Video: CRS-5 Launch

[voidptr]

I'm curious about what Elon means by the hypersonic grid fins running out of hydraulic fluid? It is a closed system, is it not? How can it 'run out'?

Also, so, as speculated on here, it sounds like the issue was more related to the final burn than steering. Either way, it seems like the chance of success was significantly more 50%

Sometimes rocket designers use an open loop hydraulic system, it's lighter and cheaper to carry a few minutes worth of hydraulic fluid and dump it overboard once it's passed through the actuator than include the plumbing to recycle back up to the reservoir. Unfortunately, it does make that system a limited resource for the flight, and if you have an actuator that seeks back and forth more than expected, you may drain the system faster than intended. Conestoga had the same thing happen on one of their test flights in the 90s.

 

[Afdyce]

Hello @Doug.
Thanks a million for posting this! My wife and 15 year old son joined me to watch over breakfast (it was just before 10.00 in the morning here) and it was great. Just getting the used booster to the platform was a major achievement and the rest of the launch was text book.

I grew up in the Apollo era when we all felt excited about every launch. NASA representatives used to visit my school in the UK and we all watched the moon landing.

I took my daughter to watch the last Discovery Shuttle launch from the top of the causeway bridge that leads to Port Canaveral in 2011 and it was awesome.

Thanks for helping get our two "digital natives" interested in Space Flight, they have a much better chance of getting to experience it than I have!