SpaceX Dragon XL

[woods170]

How many Draco Thrusters on Dragon XL?  20?

Judging by the image: Four triplets and 4 tail thrusters around the hatch. So 16.

That is correct for the current design iteration.

[DistantTemple]

How many Draco Thrusters on Dragon XL?  20?

Judging by the image: Four triplets and 4 tail thrusters around the hatch. So 16.

That is correct for the current design iteration.

It is brilliant to get all these new data points: "That is correct for the current design iteration."

So just to go wild with future possibilities.
1. It is habitable space in that it is internal space for astronauts to enter. To make it into a human spaceflight vehicle it "just" has to have its own ECLSS. Which is "just" another item in the SX tool box. (Or is this already included) (It would be good to include it for emergency purposes for the current planned missions)
2. SX can make the cylinder any length (up to F9S1 length) so any variation for another purpose can have appropriate length tanks (or space to place tanks, if the store-able propellants are within their own tanks, as in the D2), or habitable volume.
3. SX will show how much space hardware provision has moved on when it goes from contract in 2020 to flying a test vehicle in likely 2023!!! It will show how agile SX is, how cost effective (yet again), how it can successfully poivot to customer requirements, and how its own goals and R&D position it to answer such orders.

This (3.) will give SX immense "cred" with NASA, and the US and other governments. This will help them become a provider of choice with their established products, and a credible one for a wider range of projects, as well as project confidence onto the SS and SH, and SX's Mars plans.

It will seem realistic that "Space Exploration Technologies" could have a vast fleet/empire of ships, launch facilities, outposts, stations. An be the leading experts.

[Paul451]

1. [...] it "just" has to have its own ECLSS. Which is "just" another item in the SX tool box. (Or is this already included) (It would be good to include it for emergency purposes for the current planned missions)

Not required in the spec. And (IMO) it won't have anything not required. It seems very narrowly designed to meet the job.

2. SX can make the cylinder any length (up to F9S1 length) so any variation for another purpose can have appropriate length tanks (or space to place tanks, if the store-able propellants are within their own tanks, as in the D2), or habitable volume.

A) The main cylinder is the pressure vessel, not the propellant tanks. The prop.tanks are in the bottom ring, around the docking tunnel. Hard to "extend" in the normal way you'd lengthen a tank.

B) The whole thing launches inside a payload fairing. It can't be longer than the inside cylindrical volume of the fairing. 6.7m, IIRC, unless they use a larger fairing.

[woods170]

1. [...] it "just" has to have its own ECLSS. Which is "just" another item in the SX tool box. (Or is this already included) (It would be good to include it for emergency purposes for the current planned missions)

Not required in the spec. And (IMO) it won't have anything not required. It seems very narrowly designed to meet the job.

Indeed. Over the past two weeks I've seen some pretty wild ideas being floated here about the supposed "could be" capabilities of DragonXL.

But people should realize that DragonXL, like Dragon 1, is a cargo vehicle. When docked to Gateway it basically functions as a combined supplies storage and waste dump. Cargo that has been taken out will almost immediately be replaced with waste. That is because unlike ISS, the Gateway doesn't have a huge amount of pressurized living- and working space.
As such, the DragonXL only sports a rudimentary environmental control system: radiators to get rid of excessive heat, heaters to avoid cold-spots, fans for airflow to prevent static CO2 build-up, moisture control to prevent condensation, and filters to deal with free-floating debris and dust. Basically the same stuff that already exists on Dragon 1. ATV, HTV and Cygnus had/have similar environmental control systems.

Other functions that specifically exist to support human life are NOT part of the requirements for DragonXL. Nor are they part of the design. So, stuff like CO2 scrubbing, oxygen replenishment, providing potable water, providing heat to prepare food, human hygiene and waste management, etc. are NOT provided by DragonXL.

[TheRadicalModerate]

1. [...] it "just" has to have its own ECLSS. Which is "just" another item in the SX tool box. (Or is this already included) (It would be good to include it for emergency purposes for the current planned missions)

Not required in the spec. And (IMO) it won't have anything not required. It seems very narrowly designed to meet the job.

Indeed. Over the past two weeks I've seen some pretty wild ideas being floated here about the supposed "could be" capabilities of DragonXL.

