Author Topic: SpaceX Falcon 9/Dragon CRS-3 SpX-3 PROCESSING/Pre-LAUNCH UPDATES  (Read 204780 times)

Offline Space Pete

Interesting note there:

"(first use of SpX built ExPA)"

ExPA is ExPrESS Pallet Adapter - the type of FRAM (Flight Releasable Attachment Mechanism) used for attaching external payloads to the ISS ELCs (ExPrESS Logistics Carriers).

I would have assumed that NASA would provide it to the payload team as GFE, as they have always done, but it seems SpaceX are now building their own for use with Dragon! Very interesting - shows that they prefer to use their own hardware rather then government provided. Out of interest, I wonder if SpaceX were able to build it more cheaply than government?
« Last Edit: 08/07/2013 02:32 PM by Space Pete »
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Online Chris Bergin

Launch date latest for CRS-3/SpX-3 - now 2014.

Article by Pete Harding (with the meat) and the dates covered by yours truly.

http://www.nasaspaceflight.com/2013/08/nasa-planners-switch-spacex-dragon-mission-2014/

Offline yg1968

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Launch date latest for CRS-3/SpX-3 - now 2014.

Article by Pete Harding (with the meat) and the dates covered by yours truly.

http://www.nasaspaceflight.com/2013/08/nasa-planners-switch-spacex-dragon-mission-2014/

Good article!

Was any reason given for giving priority to ORB-1 over the SpX-3 flight?

Offline Antares

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Suff takes a look at the bench.  "Who's ready to go in December?"
If I like something on NSF, it's probably because I know it to be accurate.  Every once in a while, it's just something I agree with.  Facts generally receive the former.

Offline mlindner

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Chris what was the source of the 800kg limit on Dragon. I find that hard to believe.
Internal combustion engine in space. It's just a Bad Idea.TM - Robotbeat

Offline guckyfan

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Chris what was the source of the 800kg limit on Dragon. I find that hard to believe.

Me 2.

It would have to be a limit of the launch vehicle. But they did carry a vacuum freight and the combined weight of vacuum and pressurized cargo did exceed those 800kg, I am sure.


Offline Space Pete

Chris what was the source of the 800kg limit on Dragon. I find that hard to believe.

My source was a recent (late July) ISS status presentation to the NASA Advisory Council by ISS Program Director Sam Scimemi.

The slide in question is attached - see the last line:

"The F9v1.1 rocket is planned to increase the upmass capability from 800 kg to 1580 kg of cargo."

Don't know whether that's total cargo or just pressurised cargo though.

I agree they are unbelievable numbers - Dragon was sold as having 3,300kg of up-mass. Progress can do 2,500kg. Maybe an example of over-optimistic SpaceX performance claims.
« Last Edit: 08/15/2013 09:23 AM by Space Pete »
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Offline ChrisWilson68

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Chris what was the source of the 800kg limit on Dragon. I find that hard to believe.

My source was a recent (late July) ISS status presentation to the NASA Advisory Council by ISS Program Director Sam Scimemi.

The slide in question is attached - see the last line:

"The F9v1.1 rocket is planned to increase the upmass capability from 800 kg to 1580 kg of cargo."

Don't know whether that's total cargo or just pressurised cargo though.

I agree they are unbelievable numbers - Dragon was sold as having 3,300kg of up-mass. Progress can do 2,500kg. Maybe an example of over-optimistic SpaceX performance claims.

In CRS-1, Dragon on Falcon 9v1.0 delivered 905 kg of cargo.  That flight also included an additional 150 kg Orbcomm satellite.  And the upper stage was originally supposed to do a second burn to put the Orbcomm satellite in a higher orbit, so the second stage clearly still had some significant performance to spare.  Clearly 800 kg was not the upper limit of what Dragon could carry on F9v1.0.

Perhaps the the slide means that the increase in performance will be somewhere between an 800 kg increase and a 1580 kg increase.

