Author Topic: SpaceX Dragon XL  (Read 245190 times)

Offline pochimax

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Re: SpaceX Dragon XL
« Reply #620 on: 11/16/2021 09:26 am »
So ...this contract finally started?  :)

Offline su27k

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Re: SpaceX Dragon XL
« Reply #621 on: 11/17/2021 02:39 am »
So ...this contract finally started?  :)

I don't think there's any sign that this is started?

Online tbellman

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Re: SpaceX Dragon XL
« Reply #622 on: 11/17/2021 09:14 am »
So ...this contract finally started?  :)

I don't think there's any sign that this is started?

If I'm understanding the information on the usaspending page right, it seems that there was a payout of $5.5M to SpaceX in May, and another $1.7M in July, plus a few hundred thousand dollars total in other months.  (See the "Outlayed Amount" column in the table under Award History, in the "Federal Account Funding" tab.)  So there's been a little bit of activity, but it's not much.

Offline su27k

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Re: SpaceX Dragon XL
« Reply #623 on: 11/17/2021 09:50 am »
So ...this contract finally started?  :)

I don't think there's any sign that this is started?

If I'm understanding the information on the usaspending page right, it seems that there was a payout of $5.5M to SpaceX in May, and another $1.7M in July, plus a few hundred thousand dollars total in other months.  (See the "Outlayed Amount" column in the table under Award History, in the "Federal Account Funding" tab.)  So there's been a little bit of activity, but it's not much.

This was discussed before, NASA is just giving them some study money without giving them authority to proceed, confirmed by GAO report:

Quote from: GAO-21-306
According to project officials, NASA did not provide SpaceX with authority to proceed in October 2020, as originally planned, due to funding constraints from operating under a continuing resolution and NASA having other funding priorities. As a result, there is a risk that the logistics mission may not be capable of supporting the Artemis III mission at the end of 2024.

<snip>

To try to mitigate this schedule risk, the project is also working with the Gateway program and the Advanced Exploration Systems division to obtain funding and with SpaceX on four special studies to prepare for the authority to proceed. For example, project officials said one study tasked SpaceX to develop an updated schedule to inform the launch readiness date for the initial mission. The project is also assessing whether it could tailor the current schedule and performance requirements if the authority to proceed continues to be delayed.
« Last Edit: 11/17/2021 09:50 am by su27k »

Online DanClemmensen

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Re: SpaceX Dragon XL
« Reply #624 on: 11/17/2021 05:32 pm »
So ...this contract finally started?  :)

I don't think there's any sign that this is started?

If I'm understanding the information on the usaspending page right, it seems that there was a payout of $5.5M to SpaceX in May, and another $1.7M in July, plus a few hundred thousand dollars total in other months.  (See the "Outlayed Amount" column in the table under Award History, in the "Federal Account Funding" tab.)  So there's been a little bit of activity, but it's not much.

This was discussed before, NASA is just giving them some study money without giving them authority to proceed, confirmed by GAO report:

Quote from: GAO-21-306
According to project officials, NASA did not provide SpaceX with authority to proceed in October 2020, as originally planned, due to funding constraints from operating under a continuing resolution and NASA having other funding priorities. As a result, there is a risk that the logistics mission may not be capable of supporting the Artemis III mission at the end of 2024.

<snip>

To try to mitigate this schedule risk, the project is also working with the Gateway program and the Advanced Exploration Systems division to obtain funding and with SpaceX on four special studies to prepare for the authority to proceed. For example, project officials said one study tasked SpaceX to develop an updated schedule to inform the launch readiness date for the initial mission. The project is also assessing whether it could tailor the current schedule and performance requirements if the authority to proceed continues to be delayed.
This shows a profound disconnect within NASA. Dragon XL is the resupply craft for Gateway, but Gateway is optional for Artemis 3. For Artemis 3, Orion and Starship HLS will meet in NRHO whether or not Gateway is present. Starship HLS will have far more cargo capacity than Dragon XL and can boost from Earth with the supplies that would otherwise reach NRHO via Dragon XL, needing at most an additional tanker load of propellant. Gateway may have a Dragon XL delivery interface that HLS does not support (e.g., for propellant transfer) but by definition it does have the capability to carry anything that would otherwise be transferred to it from Gateway.

