China to launch Shenzhou-7 between Sept. 25-30

[JamesG]

The knees up and bent positioning seems like it would be very awkward especally under hi-g. Notice that they were using a stick to push buttons on the control panel. LOL!

 

[Moonwalker]

Notice that they were using a stick to push buttons on the control panel. LOL!

That's not something new. That's also the case onboard Soyuz.

 

[Master of Blades]

{image}

OMG, there are many people around the launch pad! :blink:

Well... I must say that the Chinese have better photographers than NASA, this picture really looks "epic"

 

[SiberianTiger]

The knees up and bent positioning seems like it would be very awkward especally under hi-g.

Quite opposite, the spacesuit is designed to provide most comfort in this position. Also, it helps to let more blood to flow into the brain vessels.

Notice that they were using a stick to push buttons on the control panel. LOL!

Didn't Apollo crews have the same?

 

[Moonwalker]

Well... I must say that the Chinese have better photographers than NASA, this picture really looks "epic"

Are you serious? :blink:

http://www.nasa.gov/images/content/276640main_2onpad_full.jpg

http://spaceflight.nasa.gov/gallery/images/shuttle/sts-124/hires/sts124-s-024.jpg

http://spaceflight.nasa.gov/gallery/images/shuttle/sts-123/hires/iss016e032708.jpg

http://www.nasa.gov/images/content/273501main_uplift-lg.jpg

 

[Urwumpe]

Didn't Apollo crews have the same?

No, Apollo was almost flying with their heads against the panel. But the Shuttle has such a stick on-board. It is just rarely used.

 

[Moonwalker]

No, Apollo was almost flying with their heads against the panel. But the Shuttle has such a stick on-board. It is just rarely used.

It's basically used during entry. Isn't it?

 

[Urwumpe]

It's basically used during entry. Isn't it?

Not automatically - except in emergency, you don't need to operate switches, which you can't reach from your seat. The MLS and TACAN switches would be the critical objects, but these are usually set before seating.

 

[Moonwalker]

Not automatically - except in emergency, you don't need to operate switches, which you can't reach from your seat. The MLS and TACAN switches would be the critical objects, but these are usually set before seating.

Sure you don't operate switches which you can't reach from your seat But I noticed that they use a small stick to point to data displayed on the MFD's/CRT's during entry.

Concerning TACAN: I think it got replaced by GPS together with the MEDS update or a little later. And I'm not quite sure about the MLS today. On earlier missions it was enabled during TAEM.

 

[Urwumpe]

Concerning TACAN: I think it got replaced by GPS together with the MEDS update or a little later. And I'm not quite sure about the MLS today. On earlier missions it was enabled during TAEM.

TACAN does still exist in the Shuttle, the checklists mention it.

MLS is enabled, but not included in the guidance - that Inclusion is a task you do with the keyboard.

 

[Moonwalker]

TACAN does still exist in the Shuttle, the checklists mention it.

Depends on the mission checklists and so the corresponding Shuttle you were looking at

The STS-123 checklists for example don't mention TACAN at all but GPS instead. Not a miracle since the TACAN onboard Endeavour got replaced by the GPS before STS-118. On overhead panel O7 you can find switches for GPS 1 to 3 now instead of TACAN 1 to 3 and its channel selectors (the corresponding HSI source selector switch labels on panel F6 & F8 changed from TACAN to GPS as well).

I didn't knew it too before using SSM07 which can be a gain of knowledge Sadly it doesn't simulate TACAN on older missions, but it doesn't make a difference really beside the missing channel selectors. Meanwhile TACAN is going to be out of date anyway.

http://en.wikipedia.org/wiki/STS-118

 

[Urwumpe]

Depends on the mission checklists and so the corresponding Shuttle you were looking at

Of course. No Orbiter is like the other.

The STS-123 checklists for example don't mention TACAN at all but GPS instead. Not a miracle since the TACAN onboard Endeavour got replaced by the GPS before STS-118. On overhead panel O7 you can find switches for GPS 1 to 3 now instead of TACAN 1 to 3 and its channel selectors (the corresponding HSI source selector switch labels on panel F6 & F8 changed from TACAN to GPS as well).

Endeavour is also the most special of all orbiters. It has many differences, not only in the navigation gear, but also in communication systems and power subsystem. But still, the other two still use TACAN and will do so until their retirement.

