Author Topic: SpaceX Dragon XL  (Read 219061 times)

Offline CorvusCorax

  • Full Member
  • ****
  • Posts: 1575
  • Germany
  • Liked: 3135
  • Likes Given: 2305
Re: SpaceX Dragon XL
« Reply #100 on: 03/28/2020 10:58 am »
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 :)

My thought, too. If this thing get's a docking or mating adapter on both ends, it would be pretty ideal for a modular space station - probably for a tiny fraction of the price of conventional space stations but with significantly higher DeltaV - a station entirely built from these would basically be a orbit-assembled spaceship. All it needs on top of that is propellant transfer capability for refueling.

It kinda loses its big significance when you bring Starship into the picture, but Starship - essentially, is still a launch and reentry vehicle, even if used for interplanetary work with long coast times - it will launch on a planet surface and will be landing somewhere.

Dragon XL habitats on the other hand would fall more in the "living and working in space" category.

Online volker2020

  • Full Member
  • **
  • Posts: 269
  • Frankfurt, Germany
  • Liked: 286
  • Likes Given: 685
Re: SpaceX Dragon XL
« Reply #101 on: 03/28/2020 11:34 am »
It kinda loses its big significance when you bring Starship into the picture, but Starship - essentially, is still a launch and reentry vehicle, even if used for interplanetary work with long coast times - it will launch on a planet surface and will be landing somewhere.

I think that one is easy. The NASA does either not believe that the Starship development is feasible, or worst case, they see it as a competitor to the Senate Launch System.

Offline dror

  • Full Member
  • ****
  • Posts: 730
  • Israel
  • Liked: 245
  • Likes Given: 593
Re: SpaceX Dragon XL
« Reply #102 on: 03/28/2020 11:36 am »
I'm both exited for the win and disappointed for the plan.
I really thought that the next Dragon would be a mini Starship of sort.
Space is hard immensely complex and high risk !

Online dgmckenzie

Re: SpaceX Dragon XL
« Reply #103 on: 03/28/2020 11:37 am »
If it is supposed to transfer both pressurized and unpressurized cargo, how could it have docking at both ends?

Offline woods170

  • IRAS fan
  • Senior Member
  • *****
  • Posts: 11397
  • IRAS fan
  • The Netherlands
  • Liked: 15259
  • Likes Given: 9481
Re: SpaceX Dragon XL
« Reply #104 on: 03/28/2020 11:42 am »
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?

Volume is substantially larger than cargo D2.
No propellant for transfer.

This is NOT Progress-on-steroids. More like Cygnus with unpressurized cargo capabilities.

Offline woods170

  • IRAS fan
  • Senior Member
  • *****
  • Posts: 11397
  • IRAS fan
  • The Netherlands
  • Liked: 15259
  • Likes Given: 9481
Re: SpaceX Dragon XL
« Reply #105 on: 03/28/2020 11:44 am »
It looks like an FHE and a plain ol' Dragon 2, even outfitted with a bunch of ECLSS and crew consumables that they don't need, could take 4.5 t to NRHO with no problem.  Surely if they stripped out all the crew-critical stuff from D2 it would carry 5 t as-is?  Why the redesign?
Volume
And cost.

I can't imagine that the NRE for a new design would amortize over the number of likely Gateway logistics missions.  Even if D2 isn't the optimal design, it's one that exists already.  That's worth quite a bit.

I can understand the volume issue.  D2 has only half the pressurized volume of Cygnus.

The only really new thing is the pressure vessel. Different than those of cargo Dragon, Crew Dragon and Cargo D2. However, built with same materials and tooling.

Offline woods170

  • IRAS fan
  • Senior Member
  • *****
  • Posts: 11397
  • IRAS fan
  • The Netherlands
  • Liked: 15259
  • Likes Given: 9481
Re: SpaceX Dragon XL
« Reply #106 on: 03/28/2020 11:48 am »
Spaceflight Now has a scoop with a lot more info than everyone else:
https://spaceflightnow.com/2020/03/27/nasa-picks-spacex-to-deliver-cargo-to-gateway-station-in-lunar-orbit/

Also despite some posters being adamant that this will fly without a fairing based on their own rampant speculation, this article puts that presumption to rest:
Quote
  SpaceX is building off the company’s Dragon 2 spacecraft designed to ferry crew and cargo to the International Space Station. Unlike the Dragon 2, which flies without an aerodynamic shroud on top of SpaceX’s Falcon 9 rocket, the Dragon XL will lift off inside a payload fairing on the company’s bigger Falcon Heavy launcher, according to Dan Hartman, NASA’s Gateway program manager at the Johnson Space Center in Houston.

