SpaceX Falcon 9/Dragon COTS Demo (C2+) GENERAL DISCUSSION

[FinalFrontier]

cargo there is removed by the SSRMS and placed outside the station as needed. No internally needed cargo is carried in the trunk section.
and the soviets never used it for manned missions as originally intended.

So what is carried in the trunk if it's just going to be placed outside the station? Does that mean that the trunk doesn't have a hatch at all, or is it accessible after it's berthed to the station?

Its in my original post but I don't mind reposting.

No the trunk has no hatch, the back end of the trunk is totally open to space. The the trunk itself is simply a barrel section of metal with various components for the solar panels and electrical in the top most section below dragon as well as an internal lateral frame for mounting external cargo.

It is 100% accessible while berthed, the SSRMS along with dexter are used to remove external hardware from it.

As to what it carrys:

- ORUS (orbitaln replacement units)

-Exposed experiment modules

-Demonstrators
-Pump modules, radiator replacement (where applicable based on sizing), ect


Basically anything you need in terms of external hardware for station is in the trunk, as the trunk is open to space and is not a pressurized or returnable/reusable part of the dragon spacecraft itself.

[manboy]

So what is carried in the trunk if it's just going to be placed outside the station?

Unpressurizd cargo. Sometimes experiments, other times it will be hardware.

Does that mean that the trunk doesn't have a hatch at all, or is it accessible after it's berthed to the station?

There's no hatch. At launch the bottom of the trunk is covered by the top of the second-stage. After Dragon separates from the second stage the bottom of the trunk is exposed for the remainder of the flight. The robot arm removes the unpressurized cargo from the bottom of the trunk.

And what about the extended trunk design, what's the point if it's only there for support systems that already fit in the regular design?

Its for larger unpressurized cargo.

[Idiomatic]

I bet it could bring up more ssrms.

[FinalFrontier]

I bet it could bring up more ssrms.

No.

[manboy]

I bet it could bring up more ssrms.

No.

Musk did say the trunk could be stretched but I wonder how long you could make it?

[Idiomatic]

I bet it could bring up more ssrms.

No.

I mean, I assume it isn't needed. But the Canadarm2 has a mass of only 1,800kg. No reason you couldn't bring up more. Why No? Dextre doesn't look very heavy or bulky either.

[manboy]

I bet it could bring up more ssrms.

No.

I mean, I assume it isn't needed. But the Canadarm2 has a mass of only 1,800kg. No reason you couldn't bring up more. Why No? Dextre doesn't look very heavy or bulky either.

Volume would be the problem.

[joek]

Musk did say the trunk could be stretched but I wonder how long you could make it?

DragonLab specs extended trunk @4.3m length (+2m from standard length of 2.3m); no idea what the effective limit is.

[ArbitraryConstant]

Musk did say the trunk could be stretched but I wonder how long you could make it?

DragonLab specs extended trunk @4.3m length (+2m from standard length of 2.3m); no idea what the effective limit is.

heh

It occurs to me that Super Draco's thrust (67 kN) is pretty close to Apollo Service Module's main engine (91 kN), and would probably be even closer with a proper vac-optimized expansion nozzle.

No demand for it now, but if they ever wanted to that would make a pretty good Dragon service module.

[sanman]

But if you're going to keep making the trunk bigger, then why not just put rockets there, since it's in the back already? (aka. service module)

[Idiomatic]

I bet it could bring up more ssrms.

No.

I mean, I assume it isn't needed. But the Canadarm2 has a mass of only 1,800kg. No reason you couldn't bring up more. Why No? Dextre doesn't look very heavy or bulky either.

Volume would be the problem.

Myeh. Elon seemed to think that the trunk was very extendable.

[manboy]

I bet it could bring up more ssrms.

No.

I mean, I assume it isn't needed. But the Canadarm2 has a mass of only 1,800kg. No reason you couldn't bring up more. Why No? Dextre doesn't look very heavy or bulky either.

Volume would be the problem.

Myeh. Elon seemed to think that the trunk was very extendable.

I feel as though joek covered this.

[joek]

Myeh. Elon seemed to think that the trunk was very extendable.

Volume or length in any given dimension is not the only (or necessarily the most important) constraint.

[Nathan]

I bet it could bring up more ssrms.

No.

I mean, I assume it isn't needed. But the Canadarm2 has a mass of only 1,800kg. No reason you couldn't bring up more. Why No? Dextre doesn't look very heavy or bulky either.

Volume would be the problem.

Myeh. Elon seemed to think that the trunk was very extendable.

One would assume a custom trunk could be built if the customer was willing to pay.

[Silmfeanor]

But if you're going to keep making the trunk bigger, then why not just put rockets there, since it's in the back already? (aka. service module)

Excuse me? What do you mean?
Rockets in the trunk would require new connections and disconnects aswell as new hardware, thruster attachment points, software and would shrink the purpose of the trunk ( ie bringing unpressurized cargo up )

[Jim]

Myeh. Elon seemed to think that the trunk was very extendable.

Still doesn't mean it can carry an SSRMS?  The loads are different than the shuttle. 

Also, why?  There is no need for another one.

[FinalFrontier]

But if you're going to keep making the trunk bigger, then why not just put rockets there, since it's in the back already? (aka. service module)

Un-needed as well as a hindrance and detriment to the design.

[Dave G]

The the trunk itself is simply a barrel section of metal with various components for the solar panels and ...

I thought the trunk, interstage, and skirt were composite.

[FinalFrontier]

The the trunk itself is simply a barrel section of metal with various components for the solar panels and ...

I thought the trunk, interstage, and skirt were composite.

I used metal as a loose term not sure what it's made out of exactly. Basically trying to point out its a barrel section of thin re-enforced material, not some thick pressurized monolith that's integrated into the vehicle itself, thats all.

[peter-b]

I used metal as a loose term not sure what it's made out of exactly. Basically trying to point out its a barrel section of thin re-enforced material, not some thick pressurized monolith that's integrated into the vehicle itself, thats all.

If I remember correctly, the Dragon trunk is a composite (probably carbon fibre-reinforced polymer) layup built on the same former as the Falcon 9 interstages. I may be incorrect, so don't quote me on this.