Author Topic: SpaceX Falcon 9 v1.1 - Jason 3 - SLC-4E Vandenberg - Jan 17, 2016 - DISCUSSION (Read 594345 times)

Lars-J · « **Reply #620 on:** 01/14/2016 12:59 am »

Well we know at least one upcoming mission will fly with tanks partially loaded as things are right now - the Dragon 2 in-flight abort with the 3-engined stage currently in storage at VAFB. (Unless those plans change, that mission has been punted down the line a bit)

Dante80 · « **Reply #621 on:** 01/14/2016 01:51 am »

https://www.flickr.com/photos/nasakennedy/sets/72157651824508130

New photos of Jason-3 encapsulation

Steven Pietrobon · « **Reply #622 on:** 01/14/2016 04:16 am »

Quote from: Semmel on 01/13/2016 07:53 am

But only if the thrust of the first stage at liftoff has so little margin that it cant lift a full first stage plus full larger second stage plus heavy LEO satellite. Or in other words, the thrust must be such that it is possible to lift large rocket + GTO sat but not large rocket + LEO sat. The difference is pretty small, not sure how you would end up with a rocket like that.

That's not the case. In both cases upper stage plus propellant plus payload mass is identical. Thus, the first stage experiences the same acceleration.

NovaSilisko · « **Reply #623 on:** 01/14/2016 04:43 am »

Quote from: Dante80 on 01/14/2016 01:51 am

https://www.flickr.com/photos/nasakennedy/sets/72157651824508130

New photos of Jason-3 encapsulation

Feels nice to see the NASA meatball on a Falcon fairing. A bigger one than was on DSCOVR - you could barely make it out back then.

Oersted · « **Reply #624 on:** 01/14/2016 09:46 am »

Here is a thought I would like to throw out there...

If SpaceX nails the barge landing, what keeps them from trying to refly the stage and basically use it for their first reflight test?

Fuel and launch costs are no biggy.

Vandenberg does not present huge scheduling problems, I think.

The stage is not one they want to preserve after a Jason 3 successful barge landing since it is neither the first historical stage that landed nor the most recent version of the Falcon that they would want to analyse in depth after landing.

If reflight (with a dummy second stage plus payload) and a second landing works out well, the stage will be a worthy addition to the Smithsonian and it will bode well for reflight attempts of the new Falcon version.

Looks to me like an almost free attempt at nailing reuse without endangering a proper payload.

Alastor · « **Reply #625 on:** 01/14/2016 02:03 pm »

Free or not, there is no use in trying to refly a first stage if you know that it won't work.
I would go as far as stating that it's useless trying it if you don't know that it actually has a chance to work.

SX was until now focused on trying to land anything. they are ow focused on trying to repeat that success, and I very much doubt they have had the opportunity to make sure that anything is ready to fly again beyond that point.

Of course, there is always a chance that upon inspection of the landed stages they discover that it seems indeed fine to fly again, but according to murphy's law, it is very unlikely to happen.

So you can probably expect them to rather use these first landings as opportunities to make small improvements and to explore the failure tree of the vehicle, probably making at least some destructive testing and so on, to maximize the chance of a successfull relaunch later down the line.

We know that they have not had the opportunity to do as much of that as the engineers might have wanted to do on the first landed first stage, as it will go to a museum (don't get me wrong, that's a good move, that's perfect PR : "SpaceX, making history", etc).

Expect the next landed first stage to be torn down to pieces ! There probably won't be much left to fly back once they are done with it.

Jet Black · « **Reply #626 on:** 01/14/2016 02:16 pm »

Quote from: Oersted on 01/14/2016 09:46 am

If SpaceX nails the barge landing, what keeps them from trying to refly the stage and basically use it for their first reflight test?

It depends very much on what they will learn from doing so. While fuel and launch costs may be small, staff time often isn't both in a direct financial sense, and also the sense that they could be doing something more productive.

Oersted · « **Reply #627 on:** 01/14/2016 06:04 pm »

Quote from: Alastor on 01/14/2016 02:03 pm

Free or not, there is no use in trying to refly a first stage if you know that it won't work.
I would go as far as stating that it's useless trying it if you don't know that it actually has a chance to work.