Offline aga

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In CRS-1, Dragon on Falcon 9v1.0 delivered 905 kg of cargo.

where is this number from?
acc. to the crs-1 press kit (http://www.nasa.gov/pdf/694166main_SpaceXCRS-1PressKit.pdf) crs-1 dragon delivered 400 kg of cargo (it was 905 kg with packing)
42

Offline ChrisWilson68

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In CRS-1, Dragon on Falcon 9v1.0 delivered 905 kg of cargo.

where is this number from?
acc. to the crs-1 press kit (http://www.nasa.gov/pdf/694166main_SpaceXCRS-1PressKit.pdf) crs-1 dragon delivered 400 kg of cargo (it was 905 kg with packing)

Yeah, the 905 kg includes packaging.  That's the only number that's meaningful in terms of the vehicle's performance capabilities.

How much of the upmass is packaging versus useful cargo depends on the nature of the cargo and has nothing to do with the vehicle (Dragon + F9) capabilities.

Offline sublimemarsupial

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Perhaps the the slide means that the increase in performance will be somewhere between an 800 kg increase and a 1580 kg increase.

To me this is how the slide reads, that the delta between F9v1.0 and F9v1.1 is an additional 800-1580 kg (with the exact value not yet known pending performance verification in flight), not that the absolute limit is 800kg with F9v1.0 and 1580kg with v1.1

Online edkyle99

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In CRS-1, Dragon on Falcon 9v1.0 delivered 905 kg of cargo.

where is this number from?
acc. to the crs-1 press kit (http://www.nasa.gov/pdf/694166main_SpaceXCRS-1PressKit.pdf) crs-1 dragon delivered 400 kg of cargo (it was 905 kg with packing)

Yeah, the 905 kg includes packaging.  That's the only number that's meaningful in terms of the vehicle's performance capabilities.

How much of the upmass is packaging versus useful cargo depends on the nature of the cargo and has nothing to do with the vehicle (Dragon + F9) capabilities.
This is a NASA slide.  NASA cares not about the vehicle performance.  It cares about how much actual deliverable payload can be hauled to ISS.  Packing mass is the same as spacecraft dry mass in their eyes.  This is why the numbers seem low.  SpaceX can talk about the total mass, which includes the packing mass, but in doing so it "overlooks" the real payload deliverable mass capability.  BTW, these numbers seem likely to me to be pressurized cargo mass.

Progress can haul 2.5 tonnes because it carries dense propellant and water to transfer to ISS.  Much less packing mass for liquids!

 - Ed Kyle
« Last Edit: 08/15/2013 02:34 PM by edkyle99 »

Offline joek

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... Packing mass is the same as spacecraft dry mass in their eyes. ...

NASA does distinguish between the two.  NASA defines "usable cargo" and "customer cargo".  Pressurized mass is based on "customer cargo" which includes packing (and on which the $/kg is based).  That makes sense as the provider has no control over NASA packaging.
Quote from: CRS contract
1.0 SCOPE

...  Cargo combined with packing materials and/or flight support equipment is referred to as “customer cargo”.  NASA will provide external cargo to the Contractor without flight support equipment, referred to as “usable cargo.” 

2.4. CARGO INTEGRATION

The Contractor shall safely integrate NASA cargo into the cargo module and or external carrier.  NASA will provide pressurized cargo already packed to the Contractor.  NASA will provide unpressurized (external) cargo without flight support equipment to the Contractor.

ATTACHMENT V.1. GLOSSARY

Customer Cargo -- Cargo and/or payloads including packing materials, attachment hardware and/or FSE.  For internal cargo, this definition only includes systems racks and International Standard Payload Racks (ISPRs); other racks are excluded.

Usable Cargo -- Cargo and/or payloads without any packing material, attachment hardware or FSE.


Offline mlindner

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Chris what was the source of the 800kg limit on Dragon. I find that hard to believe.

My source was a recent (late July) ISS status presentation to the NASA Advisory Council by ISS Program Director Sam Scimemi.

The slide in question is attached - see the last line:

"The F9v1.1 rocket is planned to increase the upmass capability from 800 kg to 1580 kg of cargo."

Don't know whether that's total cargo or just pressurised cargo though.

I agree they are unbelievable numbers - Dragon was sold as having 3,300kg of up-mass. Progress can do 2,500kg. Maybe an example of over-optimistic SpaceX performance claims.

I'd suggest you pull the line from the article because we don't know exactly what value is being qualified here.
Internal combustion engine in space. It's just a Bad Idea.TM - Robotbeat

Offline Space Pete

I'd suggest you pull the line from the article because we don't know exactly what value is being qualified here.