It gon be in a fairing!

Correct. It will be launched inside the standard FH fairing. Extended fairing not required. Sized to fit inside the standard fairing.

Offline woods170

  • IRAS fan
  • Senior Member
  • *****
  • Posts: 11397
  • IRAS fan
  • The Netherlands
  • Liked: 15259
  • Likes Given: 9481
Re: SpaceX Dragon XL
« Reply #107 on: 03/28/2020 11:53 am »
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

Can'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.

Offline woods170

  • IRAS fan
  • Senior Member
  • *****
  • Posts: 11397
  • IRAS fan
  • The Netherlands
  • Liked: 15259
  • Likes Given: 9481
Re: SpaceX Dragon XL
« Reply #108 on: 03/28/2020 11:58 am »
If 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

Quote 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 packages

https://forum.nasaspaceflight.com/index.php?topic=48353.msg2018139#msg2018139

Which 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.
« Last Edit: 03/28/2020 12:31 pm by woods170 »

Offline Cherokee43v6

  • Full Member
  • ****
  • Posts: 1142
  • Garner, NC
  • Liked: 885
  • Likes Given: 225
Re: SpaceX Dragon XL
« Reply #109 on: 03/28/2020 12:00 pm »
A few things I'm noticing about the DragonXL image released by SpaceX and NASA that is included with the article.

First, it is important to note that the image is placed in Earth Orbit with the moon in the distance.  By implication of the preceding the image shows the DragonXL separating from the Falcon Heavy Stage-2.  Therefore:

1) DragonXL launches with its docking port in a 'down' orientation on the rocket stack.  If the DXL does not return to Earth, then this orientation makes sense as there is no reason to protect a heat shield and it puts the mission critical docking mechanism in the protected position instead.

2) The image shows a 'docking mechanism' looking very much like the front end of the D2 as opposed to a berthing mechanism as used on the Cargo Dragon

3) Support/service elements (ie solar panels, external cargo) appear to ride exposed under the fairing that gets jettisoned during the launch as there does not appear to be a 'frunk'.
« Last Edit: 03/28/2020 12:01 pm by Cherokee43v6 »
"I didn't open the can of worms...
        ...I just pointed at it and laughed a little too loudly."

Offline woods170

  • IRAS fan
  • Senior Member
  • *****
  • Posts: 11397
  • IRAS fan
  • The Netherlands
  • Liked: 15259
  • Likes Given: 9481
Re: SpaceX Dragon XL
« Reply #110 on: 03/28/2020 12:01 pm »
[...]
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...  ;)


Yes, very much this.

Dragon XL disposal will be back to Earth. Destructive reentry in Earth's atmosphere.

Offline woods170

  • IRAS fan
  • Senior Member
  • *****
  • Posts: 11397
  • IRAS fan
  • The Netherlands
  • Liked: 15259
  • Likes Given: 9481
Re: SpaceX Dragon XL
« Reply #111 on: 03/28/2020 12:04 pm »
[...]
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.

The same kind of reasoning was used when some countries started dumping nuclear waste in the oceans in the 1960s.

What a civilized bunch of people is supposed to do is properly clean up the mess they made. Just randomly dumping Gateway waste on the lunar surface is NOT the way to go. Neither is sending it into lunar orbit or solar orbit.

Offline CorvusCorax

  • Full Member
  • ****
  • Posts: 1575
  • Germany
  • Liked: 3135
  • Likes Given: 2305
Re: SpaceX Dragon XL
« Reply #112 on: 03/28/2020 12:15 pm »
You could use a Dragon XL docked to lunar gateway as a "impact mass container" and fill it up with defined amounts of no-longer-needed stuff until it reaches its design mass.

Once the design mass is reached, you detach on a science mission involving a lunar impact as well as a bunch of telescopes analyzing dust, seismic measurements, etc...