But people should realize that DragonXL, like Dragon 1, is a cargo vehicle. When docked to Gateway it basically functions as a combined supplies storage and waste dump. Cargo that has been taken out will almost immediately be replaced with waste. That is because unlike ISS, the Gateway doesn't have a huge amount of pressurized living- and working space.
As such, the DragonXL only sports a rudimentary environmental control system: radiators to get rid of excessive heat, heaters to avoid cold-spots, fans for airflow to prevent static CO2 build-up, moisture control to prevent condensation, and filters to deal with free-floating debris and dust. Basically the same stuff that already exists on Dragon 1. ATV, HTV and Cygnus had/have similar environmental control systems.

Other functions that specifically exist to support human life are NOT part of the requirements for DragonXL. Nor are they part of the design. So, stuff like CO2 scrubbing, oxygen replenishment, providing potable water, providing heat to prepare food, human hygiene and waste management, etc. are NOT provided by DragonXL.

Steps for converting D2 into DXL:

1) Keep the D2 "bus" (thrusters, tankage, avionics, etc.) pretty much as-is, mod removing the SuperDracos.

2) Replace the trunk with the "roof rack", which has D1-like solar wings and some payload attachment points, instead of the wraparound solar skin of the D2 trunk.

3) Replace the D2's frustum-shaped pressure vessel with a long cylindrical one, with more volume but less ECLSS.

This is what they've bid to NASA for the Gateway Logistics System contract.  But once they've made the bus so it can handle both D2 and DXL, they can swap other things in place of the D2 and DXL pressure vessel, for other missions.

Will they swap in other things?  Certainly not for the GLS contract.  But if there's a market for other applications, the cost for building something to serve that market is now even lower than it was.

[Tomness]

......

Other functions that specifically exist to support human life are NOT part of the requirements for DragonXL. Nor are they part of the design. So, stuff like CO2 scrubbing, oxygen replenishment, providing potable water, providing heat to prepare food, human hygiene and waste management, etc. are NOT provided by DragonXL.

Which I find fascinating since one of the requisite is providing space to do work and  being in there longer then in and out. So if they are able to do that with out CO2 scrubbing, O2 replenishing. More the merrier

....

  But if there's a market for other applications, the cost for building something to serve that market is now even lower than it was.

Which I think this would be perfect for providing a  proving ground for ISS & SpaceX Comercial Crew Dragon Free Flyer

[anof]

......

Other functions that specifically exist to support human life are NOT part of the requirements for DragonXL. Nor are they part of the design. So, stuff like CO2 scrubbing, oxygen replenishment, providing potable water, providing heat to prepare food, human hygiene and waste management, etc. are NOT provided by DragonXL.

Which I find fascinating since one of the requisite is providing space to do work and  being in there longer then in and out. So if they are able to do that with out CO2 scrubbing, O2 replenishing. More the merrier

Usually there is an air duct that is installed in cargo ships to circulate air for crew operations. One difference is that Dragon XL will have a smaller docking port.

[Paul451]

anof, fix your quotes.

Other functions that specifically exist to support human life are NOT part of the requirements for DragonXL. Nor are they part of the design. So, stuff like CO2 scrubbing, oxygen replenishment, providing potable water, providing heat to prepare food, human hygiene and waste management, etc. are NOT provided by DragonXL.

Which I find fascinating since one of the requisite is providing space to do work and  being in there longer then in and out. So if they are able to do that with out CO2 scrubbing, O2 replenishing. More the merrier

Usually there is an air duct that is installed in cargo ships to circulate air for crew operations. One difference is that Dragon XL will have a smaller docking port.

Hmm, I wonder if D2's atmospheric life-support system could do that for DXL, if a DXL was used as a stand-alone LEO lab space.

[Jim]

This (3.) will give SX immense "cred" with NASA, and the US and other governments. This will help them become a provider of choice with their established products, and a credible one for a wider range of projects, as well as project confidence onto the SS and SH, and SX's Mars plans.

Stop with the hype

[woods170]

This (3.) will give SX immense "cred" with NASA, and the US and other governments. This will help them become a provider of choice with their established products, and a credible one for a wider range of projects, as well as project confidence onto the SS and SH, and SX's Mars plans.

Stop with the hype

Not matter how many times you "order" people to do so (have you never heard of the word "please"?) it won't happen. SpaceX hyperbole is at least as persistent as SLS- and ULA hyperbole.

Wasted effort.

[TheRadicalModerate]

Usually there is an air duct that is installed in cargo ships to circulate air for crew operations. One difference is that Dragon XL will have a smaller docking port.

Why do you think that DXL will have a smaller port?  I can't imagine that it won't be IDSS-compliant; there's no reason for it not to be.

