SpaceX Updates (Thread 5)


Recommended Posts

SarK0Y

 

much fluid to use was off by 10%, so they're upping it by 50% to have reserves. We're talking about 20-30 liters here.

a bit windy zeros that reserve.

Link to post
Share on other sites
Unobscured Vision

My goodness. Doc isn't the one who makes those decisions, he's just letting the rest of us know about them and giving us his (obviously educated) take on it as they happen.

 

As for me, I'm an "Armchair Engineer", meaning that I've got enough of an education to know what it means two to four levels down into the mix and how to deal with it, and I've got the resources/wherewithal to find out the other 60% that I don't know. I could probably fix something but not design it.

 

Seriously, lower tones, please. We're all aiming for the same direction here. :yes:

Link to post
Share on other sites
DocM

Soft landing against bunker penetrator -- nice shot, DocM. Orange vs. Apple. would you like to compare docking w/ anti-aircraft missile??? :D

The guidance system doesn't know the difference until the F9 leg radars say "thar she blows!" and the landing system engages. That's 99% of the path from apogee to the deck.

Link to post
Share on other sites
flyingskippy

The grid fins simply steer the munition to the target. No different than grid fins on the F9 steering the booster to the barge. It allows for the stage to glide ballisticly towards the barge without wasting fuel making course changes with a Merlin. Whatever parasitic drag the fins add only helps slow the stage down before landing.

Link to post
Share on other sites
SarK0Y

The guidance system doesn't know the difference until the F9 leg radars say "thar she blows!" and the landing system engages. That's 99% of the path from apogee to the deck.

the difference is, that you have less room (for f9) to push equipment in. it's first moment. 2nd one is, penetrator doesn't need to have so accurate positioning, it can hit walls at different angles & result will be the same. 3rd is, penetrator is free falling thing, thereby aerodynamic steering becomes more efficient.

Link to post
Share on other sites
DocM

That's the difference between having a terminal guidance system programmed for landings vs. a bomb.

You seem to be under the impression they're a bunch of of rookie cowboys when that's not th9e case at all. Sure they have fresh grads,from the best schools, but they've also headhunter every major company from TRW, Lockheed, Boeing, Northrop-Grumman and Rocketdyne to BMW, Ford, Microsoft, NASA, the military, Silicon Valley companies and beyond. All have skills they need.

Those are the designers and the project managers, not some amateurs. Argue with them.

Link to post
Share on other sites
malenfant

Someone's going to have to come up with a new classification of Internet lunatic just for this guy. Jeez.

Link to post
Share on other sites
Beittil

And the worst part is, people keep replying to him! Even DocM, despite saying on more than one occasion that he should/would stop doing so :p

  • Like 1
Link to post
Share on other sites
DocM

Yeah, I did and shouldn't have. Dammit.

Link to post
Share on other sites
SarK0Y

And the worst part is, people keep replying to him! Even DocM, despite saying on more than one occasion that he should/would stop doing so :p

No magic: my estimations/predictions have worked so well :)

 

DocM, actually i feel some pity to spacex -- say them that stage has to be programmed to make kamikaze maneuver, if it depletes fuel for safe landing. Thereby there minimizes losses.

Link to post
Share on other sites
SarK0Y

 

But in a Jan. 13 order, Judge Susan Braden denied ULAs motion to dismiss. In the order, she also said SpaceX and the Air Force would begin mediation this month. In addition, the order said the Air Force has told the court it would not make a final decision on certain launch contract awards until later in 2015.

it's just tactical victory for the Musk, but strategically he hasn't demonstrated any capabilities to provide cheap alternatives. Frankly, it's extremely unwise on his behalf to tease such monster like ula.

Link to post
Share on other sites
DocM

Moore's Law applies to Falcon 9.

Sounds like we're going to see the fabeled NLS-2 16.67 tonne Falcon 9 this spring. The one where the engines go all the way to 100% throttle instead of the 80% we've been seeing.

Peter B. de Selding @pbdes (Space News)

SES: We may skip spring SpaceX launch slot & wait till mid-year to let someone else be 1st using Falcon 9 main engine in full-thrust regime.

Link to post
Share on other sites
flyingskippy

Have they not throttled them to 100% before?