Offline pochimax

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Re: SpaceX Dragon XL
« Reply #625 on: 11/21/2021 08:48 am »
So ...this contract finally started?  :)

I don't think there's any sign that this is started?

If I'm understanding the information on the usaspending page right, it seems that there was a payout of $5.5M to SpaceX in May, and another $1.7M in July, plus a few hundred thousand dollars total in other months.  (See the "Outlayed Amount" column in the table under Award History, in the "Federal Account Funding" tab.)  So there's been a little bit of activity, but it's not much.

This was discussed before, NASA is just giving them some study money without giving them authority to proceed, confirmed by GAO report:

Quote from: GAO-21-306
According to project officials, NASA did not provide SpaceX with authority to proceed in October 2020, as originally planned, due to funding constraints from operating under a continuing resolution and NASA having other funding priorities. As a result, there is a risk that the logistics mission may not be capable of supporting the Artemis III mission at the end of 2024.

<snip>

To try to mitigate this schedule risk, the project is also working with the Gateway program and the Advanced Exploration Systems division to obtain funding and with SpaceX on four special studies to prepare for the authority to proceed. For example, project officials said one study tasked SpaceX to develop an updated schedule to inform the launch readiness date for the initial mission. The project is also assessing whether it could tailor the current schedule and performance requirements if the authority to proceed continues to be delayed.

Yes, Problem is the information given in the recent Artemis OIG report, which in page 59 (page 65 of the document) says 56.4 millions obligated to SpaceX under this contract. It is in disagreement with the award history.

https://oig.nasa.gov/docs/IG-22-003.pdf

On the other hand, they have now the flag that will fly in the first vehicle.

https://twitter.com/NASA_Gateway/status/1457818962327228417

Offline seb21051

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Re: SpaceX Dragon XL
« Reply #626 on: 11/28/2021 09:27 pm »
Don't know if this is the right place to ask this question, so please redirect if needed.

I assume its feasible to send a Crew Dragon to the Gateway. Would it have to be with a FH or F9?

Offline MATTBLAK

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Re: SpaceX Dragon XL
« Reply #627 on: 11/28/2021 10:22 pm »
Falcon Heavy. And Dragon would need some sort of delta-v increase; more fuel essentially.
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Online DanClemmensen

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Re: SpaceX Dragon XL
« Reply #628 on: 11/29/2021 12:53 am »
Don't know if this is the right place to ask this question, so please redirect if needed.

I assume its feasible to send a Crew Dragon to the Gateway. Would it have to be with a FH or F9?

I can think of four issues, but I don't have answers.

* Delta V to get Crew Dragon to NRHO in the first place. FH can probably do this.
* Crew Dragon Service module Delta V to rendezvous and dock with Gateway. Dragon XL will do this but probably expends most of it propellant, so a crew version of Dragon XL is not as simple as a the Dragon 2 twins.
* Crew Dragon Service module Delta V to send Crew Dragon back to re-entry.
* Crew Dragon heat shield for this high-velocity re-entry.

I'm guessing at a minimum you need a new service module. I suspect you also need a new heat shield. At this point you have just re-invented Orion.  Why bother? just send a crewed Starship.

Offline seb21051

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Re: SpaceX Dragon XL
« Reply #629 on: 11/29/2021 02:48 am »
Understood. I came upon the idea while thinking of Orion. NASA likes to have a backup plan, they already had to send a few Astronauts that would have gone with Starliner on Crew Dragon.

