RCgothic

Anyone got any clue what this might be? TFR for Friday, possibly Static Fire Wednesday.

Having finished the video, I'd agree that seems like a fair assessment. I do think it would be mad not to try and keep Starship in the mix just because it has *so* much capability. But it's probably going to the moon at some point whether or not NASA funds it.

FSH, HLS, SLS. NASA. Your names are bad and you should feel bad.

Based on 100t payload to LEO, 30t landing propellant, a regular Starship mass of 80t, and an ISP of 370s, Starship can push ~88t total to TLI. An expendable starship can ditch all the unnecessary weight, heat shield, fins, fairing. Falcon9 upper stage has a dry weight to propellant ratio of 4%. The square cube law is friendly to Starship. If expendable Starship weighs 4% of 1250t of propellant dry, that's 50t. So Starship Expendable can send ~38t to TLI without considering expending Superheavy. But that's not the best use of a Starship. Raptors are super-cheap by engine standards. Put a 3t Raptor powered kick stage on top of Starship, and send 38t to TLI without even expending Starship. ... And whilst we're at it, 370s ISP and a Methalox mass fraction trump 465s ISP on an EUS. An RVac kick stage weighing 99t wet can put a 1t payload through over an extra 1km/s compared to EUS weighing 130t in LEO. Assuming the 1t payload could get there on an SLS without being shaken to pieces.

Do you want to crash a spacecraft? Because that's how you crash a spacecraft. ;-p Gives them six months' float to beat SLS to orbit. It'll be so so funny if SLS is never the world's most powerful rocket.

Dragon XL getting a highlight today.

Some new Dragon XL art

Vibration is difficult to deal with. A tethered platform at a distance from the main barge would be outside the vibration zone, but it's probably not worth the cost of setting up and collecting each launch.

I suspect so. I don't recall any proper attempts since one of the ships took a bad knock to the radar. Perhaps they figure there's too much risk of damage, and if fishing the fairings out of the ocean works...

Got to pick up the build pace! They're in danger of not having a fresh prototype ready to go immediately after launch.

Without the drop tanks it becomes single stage, which would be huge?

Looking forward to flight nine!

I don't think tower catch is going to be that difficult really. Hover by the tower and have multiple redundant arms grab some passive grab targets. It's nothing Boston Dynamics couldn't do in their sleep. Might take SpaceX a few tries to catch up, but it's neither impossible nor infeasible.

They didn't quite get to static fire today.

Orbital Launch Tower pilings are now visible:

I think getting authorisation for BN1 to significantly depart from the airspace over the site may be a challenge at this stage. I'm betting pretty much straight up and down again. But it could be to 10km rather than 150m SN5/6 style.

BN1 is in stack up:

SN11 was cryo-proofed last night and tested RCS thrusters, clearing the way to static fire. Apparently they've changed some of the venting locations for this prototype as well.

I don't like the heat shield contacting regolith tbh.

An interesting article. I think the biggest takeaway is the chief scientist at arecibo doesn't want to replace it like for like, but with a compact parabolic reflector array on a tiltable platform situated within the arecibo depression. It'd have twice the sky coverage (including visibility of the galactic core) and five times the radar power. Current estimate is under half a billion dollars. https://skyandtelescope.org/astronomy-news/arecibo-to-be-determined-future/

I agree with your analysis that a 1st stage for a rocket with half the payload of Falcon 9probably weighs about half as much, ~14t, and that six Rutherford's aren't going to cut it for a landing. Probably needs at least 9 auxiliary Rutherfords, (octoweb arrangement?) and they'd have to be firing on ascent so as not to be dead weight whilst retaining enough charge for a landing. Rutherfords are only 25cm across though, so it's easy to squeeze 9 into a 1.5m diameter, leaving a 1.5m wide annulus for the main engines. For a takeoff TWR of 1.5 Neutron would need ~4MN of thrust. Nine Rutherfords barely dent that. And it'll need four more engines more powerful than Merlin 1D. Or alternatively six 640kN engines. Feasible. 15 is a lot of engines for a first stage though.

I presume vestigial helium tanks are just a small mass penalty and they always planned to go back to autogenous pressurisation and so never removed the system.

As tater said, SN12, 13 and 14 were scrapped due to (as yet unknown) upgrades to SN15 and subsequent prototypes. (Landings excepted) testing has gone pretty smoothly so far, so it wouldn't be worth delaying flight experience with SN15-type prototypes in order to get more flight experience with SN8-type ones. Totally worth the manufacturing practice though.

Helium ingestion caused low thrust. Oops.