SpaceX Falcon 9 v1.1 - Dragon - CRS-5/SpX-5 -Jan. 10, 2015 - DISCUSSION

[Prober]

The focus should be extra payload to the ISS not extra fuel available to land the launcher

You think they should design and build a new larger Dragon until mid December?

not possible

what's hidden in the trunk is what I wish to see

[Darga]

Are any NASA assets going to be imaging this return attempt like some of the previous ones?

[mheney]

There's a drone in the area as we type ...

[kevin-rf]

There's a drone in the area as we type ...

Duck

[cscott]

The drone is actually currently on the west coast; the landing we here are interested in is just of the east coast.

That said, it sure would be nice to borrow it next week!

[joshcryer]

The focus should be extra payload to the ISS not extra fuel available to land the launcher

The focus for SpaceX is always to meet CRS requirements, they have no obligation to meet any payloads beyond those baseline requirements. It's also in NASA's interest and the countries interest that new technology development happens, so NASA isn't going to complain nor should it.

[baldusi]

For reusable missions, I think adding grid fins will more than make up for their weight and increase payload margin, because they add very little drag going up, but appreciable drag coming down, resulting in less fuel needed for the landing burn. Not that I calculated the numbers or anything, but just notionally, it seems likely.

see this is where things are going wrong.  CRS-5 is a contracted ISS supply mission, and that should be the total focus.  Max payload right now should be the focus with the Orbital losses.   Everyone seems to be excited with good reason, about the landing legs etc., but let's not forget the mission is supplies to the ISS, not reusability.

The focus should be extra payload to the ISS not extra fuel available to land the launcher

Dragon is most certainly volume limited for Dragon missions to the ISS (Enchanced Cygnus might have higher payload at 3X the pressurized volume). And they really can't get their first stage back if it has any issues going up. So I believe that the return demonstration will not affect anything at all on mission assurance.

[Roy_H]

May be a silly question here but I assume Dragon is volume limited because of it's shape, and the shape is required because it has to return back and is aero dynamically stable due to this shape. Cygnus doesn't return so there are no compromises in terms of the shape and volume.

Am I correct in my thinking?

The focus should be extra payload to the ISS not extra fuel available to land the launcher

That's all well and good, but Dragon, much more so than Cygnus, is volume limited, not weight limited.

Generally, but the constraints on Dragon's volume and size aren't due just to the requirement/feature that it can return from orbit intact, but are also due to how it is intended to eventually carry people as well.

Of course, it is quite possible that if SpaceX had had the Falcon 9 1.1 from the start, they just might have designed Dragon somewhat bigger.  Or maybe not: the base of Dragon fits the diameter of Falcon, and Falcon's diameter is what American highways can tolerate.

" if SpaceX had had the Falcon 9 1.1 from the start, they just might have designed Dragon somewhat bigger."

No, SpaceX planned on Falcon 9 v1.1 all along, and the 1.0 versions flew with reduced load to the ISS. SpaceX would never be able to fulfill their contract with NASA if they stayed with v1.0.

[Avron]

The focus should be extra payload to the ISS not extra fuel available to land the launcher

The focus for SpaceX is always to meet CRS requirements, they have no obligation to meet any payloads beyond those baseline requirements. It's also in NASA's interest and the countries interest that new technology development happens, so NASA isn't going to complain nor should it.

I think we always need to understand that its a partnership between a gov. agency and SpaceX. with SpaceX mission "to revolutionize space technology".

[Kaputnik]

No, SpaceX planned on Falcon 9 v1.1 all along, and the 1.0 versions flew with reduced load to the ISS. SpaceX would never be able to fulfill their contract with NASA if they stayed with v1.0.

I think you may be confusing v1.1 with block II. I'm pretty sure SpaceX didn't set out to fly only five F9s then do a complete overhaul of the engines, thrust structure, tankage, and TEL. I mean, why would you do that?

[nadreck]

No, SpaceX planned on Falcon 9 v1.1 all along, and the 1.0 versions flew with reduced load to the ISS. SpaceX would never be able to fulfill their contract with NASA if they stayed with v1.0.

I think you may be confusing v1.1 with block II. I'm pretty sure SpaceX didn't set out to fly only five F9s then do a complete overhaul of the engines, thrust structure, tankage, and TEL. I mean, why would you do that?

Because the design of the F9 and F9 V1.1 is a highly iterative design. It can be argued that several changes have crept in after the first v1.1 but since those changes were not major structural or propulsion changes they didn't feel a need to elaborate on it with moniker like V1.2

[Prober]

The focus should be extra payload to the ISS not extra fuel available to land the launcher

The focus for SpaceX is always to meet CRS requirements, they have no obligation to meet any payloads beyond those baseline requirements. It's also in NASA's interest and the countries interest that new technology development happens, so NASA isn't going to complain nor should it.

