SpaceX Falcon 9 v1.1 - Jason 3 - SLC-4E Vandenberg - Jan 17, 2016 - DISCUSSION

[Lars_J]

A mission is successful if the primary payload is within its 3 sigma predicted contractual orbit elements.  Jason-3 is a 2-burn mission.

I'll wait for Jim on this. 
But if the mission requires 2 burns then ver 1.0 should never have won this bid.  Don't think the merlin on ver 1.0 could restart 

The COTS-1 mission demonstrated M1C-Vac restart.

[JBF]

The COTS-1 mission demonstrated M1C-Vac restart.

I wonder what changed that caused an issue.

[cambrianera]

The COTS-1 mission demonstrated M1C-Vac restart.

I wonder what changed that caused an issue.

I think it's a shared curiosity.
Anyway the engine is different; the thrust is doubled!

[woods170]

Does Jason need the restart? If not, then your point is?

His point was that the F9v1.1 demo flight was successful, but anticipating that some naysayer was going to argue based on the restart issue.

Even mentioning that someone would complain is kind of a self-fulfilling prophecy, wouldn't you say?

Absolutely. However: making the remark I made will keep at least 90 percent of the potential naysayers away. They don't wanna make fools of themselves knowing that people are expecting them to say nay.

[Lars_J]

The COTS-1 mission demonstrated M1C-Vac restart.

I wonder what changed that caused an issue.

How about a whole new engine? M1D uses a new turbo pump and a different manufacturing process.

[Mangala]

Does Jason need the restart? If not, then your point is?

Edit: that was curt, sorry. At only 553kg the Falcon 9 v1.1 should be able to do a direct insert (without restart) to the required 1336 km × 1336 km; 66°orbit.

Orbit an weight from Gunter's page http://space.skyrocket.de/doc_sdat/jason-2.htm

This is a very interessing question for me, because it maybe could clarify a debate that I used to have in a french forum about space and the true cost of an Falcon-9 launch.
More especially, we discussed the 82 millions dollars contract that SpaceX won to launch the Jason-3 spacecraft in the context of this document:http://oig.nasa.gov/audits/reports/FY11/IG-11-012.pdf.
My question for you guys it's about the fact that, if Jason-3 spacecraft needs a restart, did this condition could have put the Minotaur IV out of the competion to launch it, althouhg it seems to have the capacity to launch a such spacecraft in polar orbite such as the document that have cited seems to show?
Thanks for your attention and excuse me for my poor english.

[Jason1701]

This might clarify some of the confusion over the switch of launch vehicles.

http://www.spacenews.com/article/features/39075profile-jim-norman-director-launch-services-nasa-human-exploration-and

Speaking of different core propulsive modules, NASA Launch Services booked the U.S.-French Jason-3 mission on a Falcon 9 1.0, which SpaceX has now discontinued in favor of upgraded Falcon 9 v1.1. Are they allowed to make that switch?

Yes. A term on our NLS 2 contract is that any of our providers can offer to substitute a vehicle that has already had a successful flight for any vehicle that was already awarded a launch service contract, as long as there is no additional cost to the government. It is up to the Launch Services Program to review that offer and determine if it is in the best interest of NASA to accept that offer. That’s what happened in this case. That review happened shortly after the successful first flight of Falcon 9 v1.1 on Sept. 29. There’s no change in NASA’s firm, fixed price launch service contract with SpaceX.

Just so you know, this isn’t the first time we’ve done this. We switched the Mars Reconnaissance Orbiter mission, which launched in 2005, to an Atlas 5 from an Atlas 3B. It doesn’t happen often, but it has happened, I think, with each of our launch service providers.

[butters]

That's a refreshingly reasonable policy. I'm not at all surprised that people were expecting more rigid regulations. Still puzzling, though, is that certain very knowledgeable insiders seemed to think that the "bait-and-switch" was a big deal and not welcomed by some stakeholders.

