[WIP] KerbX - A SpaceX analogue for KSP

[XNerd_Bomber]

or they are testing the falcon heavy

Well, considering that a Falcon Heavy, is basically a Falcon 9 v1.1, with two more first stages attached, and they have yet to launch a Falcon 9 v1.1, it's safe to say that they're just testing the Falcon 9 v1.1.

[CAPFlyer]

I believe we've seen a re-designation of the Falcon 9 v1.1 to the F9-R (or Falcon 9-R) by SpaceX in that tweet posted previously. Makes sense anyway since this will be the only version made and they don't plan on offering a "non-reusable" version once they prove out the design.

[NannerManCan]

Do you think we'll see video's of the attempted landings? Aren't there already on board camera's on the falcon 9? It would look pretty cool watching it activate its engines right before landing in the water

[con247]

I believe we've seen a re-designation of the Falcon 9 v1.1 to the F9-R (or Falcon 9-R) by SpaceX in that tweet posted previously. Makes sense anyway since this will be the only version made and they don't plan on offering a "non-reusable" version once they prove out the design.

For extra payload to orbit some will be disposable. Reusability takes a lot of payload capacity away.

[Zaran]

For extra payload to orbit some will be disposable. Reusability takes a lot of payload capacity away.

Normally for rockets such as the Falcon 9 you get 1-2.5% of your pad mass into orbit, the Falcon 9v1.1 in disposable mode can take 3-4% mass to orbit, they use this extra 2% margin for return systems in the F9-R. Overall the rocket still has more mass to orbit capability than the original Falcon 9 even in -R mode taking 1-2.5% to orbit.

[Netris]

But, if I understand correctly, it'll have to load more fuel to return to earth. Wouldn't be less efficient ? I mean, if you have some fuel you don't use for the ascent, you've an extra weight in your rocket. Is it that cheaper ?

[Zaran]

It is, the rocket costs about $50 million USD to make, the fuel costs $200,000. All these margins and factors for return are built into the new Falcon 9, take the new Merlins, they have the best thrust to weight ratio of any rocket engine in the world, the first stage tank, as far as I know, weighs less than an Falcon 9 v1.0 first stage of that size would thanks to clever engineering techniques and materials used.

Simply put, the Falcon 9-R is the most technically advanced rocket ever, in both the fact that it will return to launch site and the underlying engineering used on it.

[Netris]

Wouldn't be cheaper to have a few parachutes than 200 000$ of fuel ? That way you could use that fuel to launch a bit heavier payloads.

[BioSehnsucht]

The idea is to fly it back to the launch site and reuse it quickly (like an airplane, in that sense) rather than after fishing it out of the water ir wherever it landed and then transporting it back to launch site (like shuttle)

[Netris]

That makes sense ^^

[thefeeblespark]

Wouldn't be cheaper to have a few parachutes than 200 000$ of fuel ? That way you could use that fuel to launch a bit heavier payloads.

And to an extent, parachutes can be troublesome.

1. They have to be EXTREMELY big. Think of how big they have to be to stop the dragon, and then imagine it for the first stage...

2. They have to get out FAST. That means large explosive bolts, which are somewhat dangerous when you are dealing with rocket fuel...

[Zaran]

I should note, its $200,000 of fuel for the whole rocket, both stages fully topped up not JUST for the return.

Also they tried parachutes on flight 1 and 2, those rockets are at the bottom on the ocean in little pieces were they broke up on impact.

[con247]

Wouldn't be cheaper to have a few parachutes than 200 000$ of fuel ? That way you could use that fuel to launch a bit heavier payloads.

Parachutes would basically require a water landing. Salt water would ruin the rocket.

[B787_300]

Salt water would ruin the rocket.

Oh? what about the SRBs for the Space Shuttle, all salt water means is that you have to do more cleaning and more checks for corrosion. there is nothing about landing in salt water that means you cannot reuse a rocket, provided that the landing is gentle enough.

