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> "The launch abort system (LAS) is a key reason that Orion is intended to become the safest spacecraft ever built. In an emergency it could activate to pull th

by avmich 12y ago

> "The launch abort system (LAS) is a key reason that Orion is intended to become the safest spacecraft ever built. In an emergency it could activate to pull the crew module and the astronauts it will carry away from the launch pad and the rocket in milliseconds" NASA officials wrote on their Web site. A very strange statement. Safety systems like that are used since Mercury flights. And what kind of milliseconds are we talking here? Thousands? Hundreds? Even with 20g acceleration - pretty harsh by today's standard even for abort systems - in 0.1 second you're only going to get 1 meter away - not quite too far.

chton 12y ago
2 Things: Firstly, the quoted sentence, if you shorten it, says "In an emergency it could activate in milliseconds". This is quite different from the speed or time to get away, just how long the engine takes to start burning and pulling away. Anything measured in milliseconds rather than seconds at that point might save lives. Secondly, the system is very much like the one used on Apollo modules, both in philosophy and application, but they haven't been used since. The space shuttle didn't have anything similar, nor does soyuz or anything else. A return to this kind of early-stage abort system is an important development, and one that can only happen if the rocket is designed specifically with it in mind.
- avmich 12y ago
  > Anything measured in milliseconds rather than seconds at that point might save lives. Yes, but if you're talking about system reaction - the start of motion - rather than result - the safety distance - then it's nothing surprising here. These systems always worked in under 1 second time frame - don't know exact timing, but it's all electronics. At this point it becomes rather misleading about what is being said - this system claims a particularly fast reaction between first sensor detection and detecting raising temperature of the charge of solid rocket pulling the capsule away? Or something else? It's mentioned without specifying necessary details, so it can be understood differently - that's why it looks strange. > The space shuttle didn't have anything similar, nor does soyuz or anything else. Pad abort system is used on all Soyuz spacecrafts, which fly since 1960-s. Was even used in Soyuz-18 flight abort. Pad abort system was used for TKS flights - unmanned, but the spacecraft was built to carry people. Pad abort system is used for Shenzhen spacecraft flights. Those systems weren't used in Space Shuttle - but were used elsewhere. That means the claim "safest spacecraft ever built", considering that some relevant comparable spacecrafts are from outside the US, is lacking specification "in US". Which makes the statement look strange.

by avmich 12y ago

chton 12y ago

2 Things: Firstly, the quoted sentence, if you shorten it, says "In an emergency it could activate in milliseconds". This is quite different from the speed or time to get away, just how long the engine takes to start burning and pulling away. Anything measured in milliseconds rather than seconds at that point might save lives. Secondly, the system is very much like the one used on Apollo modules, both in philosophy and application, but they haven't been used since. The space shuttle didn't have anything similar, nor does soyuz or anything else. A return to this kind of early-stage abort system is an important development, and one that can only happen if the rocket is designed specifically with it in mind.

avmich 12y ago
> Anything measured in milliseconds rather than seconds at that point might save lives. Yes, but if you're talking about system reaction - the start of motion - rather than result - the safety distance - then it's nothing surprising here. These systems always worked in under 1 second time frame - don't know exact timing, but it's all electronics. At this point it becomes rather misleading about what is being said - this system claims a particularly fast reaction between first sensor detection and detecting raising temperature of the charge of solid rocket pulling the capsule away? Or something else? It's mentioned without specifying necessary details, so it can be understood differently - that's why it looks strange. > The space shuttle didn't have anything similar, nor does soyuz or anything else. Pad abort system is used on all Soyuz spacecrafts, which fly since 1960-s. Was even used in Soyuz-18 flight abort. Pad abort system was used for TKS flights - unmanned, but the spacecraft was built to carry people. Pad abort system is used for Shenzhen spacecraft flights. Those systems weren't used in Space Shuttle - but were used elsewhere. That means the claim "safest spacecraft ever built", considering that some relevant comparable spacecrafts are from outside the US, is lacking specification "in US". Which makes the statement look strange.