[DistantTemple]

the bold and strike-through are changes to my original text quoted

This (3.) will give SX immense "cred"build SX track record for a wider range of space services with NASA, and the US and other governments. This will help them become a provider of choice with their established products, and a credible one for a wider range of projects, as well as project confidence onto the SS and SH, and SX's Mars plans.

Stop with the hype

There its not hype now. However coincidentally it was somewhat "in the mood" of NASA's announcement web page for Demo2 released on the 17 April (yesterday) emotively portraying SpaceX in the progression; Apollo, Space Shuttle, Dragon2.
So even NASA is giving it "hype" now.  :-)

[lrk]

Usually there is an air duct that is installed in cargo ships to circulate air for crew operations. One difference is that Dragon XL will have a smaller docking port.

Why do you think that DXL will have a smaller port?  I can't imagine that it won't be IDSS-compliant; there's no reason for it not to be.

Smaller than the CBM on Dragon 1, I presume was the intention.  As I understand things it will be the same as on both Dragon 2 crew & cargo configurations.

[Johnnyhinbos]

Usually there is an air duct that is installed in cargo ships to circulate air for crew operations. One difference is that Dragon XL will have a smaller docking port.

Why do you think that DXL will have a smaller port?  I can't imagine that it won't be IDSS-compliant; there's no reason for it not to be.

Smaller than the CBM on Dragon 1, I presume was the intention.  As I understand things it will be the same as on both Dragon 2 crew & cargo configurations.

I think the use of “docking” is misleading in anof’s post, and was perhaps used to generically.

[anof]

Usually there is an air duct that is installed in cargo ships to circulate air for crew operations. One difference is that Dragon XL will have a smaller docking port.

Why do you think that DXL will have a smaller port?  I can't imagine that it won't be IDSS-compliant; there's no reason for it not to be.

Smaller than the CBM on Dragon 1, I presume was the intention.  As I understand things it will be the same as on both Dragon 2 crew & cargo configurations.

I think the use of “docking” is misleading in anof’s post, and was perhaps used to generically.

Yes. I was trying to say too much with not enough words. Previously most cargo craft used a CBM. Now the Dragon XL will carry cargo and not use a CBM.

[Restless]

This (3.) will give SX immense "cred" with NASA, and the US and other governments. This will help them become a provider of choice with their established products, and a credible one for a wider range of projects, as well as project confidence onto the SS and SH, and SX's Mars plans.

Stop with the hype

Not matter how many times you "order" people to do so (have you never heard of the word "please"?) it won't happen. SpaceX hyperbole is at least as persistent as SLS- and ULA hyperbole.

Wasted effort.

Jim is right. This is a forum, not a fan club. We should refrain from gushing admiration and stick to space flight.

[Coastal Ron]

This (3.) will give SX immense "cred" with NASA, and the US and other governments. This will help them become a provider of choice with their established products, and a credible one for a wider range of projects, as well as project confidence onto the SS and SH, and SX's Mars plans.

Stop with the hype

Not matter how many times you "order" people to do so (have you never heard of the word "please"?) it won't happen. SpaceX hyperbole is at least as persistent as SLS- and ULA hyperbole.

Wasted effort.

Jim is right. This is a forum, not a fan club. We should refrain from gushing admiration and stick to space flight.

You can't admire something on a forum? I don't think our members know that... 

Besides, Boeing and ULA have touted for years that one of their strengths has been dependability, and here we have SpaceX now in a position to tout the same - with a history to back it up.

And if you don't think "cred" matters, then I don't think you read the selection statement where one of the criteria for awarding a contract was history - and SpaceX was called out specifically for its history of reliable performance.

[DistantTemple]

Thankyou Coastal Ron. Exactly the point I was thinking of... But you explained better. I was not just cheer-leading!

[Joffan]

We've kind of danced around the idea of Dragon XL visiting ISS in this thread, but to me this would seem to be a natural opportunity for both proving out the vehicle (a qualification mission) and taking advantage of a large-volume delivery capability to ISS. Plus ISS has established processes for visiting vehicles, and Dragon XL would have long heritage from predecessor Dragons by that point, both of approach to ISS and of autonomous docking.

[wannamoonbase]

We've kind of danced around the idea of Dragon XL visiting ISS in this thread, but to me this would seem to be a natural opportunity for both proving out the vehicle (a qualification mission) and taking advantage of a large-volume delivery capability to ISS. Plus ISS has established processes for visiting vehicles, and Dragon XL would have long heritage from predecessor Dragons by that point, both of approach to ISS and of autonomous docking.

Using a FH to send things to ISS seems like an expensive waste.