Quote:
Originally Posted by byblow
I would love to hear opinions about Elon Musk's announcement a
fully reusable, two-stage launcher. In this SpaceX animated video --
http://www.youtube.com/watch?v=p176UpWQOs4 -- the launcher reminds me
of the Falcon 9; it looks like the first stage has nine engines. |
How can anyone fail to admire SpaceX for attempting this? The video is awe-inspiring. I'm sure many rocket experts have already dissected it frame-by-frame, but I've found no such discussions online. Perhaps that can begin here...
For my part, a few layman's observations and questions:
First Stage:
- Yes, it looks a lot like Falcon 9, byblow. SpaceX says they're all about economies of scale, so I guess it's no surprise this appears to be an evolutionary design.
- It's nice how the landing gear fold into aerodynamic nacelles and tuck against the body for launch.
- Is there an ablative surface on the front of the first stage? The video doesn't show this clearly. However, after separation the second stage appears to fire against the first stage as it departs. A clever way of conserving energy and saving fuel?
- What happens to the black interstage element between separation and landing? Does it retract into the body somehow?
Second stage:
- Look at how the rocket nozzle both emerges from and contracts into the body, with the landing gear rocking in and out to provide clearance - very clever.
- The ablative surface is asymmetrical, with more of it on one side. That means there's only one good orientation for re-entry, yes?
- Will the ablative surface pose any difficulties for mating the payload atop it?
- After the re-entry burn we don't see the main rocket firing again; as the stage touches down we only see small, side-rockets firing. Any thoughts as to what's going on here?
Dragon:
- Do we see anything which hasn't been shown in previous videos? It doesn't appear so, but perhaps I'm missing something.
- What is the small surface, shown at the 'top' of Dragon, which folds down prior to ISS docking?
Wow, so much going on here. Somebody please help me out: for SpaceX to pull this off, are they banking on using atmospheric oxygen for the propulsive landings? It seems doing so could save a great deal of weight, but... is such an approach readily possible? Do there exist rocket engines with the ability to switch from LOX to air-derived O2?