Register here

Author Topic: SpaceX (general discussion)  (Read 154410 times)

Offline Michel Van

  • Senior Member
  • CLEARANCE: Top Secret
  • **
  • Posts: 3854
Re: SpaceX (general discussion)
« Reply #1080 on: March 14, 2018, 10:39:26 am »
My SWAG would be "before 2025 but not much".

edit:  I'm wondering how much trouble they'll have with the heat shield.  The upper stage is far larger than the Shuttle Orbiter and it has to deal with higher reentry speeds.  (Coming back from the moon - something like 25k mph- and from Mars.)

Here is SpaceX again innovative:
they took NASA "Phenolic impregnated carbon ablator" short PICA and improved it to PICA-X
standard lightweight PICA withstand 12.4 km/s (28,000 mph) at 135 km altitude with Stardust sample-return capsule

While PICA-X ver 1 & 2 were innovative in more easier production and  lower cost on Dragon 1 & 2
now work SpaceX on PICA-X version 3, improves upon its heat shielding capacity, guess what for BFR !

Dan Rasky: about SpaceX's Rapid Prototyping Design Process in 2016.

Source Wiki
I love Strange Technology

Offline Flyaway

  • CLEARANCE: Top Secret
  • ***
  • Posts: 1180
Re: SpaceX (general discussion)
« Reply #1081 on: March 15, 2018, 10:48:49 am »
SpaceX wins lucrative new contracts to fly GPS and earth-imaging satellites

The US Air Force has announced a deal with SpaceX, Elon Musk’s rocket company, to fly three of the newest generation of Global Positioning System satellites into space, at an average cost of $97 million per flight. The service also contracted with United Launch Alliance, a joint venture of Boeing and Lockheed Martin, for two launches carrying space-surveillance satellites and some experimental hardware, at an average cost of $177 million per flight.

Yet in the commercial world, price is king: SpaceX also announced a deal with DigitalGlobe, a satellite imaging company, to launch two new satellites in 2020, on previously-flown Falcon 9 rockets. While those prices were not disclosed, Musk has said previously that flying on a reused rocket could come with a 30% discount. SpaceX is the only company operating reusable boosters, and has flown six missions using them.

Offline Tuna

  • CLEARANCE: Restricted
  • Posts: 3
  • I really should change my personal text
Re: SpaceX (general discussion)
« Reply #1082 on: Yesterday at 10:31:57 am »

Interesting video fredymac, it is a wonder why SpaceX are even bothering with the Block 5 Falcon 9 rocket when they said that all future production of the Falcon 9 would be stopped and all future production would be concentrated on the BFR?  ???  :-\

No, SpaceX said all future development will be stopped. They have at least 50 launches on the manifest for the next 4 years, and can't just postpone those indefinitely until BFR is operational.

Watched that video earlier today and if I remember correctly they said the block 5 is the design freeze point for Falcon 9 and after seven successful launches of the block 5 standard it can be classed as human spaceflight/astronaut rated.

Design and engineering efforts switch to BFR while block 5 is in production I believe.

I would like to point out that the developement freeze is imposed on SpaceX by NASA. SpaceX likes incremental development, making small changes to almost every successive rocket, tweaking it to get a little bit more performance every launch, as opposed to making the design what they want from the beginning and sticking with it. NASA is pretty adamantly opposed to this, because they feel that each change in the rocket introduces the possibility of a previously unknown safety issue. To be fair, they have a point -- the loss of AMOS-6 was a textbook example of such an occurrence. SpaceX had introduced densified propellant, oxidizer and even densified helium pressurization fluid, to fit more into the same tanks and to push more through with the same pumps. The densified helium caused some of the oxidizer to freeze solid, which eventually caused the loss of the vehicle and it's payload. However, at the same time it was tweaks like densification that allowed Falcon 9 to reach the kind of performance that makes reusability viable at a low cost.

But anyway, one of the criteria NASA has set for commercial operators to human-rate their rockets is to launch exactly the same design, with no changes *at all* for a given number of times, IIRC 9. SpaceX has chosen "Block 5" to be this point where the development of Falcon 9 ends. Now, of course, all their development engineers had no more work to do on the F9, so it of course makes sense for them to start working on the next big thing.