SpaceX--Spacecraft, rockets, and Mars

[Jace, Extat]

Dude. I'm glad you keep this thread updated. I'm no good at following this stuff but I love popping in here for updates. 

Just want you to know you're appreciated.

[SpaceChampion]

Aww, shucks ma'am.  Thanks. 

[Ser Scot A Ellison]

Yeah, I saw the video of the explosion.  Sucks, but it is a hazard of getting up to LEO.  Is Musk interested in the space elevator ideas that have been floated?  

[Altherion]

26 minutes ago, Ser Scot A Ellison said:

Is Musk interested in the space elevator ideas that have been floated?  

No. SpaceX has been able to get where it is using the relatively limited resources that it has used because it has stood on the shoulders of giants. There are no such giants in space elevator construction. A project like that would almost certainly require the resources of a nation state on the scale of the US or China much as the original space programs required a non-trivial fraction of the total budgets of the US and USSR. Musk is rich, but he's not that rich. Also, keep in mind that we don't actually have the materials to build a space elevator even if somebody did want to spend the money. Google looked into this a few years ago and decided to put the project into a deep freeze pending the development of either significantly longer carbon nanotubes or some other material with adequate tensile properties.

[SpaceChampion]

I believe a year or so ago carbon nanotubes were ruled out as ever having enough tensile strength to make a space elevator work for Earth.  This is due a newly discovered failure mode for the tubes that reduced their tensile strength substantially.  For Moon or Mars however, still might work.

 

This is neat:  Someone overlaid the video of the Dragon launch pad abort test from last year with yesterday's accident to show that Dragon would have escape the fire just fine.

 

[SpaceChampion]

Sounds incredible but today Bill Nye said he was told by SpaceX (since he's president of the Planetary Society and they would have a LightSail as a secondary payload on it) that the first Falcon Heavy launch is still scheduled for November.

Perhaps it was just a SpaceX PR person running on autopilot because it any delay isn't official yet.  The launch pad (39A) isn't even quite ready yet, let alone the difficulties with having a Return To Flight process complete by then, so it's all doubtful.

Or maybe SpaceX is just that awesome, I don't know.  :shrug:

 

[Jace, Extat]

So everything I've read on Musk makes me really like him (his obvious James Bond villainness included), but am I missing anything about this guy? He seems pretty dope to me.

[Altherion]

1 hour ago, Pony Queen Jace said:

So everything I've read on Musk makes me really like him (his obvious James Bond villainness included), but am I missing anything about this guy? He seems pretty dope to me.

His mode of operation is generally to promise either more than he can deliver or faster than he can deliver it, but given that what he does eventually deliver is generally pretty awesome, most people tolerate this. Also, if you're looking for work at his companies, it's reportedly pretty intense (i.e. he works very hard himself and expects the same of his employees), but anyone smart enough to work for SpaceX or Tesla should be smart enough to know what they're getting into.

I'd be pretty surprised if they went ahead with the Falcon Heavy launch in November. Did they conclusively prove what exactly caused the most recent failure?

[SpaceChampion]

10 hours ago, Altherion said:

I'd be pretty surprised if they went ahead with the Falcon Heavy launch in November. Did they conclusively prove what exactly caused the most recent failure?

Nothing official yet.  I think Bill Nye was just wrong.  I read the LightSail is suppose to be on the 2nd FH launch anyway, not the first, so he's wrong about that, unless it was moved up.

 

I've only seen two lines of speculation regarding what might have caused the fire.  One, that the AMOS-6 satellite in the payload bay leaked hypergolic fluids that mixed and exploded.  Two, that static electricity built up in the LOX line, which can do so in many 10's of thousands of kilovolts in half a minute.  Liquid oxygen is 1000x less viscous than water, so higher flow rates can build up the static charge fast.

I don't know if any of those have been ruled out though.

 

 

[SpaceChampion]

 

[Ser Scot A Ellison]

Hope they get it figured out quickly and get back on target.

