Author Topic: SpaceX Falcon 9 FT - ORBCOMM-2 - Dec. 21, 2015 (Return To Flight) DISCUSSION (Read 1360695 times)

Comga · « **Reply #1280 on:** 12/21/2015 05:16 am »

Quote from: Ohsin on 12/20/2015 11:26 pm

Quote
Launch & landing can be seen on the http://SpaceX.com webcast or in person from Cape Canaveral public causeway at 8:33pm local tmrw
https://twitter.com/elonmusk/status/678732298532085761

Almost feel like it's interrupting your detailed discussion of launch economics with news about the RTF, but this is interesting.
Launch & landing says that SpaceX will, indeed, broadcast the landing attempt.

Steven Pietrobon · « **Reply #1281 on:** 12/21/2015 05:24 am »

Quote from: OxCartMark on 12/21/2015 05:00 am

Allow me to expand on the term "Monte Carlo Analysis". Elon told his team that if they can get the 11 satellites where they need to be and if they car also land the stage in one piece he'd send them all to Monte Carlo for a week. After some discussion among the team members they concluded that they had a better chance of winning the bet on Monday.

I think that is meant to be a joke. Monte Carlo Analysis is performing many simulations where random variables like weather, engine performance, propellant temperatures, etc. are varied according to their probability distributions. This is used to estimate a mean and variance of the expected orbit, which can then be used to estimate a probability of a successful mission assuming most likely a normal distribution for the orbit. I do Monte Carlo simulations all the time, but for analysing digital communication systems.

wxmeddler · « **Reply #1282 on:** 12/21/2015 06:01 am »

Quote from: Steven Pietrobon on 12/21/2015 05:24 am

I think that is meant to be a joke. Monte Carlo Analysis is performing many simulations where random variables like weather, engine performance, propellant temperatures, etc. are varied according to their probability distributions. This is used to estimate a mean and variance of the expected orbit, which can then be used to estimate a probability of a successful mission assuming most likely a normal distribution for the orbit. I do Monte Carlo simulations all the time, but for analysing digital communication systems.

This is correct. Happens in weather modeling all the time; use it to estimate ranges, means, and kurtosis.

Rocket Science · « **Reply #1283 on:** 12/21/2015 06:46 am »

Hmmm... "Don't launch, if you can't land".... We had another partially reusable launch system, it was called the Shuttle. We had launch constraints and landing constraints for RTLS, abort sites and EOM. Now these were (are) for totally different stages of each system and one was manned. Still; "don't launch, if you can't land" should be familiar to us here... We have to be patient enough to watch the engineering experiment and decision making play out and make the case for stage recovery and potential reuse.

joek · « **Reply #1284 on:** 12/21/2015 07:19 am »

Quote from: QuantumG on 12/21/2015 03:43 am

I think the payload on this launch is insured for about $76M.

Do you know if that is just launch insurance or everything (ground ops, launch, first year, etc.)?

vanoord · « **Reply #1285 on:** 12/21/2015 08:05 am »

Quote from: a_langwich on 12/21/2015 03:32 am

If the landing gear collapses and an airline "totals" an airplane, they aren't in the hole for the entire revenue that airplane would have made over the rest of its career (even assuming such a crystal-ball number could be calculated). They are only out the cost of the airplane (+ costs for delays, possibly canceled flights, etc, none of which would approach the total-future-revenue figure).

More likely, if SpaceX managed to get launch prices down sharply, then it is likely the business case for launching a payload could be closed for much cheaper payloads.

I'd expect the costs of losing a plane to be the cost of replacement, plus the loss of revenue / profit (and consequential losses) until that replacement enters service. It's similar to what you say, but slightly different.

In SpaceX's case, the cost of losing a first stage will become the cost of replacement in the 'fleet', presumably factored against how many times that stage can be re-used - i.e. if a first stage can be used five times in total and it's lost on flight 4 then the 'cost' of that loss from the point of view of the vehicle itself is - at worst - 2/5 of the initial cost and probably less given that there may be a premium that can be charged for the first flight of an unused stage.

Plus, of course, the loss of payload and the consequential costs of delays to the next flights.

The killer cost, however, would be the reluctance of future customers to commit to flying on a vehicle that had a habit of failing.

There's a pay-off between the lowered costs of reusability and the potential for lower reliability because of it. Presumably initially the re-launch costs will be sufficiently low to overcome concerns about reliability, but in the longer-term that may change.

(And yes, those lower costs will certainly be attractive to those potential customers to whom the launch price is currently a barrier).

None of us know how easily a stage can be re-used and with what reliability - it's going to be interesting finding out.

georgegassaway · « **Reply #1286 on:** 12/21/2015 08:18 am »

Sorry to interrupt the RTF thread's discussion of non-RTF related issues of generic Falcon reuseability economics for the umpteenth-hundred time, with something directly related to watching this flight and landing......

Musk tweeted:

Quote

Launch & landing can be seen on the http://SpaceX.com webcast or in person from Cape Canaveral public causeway at 8:33pm local tmrw

https://twitter.com/elonmusk/status/678732298532085761

OK, on a non-space forum, someone asked if the mention of "Launch and landing can be seen on the webcast", means that SpaceX WILL show the landing live. It's been interesting that nobody here seems to have picked up on that part of the tweet.

