[edge17]

Scientifically speaking, a successful mission is one where you've gathered all the data for analysis and can work with it long after the mission is over.

It's like, if SpaceX launches a rocket and it explodes - a real failure would be if they captured no telemetry and had no idea what happened vs knowing everything that happened and being able to replay the mission after the fact. Often times the data is far more important than the outcome.

[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...

[twblalock]

I cannot think of any situation where the rocket exploding on the pad would not cause the mission to be considered a failure.

[taneq]

In a commercial sense, you're right, but if they have telemetry from the recent mishap which allows them to identify and fix a serious design flaw, then it absolutely is beneficial to their R&D. Especially when you consider that they're winding up for manned missions. Losing a satellite on the launch pad is not so much of an issue compared with losing an ISS crew.

[ocdtrekkie]

This is the "everyone deserves a trophy" definition of space travel success.

[uxp]

Science is not a white/black min/max field. Failure in science is to end up not knowing more about why your original idea or theory is either wrong or right. It's the literal equivalent to a sealed glass of water containing the same exact (to the molecule) amount of volume after a period of time attempting to change it through external forces. You've learned nothing.

When a rocket explodes on a launch pad, and you've gathered petabytes of telemetry data and sensory data from all of it's systems, you can study and research that data to figure out what went wrong and put procedures and systems in place to mitigate that in the future. You learn from the mistakes, thus the outcome of the failure is a success. This doesn't mean we should stand in the viewing area of SpaceX's control center and cheer them on for their work in making a rocket explode. They still failed their mission, but they can make their future missions more safe and more robust because of what they learned in a real world failure situation.

[Retra]

And if a SpaceX rocket explodes because someone simply failed to do their job properly, then what?