The dream of a crewed flight on Dreamchaser is still a goal of SNC. There must be a substantial number of common parts between the cargo variant and the crew variant. To take advantage of volume pricing, I wonder if SNC is stocking any common components for a crew variant while building the two cargo versions. Being willing to inventory such items would help "buy down" the initial investment needed.
One thing that I have been wondering about is whether it would be possible to retrofit a cargo DC and make it into a crewed DC (if this retrofit were to happen, it would only be done once CRS2 is completed).
Quote from: yg1968 on 11/27/2017 02:16 pmOne thing that I have been wondering about is whether it would be possible to retrofit a cargo DC and make it into a crewed DC (if this retrofit were to happen, it would only be done once CRS2 is completed). I highly doubt it, as I suspect some of the differences are inherent to the airframe itself. I have also wondered how easily DC could be modified to become a crew return vehicle only. No launch abort requirements, etc. Ever since the demise of X-38/CRV I suppose I've been a believer that a lifting body direct to landing facility return vehicle makes a lot more sense as an assured crew return vehicle than a high G reentry, remote splashdown/touchdown capsule.
Quote from: yg1968 on 11/27/2017 02:16 pmOne thing that I have been wondering about is whether it would be possible to retrofit a cargo DC and make it into a crewed DC (if this retrofit were to happen, it would only be done once CRS2 is completed).Obviously depends on how different they are. NASA say it's hugely difficult to turn a cargo vehicle in to a crewed return vehicle. ECLSS is needed and apparently it has to be "docked" rather than berthed because there is no "unberth" mode that a vehicle can manage without the intervention of the arm (which no one would be aboard the station to operate in an evacuation) evne if it was equipped with the necessary fine guidance and RCS thrusters.
The cargo version doesn't have windows, which would mean a converted crew version could only operate autonomously. And I wouldn't want to cut into an already flown composite body. Production really isn't that expensive. It wouldn't really surprise me if the cost of new vs converted was nearly the same, or even cheaper.
Quote from: rayleighscatter on 11/27/2017 08:40 pmThe cargo version doesn't have windows, which would mean a converted crew version could only operate autonomously. And I wouldn't want to cut into an already flown composite body. Production really isn't that expensive. It wouldn't really surprise me if the cost of new vs converted was nearly the same, or even cheaper.I don't know if the windows are a requirement but I suppose that a periscope (or cameras) could also be used. Sirangelo said (a while ago) that making a DC wasn't that expensive. So you are right about that. But I sort of wonder if you don't make the crewed DC right away, is that capability lost after a while?
Quote from: yg1968 on 11/28/2017 08:49 pmQuote from: rayleighscatter on 11/27/2017 08:40 pmThe cargo version doesn't have windows, which would mean a converted crew version could only operate autonomously. And I wouldn't want to cut into an already flown composite body. Production really isn't that expensive. It wouldn't really surprise me if the cost of new vs converted was nearly the same, or even cheaper.I don't know if the windows are a requirement but I suppose that a periscope (or cameras) could also be used. Sirangelo said (a while ago) that making a DC wasn't that expensive. So you are right about that. But I sort of wonder if you don't make the crewed DC right away, is that capability lost after a while?The knowledge will be lost over time as engineers retire or leave but the production methods are now common at many aerospace companies. It wouldn't be hard to farm out production of another craft.I suppose the hybrid abort engines would be the most likely place to lose both knowledge and production ability.
The cargo version can either be docked or berthed according to SNC.
I don't know if the windows are a requirement but I suppose that a periscope (or cameras) could also be used. Sirangelo said (a while ago) that making a DC wasn't that expensive. So you are right about that. But I sort of wonder if you don't make the crewed DC right away, is that capability lost after a while?