I didn't knew it too before using SSM07 which can be a gain of knowledge Sadly it doesn't simulate TACAN on older missions, but it doesn't make a difference really beside the missing channel selectors. Meanwhile TACAN is going to be out of date anyway.

I would not bet on that. TACAN and MLS will not get replaced that easy by satellite navigation, until LAAS can replace the extra data, these emitters provide. TACAN is more than a VOR, and MLS far more as a better ILS. LAAS will provide a lot of the extra information transmitted, but LAAS is still in development.

 

[Moonwalker]

I would not bet on that. TACAN and MLS will not get replaced that easy by satellite navigation, until LAAS can replace the extra data, these emitters provide. TACAN is more than a VOR, and MLS far more as a better ILS. LAAS will provide a lot of the extra information transmitted, but LAAS is still in development.

Ground based nav aids are not the future anymore. Of course they're still used and also mandatory for IFR, still. But GPS is more and more replacing ground based nav aids used for enroute navigation, less than ever in civil/commercial aviation (TACAN isn't used on commercial airplanes anyway).

 

[Urwumpe]

Ground based nav aids are not the future anymore. Of course they're still used and also mandatory for IFR, still. But GPS is more and more replacing ground based nav aids used for enroute navigation, less than ever in civil/commercial aviation (TACAN isn't used on commercial airplanes anyway).

Yes, TACAN is a military system - and if I remember correctly, also the basis for carrier landing systems - and air refueling.

The problem with GPS is it's accuracy. It is better as TACAN, but still even with all augmentation systems available, on a factor 3-8 less accurate as even Cat 1 ILS. That's why LAAS (local area augmentation system) still can't replace ILS or MLS. LAAS also supplies the information, MLS transmits to the plane (Runway data), so it will at one point be able to place them - but it is not operation yet.

 

[Moonwalker]

Yes, TACAN is a military system - and if I remember correctly, also the basis for carrier landing systems - and air refueling.

The problem with GPS is it's accuracy. It is better as TACAN, but still even with all augmentation systems available, on a factor 3-8 less accurate as even Cat 1 ILS. That's why LAAS (local area augmentation system) still can't replace ILS or MLS. LAAS also supplies the information, MLS transmits to the plane (Runway data), so it will at one point be able to place them - but it is not operation yet.

For approach you still need a ground based aid of course because you have to follow a static and relatively precise path (usually 3° as we know). LAAS doesn't provide it yet.

For long range cruise, ground based nav aids aren't really required anymore, at least not on modern airplanes (glass cockpit...). You can still receive signals to your VOR and NDB equipments in a glass cockpit, but navigation actually is done by the INS (inertial navigation system) and flight management computer which gets the line of position from the aircrafts movement (accelerometers, gyros...) and from GPS as well (older INS in the 1970's and 1980's used DME signals to get the line of position). You just follow a pre-programmed route. VOR's and NDB's exist in the database of the FMC but just as virtual waypoints. The line of position comes from the INS and GPS. Of course VOR's and NDB's are still received and displayed but not really required during cruise. In future you'll just follow virtual waypoints only I think (which actually is the case already).

Since 2005, provision of those nav aids is going to be reduced in Germany (but I don't know about TACAN, which anyway is carried onboard for air refueling). We even have the best/newest nav aids as far as I know. The USA is covered with lots of old VOR's and NDB's. Blackouts and missing spare parts for the old equipment is the order of the day. But it's also a large country with lots of those aids, "still". But Endeavour shows that TACAN is not really a requirement anymore. Quite the opposite, GPS even enables Endeavour to land almost everywhere as long as MLS is available

 

[Urwumpe]

Well, still, you have different classes of quality when you do RNAV. GPS+INS is already considered the highest level of quality, but when you look, how hard the European Air Traffic Control has it, to implement it, GPS is not yet the solution to all problems. We have a much higher traffic density over some regions in germany, as the USA have in the approach regions of a international airport.

It will still take a while until the space based augmentation system in Europe will become operational and much longer until enough aircrafts will use it, to justify using only GPS/GALILEO.

 

[Moonwalker]

Of course GPS is not the solution to everything (especially approach). But GPS already is used on each modern INS equiped commercial aircraft because it is much more usefull than any kind of VOR, NDB and TACAN only. All I say is that those nav aids are going to be out of date. Onboard Endeavour it is already out of date