logoalt Hacker News

GMoromisatotoday at 6:15 AM1 replyview on HN

There were a lot of mistakes with Challenger and Columbia--I totally agree. But I don't think it was money. It's not like the NASA administrator gets a bonus when a rocket launches (unlike some CEOs, maybe).

I think the problem with both Challenger and Columbia was that there were so many possible problems (turbine blade cracks, tiles falling off, etc.) that managers and even engineers got used to off-nominal conditions. This is the "normalization of deviance" that Diane Vaughan talked about.

Is that what's going on with the Orion heat shield? I don't think so. I think NASA engineers are well aware of the risks and have done the math to convince themselves that this is safe.


Replies

irjustintoday at 7:01 AM

> It's not like the NASA administrator gets a bonus when a rocket launches

It's related to funding. I mean it's always money, right?

But in Challenger's case, there was very heavy pressure to launch because of delays and the rising costs. I remember in a documentary they explicitly mentioned there was a backlog of missions and STS-51 had been delayed multiple times. To rollout/fuel, costs a LOT and challenger had been out on the pad for a while. Rollback was a material risk+cost.

For columbia, yea less about money. They ignored the requests to repoint spy sats and normalized foam strikes.

> I think NASA engineers are well aware of the risks and have done the math to convince themselves that this is safe.

And that's the way it should be. Everything has a risk value regardless if we calculate it or not. It's never 0... (maybe accidentally going faster than light is though?) We just need to agree what it is and is acceptable.

Story time - I was a young engineer at National Instruments and I remember sitting in on a meeting where they were discussing sig figs for their new high precision DMMs. Can we guarantee 6... 7 digits? 7? and they argued that back and forth. No decisions but it really stuck with me. When you're doing bleeding edge work the lines tend to get blurry.

show 2 replies