This isn't "dumping garbage" - it's "science"! ;)

Offline Jcc

  • Full Member
  • ****
  • Posts: 1193
  • Liked: 403
  • Likes Given: 203
Re: SpaceX Dragon XL
« Reply #113 on: 03/28/2020 12:22 pm »
If it is supposed to transfer both pressurized and unpressurized cargo, how could it have docking at both ends?
A detachable trunk and propulsion unit. Of course that adds weight and reduces cargo capability, but could be done.

Offline ValmirGP

Re: SpaceX Dragon XL
« Reply #114 on: 03/28/2020 12:25 pm »
You could use a Dragon XL docked to lunar gateway as a "impact mass container" and fill it up with defined amounts of no-longer-needed stuff until it reaches its design mass.

Once the design mass is reached, you detach on a science mission involving a lunar impact as well as a bunch of telescopes analyzing dust, seismic measurements, etc...

This isn't "dumping garbage" - it's "science"! ;)

This is not science, it's just littering. You can´t expect science to be made out of an impact of something filled with vast amounts of materials of witch you don't know the exact and precise composition. The results would be inconclusive at best. As in "I'm seeing lots of organics. Did I just hit an alien inhabitant or was that the contents of expent food containers?"
« Last Edit: 03/28/2020 12:27 pm by ValmirGP »

Offline Robotbeat

  • Senior Member
  • *****
  • Posts: 36112
  • Minnesota
  • Liked: 20449
  • Likes Given: 10611
Re: SpaceX Dragon XL
« Reply #115 on: 03/28/2020 12:53 pm »
If it is supposed to transfer both pressurized and unpressurized cargo, how could it have docking at both ends?
It would need a different variant. But I think putting a docking tunnel through the propulsion section is the harder part, which is already done as part of the basic design.
Chris  Whoever loves correction loves knowledge, but he who hates reproof is stupid.

To the maximum extent practicable, the Federal Government shall plan missions to accommodate the space transportation services capabilities of United States commercial providers. US law http://goo.gl/YZYNt0

Offline Robotbeat

  • Senior Member
  • *****
  • Posts: 36112
  • Minnesota
  • Liked: 20449
  • Likes Given: 10611
Re: SpaceX Dragon XL
« Reply #116 on: 03/28/2020 12:58 pm »
If 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

Quote 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 packages

https://forum.nasaspaceflight.com/index.php?topic=48353.msg2018139#msg2018139

Which 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.
Well that’s neat. Implies *a* deep space Canadarm could in principle operate on a detached Dragon XL, ie for servicing missions.
Chris  Whoever loves correction loves knowledge, but he who hates reproof is stupid.

To the maximum extent practicable, the Federal Government shall plan missions to accommodate the space transportation services capabilities of United States commercial providers. US law http://goo.gl/YZYNt0

Offline aero

  • Senior Member
  • *****
  • Posts: 3618
  • 92129
  • Liked: 1136
  • Likes Given: 358
Re: SpaceX Dragon XL
« Reply #117 on: 03/28/2020 01:19 pm »
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.
Retired, working interesting problems

Offline Jimmy Murdok

  • Full Member
  • **
  • Posts: 202
  • Lausanne - Barcelona
  • Liked: 177
  • Likes Given: 186
Re: SpaceX Dragon XL
« Reply #118 on: 03/28/2020 01:25 pm »
I´m trying to figure out the size of the vehicle.
I´ve modeled the ISA adaptor and used 3.7m (F9 diameter) as a baseline. Looks like more or less make sense.
The model has been sketched a in Onshape, so is parametric. It´s public via link access to see and export and can also be copied with a free Onshape account.

https://cad.onshape.com/documents/d32435cb16f1fe696165b0f7/w/e324511fb848d24897bf37cf/e/ee2f5052c152507f6ad3cb66

Happy to get feedback on the size. I can easily add the solar panels and even fuel tanks if some speculation that make sense is provided with: sizes, pictures or even pencil sketches.


Offline CorvusCorax

  • Full Member
  • ****
  • Posts: 1575
  • Germany
  • Liked: 3135
  • Likes Given: 2305
Re: SpaceX Dragon XL
« Reply #119 on: 03/28/2020 01:27 pm »
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.

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.

Tags:
 

Advertisement NovaTech
Advertisement SkyTale Software GmbH
Advertisement Northrop Grumman
Advertisement
Advertisement Brady Kenniston
Advertisement NextSpaceflight
Advertisement Nathan Barker Photography
0