Dragon XL revealed as NASA tie SpaceX to Lunar Gateway supply contract

[Chris Bergin]

https://www.nasaspaceflight.com/2020/03/dragon-xl-nasa-spacex-lunar-gateway-supply-contract/

https://twitter.com/NASASpaceflight/status/1243619087596621824

[Ronsmytheiii]

I find it interesting that the trunk seems to be a Dragon 1.0 design and not a 2.0 trunk, any reason?

[lrk]

I find it interesting that the trunk seems to be a Dragon 1.0 design and not a 2.0 trunk, any reason?

D1 solar arrays have more area and provide a lot more power than D2.
Not sure why the power demands would be higher though. 

[GWH]

Does it need power while docked? Maybe that type of panels would be in a better or more flexible position while docked to Gateway? Better for thermal management while in transit?

[russianhalo117]

I find it interesting that the trunk seems to be a Dragon 1.0 design and not a 2.0 trunk, any reason?

interpretive artistic license and thermal management  is all that comes to mind at this time until SpaceX updates there site.

[Robotbeat]

It also gives redundancy in case of failure or degradation.

[Steven Pietrobon]

Attached is an enhanced and enlarged picture of Dragon XL. Looks like four triplets of thrusters and four forward facing thrusters. There is a grapple attachment point at the base of the container. The solar arrays are attached to the base of the trunk, instead of the middle as with Dragon 1. There is also something else attached to the base of the trunk, but I don't know what that is. It might be a heat radiator. A standard docking port is at the front. I'm presuming that Dragon XL is launched inside a standard fairing, since it looks a bit delicate with the exposed silver mylar insulation.

[Steven Pietrobon]

Based on the diameter of the docking port, I get a diameter of only 3.1 to 3.3 m for Dragon XL, compared to 3.7 m for Dragon 1.

[fast]

Looks like docking port, propulsion and tanks are at the front. In the middle pressurized cargo and at the back is trunk with solar panels and radiators.
At launch the docking port is looking down at the second stage.

How about late cargo?
 

[BrianNH]

A smaller diameter would make sense.  If the artist impression is accurate, this looks like it is designed to be launched under a payload fairing.  It doesn’t look very aerodynamic.

[woods170]

I find it interesting that the trunk seems to be a Dragon 1.0 design and not a 2.0 trunk, any reason?

What you perceive to be the trunk is not, in fact, the trunk. Dragon XL does NOT have a trunk.

This is because Dragon XL is launched inside a fairing. The unpressurized cargo is stowed, unshielded, on the far end of the vehicle.

The deep space Canadarm cannot reach the cargo there while operating from the Gateway structure. Which is why a powered grapple fixture is mounted on the side of Dragon XL.

If you look closely at the artist impression, you will note the grapple fixture.

[woods170]

Attached is an enhanced and enlarged picture of Dragon XL. Looks like four triplets of thrusters and four forward facing thrusters. There is a grapple attachment point at the base of the container. The solar arrays are attached to the base of the trunk, instead of the middle as with Dragon 1. There is also something else attached to the base of the trunk, but I don't know what that is. It might be a heat radiator. A standard docking port is at the front. I'm presuming that Dragon XL is launched inside a standard fairing, since it looks a bit delicate with the exposed silver mylar insulation.

What you perceive to be the trunk is not the trunk. It is the main body of the pressurized container.

[woods170]

Looks like docking port, propulsion and tanks are at the front. In the middle pressurized cargo and at the back is trunk with solar panels and radiators.
At launch the docking port is looking down at the second stage.

How about late cargo?
 

Emphasis mine.

Correct. Most of the propulsion stuff is situated around the tunnel which connects the docking port to the pressure vessel.

Also: no trunk.

[woods170]

A smaller diameter would make sense.  If the artist impression is accurate, this looks like it is designed to be launched under a payload fairing.  It doesn’t look very aerodynamic.

Correct. It will launch on FH under the standard Falcon 9/FH fairing.

[Robotbeat]

Looks like docking port, propulsion and tanks are at the front. In the middle pressurized cargo and at the back is trunk with solar panels and radiators.
At launch the docking port is looking down at the second stage.

How about late cargo?
 

Emphasis mine.

Correct. Most of the propulsion stuff is situated around the tunnel which connects the docking port to the pressure vessel.

Also: no trunk.

That’s interesting! Means they could maybe make a variant with docking ports on both ends to serve as a small station or deep space transfer vehicle element.

[Caspar_Stanley]

Just wanted to add to the discussion with some neat renders I did. I would appear that my version is a bit too long and doesn't fit in the standard fairing. Woops.

[Ronsmytheiii]

Looks like docking port, propulsion and tanks are at the front. In the middle pressurized cargo and at the back is trunk with solar panels and radiators.
At launch the docking port is looking down at the second stage.

How about late cargo?
 

Emphasis mine.

Correct. Most of the propulsion stuff is situated around the tunnel which connects the docking port to the pressure vessel.

Also: no trunk.

That’s interesting! Means they could maybe make a variant with docking ports on both ends to serve as a small station or deep space transfer vehicle element.

Yeah, this is a very different craft from Dragon 1.0 or 2.0. Seems more like a SpaceX version of the Soviet TKS spacecraft than any other vehicle.

https://en.wikipedia.org/wiki/TKS_(spacecraft)

[woods170]

Just wanted to add to the discussion with some neat renders I did. I would appear that my version is a bit too long and doesn't fit in the standard fairing. Woops.

Welcome to the forum. Excellent renders for a first try at this vehicle.
Few remarks: thruster pods have 3 instead of 4 thrusters and are larger. Pressurized section is too long, as you had already noted.

[brickmack]

I'm also working on a model of Dragon-XL. Normally I wait until I've got an actual scene done to post renders, but since theres some uncertainty about the vehicle configuration I figured I'd post some test shots for discussion purposes

From counting pixels in the single official render (comparing against known width of the Dragon 1 heritage solar arrays), I got a length for the barrel section of the pressurized portion of 3.05 meters, which is slightly shorter than that of the F9 S2 LOX tank, but a small enough difference that I'm quite certain its just a measurement error, not a separate design. Dome profile is also traced from the F9 tank design. Woods170 above claimed the grapple fixture is a Power Data Grapple Fixture, looks more like a normal Flight-Releasable Grapple Fixture to me but I'll defer to him for now and use PDGF

On the top, I've assumed mounting for two FRAM-sized unpressurized payloads, next to the solar array mounts (one is visible in the official render). It looks like there could indeed be room for a second docking port as well

Looks like it fits quite comfortably in the standard fairing.

Edit: revised based on reddit discussions

[ace5]

I also think the diameter is around ~3.3 ~3.5