Neither Crew Rated Starship or Crewed Orion have flown to orbit as of yet. We just likes to keep something in our back pocket . . .

I'm pretty sure CSS and Orion will fly successfully before 2024/5.

The requirement that SX now provide motel accommodations on DXL seems odd. It makes sense as a tug, but will they fill up the crew area with cargo when it is sent out to the Gateway? Or will they change the requirement down the line to make it a transit crew carrier as well? Just in case Orion is not ready?
« Last Edit: 11/29/2021 03:01 am by seb21051 »

Online DanClemmensen

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Re: SpaceX Dragon XL
« Reply #630 on: 11/29/2021 03:06 am »
Understood. I came upon the idea while thinking of Orion. NASA likes to have a backup plan, they already had to send a few Astronauts that would have gone with Starliner on Crew Dragon.

Neither Crew Rated Starship or Crewed Orion have flown to orbit as of yet. We just likes to keep something in our back pocket . . .

I'm pretty sure CSS and Orion will fly successfully before 2024/5.

Apparently, Orion has now been around for so long that NASA just assumes it will work and actual crew rating is just a formality. If Orion cannot be made to work, Artemis must be cancelled or radically changed. At this point the logical backup plan is Starship. The only Starship feature that is not also needed by Starship HLS is high-velocity re-entry, so Artemis already depends on Starship. Of course, the only reason for Dragon XL is Gateway, and Artemis does not really need gateway: it's a holdover from earlier cancelled programs.

Offline seb21051

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Re: SpaceX Dragon XL
« Reply #631 on: 11/29/2021 04:22 am »
Understood. Gateway just seems to be a way to keep more companies in the game.

Ultimately, there seems very little that SS could not do in this project, as long as they keep enough filled tankers around. One in LEO and one in LO and, as we say in the Old Country, "Bob's Yer Uncle"

Offline Zed_Noir

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Re: SpaceX Dragon XL
« Reply #632 on: 11/29/2021 06:24 am »
<snip>
The requirement that SX now provide motel accommodations on DXL seems odd. It makes sense as a tug, but will they fill up the crew area with cargo when it is sent out to the Gateway? Or will they change the requirement down the line to make it a transit crew carrier as well? Just in case Orion is not ready?


It was previously stated elsewhere in this forum that the Dragon XL is the backup toilet for the Gateway and additional accommodation space since the usable pressurized volume in the HALO module isn't very big.

Offline clongton

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Re: SpaceX Dragon XL
« Reply #633 on: 11/29/2021 06:58 pm »
Don't know if this is the right place to ask this question, so please redirect if needed.

I assume its feasible to send a Crew Dragon to the Gateway. Would it have to be with a FH or F9?

<snip> I suspect you also need a new heat shield. At this point you have just re-invented Orion.  Why bother? just send a crewed Starship.</snip>

Dragon does not need a new heatshield. The current heatshield is already rated for lunar and Mars reentry into Earth's atmosphere.

According to SpaceX; PICA-X, which is SpaceX's proprietary derivative of the PICA (Phenolic Impregnated Carbon Ablator) heatshield designed by NASA, can withstand reentries from "Lunar and Martian Velocities". Martian velocities being even higher, of course.

PICA itself was used on the Stardust spacecraft which reentered at a speed of 46,500km/h. Apollo craft generally reentered at a speed of ~40,000km/h. An Earth reentry from Mars would, depending on how much energy you choose to expend, be between 49,000km/h-77,000km/h. Wired article.

Another source is testimony that Garret Reisman himself offered, on page 4, where he says: Designed in partnership with NASA and fabricated by SpaceX, Crew Dragon’s heat shield is made of PICA-X, a high-performance improvement on NASA’s original phenolic impregnated carbon ablator (PICA). PICA-X is designed to withstand heat rates from a lunar return mission, which far exceed the requirements for a low Earth orbit mission.
« Last Edit: 11/29/2021 07:00 pm by clongton »
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Online DanClemmensen

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Re: SpaceX Dragon XL
« Reply #634 on: 11/29/2021 07:13 pm »
Don't know if this is the right place to ask this question, so please redirect if needed.

