Lasting only three minutes from liftoff to ocean impact, the purpose of the atmospheric test was to demonstrate the production LAS and to collect detailed data on its performance. The LAS is designed to instantly pull the crew module away from its launch vehicle in extreme emergency situations that might occur before or during launch.<\/p>\n<\/p>\n
See Also<\/h4>\n\n- LIVE: Orion AA-2<\/li>\n
- L2 Orion Section<\/li>\n
- Click here to Join L2<\/li>\n<\/ul>\n
The key sequence in the short flight was an even shorter period of twenty seconds or so where the LAS pulled the Crew Module simulator away from a firing solid rocket motor.<\/p>\n
The LAS is designed to quickly separate a crew in Orion in a launch emergency, get them as far away from the emergency as safely possible, and allow the Orion Crew Module to parachute into the ocean.<\/p>\n
Ascent Abort-2 (AA-2) intentionally runs that emergency abort sequence. Three motors in the LAS fired in that short sequence of a few seconds and then the test was essentially over before the three minutes was up while the hardware was airborne.<\/p>\n
NASA and its Orion contractor team recorded test data from real-time telemetry and in onboard data recorders, but the major hardware for the test fell into the ocean. A set of a dozen data recorders were ejected from the Crew Module test article for recovery before it hit the water and sunk.<\/p>\n
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Three-minute test within four-hour launch window<\/p>\n
Liftoff occurred at 7 am Eastern time (1100 UTC) Tuesday at the opening of a four-hour launch window. The test vehicle launched from Launch Complex-46 at CCAFS.<\/p>\n
![\"\"](\"https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2019\/07\/NSF-2019-07-02-12-44-01-816.jpg\")
<\/p>\n
AA-2 lifts off \u2013 via Jack Beyer for NSF<\/p>\n
AA-2 was a test of the Orion LAS, the second and last planned for the program. The first, Pad Abort-1 (PA-1), was conducted in 2010. \u201c[They are] the two, I\u2019ll call them corners of the box that represent the most challenging conditions,\u201d NASA Orion Program Manager Mark Kirasich said.<\/p>\n
The PA-1 test represented an abort from standing still on the launch pad. \u201cWhen you\u2019re starting from a standstill, the most important thing is to get far away so that the wind doesn\u2019t bring you back in,\u201d he added. \u201cSo when you\u2019re starting from a standstill it\u2019s all about thrust times time, the area under the curve, to get away as far as you can.\u201d<\/p>\n
AA-2 tested the LAS under challenging atmospheric flight conditions. \u201cIt\u2019s not exactly at the maximum dynamic pressure, because we want to get a couple of different objectives but you\u2019re going really fast and you\u2019re still in the atmosphere,\u201d he said. \u201cSo there\u2019s a tremendous air pressure which exerts a force as this abort system is trying to pull you away.\u201d<\/p>\n
\u201cThe aerodynamic factors are trying to keep you in place so that\u2019s the key thing about the in-flight abort test, to make sure that we can not only overcome [the aerodynamics]. The harder part is to control, because the aerodynamics are pushing you all over the place under those circumstances.\u201d<\/p>\n
![\"\"](\"https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2019\/07\/vlcsnap-2096-06-16-21h52m52s583.png\")
<\/p>\n
Credit: NASA\/Ames\/Timothy Sandstrom.<\/p>\n
(Photo Caption: Image from a video of an Orion abort simulation produced by the NASA Advanced Supercomputing (NAS) Division at Ames Research Center. Colored plumes indicate high pressure (red) and low pressure (blue).)<\/em><\/p>\nAfter the Orion program was re-scoped following its cancellation along with all of Constellation, the AA-2 test was the only in-flight \u201cascent abort\u201d test brought forward and the program had to pick a single abort condition to test.<\/p>\n
\u201cIn the Constellation program we did have more in-flight abort tests planned and what we did was we picked apart that in-flight profile more,\u201d Kirasich said. \u201cI\u2019ll give you a \u2018for example.\u2019<\/p>\n
