SpaceX Reusable Launch System

An animation of a launch of SpaceX Falcon 9 with Dragon showing powered vertical return of both stages and the Dragon

Credits: SpaceX
www.spacex.com/assets/video/spacex-rtls-green.mp4

Category:

Science & Technology

Tags:

• spacex
• VTVL
• reusable
• rocket

[DrZond]

The reason everything they are doing makes fantastic sense to me is that long ago I read a book called "Thrust Into Space" by Maxwell Hunter. It's all about the mass ratio and all the tricky things you can do to finagle it. Geary Hudson has written some great stuff on this too.

[HobbySpacer]

@DrZond I heard Max talk a few times at the Space Access Society conferences. He was clearly a really smart guy and also very soft-spoken and mild mannered. Too bad he isn't around to see what is happening with the suborbital RLVs and to advise SpaceX. Gary still comes to the conferences and always gives an excellent presentation.

[DrZond]

I think this development is fantastic. Question. If this vehicle is taking off from Cape Canaveral, are all stages also landing at Cape Canaveral? Are all stages completing an orbit? including the first?

[HobbySpacer]

@DrZond The animation shows the 3 parts returning to the same site. However, Elon said there were some incorrect details in the animation plus some proprietary details left out. It appears that the 1st stage does not go around but instead flies back to the pad. If that turns out to be too hard, maybe they will try an alternative. E.g. Bezos has a patent app in which the 1st stage lands on an off-shore barge. It looks like the 2nd stage does go around.

[HobbySpacer]

@quotoo Rapid re-flight is crucial for lo costs ops. Need to get all parts back to launch site directly & safely. Parachutes won't do it. Need powered return or to glide. Wings use up wt & useless in space. Wings vs return fuel is a design trade.

Rapid reuse gives a high flight rate that more than makes up for payload mass lost to return system mass.

Fuel is tiny fraction of costs: ~$200k for all fuel vs ~$55M for F9 hardware

Rapid reuse lowers cost to orbit by factor ~100 over ELV.

[HobbySpacer]

"thought it would be inefficient to carry fuel not only for take off but also for landing"

Airplanes do it all the time. It's extremely inefficient to throw a vehicle away for each flight. Far better to sacrifice some payload to gain a huge increase in cost-effectiveness. Can easily make up the lost payload capacity with extra flights.

[Tribersman]

@DrZond

Indeed, but I still consider the idea way too optimistic, clearly the 1st stage didn't reached orbital speed so braking will be easier and parachute can be used

The second stage on the other hand IS on LEO, so they need another abrasive shield, at this point they could even make it into a shuttle.

Conceptually anything that don't leave debris (even on LEO) is cool.

What annoy me is how this video is trying to look awesome "look no parachute", so lying a little.

[PlutonGB]

why dont they use parachutes? isnt that cheaper?

[sufizmjim]

Looks cool, but the amount of fuel needed seems impractical. Then alas, I am no rocket scientist .

[miketv]

@Odo987 I stand corrected....awesome

[Odo987]

@miketv Yes, really. Landing the first stage vertically is actually the easiest of the three recovery scenes. Plenty of rockets have already done this, including DC-X, Scorpius, Project M, Xombie, and Blue Ball.

[miketv]

00:58 really?

[DrZond]

@HobbySpacer Thank you for that answer. It seemed inconceivable that the first stage could amount to a single-stage-to-orbit with the whole upper stages contributing to it's mass.

[docmordrid]

@Zond:

PICA-X is ablative, but very tough. SpaceX estimates their shield could be reused for up to dozens of flights, and measurements taken on the landed Dragon tend to bear that out.