I think we always need to understand that its a partnership between a gov. agency and SpaceX. with SpaceX mission "to revolutionize space technology".

I've obtained the insight into the answers that I was looking for regarding cargo.  It came from Jim in another thread regarding Tang, TP etc.
 

[mme]

The focus should be extra payload to the ISS not extra fuel available to land the launcher
...

I've obtained the insight into the answers that I was looking for regarding cargo.  It came from Jim in another thread regarding Tang, TP etc.
 

It has nothing to do with whether the cargo is just Tang, T-shirts, and TP (and CATS).  As many have pointed out, it has to do with meeting the requirements of the mission.  Your initial complaint is full of assumptions. First that NASA wants more cargo on CRS-5.  Second that the F9 and Dragon can carry this imagined additional cargo.  Third that SpaceX is that refusing to deliver the cargo that NASA wants.  Fourth is that the reason that SpaceX is refusing to  carry this additional cargo is so they can try to land the first stage on a barge. That's a lot of assuming.

[Henchman21]

any idea why things have been quite recently?

[Prober]

The focus should be extra payload to the ISS not extra fuel available to land the launcher
...

I've obtained the insight into the answers that I was looking for regarding cargo.  It came from Jim in another thread regarding Tang, TP etc.
 

It has nothing to do with whether the cargo is just Tang, T-shirts, and TP (and CATS).  As many have pointed out, it has to do with meeting the requirements of the mission.  Your initial complaint is full of assumptions. First that NASA wants more cargo on CRS-5.  Second that the F9 and Dragon can carry this imagined additional cargo.  Third that SpaceX is that refusing to deliver the cargo that NASA wants.  Fourth is that the reason that SpaceX is refusing to  carry this additional cargo is so they can try to land the first stage on a barge. That's a lot of assuming.

your post is full of assuming and twisting of my words

[meekGee]

No, SpaceX planned on Falcon 9 v1.1 all along, and the 1.0 versions flew with reduced load to the ISS. SpaceX would never be able to fulfill their contract with NASA if they stayed with v1.0.

I think you may be confusing v1.1 with block II. I'm pretty sure SpaceX didn't set out to fly only five F9s then do a complete overhaul of the engines, thrust structure, tankage, and TEL. I mean, why would you do that?

Absolutely they did.  I spoke with someone in the know within SpaceX just after the first flight of F9 1.0, and already an inner group there knew about propulsive RTLS.

F9 1.0 was a learning iteration.

[ugordan]

I'm pretty sure SpaceX didn't set out to fly only five F9s then do a complete overhaul of the engines, thrust structure, tankage, and TEL. I mean, why would you do that?

1.5 years before F9 ever flew, the User Guide talked of a weight reduction campaign and engine thrust upgrade for the Block 2. According to SpaceXer comments I've seen elsewhere, v1.0 was very much a "battleship" approach where certain design decisions were made consciously with the primary intent of getting off the ground as fast as possible instead of making the design more optimal from the start. The 3x3 engine pattern was just one such area of planned improvement.

[meekGee]

I'm pretty sure SpaceX didn't set out to fly only five F9s then do a complete overhaul of the engines, thrust structure, tankage, and TEL. I mean, why would you do that?

1.5 years before F9 ever flew, the User Guide talked of a weight reduction campaign and engine thrust upgrade for the Block 2. According to SpaceXer comments I've seen elsewhere, v1.0 was very much a "battleship" approach where certain design decisions were made consciously with the primary intent of getting off the ground as fast as possible instead of making the design more optimal from the start. The 3x3 engine pattern was just one such area of planned improvement.

Yup.  After F1, they had a flexible approach.  I remember F5 (Delta-II class) was the next thing they were going to build, but already there was an optional F9, even on public literature.

As things happened, they got a shot at jumping straight to F9, and the rest is history, but F9 1.0 was the "end of a line", not the beginning of one.  Once the business path to F9-class vehicles was set, they already started down the path of RTLS and F9 1.1.

... and, we're OT.  Continue in the general SpaceX thread.

[guckyfan]

It has nothing to do with whether the cargo is just Tang, T-shirts, and TP (and CATS).  As many have pointed out, it has to do with meeting the requirements of the mission.  Your initial complaint is full of assumptions. First that NASA wants more cargo on CRS-5.  Second that the F9 and Dragon can carry this imagined additional cargo.  Third that SpaceX is that refusing to deliver the cargo that NASA wants.  Fourth is that the reason that SpaceX is refusing to  carry this additional cargo is so they can try to land the first stage on a barge. That's a lot of assuming.

your post is full of assuming and twisting of my words

Then please explain what you were talking about. Certainly I don't get it.

[Sohl]

any idea why things have been quite recently?

Yes, it's almost as if there was a new NASA space flight that people on NASAspaceflight.com wanted to talk about in other subforums.