\u201cWhen you abort at a very high altitude there\u2019s less atmosphere, so there\u2019s not as much aerodynamic force on the vehicle. So you have to control your attitude differently, [in that example] it\u2019s more of a reaction control system thruster test as opposed to where we\u2019re right in the thick of the atmosphere it\u2019s really the [LAS] attitude control motor that we\u2019re testing, the dynamics in that.\u201d<\/p>\n
The key sequence in the short flight was an even shorter period of twenty seconds or so where the LAS pulled the Crew Module simulator away from a firing solid rocket motor.<\/p>\n
The LAS is designed to quickly separate a crew in Orion in a launch emergency, get them as far away from the emergency as safely possible, and allow the Orion Crew Module to parachute into the ocean.<\/p>\n
Ascent Abort-2 (AA-2) intentionally runs that emergency abort sequence. Three motors in the LAS fired in that short sequence of a few seconds and then the test was essentially over before the three minutes was up while the hardware was airborne.<\/p>\n
NASA and its Orion contractor team recorded test data from real-time telemetry and in onboard data recorders, but the major hardware for the test fell into the ocean. A set of a dozen data recorders were ejected from the Crew Module test article for recovery before it hit the water and sunk.<\/p>\n
Spaceflight news subscription (adsbygoogle = window.adsbygoogle || []).push({});<\/p>\n Three-minute test within four-hour launch window<\/p>\n Liftoff occurred at 7 am Eastern time (1100 UTC) Tuesday at the opening of a four-hour launch window. The test vehicle launched from Launch Complex-46 at CCAFS.<\/p>\n AA-2 lifts off \u2013 via Jack Beyer for NSF<\/p>\n AA-2 was a test of the Orion LAS, the second and last planned for the program. The first, Pad Abort-1 (PA-1), was conducted in 2010. \u201c[They are] the two, I\u2019ll call them corners of the box that represent the most challenging conditions,\u201d NASA Orion Program Manager Mark Kirasich said.<\/p>\n The PA-1 test represented an abort from standing still on the launch pad. \u201cWhen you\u2019re starting from a standstill, the most important thing is to get far away so that the wind doesn\u2019t bring you back in,\u201d he added. \u201cSo when you\u2019re starting from a standstill it\u2019s all about thrust times time, the area under the curve, to get away as far as you can.\u201d<\/p>\n AA-2 tested the LAS under challenging atmospheric flight conditions. \u201cIt\u2019s not exactly at the maximum dynamic pressure, because we want to get a couple of different objectives but you\u2019re going really fast and you\u2019re still in the atmosphere,\u201d he said. \u201cSo there\u2019s a tremendous air pressure which exerts a force as this abort system is trying to pull you away.\u201d<\/p>\n \u201cThe aerodynamic factors are trying to keep you in place so that\u2019s the key thing about the in-flight abort test, to make sure that we can not only overcome [the aerodynamics]. The harder part is to control, because the aerodynamics are pushing you all over the place under those circumstances.\u201d<\/p>\n Credit: NASA\/Ames\/Timothy Sandstrom.<\/p>\n (Photo Caption: Image from a video of an Orion abort simulation produced by the NASA Advanced Supercomputing (NAS) Division at Ames Research Center. Colored plumes indicate high pressure (red) and low pressure (blue).)<\/em><\/p>\n After the Orion program was re-scoped following its cancellation along with all of Constellation, the AA-2 test was the only in-flight \u201cascent abort\u201d test brought forward and the program had to pick a single abort condition to test.<\/p>\n \u201cIn the Constellation program we did have more in-flight abort tests planned and what we did was we picked apart that in-flight profile more,\u201d Kirasich said. \u201cI\u2019ll give you a \u2018for example.\u2019<\/p>\n \u201cWhen you abort at a very high altitude there\u2019s less atmosphere, so there\u2019s not as much aerodynamic force on the vehicle. So you have to control your attitude differently, [in that example] it\u2019s more of a reaction control system thruster test as opposed to where we\u2019re right in the thick of the atmosphere it\u2019s really the [LAS] attitude control motor that we\u2019re testing, the dynamics in that.\u201d<\/p>\n<\/p>\n<\/p>\n