[JBF]

That's a refreshingly reasonable policy. I'm not at all surprised that people were expecting more rigid regulations. Still puzzling, though, is that certain very knowledgeable insiders seemed to think that the "bait-and-switch" was a big deal and not welcomed by some stakeholders.

It was a big deal until SpaceX proved out the v1.1.

[Robotbeat]

...and remember, Shotwell said they kept the pieces needed for a v1.0 Falcon 9 until they had a successful v1.1 launch. That was probably the result of some sort of compromise, but sounds perfectly acceptable to me.

[MP99]

That's a refreshingly reasonable policy. I'm not at all surprised that people were expecting more rigid regulations. Still puzzling, though, is that certain very knowledgeable insiders seemed to think that the "bait-and-switch" was a big deal and not welcomed by some stakeholders.

Given the size of the payload and twice the Merlin Vac thrust, I wonder what the burnout G's will be, and if that's an issue?

Cheers, Martin

[pippin]

Even if it was: water is cheap.

[Lar]

Even if it was: water is cheap.

Meaning what? That a tank full of water should be added to the payload (somewhere) and ... vented when in orbit? Left there? Allowed to deorbit? I think all of those things might require some development effort.  I like your idea, I think, but it would add some cost in any case... changing the payload adapter to hold the tank, developing and testing vent valves or else station keeping etc. [1]

Probably better to add a bazillion cubesats and dispensers to increase the weight as the engineering for that seems more close to done. Or seek out other secondaries.

I think while this is not a terrible idea, an even better use of money would be to put it into doing things with the second stage. Use the extra performance to reduce the amount of fuel the second stage needs to use to complete the primary, so that it has leftover fuel to experiment with, and/or weight margin to allow adding PICA-X...

1 - Or has there been work done with water tanks already?

[kevin-rf]

He's talking about ballasting the stage to keep the g's down. You can add weight by attaching  water tanks,  concrete, steal weights, or lead weights to the stage. There are probably more ways than one can count.

[pippin]

Exactly. That's what everybody else does, I'm pretty sure SpaceX will get it done as well if they need to.

[Lurker Steve]

He's talking about ballasting the stage to keep the g's down. You can add weight by attaching  water tanks,  concrete, steal weights, or lead weights to the stage. There are probably more ways than one can count.

Do they really use a liquid ? I imagine you wouldn't want your ballast sloshing around. Or is that water tank designed to hold exactly as much water as needed.

I imagine there would be some type of ballast on every flight, just to somewhat even out the payload mass between flights or to balance the stage so that one side isn't heavier than the other.

[Danderman]

Ballast = secondary payloads.

[Lar]

Exactly. That's what everybody else does, I'm pretty sure SpaceX will get it done as well if they need to.

Thanks for clarifying... I would love to know where the ballast is put, is it just wedged in wherever it can fit? Is this mission likely to have more complexity than the average mission with respect to ballast being added?

Edit: I was reminded via PM that launch vehicles are not typically ballasted but rather are throttled back or engines shut down if g loads need adjusting.

So that brings me back to why wouldn't the added liftable mass available go to secondary payloads or S2 experiments or just be ignored (planned around)

Edit again, I was further reminded that ballast is typically only used if something changed in the mission design really late, some component was dropped that massed enough that ballast needed to take its place...

[pippin]

Don't know, but Ariane, for example, puts ballast on every mission, they don't throttle back. It's on the stage, I don't know whether on the ESP or the ESC, in this case it would have to be on the upper stage.

If SpaceX have the throttling capability and they fly to a special orbit that requires a custom mission profile, they might as well throttle but keep in mind that there are limits to throttling and ballasting really isn't complicated.
I believe Ariane uses steel, not water, but water is cheap and heavy enough....

[slavim]

Water sloshes around. And if it doesn't, it expands when it freezes.

Antares has a solid second stage so it would have to ballast for every mission (IMO).