Space X to build reusable launch vehicle

Skipjack · Post by **Skipjack** » Tue Oct 25, 2011 5:46 pm

To buy you need to have money to pay, the source of money makes the difference, paying by tax money to help to develop a private enterprise is a subsidizing.

As I said elsewhere, then you can just as well as the government to stop paying for anything including and especially the military and the fracking banks, or the fracking car industry.

charliem · Post by **charliem** » Tue Oct 25, 2011 5:48 pm

GIThruster wrote:
charliem wrote:So, if we made a new Falcon9VTVL with these engines, total thrust (vacuum) would be 1,395,000 lbf, or a 25.7% more.
IIRC, the optimization in Merlin 1D is they extended the cone to get more thrust in vacuum. It would get less thrust at sea level so you don't want to use them for the first stage. They're intended for second stage only.

Hi GIThruster.

If you follow the link I left before, or this one you'll see that the Merlin 1D, like its 1C older brother, is going to have 2 versions. The plan is to fit the Falcon 9 first stage with the atmospheric version from the seventh flight onwards (140.000 lbf thrust at sea level per 9).

GIThruster · Post by **GIThruster** » Tue Oct 25, 2011 6:42 pm

Thanks for the correction.

Your calc does simplify some things. Would be good to see separate calcs for both stages and the capsule, but it does indeed seem they can do as is in the vid.

Skip, I'm surprised they've abandoned the sea retrieval. Do you have a source on that? I missed that entirely. And does anyone know where is the planned landing zone? I think the main production facility is in Hawthorne, CA.

Skipjack · Post by **Skipjack** » Tue Oct 25, 2011 8:20 pm

Skip, I'm surprised they've abandoned the sea retrieval. Do you have a source on that? I missed that entirely.

I am sorry, I cant remember anymore where I read that. It could have been some interview with Elon Musk somewhere. IIRC, they were really frustrated with how difficult the sea retrieval turned out to be.

And does anyone know where is the planned landing zone? I think the main production facility is in Hawthorne, CA.

SpaceX have been playing this card rather close to their bodies so far. Some speculate that they are planning to return to the launch site. Others speculate that their plans to build a new spaceport in Texas has something to do with it...
There also is a Blue Origin patent (which wont hold, btw) for landing a VTOL vehicle first stage on an off shore barge.
So something like that could be an options as well.
There has not been any official clarification on the matter that I am aware off. So all we can do at the moment is speculate.
I think that it could be quite possible that they will first try to simply land somewhere downrange (e.g. on a barge). And then work their way towards flying back to the launch site when they further optimize their engines and vehicles. But that really is just speculation.

quixote · Post by **quixote** » Tue Oct 25, 2011 11:29 pm

http://www.newscientist.com/blogs/short ... nline-news

The original concept seemed simple: the spent first stage would parachute down to a splashdown offshore, where it would be recovered by boat and hauled back to shore for refurbishment and reuse.

Overall, the idea seemed like a clumsy makeshift, and some doubted that there would be much real benefit, but it didn't seem ridiculous – just challenging.

The only problem was, it didn't work. At the Space Access conference in April, Gwynne Shotwell, SpaceX's president, admitted: "We have recovered pieces of the first stages." The first stages weren't even getting as far as deploying their parachutes – they were breaking up during atmospheric re-entry.

krenshala · Post by **krenshala** » Wed Oct 26, 2011 12:26 am

My guess is that they will launch in CA and land in TX, launch in TX and land in FL, and/or launch in FL and land in/near the Bahamas. They might even be able to launch from Kwajilain and land in CA (but I haven't looked at a map to see if that is anywhere close to possible with the numbers you guys have posted, and I'm guessing they are two far apart).

GIThruster · Post by **GIThruster** » Wed Oct 26, 2011 12:36 am

They don't have launch facilities in TX, just CA, FL and Kwajilain. Reprocessing is in CA, so landing in NV would be useful. Can't help but wonder if they'll make a move into Spaceport America with this new recovery scheme.

Skipjack · Post by **Skipjack** » Wed Oct 26, 2011 1:22 am

Interestingly the new scientist article claims that the first stage will return to the launch site...
I wonder whether that was just a guess based on the video, or whether there was actual information that caused them to write that.
Based on past experiences with New Scientist, it is probably the former.