I thi k their stated goal is that the first stages should be able to refly after very little refurbishment. So their expectation would surely be that a stage can be reflown after not much more than a refill.

Johnnyhinbos · « **Reply #628 on:** 01/14/2016 11:59 pm »

FYI, INTL Freedom is on the move...

Lar · « **Reply #629 on:** 01/15/2016 04:05 am »

Not the party thread. Howling aether... they would have lived if posted there.

benson125 · « **Reply #630 on:** 01/15/2016 08:17 am »

NRC also headed out. Interesting to note destination of each.

Alastor · « **Reply #631 on:** 01/15/2016 08:20 am »

Quote from: Oersted on 01/14/2016 06:04 pm

Quote from: Alastor on 01/14/2016 02:03 pm
Free or not, there is no use in trying to refly a first stage if you know that it won't work.
I would go as far as stating that it's useless trying it if you don't know that it actually has a chance to work.

I think their stated goal is that the first stages should be able to refly after very little refurbishment. So their expectation would surely be that a stage can be reflown after not much more than a refill.

Surely, but they never had the opportunity to inspect a landed stage before. Such devices can very much be considered as experiments, and as an experimentalist, I can tell you that an experiment doesn't ever behave exactly as you thought the first (or couple of first) time(s) !

My point is, they will most definitely at least have to make a few adjustments before they can reach their goal and refly a first stage at low cost. And this is precisely the purpose of these first vehicles : To help identify these adjustments that have to be made, or those that could be usefull.

Antilope7724 · « **Reply #632 on:** 01/15/2016 12:08 pm »

Looks like we have a series of Pacific storms headed for California with showers predicted for Saturday, Sunday, Monday and Tuesday. Hopefully SpaceX can get the launch off if it coincides with a gap between storm systems.

Johnnyhinbos · « **Reply #633 on:** 01/15/2016 12:28 pm »

Sea state isn't predicted to be so great at LZ for sunday. Here's the marine forecast for Santa Cruz Is to San Clemente Is, between 60NM and 150NM offshore.

Norm Hartnett · « **Reply #634 on:** 01/15/2016 12:30 pm »

I'm up north in Cal. but our local forecasters are talking about 15ft swells and 30ft breakers off southern SF.

Antilope7724 · « **Reply #635 on:** 01/15/2016 12:56 pm »

With conditions like that in the LZ, maybe they should just practice a water landing and save having to make barge repairs.

JasonAW3 · « **Reply #636 on:** 01/15/2016 01:24 pm »

Quote from: Antilope7724 on 01/15/2016 12:56 pm

With conditions like that in the LZ, maybe they should just practice a water landing and save having to make barge repairs.

I still say they should use a SWATH hulled craft. Minimizes pitch and roll significantly. Kind of like the big rigs in the gulf...

Johnnyhinbos · « **Reply #637 on:** 01/15/2016 02:22 pm »

Quote from: JasonAW3 on 01/15/2016 01:24 pm

Quote from: Antilope7724 on 01/15/2016 12:56 pm
With conditions like that in the LZ, maybe they should just practice a water landing and save having to make barge repairs.

I still say they should use a SWATH hulled craft. Minimizes pitch and roll significantly. Kind of like the big rigs in the gulf...

Is that a jack-up barge like vessel? I think the water depth at the LZ might be too deep. IIRC, it's ~3,000' deep there - but don't quote me with that depth!

rsdavis9 · « **Reply #638 on:** 01/15/2016 02:51 pm »

I don't have the exact long/lat but eyeing this chart (which is in fathoms) it looks like 2000 fathoms or 12000 feet. Its right on the edge of the cont. shelf so a little bit makes a big difference.
http://www.nauticalchartsonline.com/chart/zoom?chart=18022

Lee Jay · « **Reply #639 on:** 01/15/2016 02:59 pm »

Quote from: JasonAW3 on 01/15/2016 01:24 pm

Quote from: Antilope7724 on 01/15/2016 12:56 pm
With conditions like that in the LZ, maybe they should just practice a water landing and save having to make barge repairs.

I still say they should use a SWATH hulled craft. Minimizes pitch and roll significantly. Kind of like the big rigs in the gulf...

The best way to minimize pitch and roll in heavy seas is a semi-submersible, i.e. SeaLaunch.