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They just stated that the force experienced by crew on reentry would be 8g, while the force on a Soyuz capsule is just 4g. 8g is more than enough for a person t

They just stated that the force experienced by crew on reentry would be 8g, while the force on a Soyuz capsule is just 4g. 8g is more than enough for a person to black out, this seems like a major disadvantage.

api 12y ago
Luckily we have better computers than in the Apollo era. The capsule can pretty much fly itself.
rickr 12y ago
With training and G suits 8G can be sustained. I believe 9G is the limit with this equipment.
mnw21cam 12y ago
They don't have an option on that one. The acceleration experienced on re-entry depends on the speed of approach. Re-entry from low earth orbit is no big deal, hence being able to slow down with just 4G. Re-entry from a bit further away is more serious, as there is more velocity to shed. Remember that the module has been falling from more than 3600 miles up, which is a lot of energy to get rid of.
- vibrolax 12y ago
  The g-load experienced during the re-entry is more a function of the entry trajectory that is flown than the speed of entry. For example, the crews of several Soyuz missions experienced 8+ G's when the so-called "ballistic" re-entry mode occurred due to various systems problems. Apollo crews returning from the moon commonly experienced 6 - 7 g loads during re-entry The US space shuttle's entry profile was designed to limit decelerations to 3 g's (as was the ascent profile). It isn't the speed, it's how you fly the ascent/descent profile. And yes, the conical Apollo capsule form (largely re-used by Orion) is a lifting body that is actually flown through the atmosphere. http://www.chron.com/news/nation-world/article/U-S-astronaut-recalls-terrifying-Soyuz-descent-1759455.php http://www.chron.com/news/nation-world/article/U-S-astronaut...
jccooper 12y ago
Up to 12G is okay, in a proper body position. Mercury routinely came in at 8G, and those guys were usually trying to control the thing semi-manually, since the automatic systems weren't that good. These days the monkey in the can won't need to do much. The Mercury suborbitals came in at a nice 11-12G. The difference between Orion and Soyuz is a question of speed; the EFT profile was supposed to simulate a "deep space" reentry, which is faster and steeper than a low-earth-orbit rentry. You can see the difference in the Apollo program, using the same capsule but with different flight profiles: http://history.nasa.gov/SP-368/s2ch5.htm http://history.nasa.gov/SP-368/s2ch5.htm - Table 2 Apollo 7 and 9 come in at 3.3G-ish, and the rest 6.5-7G-ish. If it's actually 8G, that does seem a bit high; but Orion's actually a pretty huge thing, and denser than Apollo, so I guess that makes sense. And they only let the best trained very healthiest multiple-phD government employees ride the thing, so I don't think it's a big deal.

api 12y ago

Luckily we have better computers than in the Apollo era. The capsule can pretty much fly itself.

rickr 12y ago

With training and G suits 8G can be sustained. I believe 9G is the limit with this equipment.

mnw21cam 12y ago

They don't have an option on that one. The acceleration experienced on re-entry depends on the speed of approach. Re-entry from low earth orbit is no big deal, hence being able to slow down with just 4G. Re-entry from a bit further away is more serious, as there is more velocity to shed. Remember that the module has been falling from more than 3600 miles up, which is a lot of energy to get rid of.

vibrolax 12y ago
The g-load experienced during the re-entry is more a function of the entry trajectory that is flown than the speed of entry. For example, the crews of several Soyuz missions experienced 8+ G's when the so-called "ballistic" re-entry mode occurred due to various systems problems. Apollo crews returning from the moon commonly experienced 6 - 7 g loads during re-entry The US space shuttle's entry profile was designed to limit decelerations to 3 g's (as was the ascent profile). It isn't the speed, it's how you fly the ascent/descent profile. And yes, the conical Apollo capsule form (largely re-used by Orion) is a lifting body that is actually flown through the atmosphere. http://www.chron.com/news/nation-world/article/U-S-astronaut-recalls-terrifying-Soyuz-descent-1759455.php http://www.chron.com/news/nation-world/article/U-S-astronaut...

jccooper 12y ago

Up to 12G is okay, in a proper body position. Mercury routinely came in at 8G, and those guys were usually trying to control the thing semi-manually, since the automatic systems weren't that good. These days the monkey in the can won't need to do much. The Mercury suborbitals came in at a nice 11-12G. The difference between Orion and Soyuz is a question of speed; the EFT profile was supposed to simulate a "deep space" reentry, which is faster and steeper than a low-earth-orbit rentry. You can see the difference in the Apollo program, using the same capsule but with different flight profiles: http://history.nasa.gov/SP-368/s2ch5.htm http://history.nasa.gov/SP-368/s2ch5.htm - Table 2 Apollo 7 and 9 come in at 3.3G-ish, and the rest 6.5-7G-ish. If it's actually 8G, that does seem a bit high; but Orion's actually a pretty huge thing, and denser than Apollo, so I guess that makes sense. And they only let the best trained very healthiest multiple-phD government employees ride the thing, so I don't think it's a big deal.