GIThruster · Post by **GIThruster** » Wed Oct 26, 2011 1:38 am

To return to the launch site the first stage would need an essentially vertical launch profile, which seems to me extremely doubtful. Seems to me (without calcs) the second stage could not possibly give all the horizontal dv. I'd guess it was a presumption but I'd be thrilled to find I'm wrong.

Skipjack · Post by **Skipjack** » Wed Oct 26, 2011 2:50 am

Maybe the more powerful second stage will enable them to stage earlier, so that the first stage wont have that far to fly back?
Maybe they will make the second stage bigger and the first stage smaller?

rcain · Post by **rcain** » Wed Oct 26, 2011 9:55 pm

Skipjack wrote:
To buy you need to have money to pay, the source of money makes the difference, paying by tax money to help to develop a private enterprise is a subsidizing.
As I said elsewhere, then you can just as well as the government to stop paying for anything including and especially the military and the fracking banks, or the fracking car industry.

... not to mention 'fracking' consumers with their wound-up mortgages, insatiable credit card spending and haughty expectations ...

(sidles back out again, to avoid getting wound up in a discussion in the dreaded 'general' section).

Skipjack · Post by **Skipjack** » Wed Oct 26, 2011 10:24 pm

... not to mention 'fracking' consumers with their wound-up mortgages, insatiable credit card spending and haughty expectations ...

Well the mortage catastrophy was mainly thanks to the banks that made some really bad choices driving the mortage rates up for the consumers to levels that they could not pay them anymore...
The vast majority of those that failed to pay their mortages could have continued paying the rates that they signed off on just fine...
The credit card crisis has yet to come and again that is the fault of the banks. They did not have to basically give away a credit card with every happy meal.

rcain · Post by **rcain** » Wed Oct 26, 2011 10:35 pm

Skipjack wrote:
... not to mention 'fracking' consumers with their wound-up mortgages, insatiable credit card spending and haughty expectations ...
Well the mortage catastrophy was mainly thanks to the banks that made some really bad choices driving the mortage rates up for the consumers to levels that they could not pay them anymore...
The vast majority of those that failed to pay their mortages could have continued paying the rates that they signed off on just fine...
The credit card crisis has yet to come and again that is the fault of the banks. They did not have to basically give away a credit card with every happy meal.

In actual fact, it was mainly the wretched mortgagees (consumers), winding up the house price index so much, in the expectation of cashing in somehow on greater stored value later. greed is pretty universal it seems. some of my best friends (not) are bankers, as well as being consumers.

but please, i do not wish to divert you from the conversation about rockets. please continue, it was much more interesting

Skipjack · Post by **Skipjack** » Thu Oct 27, 2011 12:06 am

They don't have launch facilities in TX, just CA, FL and Kwajilain.

They dont have launch facilities in Texas YET

AFAIK, they are planning to have a spaceport there in the near future though.
The spaceport in Virginia is also trying to get more customers.

charliem · Post by **charliem** » Thu Oct 27, 2011 11:46 am

GIThruster wrote:To return to the launch site the first stage would need an essentially vertical launch profile, which seems to me extremely doubtful. Seems to me (without calcs) the second stage could not possibly give all the horizontal dv. I'd guess it was a presumption but I'd be thrilled to find I'm wrong.

Well, my BOE calcs say that the second stage, in its present version, cannot give that much delta-v, and I doubt very much that the new Merlin 1D Vacuum will be able to change that (its Isp is not going to grow very much), but I dont think that will be necessary.

Even following the same flight profile used for the Falcon 9 second launch, after separation the new 1st stage should retain some delta-v capability, at least 2100 m/s, maybe as much as 3000 m/s, and for powered landing is enough with less than 500 m/s so there's some slack that could be used for course reversing.

I suspect that is not going to be the hardest challenge, but controlling the reentry so the stage doesn't snap, and to keep it stable and vertical for landing.

Falcon 9 reaches a much higher speed and altitude than most of the boosters used in other launchers (for example the Space Shuttle), and that means stronger forces at reentry.

It is also much taller and slender than all the vehicles we've seen to do vertical landings until now.

Even so I'm hopeful.