Dragon XL is a missed opportunity on naming. Clearly it should be Lunar Dragon
A modified Dragon XL would make a great lunar Gateway module. Just my 2 cents. Would be better and probably cheaper than using a Cygnus.
Quote from: Unrulycow on 03/27/2020 07:22 pmDragon XL is a missed opportunity on naming. Clearly it should be Lunar DragonThe “Dragon XL” name hearkens back to Pegasus XL. Orbital developed Pegasus on private funds. NASA liked it, but IMO, said they’d love it if with 10% more capacity. Growing to Pegasus XL was a problematic effort. Dragon XL is a bit like that. NASA treating spacecraft subsystems like Lego(r) pieces.Not that this is necessarily bad. Skylab comes to mind as an adapted system. Is there any statement on whether this is a fixed price contract or CPFF/CPAF?
Quote from: Ronsmytheiii on 03/28/2020 03:44 pmQuote from: jarmumd on 03/28/2020 02:39 pmConfusing point that a Docking system could be berthed (I don't think anyone quite knows how to do this yet)Actually we do know, since the MRM-1 module launched to the ISS on STS-132 and attached using the SSRMS. mRM-1 used a “hybrid” docking system.On STS-74, the Mir Docking Module was berthed to the shuttle APAS using the shuttle RMS before the shuttle/DM docked with Mir.On STS-88, Node 1 was berthed to the shuttle APAS using the shuttle RMS, then FGB was berthed to Node 1 APAS using the shuttle RMS, to form the initial ISS complex.Berthing a vehicle/module using a docking mechanism has multiple precedents.
Quote from: jarmumd on 03/28/2020 02:39 pmConfusing point that a Docking system could be berthed (I don't think anyone quite knows how to do this yet)Actually we do know, since the MRM-1 module launched to the ISS on STS-132 and attached using the SSRMS. mRM-1 used a “hybrid” docking system.
Confusing point that a Docking system could be berthed (I don't think anyone quite knows how to do this yet)
On STS-74, the Mir Docking Module was berthed to the shuttle APAS using the shuttle RMS before the shuttle/DM docked with Mir.On STS-88, Node 1 was berthed to the shuttle APAS using the shuttle RMS, then FGB was berthed to Node 1 APAS using the shuttle RMS, to form the initial ISS complex.Berthing a vehicle/module using a docking mechanism has multiple precedents.
Quote from: Jorge on 03/28/2020 03:54 pmOn STS-74, the Mir Docking Module was berthed to the shuttle APAS using the shuttle RMS before the shuttle/DM docked with Mir.On STS-88, Node 1 was berthed to the shuttle APAS using the shuttle RMS, then FGB was berthed to Node 1 APAS using the shuttle RMS, to form the initial ISS complex.Berthing a vehicle/module using a docking mechanism has multiple precedents.However, on both STS-74 and STS-88, the orbiter had to fire its RCS thrusters to engage the docking mechanism.
Quote from: Ronsmytheiii on 03/28/2020 04:18 pmQuote from: Jorge on 03/28/2020 03:54 pmOn STS-74, the Mir Docking Module was berthed to the shuttle APAS using the shuttle RMS before the shuttle/DM docked with Mir.On STS-88, Node 1 was berthed to the shuttle APAS using the shuttle RMS, then FGB was berthed to Node 1 APAS using the shuttle RMS, to form the initial ISS complex.Berthing a vehicle/module using a docking mechanism has multiple precedents.However, on both STS-74 and STS-88, the orbiter had to fire its RCS thrusters to engage the docking mechanism.That's unique to APAS. NDS is designed not to require post-contact thrusting.
For some reason, I sense that the one single Marketing Department image we seem to have (post #1 of this thread) might be more of a Proposal-level concept, rather than anything we should put too much consideration into? Is there ANY other visualization of Dragon-XL? You know, I'm just thinking of the historical track-record between the first Marketing image of something verses what actually squirts out from production. Any thoughts?
It's 4 years away, that is forever in SpaceX terms, who knows what is possible with Starship or the revenue that Starlink is generating by then. Maybe Dragon XL will be preceeded by a SS on the lunar surface by then.
Quote from: freda on 03/28/2020 04:30 pmFor some reason, I sense that the one single Marketing Department image we seem to have (post #1 of this thread) might be more of a Proposal-level concept, rather than anything we should put too much consideration into? Is there ANY other visualization of Dragon-XL? You know, I'm just thinking of the historical track-record between the first Marketing image of something verses what actually squirts out from production. Any thoughts?counterpoint: what is the SpaceX Marketing Department? (other than elon himself)Where are their offices, what do their linked-in pages say?SpaceX in general doesnt seem to do separate marketing. They can make presentations, but those presentations tend to be heavier on engineering details (as they stand when the presentation is created) than Marketing would be.
Quote from: dgmckenzie on 03/28/2020 11:37 amIf it is supposed to transfer both pressurized and unpressurized cargo, how could it have docking at both ends?Also, SpaceX would need to build their own IDSS passive docking port. Contrary to popular belief, the current system does not have the equipment to act as a passive for other vehicles to dock (ie not androgynous)....
