SpaceX (general discussion)

[Michel Van]

I guess they modified the Second stage with Lightweight heat shield and control surface for BFR testing.
After LEO missions that Second stage will make those test during it's deorbit .
Also on some GTO missions were second Stage will have high reentry speeds testing the heat shield

on long therm that could become Concept for Second stage reuse
maybe replace second stage by a Mini BFR

 

[Flyaway]

SpaceX press release:

__
NASA’s Launch Services Program (LSP) has certified Falcon 9 as a Category 3 launch vehicle. Category 3 launch vehicles are certified to support NASA’s highest cost and most complex scientific missions. The following statement is from SpaceX President and Chief Operating Officer Gwynne Shotwell:

“LSP Category 3 certification is a major achievement for the Falcon 9 team and represents another key milestone in our close partnership with NASA. We are honored to have the opportunity to provide cost-effective and reliable launch services to the country’s most critical scientific payloads."

The process of designating launch vehicles as Category 3 is designed to assure the highest practicable probability of success. Falcon 9 has completed over 60 missions, including the NASA LSP missions Jason-3 and TESS.

Additional certification is still required for it to be certified to carry payloads with RTGs.

 

[sferrin]

SpaceX press release:

__
NASA’s Launch Services Program (LSP) has certified Falcon 9 as a Category 3 launch vehicle. Category 3 launch vehicles are certified to support NASA’s highest cost and most complex scientific missions. The following statement is from SpaceX President and Chief Operating Officer Gwynne Shotwell:

“LSP Category 3 certification is a major achievement for the Falcon 9 team and represents another key milestone in our close partnership with NASA. We are honored to have the opportunity to provide cost-effective and reliable launch services to the country’s most critical scientific payloads."

The process of designating launch vehicles as Category 3 is designed to assure the highest practicable probability of success. Falcon 9 has completed over 60 missions, including the NASA LSP missions Jason-3 and TESS.

Additional certification is still required for it to be certified to carry payloads with RTGs.

Category 4?

 

[TomS]

SpaceX press release:

__
NASA’s Launch Services Program (LSP) has certified Falcon 9 as a Category 3 launch vehicle. Category 3 launch vehicles are certified to support NASA’s highest cost and most complex scientific missions. The following statement is from SpaceX President and Chief Operating Officer Gwynne Shotwell:

“LSP Category 3 certification is a major achievement for the Falcon 9 team and represents another key milestone in our close partnership with NASA. We are honored to have the opportunity to provide cost-effective and reliable launch services to the country’s most critical scientific payloads."

The process of designating launch vehicles as Category 3 is designed to assure the highest practicable probability of success. Falcon 9 has completed over 60 missions, including the NASA LSP missions Jason-3 and TESS.

Additional certification is still required for it to be certified to carry payloads with RTGs.

Category 4?

No, Category 3 plus some additional certification of destruct systems (to make sure the RTG housings will survive a destruct event intact). Same way human-rating requires CAT 3 plus some other criteria for crew escape/survival.

 

[Grey Havoc]

https://tech.slashdot.org/story/18/11/09/1634225/the-first-detailed-look-at-how-elon-musks-space-internet-could-work

 

[TomcatViP]

Between distant places, this will allow messages to be sent about twice as fast as through the optical fibres on Earth that currently connect the internet, despite having to travel to space and back. This is because the speed of the signal in glass is slower than it is through space.

in all exactitude

The speed of light in a vacuum is 299,792,458 meters per second, or 186,282 miles per second. In any other medium, though, it's generally a lot slower. In normal optical fibers (silica glass), light travels a full 31% slower

(sourced from ggl)

But more importantly is the fact that networks are heavily branched and all that signals relay impacts the overall speed. Starlink could hence be seen as the highway of data.

 

[sferrin]

Between distant places, this will allow messages to be sent about twice as fast as through the optical fibres on Earth that currently connect the internet, despite having to travel to space and back. This is because the speed of the signal in glass is slower than it is through space.

in all exactitude

The speed of light in a vacuum is 299,792,458 meters per second, or 186,282 miles per second. In any other medium, though, it's generally a lot slower. In normal optical fibers (silica glass), light travels a full 31% slower

(sourced from ggl)

But more importantly is the fact that networks are heavily branched and all that signals relay impacts the overall speed. Starlink could hence be seen as the highway of data.

