Spaceplanes - Cases for and Against

[Eric Mc]

Sneaky.

[Beati Dogu]

Word is SpaceX have won an Air Force contract to launch an X-37B on top of a Falcon 9 in August. Previous launches have all been done with Atlas V rockets.

http://www.reuters.com/article/space-spacex-idUSL1...

[Eric Mc]

Recoverable 1st stage.

Recoverable payload.

We're nearly there.

[RobDickinson]

Interesting!

[Einion Yrth]

Eric Mc said:

Recoverable 1st stage.

Recoverable payload.

We're nearly there.

Dragon is recoverable, and as demonstrated on CRS 11, reusable. It's the second stage that presents the problem.

[Eric Mc]

I know.

Recoverable is one thing, reusable is another.

SpaceX has only flown one Dragon capsule into orbit twice - so they are beginning to achieve resuability with the capsule. I don't know how many missions each Dragon will undertake once reusability becomes the norm.

The X-37 has been reusable from the start and I would expect that it has a theoretically fairly unlimited life as a reusable vehicle.

[annodomini2]

The main question atm with regards to reuse is how much is SpaceX rebuilding their current systems for reuse?

Which they are not reporting and suggests more than they would like.

[Eric Mc]

I would assume that the base heatshield of the Dragon capsule needs to be replaced after each mission. Maybe someone can clarify if this is the case?

[Einion Yrth]

Eric Mc said:

I would assume that the base heatshield of the Dragon capsule needs to be replaced after each mission. Maybe someone can clarify if this is the case?

The PICA-X TPS was designed to be reflown, this was back in 2013 though and I've not heard whether that remains the intention; we shall see.

[Caruso]

annodomini2 said:

The main question atm with regards to reuse is how much is SpaceX rebuilding their current systems for reuse?

Which they are not reporting and suggests more than they would like.

I did read somewhere that they are still making changes to the 1st stage booster to make it easier to reuse e.g. going from Aluminium to Titanium for the grid fins. It may explain why they don't want to publish data because the reusability work isn't done yet.

[Eric Mc]

Einion Yrth said:

The PICA-X TPS was designed to be reflown, this was back in 2013 though and I've not heard whether that remains the intention; we shall see.

The one they have re-flown - did it use its original heatshield or a replacement one?

[Einion Yrth]

Eric Mc said:

Einion Yrth said:

The PICA-X TPS was designed to be reflown, this was back in 2013 though and I've not heard whether that remains the intention; we shall see.

The one they have re-flown - did it use its original heatshield or a replacement one?

It would be reasonable to infer from my post, that I don't know.

[RizzoTheRat]

This suggests the heatshield can be reused hundreds of times
http://www.spacex.com/news/2013/04/04/pica-heat-sh...

But given that the A stands for "Ablator" that seems rather surprising. If it's ablating but can do multiple re-entries doesn't that mean it's heavier than it needs to be?

I'd see ablative cooling as being a bit like fuel, you wouldn't consider the first stage not be fully reusable because it came back without it's fuel.

[Eric Mc]

Einion Yrth said:

Eric Mc said:

Einion Yrth said:

The PICA-X TPS was designed to be reflown, this was back in 2013 though and I've not heard whether that remains the intention; we shall see.

The one they have re-flown - did it use its original heatshield or a replacement one?

It would be reasonable to infer from my post, that I don't know.

I wasn't asking you specifically. It was a general question to anyone who might know.

The Orion craft was intended to have what they call a multi-use "monolithic" heatshield. However, its heatshield has to withstand much higher heating than a spacecraft endures re-entering from earth orbit. As a result, the test flight of Orion in December 2014 used an ablative heatshild using Apollo style technology. The sides of the Orion, which experience much less heat than the base, uses silica tiles based on those used on the Shuttle.

[MartG]

Caruso said:

annodomini2 said:

The main question atm with regards to reuse is how much is SpaceX rebuilding their current systems for reuse?

Which they are not reporting and suggests more than they would like.

I did read somewhere that they are still making changes to the 1st stage booster to make it easier to reuse e.g. going from Aluminium to Titanium for the grid fins. It may explain why they don't want to publish data because the reusability work isn't done yet.

There is supposed to be a 'Block 5' Falcon 9 design debuting later this year which is said to include all the lessons learned from recovering the current design of it ( as well as having greater payload )

[Beati Dogu]

It's kinda funny that a Boeing built spacecraft is to be put up on a SpaceX rocket.

In fact, Tony Bruno, the President & CEO of ULA (a Boeing & Lockheed Martin joint venture who also make the Atlas V) says they weren't asked to bid on the next X-37B launch.

[Eric Mc]

The new Boeing XS-1 - which is going to be called the Phantom Express -





Essentially, it is a winged flyback booster with an expendable payload booster mounted on the back.

Reminds me somewhat of some of the earliest Space Shuttle concepts -

[MartG]

Interesting that Boeing seem to think the mass penalty of wings is preferable to that of fuel for a vertical recovery a la SpaceX.

[Eric Mc]

I suppose with modern materials wings aren't as heavy as they used to be.

[Sylvaforever]

2fast748 said:

Eric Mc said:

That sneaked in.

I was surprised to hear it had landed after all of the speculation a while ago when NOTAMs were published but nothing happened.

It's an intriguing piece of kit, I suspect it's being used as a recyclable spy sat as much as anything. Isn't the average satellite build time 10 years so any tech on it isn't that cutting edge by the time it launches? With this thing the latest and not necessarily most reliable things can be put up with little regard for the longevity as they know its coming back anyway.

Good points there.