Quote from: aero on 03/28/2020 01:19 pmI've been wondering about the FH upmass so I checked SpaceX's web site. It is listed as 63,800kg or 140,660 lb to LEO and 16,800kg or 37,040 lb to Mars. I'm guessing that the mass numbers to Gateway are something in between. That seems like enough upmass capability to satisfy the needs of this mission. The payload just needs maneuvering thrusters like all Dragons before it.Well, it needs some DeltaV for lunar orbit insertion and departure. It won't be anywhere near whats needed for TLI levels but still significantly more than what Dragon1+2 need to take a trip round the ISS in LEO and then reenter.
I've been wondering about the FH upmass so I checked SpaceX's web site. It is listed as 63,800kg or 140,660 lb to LEO and 16,800kg or 37,040 lb to Mars. I'm guessing that the mass numbers to Gateway are something in between. That seems like enough upmass capability to satisfy the needs of this mission. The payload just needs maneuvering thrusters like all Dragons before it.
If it is supposed to transfer both pressurized and unpressurized cargo, how could it have docking at both ends?
Quote from: TrueBlueWitt on 03/27/2020 09:31 pmMy questions are:1) Is the cargo volume the same or larger than cargo D2?2) Will part of that 5t of cargo include propellent for transfer? Volume is substantially larger than cargo D2.No propellant for transfer.This is NOT Progress-on-steroids. More like Cygnus with unpressurized cargo capabilities.
My questions are:1) Is the cargo volume the same or larger than cargo D2?2) Will part of that 5t of cargo include propellent for transfer?
Quote from: yg1968 on 03/28/2020 03:56 amQuote from: Zed_Noir on 03/28/2020 03:23 amIf NASA requires it. There could be a Dragon XL variant with a grappling fixture and a full size CBM port with minor modification.On that subject and as you probably already know, Canada will be building a robotic arm for Gateway and this arm would be delivered by Dragon XL. https://www.cbc.ca/news/technology/canada-lunar-gateway-1.5037522Quote from: NASA (Attachment_01_GLS_SOW_Annex_A)1.0 The Contractor shall deliver the following DSXR [Deep Space Extravehicular Robotic System] items as unpressurized cargo to Gateway as part of one or more launch packageshttps://forum.nasaspaceflight.com/index.php?topic=48353.msg2018139#msg2018139Which is exactly why there is a grapple fixture on the side of Dragon XL. The deep space Canadarm will "walk" itself off the vehicle, onto the Gateway. The first step it takes from its stowed position is onto a grapple fixture on the side of Dragon XL.
Quote from: Zed_Noir on 03/28/2020 03:23 amIf NASA requires it. There could be a Dragon XL variant with a grappling fixture and a full size CBM port with minor modification.On that subject and as you probably already know, Canada will be building a robotic arm for Gateway and this arm would be delivered by Dragon XL. https://www.cbc.ca/news/technology/canada-lunar-gateway-1.5037522Quote from: NASA (Attachment_01_GLS_SOW_Annex_A)1.0 The Contractor shall deliver the following DSXR [Deep Space Extravehicular Robotic System] items as unpressurized cargo to Gateway as part of one or more launch packageshttps://forum.nasaspaceflight.com/index.php?topic=48353.msg2018139#msg2018139
If NASA requires it. There could be a Dragon XL variant with a grappling fixture and a full size CBM port with minor modification.
1.0 The Contractor shall deliver the following DSXR [Deep Space Extravehicular Robotic System] items as unpressurized cargo to Gateway as part of one or more launch packages
L3-GLS-1111 Robotic Arm Walk-Off The Logistics Vehicle that delivers the Robotic Arm shall support Robotic Arm selfdeployment and walk-off onto the Gateway. Rationale: The Robotic Arm delivery mission concept requires that the Logistics Vehicle provide the power, data, attach points, attachment fixtures, and computational resources necessary for the arm system to activate and deploy itself from the Logistics Vehicle and onto the Gateway.
Can we assume that the solar panels use the same design as for Dragon 1?
Quote from: yg1968 on 03/28/2020 03:56 amQuote from: Zed_Noir on 03/28/2020 03:23 amIf NASA requires it. There could be a Dragon XL variant with a grappling fixture and a full size CBM port with minor modification.On that subject and as you probably already know, Canada will be building a robotic arm for Gateway and this arm would be delivered by Dragon XL. https://www.cbc.ca/news/technology/canada-lunar-gateway-1.5037522Was thinking of contingency delivery of really bulky cargo to the ISS that requires a full size CBM hatch.