[CAPFlyer]

Oh? what about the SRBs for the Space Shuttle, all salt water means is that you have to do more cleaning and more checks for corrosion. there is nothing about landing in salt water that means you cannot reuse a rocket, provided that the landing is gentle enough.

The SRB's were specially built to deal with the salt water and had to undergo extensive (and expensive) cleaning immediately upon return to Kennedy or else corrosion would have set in. Even with all that in place, they were only able to reuse the SRB's a few times before they were unable to reuse them due to corrosion from the salt water. They only saved about 10% over building new casings by reusing them in the end, especially after the redesign following Challenger. So much of the segments had to be replaced after every flight that you were only reusing the part which was the most inexpensive to make - the casings themselves. On the other hand, they saved 50% or more on the SSME's by reusing them because there was no corrosive exposure during flight and the decontamination process was not as extensive.

As it is, the only reason Elon and the SpaceX team think that the F9-R will work is simply because the flights to date have had sufficient fuel left over to make a powered return anyway. Consider that both the Atlas V and Centaur upper stages are routinely expended with between 2% and 5% useable fuel remaining on them. Sometimes the Centaur has been deorbited with the equivalent of 20% of its usable fuel capacity left (the vehicle wasn't fully fueled on liftoff because there was not need for that much fuel given the payload and launch profile). SpaceX determined that even with 5% of the fuel left, the F9 (original) first stage and the F9 Upper Stage could return to a powered landing using 1 Merlin 1D and the Upper Stage using a pair of SuperDraco thrusters. By expanding the fuel capacity on the vehicle and, uprating all the engines you achieve a larger safety margin while not compromising the payload capability of the craft.

[CardBoardBoxProcessor]

it's... so beautiful.

[B787_300]

where did you get that photo?

[CardBoardBoxProcessor]

The man himself. Elon Musk (twitter)

[Netris]

He's not afraid

[BFGfreak]

As it is, the only reason Elon and the SpaceX team think that the F9-R will work is simply because the flights to date have had sufficient fuel left over to make a powered return anyway. Consider that both the Atlas V and Centaur upper stages are routinely expended with between 2% and 5% useable fuel remaining on them. Sometimes the Centaur has been deorbited with the equivalent of 20% of its usable fuel capacity left (the vehicle wasn't fully fueled on liftoff because there was not need for that much fuel given the payload and launch profile). SpaceX determined that even with 5% of the fuel left, the F9 (original) first stage and the F9 Upper Stage could return to a powered landing using 1 Merlin 1D and the Upper Stage using a pair of SuperDraco thrusters. By expanding the fuel capacity on the vehicle and, uprating all the engines you achieve a larger safety margin while not compromising the payload capability of the craft.

I can say that even in KSP this is very much true, I've had instances where I could have used the F9 to achieve orbit with my smaller payloads, so there is enough fuel to do a suicide burn if I so felt like trying. I imagine that if parts surviving the fall ever got added back into the inventory in a future version of KSP, such a system would be a godsend for us economical space industries, especially given the cost of our more....spectacular endeavors.

Also cool picture.

[Zaran]

Wanna see some sexy leg?..

F9R (pronounced F-niner) shows a little leg. Design is a nested, telescoping piston w A frame.

[NannerManCan]

Aw Sweet, can't wait for more grasshopper v1.1 flights and F9R, also Falcon Heavy will be awesome

Edited May 2, 2013 by NannerManCan

[Netris]

Aw Sweet, can't wait for more grasshopper v1.1 flights and F9R

I can't wait for F9H

[B787_300]

I want to see how it actually attaches to the rocket, as i think Borklund does.

[CAPFlyer]

I want to see how it actually attaches to the rocket, as i think Borklund does.

The A-frame "legs" attach to the bottom of the rocket. The top of the "A" is the foot (you can see the plate between the people). The Ram (and thus shock absorber) attaches to the F9R where the base of the nesting cut-out is in the A-frame. A simple, strong, and extremely effective design.