Looks like the pilot clique of the Astronaut office is deciding to throw some last grenades to the CCDEV participants, before they head out the door.Hopefully these are not final requirements.
This should be no prob for this program as its so early into it.
Quote from: Prober on 08/21/2011 12:37 AM This should be no prob for this program as its so early into it. Bologna. Space-X has 8 Dragons in various states of completion, & claim they can kick out another one every 6 to 8 weeks. This means they've finalized the design.
Even if that is correct, it's cargo Dragon. Crew Dragon cannot be anywhere close to finalized yet.
I'm reminded of the scene from "The Right Stuff" when Ed Harris is arguing with the german designers over the Mercury capsule. Ol' Guss, "Where's the window?"
ChefPat, you are wrong. The crew Dragons will have many differences, even if the heat shield, pressure vessel, and minor systems are mostly the same.The addition of the Super Draco's for LAS/landing is one example, which cause the propellant and thrusters to move, and will even change the outer moldline slightly ( http://www.universetoday.com/wp-content/uploads/2011/08/spacex-dragon.jpg ) . And to switch a docking collar instead of a berthing one, most of the top of the pressure vessel will be different. The Dragon design is far from finalized. Even the Cargo Dragon's are evolving. (umbilicals moved, windows removed, and more) And they will probably keep evolving. A frozen design is a relatively foreign concept to SpaceX at this stage.Perhaps the Cargo Dragon will have some of the new features carried over eventually, to streamline production. But there will still be differences.
SpaceX isn't the only one that is likely quite far in finalizing their initial crewed vehicle design. The others, especially SNC and Boeing, must be far enough along that this is going to increase their costs.And this is exactly why changing the contracting structure to give NASA more ability to change requirements halfway is a bad idea, IMO.
Rationale: Because of the criticality of piloting tasks to the success of the mission and safety of the crew during all mission phases, windows must be a part of the spacecraft design. The human-centered design process is to be used when designing windows to support expected crew piloting tasks.
Rationale: Fixed equipment, such as window instrumentation, hardware, or a condensation prevention system, that would obscure the field-of- view from the normal crew viewing position may interfere with piloting, observation, and photography tasks. Examples of piloting hardware that are exempted from this requirement are Headís Up Displays (HUD) or other devices used for piloting tasks. For detailed design considerations for inboard and outboard window view obscuration exclusion zones, consult Section 18.104.22.168 and 22.214.171.124 in JSC/SP-2010-3407 Human Integration Design Handbook (HIDH).
There is no problem. Look at the rationale (especially the second one):
Quote from: Prober on 08/21/2011 12:37 AM This should be no prob for this program as its so early into it. .Bologna. Space-X has 8 Dragons in various states of completion, & claim they can kick out another one every 6 to 8 weeks. This means they've finalized the design.They won't be able to change it without great cost. A big overrun in other words.
There's a problem, because current crewed Dragon drawings show no windows in front of the pilots, and that's a requirement.
There is no problem.
Look at the rationale (especially the second one):
This doesn't seem like a hard to solve problem. But maybe it is for some.
The "unobstructed fields-of-view" refers to the crew being able to see the window, not the station they are docking with.
Window fields-of-view for expected crew piloting tasks shall be verified by analysis and test. The analysis shall identify activities/tasks requiring visual information from outside of the spacecraft and include 3-D virtual simulations of operational scenarios depicting the interior and exterior of the vehicle. The verification shall be considered successful when the analysis shows that the windows provide the unobstructed fields-of-view necessary to support expected crew piloting tasks and the test shows that these tasks can be accomplished in the 3-D virtual simulation by trained crew personnel wearing any equipment required for flight.