Recommended Posts

DocM    12,621

 

 

 

  • Like 1

Share this post


Link to post
Share on other sites
DocM    12,621

 

  • Like 1

Share this post


Link to post
Share on other sites
AnotherITguy    142

Nice! Any word on when will the crewed Dragon Will fly?

Share this post


Link to post
Share on other sites
DocM    12,621

The current schedule is for Crew Dragon uncrewed to ISS in early Q1 2017, a crewed flight to ISS in late Q2 2017,  and the in-flight abort test in he middle - reusng  the uncrewed test flights vehicle.

Share this post


Link to post
Share on other sites
DocM    12,621
59 minutes ago, DocM said:

The current schedule is for Crew Dragon uncrewed to ISS in early Q1 2017, a crewed flight to ISS in late Q2 2017,  and the in-flight abort test in he middle - reusng  the uncrewed test flights vehicle.

Dates typo: Q2 &  Q3 2018

  • Like 1

Share this post


Link to post
Share on other sites
IsItPluggedIn    1,663

I hope they dont go public, it is what Musk has always been against, if they go public the he and the company are beholden to the shareholders. It reduces the risk that he can take and increases the regulation that the business needs to abide by. They do need extra money but I hope they can find a way around this.

  • Like 1

Share this post


Link to post
Share on other sites
DocM    12,621

They could go public and issue mostly non voting stock, with the voting stock mostly going to Musk and major stakeholders.

  • Like 1

Share this post


Link to post
Share on other sites
Unobscured Vision    2,133

If it were up to me I'd say keep the company private aside from Investors like they've been doing. No reason to mess up a good thing, and it eliminates the chances of a hostile takeover from OldSpace companies who would do it if given the opportunity.

Share this post


Link to post
Share on other sites
DocM    12,621

Flight (Twice) Proven F9 from Echostar 105/SES-11 & Bulgariasat-1 is home. Octograbber locked her down. 

 

Looks like a leg crush core crushed a bit, but they're easily replaceable.

 

 

  • Like 1

Share this post


Link to post
Share on other sites
DocM    12,621

Q: Why was Raptor thrust reduced from ~300 tons-force to ~170 tons-force?

 

A: The engine thrust dropped roughly in proportion to the vehicle mass reduction from the first IAC talk. In order to be able to land the BF Ship with an engine failure at the worst possible moment, you have to have multiple engines. The difficulty of deep throttling an engine increases in a non-linear way, so 2:1 is fairly easy, but a deep 5:1 is very hard. Granularity is also a big factor. If you just have two engines that do everything, the engine complexity is much higher and, if one fails, you've lost half your power. Btw, we modified the BFS design since IAC to add a third medium area ratio Raptor engine partly for that reason (lose only 1/3 thrust in engine out) and allow landings with higher payload mass for the Earth to Earth transport function.

 

Q: Will the BFS landing propellants have to be actively cooled on the long trip to Mars?

 

A: The main tanks will be vented to vacuum, the outside of the ship is well insulated (primarily for reentry heating) and the nose of the ship will be pointed mostly towards the sun, so very little heat is expected to reach the header tanks. That said, the propellant can be cooled either with a small amount of evaporation. Down the road, we might add a cryocooler.

 

Q: (BFS testing)

 

A: Will be starting with a full-scale Ship doing short hops of a few hundred kilometers altitude and lateral distance. Those are fairly easy on the vehicle, as no heat shield is needed, we can have a large amount of reserve propellant and don't need the high area ratio, deep space Raptor engines.

 

Next step will be doing orbital velocity Ship flights, which will need all of the above. Worth noting that BFS is capable of reaching orbit by itself with low payload, but having the BF Booster increases payload by more than an order of magnitude. Earth is the wrong planet for single stage to orbit. No problemo on Mars.

 

Q: (heat shield)

A: The heat shield plates will be mounted directly to the primary tank wall. That's the most mass efficient way to go. Don't want to build a box in box.

Q: (Tanker)

A: At first, the tanker will just be a ship with no payload. Down the road, we will build a dedicated tanker that will have an extremely high full to empty mass ratio (warning: it will look kinda weird).

Q: (Raptor scaling, Point 2 Point flights)

A: Thrust scaling is the easy part. Very simple to scale the dev Raptor to 170 tons.

The flight engine design is much lighter and tighter, and is extremely focused on reliability. The objective is to meet or exceed passenger airline levels of safety. If our engine is even close to a jet engine in reliability, has a flak shield to protect against a rapid unscheduled disassembly and we have more engines than the typical two of most airliners, then exceeding airline safety should be possible.

That will be especially important for point to point journeys on Earth. The advantage of getting somewhere in 30 mins by rocket instead of 15 hours by plane will be negatively affected if "but also, you might die" is on the ticket. 

 

Edited by DocM
  • Love 1

Share this post


Link to post
Share on other sites
DocM    12,621

 

Q: (BFR/BFS thrusters)

 

A: The control thrusters will be closer in design to the Raptor main chamber than SuperDraco and will be pressure-fed to enable lowest possible impulse bit (no turbopump spin delay).

 

Q: (Raptor construction)

 

A: Some parts of Raptor will be printed, but most of it will be machined forgings. We developed a new metal alloy for the oxygen pump that has both high strength at temperature and won't burn. Pretty much anything will burn in high pressure, hot, almost pure oxygen.

  • Like 1

Share this post


Link to post
Share on other sites
Unobscured Vision    2,133

Niiiiice ... An already-cheap lifter gets super cheap when running in SSTO mode. That'll bode extremely cost-efficient when toting crews to the ISS and other LEO Stations. Just add fuel and go. :yes: 

  • Like 1

Share this post


Link to post
Share on other sites
DocM    12,621

He says an AoM less payload to LEO in SSTO mode, which is still ~14-15 tonnes. That's a lot of Tang & Cheetos.

  • Love 1

Share this post


Link to post
Share on other sites
Unobscured Vision    2,133

Bwahaha ... heheh ... nobody will be able to compete with that for at least ten years. Need another? Load it up, fuel it up and send it up. Week turnaround time, max. (The way NASA does things it'd take two, but w/e)

 

No wonder Orbital sold out. They knew they had no way to win against SpaceX.

Share this post


Link to post
Share on other sites
DocM    12,621

Methinks a weekly turn-around is way longer than they're planning. 

  • Like 1

Share this post


Link to post
Share on other sites
Unobscured Vision    2,133

Good. Shorter = better.

Share this post


Link to post
Share on other sites
DocM    12,621

Q: Who will design and build the ISRU system for the propellant depot, and how far along is it?

 

[ISRU: liqiid methane & liquid oxygen production on Mars, rocket propellants]

A: SpaceX. Design is pretty far along. It's a key part of the whole system.

Q: Why was the location and shape of the BFS header/landing tanks changed?

A: The aspiration by the change was to avoid/minimize plumbing hell, but we don't super love the current header tank/plumbing design. Further refinement is likely.

Q: Second, Elon we need 4K rocket porn

A: Ask and you shall receive

  • Love 1

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Recently Browsing   0 members

    No registered users viewing this page.