[Future Null Infinity]

Some redditors think that a little camera drone (the ones used to capture videos) hit the Falcon 9 and caused the explosion

Video

watch above the fireball, there is something flying outward just after the explosion

but I don't think that a camera drone can cause so much damage, I think it just a flying part from the rocket

[Which Tyler]

2 hours ago, Future Null Infinity said:

Some redditors think that a little camera drone (the ones used to capture videos) hit the Falcon 9 and caused the explosion

Video

watch above the fireball, there is something flying outward just after the explosion

but I don't think that a camera drone can cause so much damage, I think it just a flying part from the rocket

 

Maybe the drone was flying over SpaceX's property, and they just wanted to take it out?

[SpaceChampion]

How I Learned To Stop Worrying and Love the Big $60B NASA Rocket

Quote

"So if NASA makes 20 SLS flights by the end of the 2030s, the rocket will roughly cost the agency a total of $60 billion, or $3 billion per flight. Now imagine NASA issuing a Request for Information for heavy lift in 2011. Say the agency was willing to pay a fixed-price sum of $10 billion to a private company to develop a 100-ton heavy lift launch vehicle and a per flight fee of $500 million. Either SpaceX, United Launch Alliance, or another company (Blue Origin, perhaps) certainly would have been capable of delivering a flight-ready rocket within a decade. After buying 20 launches, NASA would still have $40 billion left to spend on things other than rockets. During this decade, then, the agency could have focused on deep space habitats, landers, in-space propulsion, Mars gravity studies, and more. When the private rocket was ready to go in 2021, NASA would be prepared to fly meaningful missions. This isn't a hypothetical, by the way. Back in the late 2000s, United Launch Alliance outlined a path of upgrades for its Delta IV Heavy rocket that included derivatives (based upon an innovative ACES upper stage and new engines) that could get 90 tons or more to low-Earth orbit. This could be flying today for less than $10 billion. This was common knowledge to NASA and the aerospace community at the time SLS came into existence, but Congress wasn't interested."

Quote

One of the SLS critics whom I most highly regard, and who is deeply plugged into Washington space policy and favors commercial space, has rationalized the rocket and Orion like this. While NASA will spend in excess of $3 billion a year for the foreseeable future on “pork” like the rocket and spacecraft, it now also spends $2 billion to $3 billion a year on commercial crew and cargo. That money goes to SpaceX and other companies that push forward more economical means of space transportation. My source views the agency’s payments on SLS and Orion as a “stupidity tax” that allows “good money” to be spent on commercial space.

 

[Liffguard]

On 09/09/2016 at 3:35 AM, Pony Queen Jace said:

So everything I've read on Musk makes me really like him (his obvious James Bond villainness included), but am I missing anything about this guy? He seems pretty dope to me.

It seems like he can suffer a bit from the STEM-lord issue of "I'm an expert in a couple of highly technical fields and am therefore an expert in all fields." He's somewhat historically illiterate and is an unashamed proponent of american exceptionalism.

Not trying to rag on the guy, I think a lot of what he's doing is very cool. Just reminding everyone that he is just human.

[SpaceChampion]

He's said to create a reality distortion field around himself like Steve Jobs.  That's great for a competent person leading a company, bad in personal relationships.  (And bad for a not-competent person leading companies, like Elizabeth Holmes of Theranos.)

 

Looks like a Falcon Heavy is undergoing testing at the MacGregor test stand in Texas.  It's probably one with engines, just to test the structural integrity and mechanical stresses on it, see that it matches with their models.  Good to see even with recent events going as it did, they're still pressing ahead.

https://www.facebook.com/groups/spacexgroup/permalink/10154574477871318/

[SpaceChampion]

Jeff Bezos released news about Blue Origin's orbital rocket New Glenn, and promises an even bigger New Armstrong later on.  Sounds like he'll want to compete with SpaceX's MCT.  Bezos had long said he want to help colonize the solar system, but has been secretive about his plans all along.