I've seen mention/speculation that they might as well show it since there will be plenty of cameras by the public that will show it, albeit of lesser quality and I do not know of any source for a possible live stream other than SpaceX's feed. Unless say an Orlando TV station broke into Monday night's repeats to show it live. But nobody seems to have followed up the above tweet's reference to the webcast and landing (unless I missed it elsewhere)

Anyway, does it seem reasonable to take that tweet to truly mean SpaceX will show the landing on their webcast? Or that Musk may have mis-spoken?

mme · « **Reply #1287 on:** 12/21/2015 08:22 am »

Quote from: georgegassaway on 12/21/2015 08:15 am

...
Musk tweeted:
Quote
Launch & landing can be seen on the http://SpaceX.com webcast or in person from Cape Canaveral public causeway at 8:33pm local tmrw

https://twitter.com/elonmusk/status/678732298532085761

OK, on a non-space forum, someone asked if the mention of "Launch and landing can be seen on the webcast", means that SpaceX WILL show the landing live. It's been interesting that nobody here seems to have picked up on that part of the tweet.
...
Anyway, does it seem reasonable to take that tweet to truly mean SpaceX will show the landing on their webcast, or that Musk may have mis-spoken?

I read it as they intend to show both the launch and the landing. Here's hoping!

kch · « **Reply #1288 on:** 12/21/2015 08:52 am »

Quote from: georgegassaway on 12/21/2015 08:15 am

...
Musk tweeted:
Quote
Launch & landing can be seen on the http://SpaceX.com webcast or in person from Cape Canaveral public causeway at 8:33pm local tmrw

https://twitter.com/elonmusk/status/678732298532085761

OK, on a non-space forum, someone asked if the mention of "Launch and landing can be seen on the webcast", means that SpaceX WILL show the landing live. It's been interesting that nobody here seems to have picked up on that part of the tweet.
...
Anyway, does it seem reasonable to take that tweet to truly mean SpaceX will show the landing on their webcast, or that Musk may have mis-spoken?

It's odd that you didn't notice -- this was just a few posts above yours:

Quote from: Comga on 12/21/2015 05:16 am

Quote from: Ohsin on 12/20/2015 11:26 pm
Quote
Launch & landing can be seen on the http://SpaceX.com webcast or in person from Cape Canaveral public causeway at 8:33pm local tmrw
https://twitter.com/elonmusk/status/678732298532085761
Almost feel like it's interrupting your detailed discussion of launch economics with news about the RTF, but this is interesting.
Launch & landing says that SpaceX will, indeed, broadcast the landing attempt.

Jet Black · « **Reply #1289 on:** 12/21/2015 02:36 pm »

What is the reason for such a short launch window?

cscott · « **Reply #1290 on:** 12/21/2015 02:48 pm »

One theory is that they are operating on thin margins (or with a lot of sandbagging of performance) since this is the first flight of this configuration.

The other theory seems to be that keeping the LOX supercooled is expensive (in terms of amount of LOX lost in the process, presumably) so the window is short because they can't afford to have the rocket sitting fully fueled and chilled for very long.

Probably the actual answer is a combination of both.

InfraNut2 · « **Reply #1291 on:** 12/21/2015 02:51 pm »

A third theory is that the FAA is unwilling to interfere with holiday airplane traffic any more than absolutely necessary.

Jim · « **Reply #1292 on:** 12/21/2015 03:12 pm »

Launch delays are a big cost for for all satellites (spacecraft manufacturers) because they have to maintain their team at the launch site (TDY costs). They have pay for time on tracking assets around the world and constantly rescheduling them. They have to pay for enlarging the mission control team for launch and early on orbit support. And add the lost revenue of the spacecraft sitting on the ground.

So each delay does tend to cost "millions"

yg1968 · « **Reply #1293 on:** 12/21/2015 03:48 pm »

They got a substantial rebate on the flight. So they still get a "good deal" from SpaceX. These things get negotiated. So I wouldn't worry too much about the client losing millions from this delay.

JasonAW3 · « **Reply #1294 on:** 12/21/2015 04:06 pm »

Quote from: InfraNut2 on 12/21/2015 02:51 pm

A third theory is that the FAA is unwilling to interfere with holiday airplane traffic any more than absolutely necessary.

THIS strikes me as the most likely answer!

rdale · « **Reply #1295 on:** 12/21/2015 04:52 pm »

Quote from: Rocket Science on 12/21/2015 01:21 pm

Having a look for tonight's WX.

Winds 12-13 kts. gusting to 17-18 kts. Pretty sporty for a landing if they try...

That's probably a little high given the evening launch time... I'd say more 9-14kts.

Chris Bergin · « **Reply #1296 on:** 12/21/2015 05:45 pm »

If it's not already posted:
Environmental Assessment for the Space Exploration Technologies Vertical Landing of the Falcon Vehicle and
Construction at Launch Complex 13 at Cape Canaveral Air Force Station Florida:

http://www.patrick.af.mil/shared/media/document/AFD-141107-004.pdf

dgates · « **Reply #1297 on:** 12/21/2015 05:46 pm »

How do you suppose the accomplish the super-cooling of the LOX? Maybe use LN2? Perhaps they needed to replenish their LN2 supply?

ugordan · « **Reply #1298 on:** 12/21/2015 05:48 pm »

Brief SpaceX 2-pager on the launch: http://www.spacex.com/sites/spacex/files/spacex_orbcomm_press_kit_final.pdf

Fairing sep at T+12 minutes??? Must either be a big typo or they really need all the ballast they can get...

Hotblack Desiato · « **Reply #1299 on:** 12/21/2015 05:58 pm »

Quote from: dgates on 12/21/2015 05:46 pm

How do you suppose the accomplish the super-cooling of the LOX? Maybe use LN2? Perhaps they needed to replenish their LN2 supply?

liquid nitrogen helps down to -196°C (boiling point of oxygen -183°C). but oxygen freezes at -218°C, whereas nitrogen freezes at just -210°C.

I think, they have to chill down oxygen directly by the linde process, or run it through heat exchangers with liquid hydrogen (but they need to be aware that the heat exchanger could be clogged with frozen oxygen.