Link to post
Share on other sites
DocM

Not during a launch. 80%. Plus they're adding proappellant densification by chilling. More fuel/volume.

Link to post
Share on other sites
flyingskippy

Is the sat that heavy to require 100%?

Link to post
Share on other sites
DocM

I don't have specific info on which launch it'll be, but the most likely is ABS-3A & SatMex, the launch to GTO of two Boeing 702SP ion drive commsats. A dual manifest and the first of their kind. That'll need significant impulse.

BoeingAllElectricStack_Boeing.jpg

Link to post
Share on other sites
flyingskippy

First time I have seen a dual manifest launch without a support shroud between the two satellites. It is about time they come with a better design of stacking the two. It is a lot better design and simpler too.

Link to post
Share on other sites
DocM

Boeing patented this method. Each satellite is lighter too because of their use of Xenon Hall Effect ion thrusters instead of chemical.

Usually there's 1-3 tonnes of hypergolic propellants on board, but these only need a hundred kilograms of Xenon. They only plan on using ~5 kg/year for station keeping. The rest is margins.

Aerojet Hall Effect thruster

aerojet-hall-thruster-propulsion-system.

Link to post
Share on other sites
DocM

Named for an Iain M. Banks 'Culture' quote (s/f writer)

@elonmusk

Repairs almost done on the spaceport drone ship and have given it the name "Just Read the Instructions"

Link to post
Share on other sites
DocM

?@elonmusk

West Coast droneship under construction will be named "Of Course I Still Love You"

Link to post
Share on other sites
SarK0Y

 

SpaceX just accomplished something incredible, and no one's paying attention

And even if you are paying attention, you might have heard that SpaceX's latest space launch was a failure. It was actually a success.

The launch had two goals: The first was to supply the International Space Station, and that was successful; but the second one, much more important, was to land the company's Falcon rocket upright so that it could be reused.

The rocket did not land upright. But as an excellent explainer by Business Insider's Jessica Orwig shows, SpaceX actually accomplished almost all its goals. The rocket landed on its platform. But the guiding fins, which help the rocket rotate and steer, ran out of hydraulic fluid, and the rocket crashed on its pad.

 

*************************************************

And a reason why rockets are enormously expensive is because each time you use one, it gets destroyed. The space shuttle program was supposed to fix that, but it was just a massively incompetent boondoggle. If you had to blow up a Boeing 747 each time you used it, there would be very little plane flight either. So building a reusable rocket is probably the biggest low-hanging fruit in terms of making space flight affordable.

 

http://theweek.com/articles/534037/spacexs-massive-explosion-still-tremendous-success

WTF experts out the?????? :|:s  how many successful takeoffs/landings were performed by Shuttle???? how many payloads were delivered to & from LEO??? incompetent boondoggle, seriously???! :rofl: Yes, Shuttle had many TODOs ahead & there would have been possible to solve 'em thanks to cooperation with Russia. by the way, 50% more of hydraulic fluid ain't the end of this dolleful story: feathers & thrust vectoring have different lags, so the're very needs to sync them all way down + lag of feathers gets become longer with fluid spending. :)

Link to post
Share on other sites
FloatingFatMan

WTF experts out the?????? :|:s  how many successful takeoffs/landings were performed by Shuttle???? how many payloads were delivered to & from LEO??? incompetent boondoggle, seriously???! :rofl: Yes, Shuttle had many TODOs ahead & there would have been possible to solve 'em thanks to cooperation with Russia. by the way, 50% more of hydraulic fluid ain't the end of this dolleful story: feathers & thrust vectoring have different lags, so the're very needs to sync them all way down + lag of feathers gets become longer with fluid spending. :)

 

Russia? You mean the same guys that like to fit guidance components to rockets by hammering them in upside down? :p

Link to post
Share on other sites
IsItPluggedIn

Thats a great article for the masses, and the main point of the article is that SpaceX are trying to bring down costs of launches. The fact is that the shuttle was supposed to bring costs down for the space program and it didn't. 

 

Thanks for Sharing a good article.

Link to post
Share on other sites
This topic is now closed to further replies.
  • Recently Browsing   0 members

    No registered users viewing this page.