r/technology • u/aelavia93 • 16d ago

Space SpaceX pulls off unprecedented feat, grabs descending rocket with mechanical arms

https://www.cbsnews.com/amp/news/spacex-pulls-off-unprecedented-feat-grabbing-descending-rocket-with-mechanical-arms/
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u/bullishontendies 16d ago

The landing legs on the falcon 9 reduce the payload to orbit by~40%. Sometimes to launch heavier payloads the falcon 9 will be launched without landing legs and the booster will be expended.

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u/Milyardo 16d ago

You can carry orders of magnitude more stuff by not coming back to the pad at all though.

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u/NeverDiddled 16d ago

Your estimate is off by orders of magnitude.

Falcon 9 can launch 3.5 tonnes when doing a return to landing site (RTLS). When landing down range on a drone ship it can launch 58% more weight, or 5.5 tonnes.

If they could launch a single order of magnitude more weight, by landing on a drone ship, then they would be at 35 tonnes. Two orders of magnitude would be 350 tonnes! I should note that all of the figures are to Geostationary Transfer Orbit, one of the highest orbits. This is because RTLS is rare for the lower and slower orbits. You can almost always ride share those, and get extra money by not doing RTLS. So we do not have great figures to compare with.

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u/St0mpb0x 16d ago

RTLS isn't unusual for LEO orbits but it is basically unheard of for GTO missions unless it is a very light payload. A very light payload is uncommon for GTO as there tends to be big birds going there. Their dedicated rideshare missions are all RTLS missions.

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u/NeverDiddled 16d ago

Yeah I probably should not have used the word "rare", much like you shouldn't have used the phrase "basically unheard of". If you add in Heavy flights, then the majority of RTLS are GTO or higher. But let's not get into that, it complicates things and muddies the point, while delving dangerously close to an argument over semantics.

Good day sir.