If it is supposed to transfer both pressurized and unpressurized cargo, how could it have docking at both ends?
My initial though after seeing the art work for this was that it might have a docking adapter at both ends and a pass through tunnel, like one of the proposed follow ons to the ATV. I don't think this is the case as this would limit the volume for external cargo but it's still an idea for a presumably cheap station/free flyer somewhere in the Earth-Moon system.Sorry only tangentially related to dragon XL, I must try harder
Quote from: jarmumd on 03/28/2020 01:46 pmQuote from: dgmckenzie on 03/28/2020 11:37 amIf it is supposed to transfer both pressurized and unpressurized cargo, how could it have docking at both ends?Also, SpaceX would need to build their own IDSS passive docking port. Contrary to popular belief, the current system does not have the equipment to act as a passive for other vehicles to dock (ie not androgynous)....Citation needed. The standard specifies it must be androgynous (at least for active side). If it's not androgynous, it's not IDSS.For Crew Dragon, androgyny is a safety consideration as well to allow rescue. Doubtful that they'd change the spec for Dragon XL as that'd require more certification.If you're right, then you should be able to provide a reference. If you're just supposing, then you should say so.
Quote from: yg1968 on 03/28/2020 02:30 pmIf I am reading this correctly, once the robotic arm is installed on Gateway, a berthing option is also required (however, see the post below mine on berthing operations vs berthing mechanisms; the requirements below only require berthing operations to be possible, not a CBM):Quote from: NASA (Attachment_03_GLS-RQMT-001_Gateway_Logistics_Services_Requirements)3.10 EXTRAVEHICULAR ROBOTICS COMPATIBILITY The requirements in this section are applicable to Logistics Vehicles which will dock to Gateway when Extravehicular Robotics capability has been established. [...]Rationale: The capability for a docked Logistics Module to be relocated to another docking port via the Gateway EVR system reduces Gateway risk and preserves LM consumables. L3-GLS-1119 Berthing Grapple Fixture Accommodation The Logistics Module shall have a radially-installed Extravehicular Robotics-compatible Grapple Fixture located within 3.5m (11.5ft) of the docking/berthing port center to enable berthing to Gateway. [...]Rationale: Gateway operations will need the capability to relocate and berth visiting vehicles using the Robotic Arm. Constraining the relative location of the Grapple Fixture permits manipulator configurations that can provide sufficient push force to overcome resistance forces for all berthing scenarioshttps://forum.nasaspaceflight.com/index.php?topic=48353.msg2018139#msg2018139Edit: to take into account the post below.I've underlined the critical part. Docking requires to take a hit from the visiting vehicle. This is both a stress (mostly taken by the docking mechanism), and then you have to compensate the delta-v change. So, with berthing, even using IDA, APAS or any other type of IDSS-derived docking system, you save fuel on the gateway AND you reduce the stress.
If I am reading this correctly, once the robotic arm is installed on Gateway, a berthing option is also required (however, see the post below mine on berthing operations vs berthing mechanisms; the requirements below only require berthing operations to be possible, not a CBM):Quote from: NASA (Attachment_03_GLS-RQMT-001_Gateway_Logistics_Services_Requirements)3.10 EXTRAVEHICULAR ROBOTICS COMPATIBILITY The requirements in this section are applicable to Logistics Vehicles which will dock to Gateway when Extravehicular Robotics capability has been established. [...]Rationale: The capability for a docked Logistics Module to be relocated to another docking port via the Gateway EVR system reduces Gateway risk and preserves LM consumables. L3-GLS-1119 Berthing Grapple Fixture Accommodation The Logistics Module shall have a radially-installed Extravehicular Robotics-compatible Grapple Fixture located within 3.5m (11.5ft) of the docking/berthing port center to enable berthing to Gateway. [...]Rationale: Gateway operations will need the capability to relocate and berth visiting vehicles using the Robotic Arm. Constraining the relative location of the Grapple Fixture permits manipulator configurations that can provide sufficient push force to overcome resistance forces for all berthing scenarioshttps://forum.nasaspaceflight.com/index.php?topic=48353.msg2018139#msg2018139Edit: to take into account the post below.
3.10 EXTRAVEHICULAR ROBOTICS COMPATIBILITY The requirements in this section are applicable to Logistics Vehicles which will dock to Gateway when Extravehicular Robotics capability has been established. [...]Rationale: The capability for a docked Logistics Module to be relocated to another docking port via the Gateway EVR system reduces Gateway risk and preserves LM consumables. L3-GLS-1119 Berthing Grapple Fixture Accommodation The Logistics Module shall have a radially-installed Extravehicular Robotics-compatible Grapple Fixture located within 3.5m (11.5ft) of the docking/berthing port center to enable berthing to Gateway. [...]Rationale: Gateway operations will need the capability to relocate and berth visiting vehicles using the Robotic Arm. Constraining the relative location of the Grapple Fixture permits manipulator configurations that can provide sufficient push force to overcome resistance forces for all berthing scenarios