SpaceShip One - No Pressure Suit?

[Carl Orton]

Guess the real question is: At what altitude is a pressure suit required?

Was SpaceShip One pressurized? All we saw was Melville with an O2 mask.

You always see the U2 pilots with full pressure suits, but I guess that
could be because of the duration at altitude? Since Melville was only at
apogee for a few minutes, is this like us requiring O2 only if at altitude
for > 30 mins?

Just noticed and was curious..

[Ron Wanttaja]

On Sat, 26 Jun 2004 12:13:59 -0500, "Carl Orton" >
wrote:

>Guess the real question is: At what altitude is a pressure suit required?
>
>Was SpaceShip One pressurized? All we saw was Melville with an O2 mask.

My interpretation is that the cabin was sealed before takeoff. Negligible
leakage, so the ground-level pressure was maintained through the entire
flight. Melville had a mask to provide oxygen.

Pressure would have built as he exhaled CO2, but some sort of pressure
relief would have been easy to do.

Ron Wanttaja

[Steven P. McNicoll]

"Carl Orton" > wrote in message
...
>
> Guess the real question is: At what altitude is a pressure suit required?
>

Without a pressure cabin, about 50,000 feet.


>
> Was SpaceShip One pressurized?
>

Yes.


>
> All we saw was Melville with an O2 mask.
>

Which won't do him any good at all if the cabin loses pressure at altitude.


>
> You always see the U2 pilots with full pressure suits, but I guess that
> could be because of the duration at altitude? Since Melville was only at
> apogee for a few minutes, is this like us requiring O2 only if at altitude
> for > 30 mins?
>

No.

[[email protected]]

On 26-Jun-2004, "Carl Orton" > wrote:

> Guess the real question is: At what altitude is a pressure suit required?
>
> Was SpaceShip One pressurized? All we saw was Melville with an O2 mask.


It is a certainty that SpaceShip One is "pressurized." Its occupants could
not survive in a vacuum or near-vacuum regardless of available breathing
oxygen. Their blood would literally boil. But the pressurization could not
work like a conventional airplane's, wherein outside air is mechanically
compressed and forced into the cabin. At an altitude of 63 miles there is
virtually no outside air to compress.

I don't know for sure, but I would guess that the SpaceShip One cabin is
maintained at a minimum pressure of maybe 0.4 atmospheres using compressed
gas carried aboard for this purpose. If the gas were pure oxygen, it would
suffice for breathing (as the partial pressure of pure O2 at 0.4 atmospheres
is higher than plain air at sea level). But pure O2 is hazardous, so the
cockpit environment is probably more like regular air, and the occupants
must then use supplemental oxygen.

Anybody know for sure?

--
-Elliott Drucker

[Andrew Gideon]

wrote:

> Anybody know for sure?

While we're at it, I'm curious why they chose to pressurize the cabin rather
than put the pilot into a pressure suit. From my position of pure
ignorance, it would seem that a pressure suit would make for simpler
engineering of the vehicle.

- Andrew

[Elwood Dowd]

The eventual purpose of the project is space tourism. My guess is that
it is easier to fully contain the vehicle than to teach every tourist
with $30k how to operate a pressure suit, not to mention classier.

Not to mention... inflating a cabin is not new science to this
particular batch of engineers.


> While we're at it, I'm curious why they chose to pressurize the cabin rather
> than put the pilot into a pressure suit. From my position of pure
> ignorance, it would seem that a pressure suit would make for simpler
> engineering of the vehicle.

[Roy Smith]

In article >,
Elwood Dowd > wrote:

> The eventual purpose of the project is space tourism. My guess is that
> it is easier to fully contain the vehicle than to teach every tourist
> with $30k how to operate a pressure suit, not to mention classier.
>
> Not to mention... inflating a cabin is not new science to this
> particular batch of engineers.
>
>
> > While we're at it, I'm curious why they chose to pressurize the cabin
> > rather
> > than put the pilot into a pressure suit. From my position of pure
> > ignorance, it would seem that a pressure suit would make for simpler
> > engineering of the vehicle.

You might also gain some structural rigidity by pressurizing the cabin.
The lowly aluminum soda can, for example, depends on the internal
pressure for much of its strength. To get the same strength in an
unpressurized can would require a much greater wall thickness and end up
weighing more.

[Bill Hale]

Check their website. Here's what I gleaned from that...

The vessel holds its sea level pressure. It is doubly redundant,
same as the single container-space suit solution. There is no
pressurization per se. They just let it leak.

They bring in a small amount of oxygen to keep the o2 concentration
steady.

They filter off and dump C02. Bill Hale, in awe

[Carl Orton]

Cool from a "what are the bare requirements" perspective. Shows what *can*
be done for bounded conditions.

Simple elegance.

"Bill Hale" > wrote in message
m...
> Check their website. Here's what I gleaned from that...
>
> The vessel holds its sea level pressure. It is doubly redundant,
> same as the single container-space suit solution. There is no
> pressurization per se. They just let it leak.
>
> They bring in a small amount of oxygen to keep the o2 concentration
> steady.
>
> They filter off and dump C02. Bill Hale, in awe

[Pete Zaitcev]

On Sun, 27 Jun 2004 08:02:31 -0700, Bill Hale wrote:

> Check their website. Here's what I gleaned from that...
>
> The vessel holds its sea level pressure. It is doubly redundant,
> same as the single container-space suit solution. There is no
> pressurization per se. They just let it leak.

This is an interesting solution considering that while the
space trip takes only minutes, the craft spends more than an
hour under the belly of the carrier plane.

-- Pete