Wonder how difficult it would be to have a solar-powered "cloud" server up there as well.

 

[Grey Havoc]

You really don't want to be using cloud server architecture for mission critical applications.

 

[sferrin]

You really don't want to be using cloud server architecture for mission critical applications.

I meant for the average Joe Blow who might be using the network.

 

[sienar]

Given the failure rate of HDs in database applications it'd be a good way to make a very heavy piece of space junk in only a few years.

 

[sferrin]

Given the failure rate of HDs in database applications it'd be a good way to make a very heavy piece of space junk in only a few years.

Good point. Didn't think about that. Then there are the power requirements, cooling. . .

 

[NeilChapman]

Given the failure rate of HDs in database applications it'd be a good way to make a very heavy piece of space junk in only a few years.

Good point. Didn't think about that. Then there are the power requirements, cooling. . .

I don't think dissipating heat in space is much of a problem. It get's pretty cold out there. Perhaps getting the heat from a hot spot in the middle of your satellite out to space could be a problem.

--

Also - Solid State drives have been out for awhile and a number of "faster, cheaper, better" flash solutions are in the pipeline. It's likely you could get solid state solutions that last longer than 10 years. What's the life span of a satellite? 5-10?

There are other issues as well. But with transport costs dropping it's likely we'll see many changes in "space computer" tech.

https://www.militaryaerospace.com/articles/2018/09/radiaton-hardened-cubesat-space.html

https://www.militaryaerospace.com/articles/2018/10/satellites-surveillance-swap-c.html

 

[Hobbes]

Given the failure rate of HDs in database applications it'd be a good way to make a very heavy piece of space junk in only a few years.

Good point. Didn't think about that. Then there are the power requirements, cooling. . .

I don't think dissipating heat in space is much of a problem. It get's pretty cold out there. Perhaps getting the heat from a hot spot in the middle of your satellite out to space could be a problem.

--

Also - Solid State drives have been out for awhile and a number of "faster, cheaper, better" flash solutions are in the pipeline. It's likely you could get solid state solutions that last longer than 10 years. What's the life span of a satellite? 5-10?

There are other issues as well. But with transport costs dropping it's likely we'll see many changes in "space computer" tech.

https://www.militaryaerospace.com/articles/2018/09/radiaton-hardened-cubesat-space.html

https://www.militaryaerospace.com/articles/2018/10/satellites-surveillance-swap-c.html

dissipating heat in space IS a problem.

1. It's not cold in LEO (you get more sun input than on the ground due to no atmosphere).
2. Space is a vacuum, which is an excellent insulator. The only way to get rid of heat is by radiation. At the low temperatures you need (i.e. not glowing red) radiation is inefficient, so you need large radiators.

And solid-state drives are nice, but suffer the same problem as other electronics: bit flips due to cosmic radiation. You can't just stick a Seagate SSD in your satellite, you need a setup that prevents data corruption. There are space-qualified SSDs, but they are much smaller than commercial ones.

 

[Flyaway]

SpaceX’s next big BFR spaceship part finished in Port of LA tent facility

The first 9-meter (29.5-foot) diameter composite propellant tank dome for SpaceX’s full-scale BFR spaceship prototype has been spotted more or less complete at the company’s temporary Port of Los Angeles facility, unambiguous evidence that SpaceX is continuing to rapidly fabricate major components of its next-generation rocket.

 

[sferrin]

SpaceX’s next big BFR spaceship part finished in Port of LA tent facility

The first 9-meter (29.5-foot) diameter composite propellant tank dome for SpaceX’s full-scale BFR spaceship prototype has been spotted more or less complete at the company’s temporary Port of Los Angeles facility, unambiguous evidence that SpaceX is continuing to rapidly fabricate major components of its next-generation rocket.

They're not fooling around. NASA would have to wait five years to have a building built.

 

[Flyaway]

From Elon’s Twitter feed.

Btw, SpaceX is no longer planning to upgrade Falcon 9 second stage for reusability. Accelerating BFR instead. New design is very exciting! Delightfully counter-intuitive.

BFR design has changed again or speaking about the latest design?

Radical change

https://twitter.com/elonmusk/status/1063865779156729857

Didn’t take this news long to get reported!

https://www.engadget.com/2018/11/17/spacex-drops-plans-to-make-falcon-9-rockets-more-reusable/?guccounter=1

 

[Moose]

From Elon’s Twitter feed.

