Advanced Re-Entry Vehicle

[Thinking Aloud]

Yes but the shuttle could be flown, so it could obviously be controlled so that it neither skipped nor descended too fast. You could fly it, just like any plane.

But only once it's in the atmosphere. Those wings won't provide much lift where there's no air.

[Atheist-Lite]

Yes but the shuttle could be flown, so it could obviously be controlled so that it neither skipped nor descended too fast. You could fly it, just like any plane.

But only once it's in the atmosphere. Those wings won't provide much lift where there's no air.

The flying brick...20* angle of descent - hardly just like any plane.

[mistermack]

Yes but the shuttle could be flown, so it could obviously be controlled so that it neither skipped nor descended too fast. You could fly it, just like any plane.

But only once it's in the atmosphere. Those wings won't provide much lift where there's no air.

No, but you don't need much lift, when you are travelling at near-orbit speeds.
When in orbit, the shuttle is effectively weightless, and the required lift increases gradually as it slows, and as the air gets denser.

It's not just like a plane, but the shuttle IS flown, and controlled, as it says in Wikipedia. It's a compromise vehicle, that can fly in re-entry, and land conventionally.
That's why it has to be 2000 tons weight.

The Apollo re-entry capsule was tiny, but it did the job.

[mistermack]

Big correction required :

It appears that when Wikipedia list the weight of the shuttle as about 2,000 tons, they are referring to the total weight, including the fuel tank, the solid rocket boosters, and all of the fuel. It's not very clear, in fact it's totally unclear, and they don't appear to have given the weight of what I would call the shuttle, the bit that lands, at all. So best to ignore the shit I just wrote. In fact that's always good advice.

Edit : The "shuttle" part is called the orbiter in tech language, and weighs about 100 tons when it lands.

This compares with about 1.5 tons for the Apollo command module.

[MiM]

I can't really read this, because it's coded with some odd measurement system that I suppose is used widely in the English speaking world. But it seems to be aiming rather straight at your point.

http://exoaviation.webs.com/pdf_files/A ... -Entry.pdf

[mistermack]

I can't really read this, because it's coded with some odd measurement system that I suppose is used widely in the English speaking world. But it seems to be aiming rather straight at your point.

http://exoaviation.webs.com/pdf_files/A ... -Entry.pdf

Yes, it does cover it well. The straight forward free-fall is what they call "ballistic", and it was used for John Glenn. The g force of 8g would make it unusable though, for people who had spent some time in weightless conditions, compared to the "lifting" re-entry of the space shuttle, of 0.5 to 1 g.

I'm sure there are good reasons why not, but I would try to design something that re-entered more gradually, with a fail-safe design that pretty much would fly itself without breaking up. There are shapes that can maintain their attitude automatically, especially if there is something dragging from the rear, like I suggested.

John Glenn's vehicle weighed a ton. The Apollo command module was about 1.5 tons.
So with today's materials, and computing power, it should be possible to make a very lightweight and safe re-entry vehicle, of a ton, or less, that could be steered and landed fairly accurately.

The lighter the vehicle, the less heat generated, so it's the way to go I would think.

[Cormac]

Will the Virgin 1 type of tech ever get into useful orbit? If so, what are its re-entry characteristics?

(Heh hey, I said re-ENTRY)

[mistermack]

Will the Virgin 1 type of tech ever get into useful orbit? If so, what are its re-entry characteristics?

(Heh hey, I said re-ENTRY)

The virgin vehicle isn't designed to go into orbit. It would take a far far bigger version to do that. It just goes up into space, and comes back down, like a glorified air balloon.

It will certainly leave the atmosphere, and will give the impression of weightlessness, for just six minutes, as it free-falls back down to air that is dense enough to support it.

But there is no ability to reach the huge speeds of around 17,000 mph that are needed to go into orbit like the space station, not the ability to re-enter from orbit.

As it never reaches these high speeds, it doesn't need all of the heat shielding to slow it down on re-entry.

[Cormac]

Will the Virgin 1 type of tech ever get into useful orbit? If so, what are its re-entry characteristics?

(Heh hey, I said re-ENTRY)

The virgin vehicle isn't designed to go into orbit. It would take a far far bigger version to do that. It just goes up into space, and comes back down, like a glorified air balloon.

It will certainly leave the atmosphere, and will give the impression of weightlessness, for just six minutes, as it free-falls back down to air that is dense enough to support it.

But there is no ability to reach the huge speeds of around 17,000 mph that are needed to go into orbit like the space station, not the ability to re-enter from orbit.
I knew that their first commercial one won't, but didn't know if they'd plans or if it were possible to develop the approach into a try orbit capable machine.



As it never reaches these high speeds, it doesn't need all of the heat shielding to slow it down on re-entry.

[mistermack]

I'm pretty sure from memory that Virgin's hard plans are just for sub-orbital flight, with about six minutes weightlessness.

They also have plans to be able to put small satellites actually into orbit. Presumably by firing a small rocket when they reach the highest point of the flight. (I'm just guessing there).

But there is no hard planning for putting humans into orbit, just an aspiration to do it at a later date. I'm sure that they COULD do it, but they would have to have a firm idea of what kind of demand to expect, as the budget would be billions.

If it was less than billions, NASA would be going that way themselves, I would have thought.

[Cormac]

I'm pretty sure from memory that Virgin's hard plans are just for sub-orbital flight, with about six minutes weightlessness.

They also have plans to be able to put small satellites actually into orbit. Presumably by firing a small rocket when they reach the highest point of the flight. (I'm just guessing there).

But there is no hard planning for putting humans into orbit, just an aspiration to do it at a later date. I'm sure that they COULD do it, but they would have to have a firm idea of what kind of demand to expect, as the budget would be billions.

If it was less than billions, NASA would be going that way themselves, I would have thought.

I think the world needs a big space project, with something that is visually cool, and awesomely inspiring - like Apollo and the Shuttle were in their day.

(We also need a modern version of Concorde).


These projects need to be done on an accelerated scale - less than 10 years. They had more balls in the 50s, 60s, and 70s, and a much better appetite for big inspirational projects than we do now.

[mistermack]

These projects need to be done on an accelerated scale - less than 10 years. They had more balls in the 50s, 60s, and 70s, and a much better appetite for big inspirational projects than we do now.

Yeh, I think it's because of the modern climate where governments are hugely in debt.
Private capital has an easy time, these days, they can lend to governments and get good rates without much risk.
That's why there isn't much risk-taking going on privately. You've got to hand it to Richard Branson in that regard.

The US got phenomenally rich from the 2nd World War, so Kennedy could afford a big project, with what he had in the bank. It's not so cosy now.

[Cormac]

These projects need to be done on an accelerated scale - less than 10 years. They had more balls in the 50s, 60s, and 70s, and a much better appetite for big inspirational projects than we do now.

Yeh, I think it's because of the modern climate where governments are hugely in debt.
Private capital has an easy time, these days, they can lend to governments and get good rates without much risk.
That's why there isn't much risk-taking going on privately. You've got to hand it to Richard Branson in that regard.

The US got phenomenally rich from the 2nd World War, so Kennedy could afford a big project, with what he had in the bank. It's not so cosy now.

Good points.

Also, too much money being spent on extremely expensive weapons and wars...

[FBM]

When you decelerate from orbit, you automatically lose altitude unless you apply lifting thrust, which would require that the spacecraft lug around huge amounts of extra fuel, from lift-off to mission completion. You'd wind up hauling so much fuel per tonne of payload that the whole thing would turn out to be unfeasable.

[leo-rcc]