|
Author
|
Topic: What does it take to have a booster man-rated?
|
alanh_7
Member Posts: 1252
From: Ajax, Ontario, Canada
Registered: Apr 2008
|
posted 03-30-2014 11:49 AM
   
I am just curious, what does it take to have a booster man-rated? Besides a track record of event-free service and being adaptable to a manned spacecraft what else is required to rate a booster "man rated?" besides the battery of ground firing tests? Surely the Atlas V and Delta IV would fall into those categories of rockets with solid performance record. The reason I ask is because it seems like there are systems like the Saturn V that were man-rated after just two previous flights with mixed results and NASA gave the okay to fly the Saturn on Apollo 8. Atlas and Delta have flown many times and it makes me wonder how with so few flights planned, how they will ever get the SLS rocket "man rated." |
GACspaceguy
Member Posts: 2474
From: Guyton, GA
Registered: Jan 2006
|
posted 03-30-2014 04:46 PM
If it is like aircraft, it has to do with system safety analysis and level of redundancies. The Saturn V had that designed into it and those that you mention must be reviewed and modified (if required) to achieve the same. |
Jim Behling
Member Posts: 1463
From: Cape Canaveral, FL
Registered: Mar 2010
|
posted 03-30-2014 06:13 PM
An escape system tied to an abort detection system, with some redundancy in the sensors used by it.
|
YankeeClipper
Member Posts: 617
From: Dublin, Ireland
Registered: Mar 2011
|
posted 03-31-2014 07:38 AM
Control of thrust axis longitudinal oscillation/vibration during powered flight (POGO effect) and combustion stability are important too.POGO bouncing was a serious pilot safety issue as it compromised an astronaut's visual and cognitive performance. NASA stipulated in the M-G-A period that the upper limit for pilot safety for POGO was +/-0.25g. Combustion instability meant that the booster engine was potentially dynamically unstable and could not be man-rated. |
alanh_7
Member Posts: 1252
From: Ajax, Ontario, Canada
Registered: Apr 2008
|
posted 03-31-2014 10:39 AM
I know pogo was a very serious issue with the Saturn V and to my understanding the issue was never fully resolved. And yet they still allowed the manned crew to fly it. I know redundancies are an important factor, however I assume almost every launch vehicle has multiple redundancies with the possible exception to the shuttle SRBs. One they were lit that was it, though they could be jettisoned in an emergency. But the SLS will not fly that often so aside from ground testing they will likely have to flight test the entire stack in all up testing, but the tests will be so infrequent that I assume the rest program would be very much like the Saturn V. |
Robert Pearlman
Editor Posts: 42981
From: Houston, TX
Registered: Nov 1999
|
posted 03-31-2014 10:51 AM
This NASA document may be a useful read: Human-Rating Requirements for Space Systems. A human-rated system accommodates human needs, effectively utilizes human capabilities, controls hazards and manages safety risk associated with human spaceflight, and provides, to the maximum extent practical, the capability to safely recover the crew from hazardous situations. Human-rating is not and should not be construed as certification for any activities other than carefully managed missions where safety risks are evaluated and determined to be acceptable for human spaceflight. |
advertisement