Question General Spaceflight Q&A

[tblaxland]

1.Before ET SEP, you see some plasma "flames" surrounding the vessel. What causes it?

High energy collisions between the orbiter and particles in the ionosphere. At MECO, the orbiter is only just out of the mesosphere (about 105 km IIRC) and there is still plenty of "air" for it to collide with. The energy transferred to the particles is re-radiated, some of it in the visible spectrum.

3.During entry you see plasma flames. Is it caused by compressed air that heats, friction or any other? How much contribution each factor has in the heating?

Almost all of it is due to adiabatic heating from compression at the shock front.

 

[Dambuster]

High energy collisions between the orbiter and particles in the ionosphere. At MECO, the orbiter is only just out of the mesosphere (about 105 km IIRC) and there is still plenty of "air" for it to collide with. The energy transferred to the particles is re-radiated, some of it in the visible spectrum.

Do you know of any websites with information about this? It sounds quite interesting

 

[tblaxland]

Do you know of any websites with information about this? It sounds quite interesting

A web page here: http://www.uh.edu/engines/epi345.htm
And a slightly heavier scientific paper here: http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19860003776_1986003776.pdf

 

[rucinter]

Does the shuttle crew carry with them all the checklists, in printed form? For STS-131 I've counted over 1500 pages of checklists.

 

[garyw]

Yes. You can see a photo here of the flight plan (which is a collection of the checklists) here:

 

[Urwumpe]

Does the shuttle crew carry with them all the checklists, in printed form? For STS-131 I've counted over 1500 pages of checklists.

Only the flight data files. Yes, that means all ~1000 pages of it, often in multiple copies of the same checklist (For example, CDR, PLT and MS1 have all a copy of the ascent checklist during launch). Remember that the flight supplements replace pages of the base checklists, they don't add new pages.

And then add also execute packages, that are send to the crew from the ground to include last minute changes and printed over the on-board color printer.

 

[DaveS]

And then add also execute packages, that are send to the crew from the ground to include last minute changes and printed over the on-board color printer.

If the printer and Ku EA-1 works!

 

[Urwumpe]

If the printer and Ku EA-1 works!

Or you have the ISS nearby, who also have a printer in their home-office.

 

[rucinter]

Why is the Leonardo MPLM (and I'm guessing the others too) only half of the payload bay length? Does the extra space in the bay used for something else during a mission or the limitation was done due to weight concerns?

 

[garyw]

The MPLM carries quite a bit of weight so it's purposely put at the back of the orbiter for CoG reasons. All MPLM's are the same size.
Often there is a rack behind the MPLM which is used to hold ISS spare parts or other items.

 

[Urwumpe]

Why is the Leonardo MPLM (and I'm guessing the others too) only half of the payload bay length? Does the extra space in the bay used for something else during a mission or the limitation was done due to weight concerns?

Mostly commonality to other station modules, the MPLM is similar to the Columbus module in its primary structure, and the size of the Columbus module was reduced for saving costs for the Europeans, the original European module for Freedom was full-length.

 

[Orbinaut Pete]

Why is the Leonardo MPLM (and I'm guessing the others too) only half of the payload bay length? Does the extra space in the bay used for something else during a mission or the limitation was done due to weight concerns?

MPLMs are launched full of racks, which is why they have to be small. If they were any larger, the Shuttle would never get off the ground.
Modules that are larger than the MPLM (like the JPM for example) have to be launched with no racks inside them due to weight limitations.

 

[garyw]

Wasn't JPM outfitted over 2 or three launches? if I recall right it only launched with a third of the racks that it's now got.

 

[Urwumpe]

The MPLM carries quite a bit of weight so it's purposely put at the back of the orbiter for CoG reasons.

Is only a part of the reason, the IUS missions had the CoG of the heavy payload far further forward, while occupying the whole payload bay.

 

[Orbinaut Pete]

Wasn't JPM outfitted over 2 or three launches? if I recall right it only launched with a third of the racks that it's now got.

Correct.

The JPM was launched with a few system racks aboard it, and nothing else. Most of the racks for the JPM were launched in the smaller JLP on STS-123.
This is what the JPM looked like at launch - as you can see, it's pretty much empty.

 

[TSPenguin]

Or you have the ISS nearby, who also have a printer in their home-office.

What kind of printers are being used on STS and ISS?
Have they ever been upgraded and what renditions were there?
How many pages/meters of papers do they usually have?
Do they use regular paper or a special one?

 

[Urwumpe]

What kind of printers are being used on STS and ISS?

Not sure on the ISS, but the Shuttle uses ink printer that looks a lot like a Epson in the past missions, according to the Orbit Operations Checklist.

Have they ever been upgraded and what renditions were there?

often... the initial one was a thermo-printer, there had been some upgrades in the last years. The first test of a ink jet of the current type was STS-95.

http://www.shuttlepresskit.com/STS-95/dto14.htm

http://global.epson.com/newsroom/fast_facts.htm

How many pages/meters of papers do they usually have?

About 200 sheets was the last number I remember.

Do they use regular paper or a special one?

Special fire-safe paper, that follows NASA flight safety standards.

 

[rucinter]

Do they still use the famous Fischer AG-7 space pen?

 

[TSPenguin]

Thank you Urwumpe. Up until now, I was completely unaware that they had a printer on board. Thinking about it now, it makes very much sense.
I shall inquire further on my own.

 

[IronRain]

How do the astronauts talk to houston during launch and re-entry actually? because I never see any wires or something..