Btw, SpaceX is no longer planning to upgrade Falcon 9 second stage for reusability. Accelerating BFR instead. New design is very exciting! Delightfully counter-intuitive.

BFR design has changed again or speaking about the latest design?

Radical change

https://twitter.com/elonmusk/status/1063865779156729857

Didn’t take this news long to get reported!

https://www.engadget.com/2018/11/17/spacex-drops-plans-to-make-falcon-9-rockets-more-reusable/
?guccounter=1

Oh jeez what now? The big Cadillac tailfins wasn't radical enough?

 

[Grey Havoc]

Scope creep/drift? This could end up backfiring badly.

 

[sferrin]

Scope creep/drift? This could end up backfiring badly.

Which is why NASA would dither for 10 years and have nothing to show for it. With SpaceX if they decide to adjust their path they just do it.

 

[martinbayer]

Scope creep/drift? This could end up backfiring badly.

Which is why NASA would dither for 10 years and have nothing to show for it. With SpaceX if they decide to adjust their path they just do it.

I whoelheartedly concur. It's utterly refreshing to see somebody actually exercise the build/try/improve loop engineering cycle in real time again.

Martin

 

[Flyaway]

Space X’s BFR is now called Super Heavy and the BFS now called Starship. It is so called as later versions will be designed to leave our solar system.

https://techcrunch.com/2018/11/19/elon-musk-just-renamed-spacexs-big-f-rocket/?guccounter=1

 

[Tuna]

Scope creep/drift? This could end up backfiring badly.

To me, radical change and bringing up the timeline in one sentence means risk reduction. They have probably dropped things they don't know how to build yet and replaced them with something they do know how to build. Personally, I think the most likely change is that they have gotten rid of the flappy hinged airbrake/whatevers, and figured out a way to replace them with grid fins. Simply because grid fins they do know how to build, and the exposed hinge in superheated supersonic airstream seems to be the weakest point of that design.

We'll see.

 

[Flyaway]

What is going on with SpaceX and all these Big Falcon Rocket changes?

What we absolutely love about SpaceX and its founder is that they dream big. For too long, our spaceflight enterprise has moved like molasses when it comes to humans. Then a company like SpaceX comes along and radically shakes things up.

In truth, we still have our doubts about the BFR, as it is such a truly ambitious vehicle. With no government sponsor for the BFR (oops, we mean Super Heavy and Starship), SpaceX may well struggle to get the funding needed to build the rocket and spacecraft. The ongoing design and name changes don't exactly engender our confidence in the project's stability, either. It suggests that Musk is still trying to find the sweet spot between performance, cost effectiveness, and a product he can sell to customers, investors, and the government.

For the sake of humanity, we sure hope he succeeds.

 

[sferrin]

Not exactly Aviation Week.

 

[Flyaway]

Not exactly Aviation Week.

The author of that article is pretty clued up on this stuff especially when it comes to Space X, so such an easy dismissal is not really applicable here.

 

[sferrin]

Not exactly Aviation Week.

The author of that article is pretty clued up on this stuff especially when it comes to Space X, so such an easy dismissal is not really applicable here.

That hasn't been my impression.

 

[Flyaway]

Not exactly Aviation Week.

The author of that article is pretty clued up on this stuff especially when it comes to Space X, so such an easy dismissal is not really applicable here.

That hasn't been my impression.

When clearly my impression differs to yours, and I am not the only one.

 

[sferrin]

Not exactly Aviation Week.

The author of that article is pretty clued up on this stuff especially when it comes to Space X, so such an easy dismissal is not really applicable here.

That hasn't been my impression.

When clearly my impression differs to yours, and I am not the only one.

Lot's of people like Tyler Rogoway too. . . It's not my board, post what you want. More often than not, when I've seen space topics at ArsT, it's been a combination of "ye Gods" and eye-rolls. YMMV

 

[Flyaway]

NASA announces target date for first SpaceX Crew Dragon flight

SpaceX is targeting Jan. 7 for launch of its first Crew Dragon commercial ferry ship on an unpiloted test flight to the International Space Station, NASA announced Wednesday, a major milestone in the agency’s drive to end its sole reliance on Russian Soyuz crew ships for carrying astronauts to orbit.