I assume its feasible to send a Crew Dragon to the Gateway. Would it have to be with a FH or F9?

<snip> I suspect you also need a new heat shield. At this point you have just re-invented Orion.  Why bother? just send a crewed Starship.</snip>

Dragon does not need a new heatshield. The current heatshield is already rated for lunar and Mars reentry into Earth's atmosphere.

According to SpaceX; PICA-X, which is SpaceX's proprietary derivative of the PICA (Phenolic Impregnated Carbon Ablator) heatshield designed by NASA, can withstand reentries from "Lunar and Martian Velocities". Martian velocities being even higher, of course.

PICA itself was used on the Stardust spacecraft which reentered at a speed of 46,500km/h. Apollo craft generally reentered at a speed of ~40,000km/h. An Earth reentry from Mars would, depending on how much energy you choose to expend, be between 49,000km/h-77,000km/h. Wired article.

Another source is testimony that Garret Reisman himself offered, on page 4, where he says: Designed in partnership with NASA and fabricated by SpaceX, Crew Dragonís heat shield is made of PICA-X, a high-performance improvement on NASAís original phenolic impregnated carbon ablator (PICA). PICA-X is designed to withstand heat rates from a lunar return mission, which far exceed the requirements for a low Earth orbit mission.
Sorry, I'm just a casual observer, not a capsule designer. However, the fact that PICA-X material can be used to fabricate a heat shield for a Mars return does not by itself mean that the Crew Dragon heat shield has this capability. Why would SpaceX use a heavier shield than needed for re-entry from LEO on a craft that was designed specifically for an LEO mission?

This is unreasonable unless SpaceX was already contemplating Lunar or Martian missions for Crew Dragon. Possibly they were: dearMoon was originally going to be a Crew Dragon launched by FH into a lunar free return trajectory, but I thought this had been abandoned early enough to allow the heat shield to be mass-reduced.

Offline Cherokee43v6

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Re: SpaceX Dragon XL
« Reply #635 on: 11/29/2021 07:24 pm »
Don't know if this is the right place to ask this question, so please redirect if needed.

I assume its feasible to send a Crew Dragon to the Gateway. Would it have to be with a FH or F9?

I can think of four issues, but I don't have answers.

* Delta V to get Crew Dragon to NRHO in the first place. FH can probably do this.
* Crew Dragon Service module Delta V to rendezvous and dock with Gateway. Dragon XL will do this but probably expends most of it propellant, so a crew version of Dragon XL is not as simple as a the Dragon 2 twins.
* Crew Dragon Service module Delta V to send Crew Dragon back to re-entry.
* Crew Dragon heat shield for this high-velocity re-entry.

I'm guessing at a minimum you need a new service module. I suspect you also need a new heat shield. At this point you have just re-invented Orion.  Why bother? just send a crewed Starship.

I would point out that Dragon2 does not have a service module.  All of those functions are built into the Dragon craft itself.  The trunk is merely a place for cargo and the mounting of solar panels.

Considering that the fuel carried is sufficient for superdraco abort options and that the superdracos and dracos use the same fuel tanks, I do not think that the DeltaV issue is quite as bad as you might think.

As others have mentioned, PICA-X is rated for Lunar return speeds.

The one area of concern I see would be having sufficient life-support consumables for transit from LEO to NRHO and back.  The longest free-flight for Dragon2 so far is the Inspiration4 mission at approximately 4-5 days.
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Online spacenut

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Re: SpaceX Dragon XL
« Reply #636 on: 11/29/2021 08:47 pm »
It only takes what, 3 days to get to the moon?  So I think crew Dragon could carry enough consumables, if the Gateway is built.  The moon can be done with Falcon Heavy launches which includes the Dragon XL.  It doesn't need SLS.  The Gateway can be be built with Falcon Heavies.  Then a Lander launched to the Gateway with Falcon Heavy.  Then the Crew Dragon with a modified service module with extra fuel and a couple of Super Draco's. 