Quote from: yg1968 on 11/28/2017 08:49 pmI don't know if the windows are a requirement but I suppose that a periscope (or cameras) could also be used. Sirangelo said (a while ago) that making a DC wasn't that expensive. So you are right about that. But I sort of wonder if you don't make the crewed DC right away, is that capability lost after a while?Good question. Another issue is how much such a craft is actually "piloted"
3.8.4.4 Windows for Crew TasksThe spacecraft shall provide windows that are available for use by the crew through all phases offlight that provide direct, non-electronic, through-the-hull viewing and the unobstructed fields of-viewnecessary to perform crew viewing tasks. [R.CTS.177]Rationale: Windows provide direct, non-electronic, through-the-hull viewing and areessential to mission safety and success, as well as to maintaining crew situational awarenessand psychological and physical health and safety. They do not have the failure modesassociated with cameras and display systems that may not be operable during emergencieswhen most needed and are essential for piloting and photography. They also permit stellarnavigation, vehicle anomaly detection and inspection, and environmental and scientificobservations. NASA experience is that two piloting windows are required to achieve the fieldof view necessary to accomplish the breadth of piloting tasks. Because of the criticality ofwindows to crew safety and success of the mission, windows must be a part of the spacecraftdesign and available through all flight phases without obstructions to their use. Fixedequipment, such as window instrumentation, hardware, or a condensation prevention system,that would obstruct or obscure the field-of-view of the window from the normal crew viewingposition will interfere with crew tasks and must not be placed within the sight lines throughthe window; however, the following are not considered obstructions: hardware used inconjunction with piloting, such as a head's up display (HUD), crew optical alignment system(COAS), or other similar equipment; the outer mold line and hull structure of the vehicleitself; other windows and window mullions; and instrumentation applied to the window itselfwithin 13 mm (~0.5 in.) of the perimeter of the clear viewing area. For detailed designconsiderations for inboard and outboard window view obscuration exclusion zones, consultSections 8.6.3.3 and 8.6.3.4 in NASA/SP-2010-3407, Human Integration Design Handbook(HIDH), which also provides extensive guidance for window design considerations.
3.10.14.2 Hatch WindowsThe CTS shall provide a window on all sealable hatches for direct non-electric visual observationof the environment on the opposite side of the hatch. [R.CTS.174]Rationale: Direct visual observation of the environment on the opposite side of a hatchallows the crew to determine the conditions or obstructions, such as the presence of fire ordebris, on the other side of the hatch for safety purposes. Visibility is also needed for groundcrew viewing into the vehicle during pad operations and post-landing. Windows do not havethe failure modes associated with cameras and display systems that may not be operableduring emergencies when most needed.
Quote from: john smith 19 on 11/28/2017 10:32 pmQuote from: yg1968 on 11/28/2017 08:49 pmI don't know if the windows are a requirement but I suppose that a periscope (or cameras) could also be used. Sirangelo said (a while ago) that making a DC wasn't that expensive. So you are right about that. But I sort of wonder if you don't make the crewed DC right away, is that capability lost after a while?Good question. Another issue is how much such a craft is actually "piloted"As much or little as they design into it. Shuttle was not capable of autoland, Buran was fully autonomous. Heavy airliners can do fully automated CAT IIIb/Land 3 (0' vertical vis, 150' horizontal) approaches, I imagine that would be easy to build into Dream Chaser.
Quote from: JAFO on 11/28/2017 11:55 pmQuote from: john smith 19 on 11/28/2017 10:32 pmQuote from: yg1968 on 11/28/2017 08:49 pmI don't know if the windows are a requirement but I suppose that a periscope (or cameras) could also be used. Sirangelo said (a while ago) that making a DC wasn't that expensive. So you are right about that. But I sort of wonder if you don't make the crewed DC right away, is that capability lost after a while?Good question. Another issue is how much such a craft is actually "piloted"As much or little as they design into it. Shuttle was not capable of autoland, Buran was fully autonomous. Heavy airliners can do fully automated CAT IIIb/Land 3 (0' vertical vis, 150' horizontal) approaches, I imagine that would be easy to build into Dream Chaser.Slight correction, the Shuttle was capable but never fully utilized... Except for the gear which you had to deploy... From out friend Wayne Hale:https://waynehale.wordpress.com/2011/03/11/breaking-through/
As much or little as they design into it. Shuttle was not capable of autoland, Buran was fully autonomous. Heavy airliners can do fully automated CAT IIIb/Land 3 (0' vertical vis, 150' horizontal) approaches, I imagine that would be easy to build into Dream Chaser.
Quote from: JAFO on 11/28/2017 11:55 pmAs much or little as they design into it. Shuttle was not capable of autoland, Buran was fully autonomous. Heavy airliners can do fully automated CAT IIIb/Land 3 (0' vertical vis, 150' horizontal) approaches, I imagine that would be easy to build into Dream Chaser.You missed the X37b. AFAIK all its landings are autonomous.