Respectfully, I disagree - to me, the line in the slide is clear.

It says "The F9v1.1 rocket is planned to increase the upmass capability from 800 kg to 1580 kg of cargo". That says to me that the old limit was 800kg, and the new limit will be 1580kg.

If the line had been referring to the F9 V1.1 providing an increase of between 800kg and 1580kg, then surely it would have read "The F9v1.1 rocket is planned to increase the upmass capability by 800 kg to 1580 kg of cargo"?

Furthermore, such a statement wouldn't even make sense - how could SpaceX be designing a rocket whose performance parameters are so unknown? Of course there will always be minor differences between projected and actual performance, but a difference of 780kg (1580-800)? If true, that would suggest that SpaceX don't have any hard numbers to go by, and are effectively just upgrading the F9 and will "see what they get" at the end.
« Last Edit: 08/16/2013 11:03 AM by Space Pete »
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Online edkyle99

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... Packing mass is the same as spacecraft dry mass in their eyes. ...

NASA does distinguish between the two.  NASA defines "usable cargo" and "customer cargo".  Pressurized mass is based on "customer cargo" which includes packing (and on which the $/kg is based).  That makes sense as the provider has no control over NASA packaging.
Quote from: CRS contract
1.0 SCOPE

...  Cargo combined with packing materials and/or flight support equipment is referred to as “customer cargo”.  NASA will provide external cargo to the Contractor without flight support equipment, referred to as “usable cargo.” 

2.4. CARGO INTEGRATION

The Contractor shall safely integrate NASA cargo into the cargo module and or external carrier.  NASA will provide pressurized cargo already packed to the Contractor.  NASA will provide unpressurized (external) cargo without flight support equipment to the Contractor.

ATTACHMENT V.1. GLOSSARY

Customer Cargo -- Cargo and/or payloads including packing materials, attachment hardware and/or FSE.  For internal cargo, this definition only includes systems racks and International Standard Payload Racks (ISPRs); other racks are excluded.

Usable Cargo -- Cargo and/or payloads without any packing material, attachment hardware or FSE.

That all sounds accurate from a contractual standpoint, but the numbers on the slide don't seem to line up with that definition.  Perhaps the slide presentation was using an informal definition. 

Consider that the last Dragon, CRS-2, was reported to be filled with 847.8 kg of ISS supplies and 201.8 kg of packing materials (a total of 1,049.6 kg).  Some of that cargo was in the trunk, making the 800 kg believable to me only if it refers to actual deliverable, pressurized cargo.

 - Ed Kyle

Offline Nomadd

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 They say they're going to attempt to slow the first stage down after separation on the first 1.1 flight for recovery testing, although they won't actually recover it. Wouldn't the fuel needed for that have a bearing on the Dragon upmass capability? And, have they mentioned any other recovery hardware that might be on all flights where it isn't deleted for that last bit of payload some missions might need? There should be different ratings for F9s with recovery hardware and fuel compared to stripped down rockets.

Offline StephenB

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Respectfully, I disagree - to me, the line in the slide is clear.

It says "The F9v1.1 rocket is planned to increase the upmass capability from 800 kg to 1580 kg of cargo". That says to me that the old limit was 800kg, and the new limit will be 1580kg

Another reading would be 'anywhere from 800 kg to 1580 kg of cargo', so a delta.

Offline ChrisWilson68

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I'd suggest you pull the line from the article because we don't know exactly what value is being qualified here.

Respectfully, I disagree - to me, the line in the slide is clear.

If people are arguing about the interpretation, then it clearly isn't very clear.

I agree.  Consider two facts:

1. Many of us on here think the wording on the slide is ambiguous.

2. The interpretation of the slide claimed in the article is clearly inconsistent with known facts about what Falcon 9v1.0/Dragon have already delivered to the station.

Offline Kabloona

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To any engineer who has prepared technical briefings for NASA, or any NASA manager who has been on the receving end of such briefings, the meaning of the slide is utterly clear. The old capacity was 800 kg, the new capacity will be 1580 kg.

Not trying to diss anybody here, but the slide is totally unambiguous in its context of a NASA briefing. I guarantee you nobody in that briefing had any doubt as to its meaning.

The accuracy of the numbers is a different issue, of course.
« Last Edit: 08/16/2013 05:38 PM by Kabloona »

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