HN Explorer

Ask HN: How safe is space travel today?

3 points by luxurytent ↗ HN
As I watch the Inspiration 4 all-civilian crew head up into space via SpaceX, I’m wondering, how safe is space travel today?

From a lamens perspective it all looks terrifying. People sitting atop thousands of pounds of jet fuel which is burned at incredible force.

There must be so much that can go wrong but perhaps some of the fundamentals are being solved by SpaceX (and others) to the point that some of the previously scary stuff is more so part of a boring checklist?

I know there’s a few rocket scientists around here :)

3 comments

[ 3.3 ms ] story [ 15.3 ms ] thread
PaulHoule
The space shuttle was ‘unsafe at any speed’ because it had no escape system and those thermal tiles were brittle.

For falcon+dragon I’d guess the probability of a failure (no orbit) is 2% ish and loss of the crew is 0.5% ish.

The jet fuel by itself is not so bad because it needs to mix with the air to burn (you can often get away from an airplane after the crash before the fire is dangerous.) but with the liquid oxygen it can go off like a bomb.

But really they have launched many falcons so it is pretty routine.

Someone
https://spacex-info.com/stats/: The Falcon 9 rocket is currently the main workhorse for SpaceX. It accounts for 123 of the company’s 131 missions (that’s 93.89%), and has a 98.37% success rate, having only 2 failures ever.

https://en.wikipedia.org/wiki/List_of_Falcon_9_and_Falcon_He...: * Rockets from the Falcon 9 family have been launched 129 times over 11 years, resulting in 127 full mission successes (98.45%), one partial success (SpaceX CRS-1 delivered its cargo to the International Space Station (ISS), but a secondary payload was stranded in a lower-than-planned orbit), and one failure (the SpaceX CRS-7 spacecraft was lost in flight)*

⇒ 2% seems about right.

giantg2
I forget where I saw it, but I heard there's about a 1% chance of catastrophic loss.