 

[sferrin]

NASA announces target date for first SpaceX Crew Dragon flight

SpaceX is targeting Jan. 7 for launch of its first Crew Dragon commercial ferry ship on an unpiloted test flight to the International Space Station, NASA announced Wednesday, a major milestone in the agency’s drive to end its sole reliance on Russian Soyuz crew ships for carrying astronauts to orbit.

Will be glad when both them and Boeing have their first flights out of the way.

 

[TomcatViP]

January 7 is right after new year eve. I wonder if NASA will then be there to spy on SpaceX's employee for their blood level of Champagne. When you'll raise your glass at the end of the countdown guys, make sure it's filled with orange juice.

 

[Archibald]

We are living interesting times, really. Saint Elon says three words on Twitter (screw that thing name and spelling) and all of sudden, both Ars Technica and NASAspaceflight.com erupts in never-ending discussions.

 

[sferrin]

We are living interesting times, really. Saint Elon says three words on Twitter (screw that thing name and spelling) and all of sudden, both Ars Technica and NASAspaceflight.com erupts in never-ending discussions.

Lot of jealous rage directed at Elon Musk. He didn't just upset the apple cart WRT spaceflight, he set the thing on fire after.

 

[SteveO]

Any guesses out there what the "delightfully counter-intuitive" redesign will look like?

I'm thinking of the following possibilities -

1) the payload has been moved from the nose to the centre or base and fuel is moved to the nose.

2) it will land nose down via thrust reverser buckets or a raptor engine facing forward ;D

 

[Moose]

Any guesses out there what the "delightfully counter-intuitive" redesign will look like?

I'm thinking of the following possibilities -

1) the payload has been moved from the nose to the centre or base and fuel is moved to the nose.

2) it will land nose down via thrust reverser buckets or a raptor engine facing forward ;D

Over on NSF, there's some momentum behind the notion that the upper stage engines have been moved so that it will land belly-first instead of tail-first, with the booster stage taking all or nearly all the way to orbit to compensate for the less-ideal orientation. I don't see any real supporting evidence from Elon or other SpaceX denizens so it may just be out of control speculation. There's also been talk about the nose becoming more blunt with an aerospike or something like it to compensate for the increased drag.

 

[SteveO]

I'm now picturing a hammerhead upper stage

 

[Flyaway]

FCC license application sheds light on SpaceX vehicle testing plans

SpaceX has filed a license application with the Federal Communications Commission to cover testing at the company’s South Texas launch site of what may be the company’s next-generation launch vehicle.

The application, dated Nov. 19 and posted on a publicly accessible FCC database Nov. 21, seeks an experimental communications license to cover transmissions to and from an unspecified vertical takeoff, vertical landing (VTVL) vehicle that company plans to fly at its launch site under construction on the coast of the Gulf of Mexico near Brownsville, Texas.

 

[Rhinocrates]

Any guesses out there what the "delightfully counter-intuitive" redesign will look like?

IIRC, early concepts that preceded Orion included biconic and lifting body designs. It turned out that they had a hard time reconciling centre of mass and centre of pressure during re-entry. Maybe that's been a driver for a redesign of the BFG.

Falcon 9 1st stages can land with their centres of gravity very low - heavy engines at the base and empty tanks at the top. Certainly Mars will not have perfectly flat landing pads at first, so again, a low centre of gravity would be essential, which would be a good reason to shift the heavy hab and freight nearer to the base of the vehicle.

I wonder what that would mean for Lockheed's weird bottle-shaped thing that's part of their Base Camp concept?

Also, maybe if you have two big fuel tanks at either end of the inhabited section in the middle, you get a little more radiation protection over the duration of the journey than you would with the hab at one end.

Just guesses of course.

 

[Tuna]

Contour remains approx same, but fundamental materials change to airframe, tanks & heatshield

Not my original idea, but something floated on NSF that sounds more and more convincing every time I think of it: They just got help with TUFROC from NASA. They probably found that it's strong enough to form the structure of the craft, and that they can manufacture it right on the mandrel with their existing tools. That is, they are now making their tanks and airframe from their heatshield material, making the entire body of the rocket just a giant cylinder of TUFROC with tank domes in there separating the fuel, oxidizer and cargo areas. Ticks all the boxes, is a pretty radical change, and certainly makes manufacturing the thing easier.

 

[SteveO]

OK, so maybe the "delightfully counter-intuitive" redesign is all about materials and structure rather than a radical change in the look of the vehicle.