Discussion Will the SpaceX push to reusability make ArianeSpace obsolete?

[RGClark]

Just saw this commentary from July by Dr. Tillman Althaus editor of Sterne und Weltraum (Stars and Space) that also argues that by selecting the solid-fueled version of the Ariane 6 that the ESA is going backwards not forwards in technology:

Raumfahrt: Innovation sieht anders aus - Spektrum.de.
http://www.spektrum.de/alias/raumfahrt/innovation-sieht-anders-aus/1200753


Google translation to English:

Comment | 09/07/2013 |
SPACE TRAVEL
Innovation is different.
http://translate.google.com/transla...raumfahrt/innovation-sieht-anders-aus/1200753

Bob Clark

 

[Hlynkacg]

Exactly, the most important point here is to determine if the glass is half-full or half-empty :lol:

The glass is always full of 50% water and 50% air.

(unless it is in vacuum of course)

 

[N_Molson]

The glass is always full of 50% water and 50% air.

If you think to close it with something in a microgravity environnement.

Other exception : below 0°C (at sea level on Earth), the water freezes, and takes more volume (for the exact same quantity, of course).

I wish they tried to fill a glass of water in the LEM while landed, during the Apollo missions. I wonder how it looks. Like in slow motion ? Bigger drops ? More splashing around ?

 

[Hlynkacg]

If you think to close it with something in a microgravity environnement.

Other exception : below 0°C (at sea level on Earth), the water freezes, and takes more volume (for the exact same quantity, of course).

I wish they tried to fill a glass of water in the LEM while landed, during the Apollo missions. I wonder how it looks. Like in slow motion ? Bigger drops ? More splashing around ?

I imagine that you would see bigger drops and more sloshing as surface tension plays a greater role but otherwise normal.

 

[statickid]

I imagine the water would just violently boil away you wouldn't be able to see it pouring due to cloud of steam and vapor.

---------- Post added at 02:11 PM ---------- Previous post was at 02:10 PM ----------

ooohhhhh, i read it again. IN the LEM... hahah sorry

 

[Pipcard]

Another question:

If it is successful, will Skylon make expendable launchers obsolete?

 

[Urwumpe]

Another question:

If it is successful, will Skylon make expendable launchers obsolete?

No. But its successor would then.

 

[N_Molson]

Around 2500-2600 AD probably... :yes:

 

[MattBaker]

If it is successful, will Skylon make expendable launchers obsolete?

Depends on things like turnaround time, maintenance costs etc.
Also the US, Russia and China still need a launch vehicle for their more...secret stuff so they'll be interested in keeping their launchers in business.

 

[C3PO]

Another question:

If it is successful, will Skylon make expendable launchers obsolete?

How about space elevators?

 

[Pipcard]

How about space elevators?

I have doubts that such a structure would be physically possible.

 

[MattBaker]

I have doubts that such a structure would be physically possible.

It's as much possible as a completley reusable, "refuel and go" SSTO. Theoretically possible but in reality at the edge of our possiblities and thus quite hard.

 

[Pipcard]

It's as much possible as a completley reusable, "refuel and go" SSTO. Theoretically possible but in reality at the edge of our possiblities and thus quite hard.

Reusable SSTO

as opposed to

an elevator that is thousands of times taller than the tallest building ever built.

 

[MattBaker]

Reusable SSTO

as opposed to

an elevator that is thousands of times taller than the tallest building ever built.

A spaceplane that has parts having to function thousands of times longer than any of them have ever before

as opposed to

a transpacific cable just into the sky that violates no piece of our understanding of physics.

 

[RGClark]

Another question:
If it is successful, will Skylon make expendable launchers obsolete?

I like the partially air breathing Skylon. A problem I have with it is its huge development cost, $12 billion, according to Wikipedia. It's supposed to be privately funded and I think it will be difficult to raise that much by private financing for such a risky venture.
Perhaps the Skylon team should try a scaled-down version first even if it is only suborbital to demonstrate the technology before proceeding to the full scale version.


Bob Clark

 

[AnjaZoe]

A spaceplane that has parts having to function thousands of times longer than any of them have ever before

as opposed to

a transpacific cable just into the sky that violates no piece of our understanding of physics.

How long is a transpacific cable; how long is a space elevator cable?

Does a transpacific cable need to be able to carry its own weight? Does the space elevator cable need to?

Zoe

 

[C3PO]

Reusable SSTO

as opposed to

an elevator that is thousands of times taller than the tallest building ever built.

A reusable SSTO spaceplane with a turn-around of a few days and the space elevator are so far in the future, that it's impossible to say what will come first.

 

[Evil_Onyx]

How about space elevators?

The issue with space elevators is not is it technologically possible, but is it economically feasible. Just imagine the cost of putting all the hard ware up there and finding a suable counter weight and putting it in to position.

 

[MattBaker]

The issue with space elevators is not is it technologically possible, but is it economically feasible. Just imagine the cost of putting all the hard ware up there and finding a suable counter weight and putting it in to position.

It's a one time investment. It's huge but it would probably turn to profit after a couple of decades, wouldn't it?
I mean calculate the costs of every rocket launch these days...8 Atlas V, 3 Delta IV, 4 Ariane 5, 9 Proton, 15 Soyuz make something like four or five billion per year.
Estimates for a space elevator are something like $40 billion+. Probably $100 billion because let's be honest, numbers by companies are numbers by companies. But that's the costs we put into launch vehicles over two decades, maybe three decades.

Not to mention the possibilities of mining asteroids, the Moon, launch a lot of scientific experiments really cheap, build huge space stations or prostitute...uh...sell your services to governmental exploration programs like probes or manned missions to your favorite destination.


The biggest problem IMHO in space elevators is politics, what would the US do if the Chinese can launch anything for a low prize? Or the other way 'round? Could American companies/NASA/NRO use a Chinese space elevator? Do they want to? The US alone makes up something like two billion bucks in launch vehicles per year.

 

[Urwumpe]

It's a one time investment. It's huge but it would probably turn to profit after a couple of decades, wouldn't it?

Maintenance wouldn't be cheap either. Imagine inspecting 36000 km of tether. Or replace a tether that got damaged by MMOD.

You don't really build a space elevator, you rather build a space elevator industry first and then maintain one.