Even if SpaceX learn a lot from a mission, if the payload is lost then the mission failed. While one can learn from failures, when the mission is not a test, learning is not enough for the mission to be called a success.

[mastazi]

> they don't do science missions true, but they do R&D like most large for-profit entities. However I agree with you that the comparison is not compelling. R&D is not SpaceX's main objective, hence the situation described doesn't compare to a scientific mission where you send a lander on a comet and you actually get the data from the lander.

[edge17]

SpaceX has done quite a few missions to develop their rockets before getting contracts from NASA, etc. Some of those also included payloads.

[wolf550e]

SpaceX did three kinds of flights:

1. Launch contracts for paying customers where mission success was defined as "unharmed payload to correct orbit".

2. Test/demo missions with mass simulator instead of payload where mission success was defined as "unharmed payload to correct orbit" (two missions: Falcon 1 Flight 4 [0] and Falcon 9 Flight 1 [1]).

3. Rocket landing development flights with Grasshopper where mission success was defined as advancing the ability to land the booster.

SpaceX did R&D on all flights (for example they unsuccessfully tried parachute recovery), but for all flights of Falcon 1 and Falcon 9 (not Grasshopper), they always stated that mission success is to get the customer's payload unharmed to the correct orbit, or to demonstrate the ability to get the customer's payload unharmed to the correct orbit. If they defined mission success as anything else, a potential customer might think SpaceX would sacrifice the payload to advance SpaceX's own goals (like recoverability R&D), and this customer would not fly with SpaceX.

0 - https://en.wikipedia.org/wiki/Ratsat

1 - https://en.wikipedia.org/wiki/Dragon_Spacecraft_Qualificatio...