The in development BE-4 methane-oxygen (actually liquid natural gas which has a bit of ethane in it) engine will be comparable to SpaceX's Raptor engine in choice of propellants but slightly more powerful according to what info has been released so far.  (Raptor will be pure methane, not LNG, so will burn cleaner, without coking the engine as much as RP-1 or LNG.)

New Glenn is proposed to come in two variants, a two-stage and a three-stage version, the latter having an upper 3rd stage that uses a single hydrogen-oxygen BE-3 engine for its higher specific impulse in the vacuum of space for beyond-LEO missions.  The first stage will be a 7-engine reusuable stage.  Bezos tried to patent the idea of barge landing before SpaceX did it so seems likely New Glenn's first stage will land on a platform, ship or barge at sea whenever landings at KSC are not possible.

The BE-4 engine is already in development for United Launch Alliance's (who are Boeing & Lockheed) proposed Vulcan launcher.  I have questions about the viability of Vulcan but leave that for another time.

All things considered, the first stages of New Sheppard and Falcon Heavy are difficult to compare, since SpaceX's Merlin 1D engines on the FH each are only about 35-40% the thrust of a Raptor, which is slightly less thrust than a BE-4.  On a Falcon Heavy there will be 27 of them Merlins, compared to 7 BE-4s, but different fuels don't make the math straightforward.

But New Glenn will be 3.85 million pounds thrust at launch while Falcon Heavy will be 5.13 million lbf.   That makes it seems FH is the more powerful rocket but it really is how the different stages stack and timing of separation that will determine that.

If SpaceX replaced FH's 27 Merlins with 9 Raptor engines, (also replacing RP-1 kerosene fuel with methane), there would be huge performance increases.  They had been planning that at one point, but that means not reusing Falcon 9 first stages as the side boosters for FH.  Economically, SpaceX doesn't want to do that.  Replacing the 2nd stage Merlin vac engine with a Raptor still seems to be in the cards, and it's more powerful thrust will actually make 2nd stage reusability possible for some missions, landing far into the Atlantic on a 2nd drone ship.

The big question is how much payload can New Glenn send to LEO, GEO and beyond?

[SpaceChampion]

In one week Musk will be giving his presentation of the MCT design and overall Mars architecture on the 27th in Mexico at the IAC, at 1:30 CDT.  Click to find in your time zone.

It will be streamed live, here.

One notable piece of news is Musk said

And seems to like Interplanetary Transport System.

 

[Mr. Chatywin et al.]

Semi off topic, but worthy of a bump:

https://www.theguardian.com/science/2016/sep/21/chinas-tiangong-1-space-station-out-of-control-crash-to-earth

 

[SpaceChampion]

On Friday SpaceX announced it had traced the origin of the accident to the helium pressure system of the upper stage.  Helium is used to pressurize the fuel tank as fuel is drained from it during flight, since kerosene does not self-pressurize (via evaporation).  The helium pressure vessel is aluminum wrapped with a carbon fibre composite, and sits inside the liquid oxygen tank to chill it.  It's speculated by people outside SpaceX with some internal sources that harmonics during the LOX fueling created a thermal stress on the carbon fibre that caused it to shatter into thousands of pieces, mixing with the oxygen, and static build up was enough to ignite it in microseconds.  The likely solution seems to be replacing the He tank with a heavier all titanium sphere, or changing the way the carbon fibre is wrapped from a tape like wrap to a tight braid.

The methane Raptor engine would not require helium at all, since methane does self-pressurize.  Replacing the upper stage engine with a Raptor would also solve the problem, as well as offer substantial performance improvement such that flying the second stage back and landing it on a drone ship is possible.  The first stage kerosene Merlin engines would still require helium, as do its landing legs. Adding landing legs to the upper stage would then reintroduce the helium issue.

Speaking of the Raptor, Musk announced its first firing last night of a subscale version.

 

SpaceX believes it can return to flight as soon as November.

TOMMORROW along with the presentation of the design of the Mars rocket, Musk likely will have video of the Raptor test firing.