SLS is not need for any of this, neither is Orion. 

Offline envy887

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Re: SpaceX Dragon XL
« Reply #637 on: 11/29/2021 11:24 pm »
Don't know if this is the right place to ask this question, so please redirect if needed.

I assume its feasible to send a Crew Dragon to the Gateway. Would it have to be with a FH or F9?

<snip> I suspect you also need a new heat shield. At this point you have just re-invented Orion.  Why bother? just send a crewed Starship.</snip>

Dragon does not need a new heatshield. The current heatshield is already rated for lunar and Mars reentry into Earth's atmosphere.

According to SpaceX; PICA-X, which is SpaceX's proprietary derivative of the PICA (Phenolic Impregnated Carbon Ablator) heatshield designed by NASA, can withstand reentries from "Lunar and Martian Velocities". Martian velocities being even higher, of course.

PICA itself was used on the Stardust spacecraft which reentered at a speed of 46,500km/h. Apollo craft generally reentered at a speed of ~40,000km/h. An Earth reentry from Mars would, depending on how much energy you choose to expend, be between 49,000km/h-77,000km/h. Wired article.

Another source is testimony that Garret Reisman himself offered, on page 4, where he says: Designed in partnership with NASA and fabricated by SpaceX, Crew Dragonís heat shield is made of PICA-X, a high-performance improvement on NASAís original phenolic impregnated carbon ablator (PICA). PICA-X is designed to withstand heat rates from a lunar return mission, which far exceed the requirements for a low Earth orbit mission.
Sorry, I'm just a casual observer, not a capsule designer. However, the fact that PICA-X material can be used to fabricate a heat shield for a Mars return does not by itself mean that the Crew Dragon heat shield has this capability. Why would SpaceX use a heavier shield than needed for re-entry from LEO on a craft that was designed specifically for an LEO mission?

This is unreasonable unless SpaceX was already contemplating Lunar or Martian missions for Crew Dragon. Possibly they were: dearMoon was originally going to be a Crew Dragon launched by FH into a lunar free return trajectory, but I thought this had been abandoned early enough to allow the heat shield to be mass-reduced.

The Dragon TPS is constrained not by entry temperatures themselves, but by the post-entry heat pulse conducting back to the adhesive which bonds the tiles to the structure. That is why they can be, and are, used for multiple entries, even though they are ablative. It's not clear that a lunar entry would be a problem for the current TPS, since it depends what the internal temperatures would look like.

Offline hektor

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Re: SpaceX Dragon XL
« Reply #638 on: 11/30/2021 02:09 pm »
The one area of concern I see would be having sufficient life-support consumables for transit from LEO to NRHO and back.  The longest free-flight for Dragon2 so far is the Inspiration4 mission at approximately 4-5 days.

Potentially, since the actual Inspiration4 mission duration was one hour short of three days.
« Last Edit: 11/30/2021 02:10 pm by hektor »

Offline cohberg

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Re: SpaceX Dragon XL
« Reply #639 on: 11/30/2021 02:24 pm »
The one area of concern I see would be having sufficient life-support consumables for transit from LEO to NRHO and back.  The longest free-flight for Dragon2 so far is the Inspiration4 mission at approximately 4-5 days.

Potentially, since the actual Inspiration4 mission duration was one hour short of three days.

Dragon 2 was designed for 20 person days.

Quote from: SpaceX ECLSS Paper
ECLSS consumables ... last for 20 person-days

So acceptable margins for a 2 person crew (former grey dragon profile), not enough consumables for a 4 person crew round trip.
« Last Edit: 11/30/2021 03:23 pm by cohberg »

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