Even more impressive is the seeming lack of modifications needed to the Atlas V’s ground equipment currently in use by United Launch Alliance. In fact, Sierra Nevada indicates that only an adaptor to the current launch tower would be needed for vehicle access – both for the crews of Dream Chaser and support personnel who would assist astronauts with entry into the vehicle and final preparations for launch.
Human rating impacts to flight-proven existing EELVare understood– Addition of an Emergency Detection System (EDS)– Separate VIF/MLP or pad with crew ingress/egress Low non-recurring ($400M) and recurring costs ($130M/launch)
Moreover, the vehicle’s docking adapter will be removed and replaced after each mission instead of being reused.According to Mark Sirangelo, “The economics work out that it’s not really advantageous to reuse it.” This goes toward an explanation for why there is no body flap on the back of Dream Chaser, like there was on Shuttle, to protect Dream Chaser’s docking adaptor.
I really like the focus the article puts on the launch vehicle configuration. It's an Atlas 4xx because it flies with the Centaur exposed rather than enclosed; it has no fairing. This recent buffet testing should lay to rest most concerns about that, the weirdness of the "Z511" image (http://www.nasaspaceflight.com/wp-content/uploads/2012/06/Z511.jpg) notwithstanding. The article also makes the point that during an abort with zero solids the range wouldn't need to destroy the vehicle while the crew were still getting away.I'm a bit confused though about emergency egress. I get the bit shown in the photo where a gangplank from the existing mobile launch platform gets the crew into the vehicle. But what if they need to get down in a hurry? (I'm hoping the answer involves a zip-line!
Quote from: sdsds on 06/23/2012 12:33 amI really like the focus the article puts on the launch vehicle configuration. It's an Atlas 4xx because it flies with the Centaur exposed rather than enclosed; it has no fairing. This recent buffet testing should lay to rest most concerns about that, the weirdness of the "Z511" image (http://www.nasaspaceflight.com/wp-content/uploads/2012/06/Z511.jpg) notwithstanding. The article also makes the point that during an abort with zero solids the range wouldn't need to destroy the vehicle while the crew were still getting away.I'm a bit confused though about emergency egress. I get the bit shown in the photo where a gangplank from the existing mobile launch platform gets the crew into the vehicle. But what if they need to get down in a hurry? (I'm hoping the answer involves a zip-line! Sdsds, I'm not clear on your reference to the "exposed Centaur". Are you referring to the fact that a fairing would provide a uniform airflow for the Centaur behind it, whereas the Dream Chaser will not?Thanks,David
When was the last time the Centaur was launched exposed?Would be good to look up.
Quote from: Prober on 06/23/2012 01:36 pmWhen was the last time the Centaur was launched exposed?Would be good to look up.3 days ago. Shakes head.
Quote from: Chris Bergin on 06/22/2012 10:57 pmMoreover, the vehicle’s docking adapter will be removed and replaced after each mission instead of being reused.According to Mark Sirangelo, “The economics work out that it’s not really advantageous to reuse it.” This goes toward an explanation for why there is no body flap on the back of Dream Chaser, like there was on Shuttle, to protect Dream Chaser’s docking adaptor.I thought the purpose of the Shuttle body flap was to protect the SME's and for pitch control during aerodynamic reentry.
Thanks. Good article. I have one question about this paragraph:QuoteEven more impressive is the seeming lack of modifications needed to the Atlas V’s ground equipment currently in use by United Launch Alliance. In fact, Sierra Nevada indicates that only an adaptor to the current launch tower would be needed for vehicle access – both for the crews of Dream Chaser and support personnel who would assist astronauts with entry into the vehicle and final preparations for launch.Wouldn't you need a pad with crew ingress/egress as explained by Gass on page 8 of the ULA presentation at the Augustine Committee? QuoteHuman rating impacts to flight-proven existing EELVare understood– Separate VIF/MLP or pad with crew ingress/egresshttp://www.nasa.gov/pdf/361835main_08%20-%20ULA%20%201.0_Augustine_Public_6_17_09_final_R1.pdfSee also p. 5 of this ULA document:http://www.ulalaunch.com/site/docs/publications/AtlasDeltaCrewLaunch2010.pdf
Human rating impacts to flight-proven existing EELVare understood– Separate VIF/MLP or pad with crew ingress/egresshttp://www.nasa.gov/pdf/361835main_08%20-%20ULA%20%201.0_Augustine_Public_6_17_09_final_R1.pdfSee also p. 5 of this ULA document:http://www.ulalaunch.com/site/docs/publications/AtlasDeltaCrewLaunch2010.pdf
Quote from: sdsds on 06/23/2012 12:33 amI'm a bit confused though about emergency egress. I get the bit shown in the photo where a gangplank from the existing mobile launch platform gets the crew into the vehicle. But what if they need to get down in a hurry? (I'm hoping the answer involves a zip-line!
I'm a bit confused though about emergency egress. I get the bit shown in the photo where a gangplank from the existing mobile launch platform gets the crew into the vehicle. But what if they need to get down in a hurry? (I'm hoping the answer involves a zip-line!