Quote from: Zed_Noir on 03/28/2020 03:23 amIf NASA requires it. There could be a Dragon XL variant with a grappling fixture and a full size CBM port with minor modification.On that subject and as you probably already know, Canada will be building a robotic arm for Gateway and this arm would be delivered by Dragon XL. https://www.cbc.ca/news/technology/canada-lunar-gateway-1.5037522
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
Quote from: edkyle99 on 03/28/2020 01:37 amI'm guessing these have to be fully expendable Falcon Heavy launches, to get 5 tonnes of cargo to lunar orbit in a spacecraft that has to weigh 5-times-something tonnes - maybe 20 tonnes at TLI with about 1/4th of that mass needed for lunar orbit insertion. - Ed KyleCan't give you the exact numbers but my source says your mass estimate for the vehicle is way off. As in: your mass estimate for the vehicle is way too high.
I'm guessing these have to be fully expendable Falcon Heavy launches, to get 5 tonnes of cargo to lunar orbit in a spacecraft that has to weigh 5-times-something tonnes - maybe 20 tonnes at TLI with about 1/4th of that mass needed for lunar orbit insertion. - Ed Kyle
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.
Quote from: yg1968 on 03/27/2020 06:38 pmWould Dragon XL require the future elongated FH fairing?I'd assume that (like current Dragon), it is its own fairing, likely with a larger jettisoned nose cap a la Dragon 1.
Would Dragon XL require the future elongated FH fairing?
Quote from: abaddon on 03/27/2020 06:41 pmQuote from: yg1968 on 03/27/2020 06:38 pmWould Dragon XL require the future elongated FH fairing?I'd assume that (like current Dragon), it is its own fairing, likely with a larger jettisoned nose cap a la Dragon 1.Then why are the control thrusters sticking outside the trunk? Perhaps this is just a rough render for now but strange the RCS thrusters are not placed inside wether or not it uses a fairing.
Quote from: John Alan on 03/28/2020 06:40 amQuote from: baldusi on 03/28/2020 05:41 amQuote from: John Alan on 03/28/2020 02:43 am[...]And on the way back in "garbage truck" mode... take a month or two to reenter in a controlled manner.[...]Why would it need to reenter for disposal? BEO or Moon-crashing would most probably be cheaper, delta-v wise.It's always bothered me when "we" leave our "stuff" in places they should not be left... JMHO...I smile every time a spacecraft saves enough fuel, or puts itself in a <90day to re-entry orbit...to clean up after itself... Delta-v be damned... figure out how to make it work before you launch it... or just don't...Sacrifice payload or as a last resort, expend the rocket if you have to... Because someday, someone will have to clean up the mess we have made over the last 60+years in space...Again... JMHO... Space is big, I mean really big.
Quote from: baldusi on 03/28/2020 05:41 amQuote from: John Alan on 03/28/2020 02:43 am[...]And on the way back in "garbage truck" mode... take a month or two to reenter in a controlled manner.[...]Why would it need to reenter for disposal? BEO or Moon-crashing would most probably be cheaper, delta-v wise.It's always bothered me when "we" leave our "stuff" in places they should not be left... JMHO...I smile every time a spacecraft saves enough fuel, or puts itself in a <90day to re-entry orbit...to clean up after itself... Delta-v be damned... figure out how to make it work before you launch it... or just don't...Sacrifice payload or as a last resort, expend the rocket if you have to... Because someday, someone will have to clean up the mess we have made over the last 60+years in space...Again... JMHO...
Quote from: John Alan on 03/28/2020 02:43 am[...]And on the way back in "garbage truck" mode... take a month or two to reenter in a controlled manner.[...]Why would it need to reenter for disposal? BEO or Moon-crashing would most probably be cheaper, delta-v wise.
[...]And on the way back in "garbage truck" mode... take a month or two to reenter in a controlled manner.[...]
4.1 REQUIRED CAPABILITY The Contractor shall provide for the safe integration, transport and stowage of NASA-provided cargo, both pressurized and unpressurized, to the Gateway and disposal of NASA-provided cargo upon departure from the Gateway. The Contractor’s logistics vehicle shall be designed to remain docked to Gateway for one (1) year, with efficient crew access to stowage and payloads but the capability to remain longer than one year should also be considered. The nominal mission docked duration is expected to be six months. . The common launch vehicle configuration shall have one (1) successful flight prior to the GLS Missions.
Confusing point that a Docking system could be berthed (I don't think anyone quite knows how to do this yet)
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.