SpaceX Starship booster catch!

[Steveml63]

Did anybody just see the live launch of the latest SpaceX Starship?
The booster stage separated from the main rocket and then came back down to earth.
As it got closer - the rockets reignited to slow it down and it was then caught back on the tower it lifted off from just a few minutes earlier!
It was incredible to watch and an amazing feat of engineering!!!

 

[whitenemesis]

Quite remarkable!!

SpaceX catches Starship rocket booster for first time ever as it returns to Earth after launch

Elon Musk's SpaceX has succeeded in catching the Super Heavy booster as it returned to the launchpad in Texas.

www.bbc.co.uk

 

[Ted]

Amazing tech!
But wouldn’t it need much more fuel than just parachuting into the ocean after it has jettisoned?

 

[ToeKnee]

Amazing tech!
But wouldn’t it need much more fuel than just parachuting into the ocean after it has jettisoned?

What about the fuel used to collect it, dry it and transport it back to the silo?

 

[Ted]

Yes, but surely the amount of fuel to lift the extra weight (of fuel!) would be considerable.
Genuine question.
I’m also guessing that the salt water might cause some damage.

 

[ChrisPDuck]

Amazing tech!
But wouldn’t it need much more fuel than just parachuting into the ocean after it has jettisoned?

Indeed - The Rocket Problem. But in this case the booster is virtually empty (apart from the landing fuel), and the landing burn is short (~30s), so the extra fuel needed to carry the landing fuel is evidently worth the saving in re-using the booster. I would imagine that falling into the sea would destroy the booster - hitting water at speed is almost like hitting concrete.

 

[Ted]

Well the Apollo capsules with three astronauts managed ok.
From a somewhat greater height.

Thing is, you need extra EXTRA fuel to compensate for the weight of the extra fuel needed to burn for the landing.

 

[SpikyMikey]

Impressive, althought the last minute 'gimballing' to line it up looked a tad worrying for a while

 

[ChrisPDuck]

Well the Apollo capsules with three astronauts managed ok.
From a somewhat greater height.

Yes, I guess parachutes would have solved that, you're right!

Thing is, you need extra EXTRA fuel to compensate for the weight of the extra fuel needed to burn for the landing.

Exactly - and then extra fuel to compensate for THAT extra fuel. The definition of the Rocket Problem.

 

[Chrishazle]

Shame the video quality went TU for the water landing of the Ship, especially as the Starlink kit gave superb video during re-entry - what's the betting the next flight will include attempted landing of the Ship on either one of their offshore facilities or a land pad?? Hope they can recover the Ship quickly, the heat on the flaps looked severe and that was one of the points of real interest on this flight.

 

[markjay]

Well the Apollo capsules with three astronauts managed ok.
From a somewhat greater height.

Thing is, you need extra EXTRA fuel to compensate for the weight of the extra fuel needed to burn for the landing.

The Apollo capsule was retrievable, but not reusable. They were never used more than once.

Not sure that damage can be completely avoided if using parachutes (and, parachutes mean extra weight anyway...).

 

[Ted]

The Apollo capsule was retrievable, but not reusable. They were never used more than once.

I used that example to show that if parachutes are deployed, little or no damage is incurred when it hits the water.
Remember, the Ruskies used to land on dry land!
Fair point on the additional weight of the parachute(s)
I’m sure there must be a valid reason, even if it is just to satisfy a certain person’s ego.

 

[whitenemesis]

I’m sure there must be a valid reason

Economics? Must be cheaper to build the booster once and reuse it x number of times.

 

[markjay]

I used that example to show that if parachutes are deployed, little or no damage is incurred when it hits the water.
Remember, the Ruskies used to land on dry land!
Fair point on the additional weight of the parachute(s)
I’m sure there must be a valid reason, even if it is just to satisfy a certain person’s ego.

I am guessing that making the booster's electronics waterproof, and adding a floatation device, means (again) more weight, in addition to the weight of the parachutes...

 

[190]

Amazing tech!
But wouldn’t it need much more fuel than just parachuting into the ocean after it has jettisoned?

While it's remarkable that it's able to carry enough fuel to go up and come back down again, it's not as much extra weight as we might think. Empty at 275 tonnes the stage weighs less than 7.5% of it's launch weight of 3675 tonnes so if the return fuel required is in similar proportion then it's not all that much extra to carry. Even more remarkable to me is the guidance and stability control that allows it such a precision landing given It's such big thing, much bigger than Apollo's Saturn 5.

 

[m80]

It surely should be electric.
But the weight of the extra batteries for return might be an issue.

Mind, if they only launch in daylight they could use solar.

 

[Petrol Pete]

Better to bring your expensive bit of (secret) tech back to private property than to drop it into the sea in which a private individual has no jurisdiction.

 

[TC350]

I'm still impressed that Elon was able to reverse park his rocket, while there are many folk who can't reverse park their cars!

 

[st13phil]

Empty at 275 tonnes the stage weighs less than 7.5% of it's launch weight of 3675 tonnes so if the return fuel required is in similar proportion then it's not all that much extra to carry.

AIUI, the big prize is economic re-use of the stage which SpaceX have deemed impossible for an ocean drop, so it has to return to dry land.

The next leap was to do away with the legs the booster would conventionally have to carry in order to land, and transfer that mass to the gantry that catches the booster.

All in all, they demonstrated a very clever leap forward.

 

[flying haggis]

But was it a "giant leap"...