Question General Spaceflight Q&A

[diogom]

An EVA inside that thing? How can they move in there?

 

[Urwumpe]

An EVA inside that thing? How can they move in there?

The transfer compartment has always been large enough for also act as EVA airlock, it isn't easy to move there, but no problem.

 

[Eli13]

Just a few questions:
How long will the ISS stay in operation?
When its operational period is over what will they do with it? (Like a controlled re-entry with Mir or something)
Is there a chance for even more modules to be launched there?

 

[garyw]

How long will the ISS stay in operation?

I belive the USA is talking about funding until 2025

When its operational period is over what will they do with it? (Like a controlled re-entry with Mir or something)

Yes. NASA has plans for a controlled entry.

Is there a chance for even more modules to be launched there?

Yes. Russia have a couple of extra things to add but the US segement is done. It's highly unlikely the USA will add anything more when whatever Shuttle replacement vehicle comes online.

 

[Eli13]

Ok, first of all thanks for the info. Second, what will they use to do the controlled re-entry? I've heard things like de-orbiting vehicles but i honestly don't know.

 

[Orbinaut Pete]

Yes. Russia have a couple of extra things to add but the US segement is done. It's highly unlikely the USA will add anything more when whatever Shuttle replacement vehicle comes online.

Oh, I think they will.

NASA currently has plans/proposals for the following modules on the USOS:

• Node 4/DHS (Docking Hub System) - would provide additional docking ports for future commercial vehicles and additional CBM ports for future modules.
• BEAM (Bigelow Expandable Activity Module) - would be a small inflatable stowage module provided by Bigelow to test inflatable technologies.
• Inflatable suit-port demo - would provide a suit-port demo on the ISS.
• NAUTILUS-X centrifuge demo - would test a centrifuge for BEO exploration on ISS.
• Isolated habitation module - NASA may conduct a Mars-500 type mission on ISS in future, where a few crewmembers would a isolated in a separate module from the rest of the station. This would require a new module with adequate stowage & ECLSS hardware to support a crew.

The future Russian modules will be the MLM, Node Module, and two Science Power Platforms.

If more ports are available on the USOS, maybe we'll see some new science modules - I'd personally like to see a commercially funded & operated module with an experiment centrifuge.

NASA also plan to fly an MMSEV (Multi Mission Space Exploration Vehicle) to the ISS (below image).

 

[garyw]

Proposed though, not confirmed. I'd love to see more modules on the ISS. That's one reason it's up there.

As for the deorbit, I know that there have been several plans around how to get it down safely. It'll probably be a modified ATV.

 

[Eli13]

Again, thanks. That was just something on my mind that i couldn't get quite around.

 

[Izack]

I thought the Science Power Platform was canceled. Now they want two of them?

 

[Orbinaut Pete]

I thought the Science Power Platform was canceled. Now they want two of them?

Yup - on the bottom of the MLM.

 

[Krikkit]

So I was watching the vid Orbinaut Pete posted in the ISS update thread, and at one point Nespoli says something about it being very interesting when there are 15-16 people on board.

I can see how it would happen
6 expedition crew
3 TMA crew coming or going
6/7 STS crew


My question is, has this ever happened?

I am having a hard time imagining 16 people on the ISS, especially with the hectic schedule they have during STS missions.

 

[Orbinaut Pete]

So I was watching the vid Orbinaut Pete posted in the ISS update thread, and at one point Nespoli says something about it being very interesting when there are 15-16 people on board.

I can see how it would happen
6 expedition crew
3 TMA crew coming or going
6/7 STS crew


My question is, has this ever happened?

I am having a hard time imagining 16 people on the ISS, especially with the hectic schedule they have during STS missions.

No, it has never happened, nor will it ever happen. The most amount of people ever on ISS was 13, during the STS-127 mission in July 2009 (6 ISS crew, 7 Shuttle crew).

Shuttles would never visit the ISS during the rare occasions when 3 Soyuz crews are aboard (9 people). Having 3 Soyuz crews up there has only ever occurred once, in October 2009, when the crews of Soyuz TMA-14, TMA-15, and TMA-16 were all aboard ISS in order to allow a space tourist to fly.

So, I don't know why Paolo said that.

 

[FordPrefect]

Risk of hitting the ET after OMS-2 burn?

Hello fellow orbinauts,

this is something I was already wondering about serveral years ago, whenever using the great Shuttle Fleet in Orbiter, now it happened again while simulating STS-134.
In the real world, is there any kind of "evasive" (RCS) burn performed by the shuttle to attain a safe distance between the ET and the orbiter?
I ask because, the OMS-2 burn usually happens near reaching apoapsis of the initial insertion orbit. Now, that point is about 90 degrees around the central body (Earth) after ET sep, thus placing the ET then a few hundred feet in front (close to the velocity vector) of the shuttle, given the inertial attitude of both Shuttle and ET remain the same after separation.
In Orbiter, after performing the OMS-2 burn, I always end up with the ET sailing past my shuttle, not rarely at pretty uncomfortable proximity!
So I was wondering, in the real world, do they also perform a translational RCS burn to get out of the orbital path of the ET to avoid this situation?
Thank you for any feedback!

 

[Donamy]

Yes, they perform a plus Z and a plus X RCS burn, then a pitch up maneuver to photograph the ET.

 

[garyw]

Yes, they perform a plus Z and a plus X RCS burn, then a pitch up maneuver to photograph the ET.

Just to add - the calls from Houston are normally 'We see a nominal shutdown plan, you are go for the +X and go for the pitch"

Which basically means everything is looking good and they can perform the standard tank separation burns.

The 'go for the pitch' is dependant on the lighting conditions so if they launch into daylight they will perform the pitch manoeuvre.

 

[FordPrefect]

Yes, they perform a plus Z and a plus X RCS burn, then a pitch up maneuver to photograph the ET.

Thanks Don! However, if I am right, plus Z means FORWARD (along the longitudinal axis of the Orbiter) and plus X means UPWARDS. But there is no translational component in it, is there?

Not sure what I am doing wrong in the Orbiter simulation, but I exactly do that, thrust forward and up and do the pitch up (for the ET photos) and still, when reaching the time for the OMS-2 burn, the ET is always floating pretty close to my (Shuttle's) velocity vector a few hundred feet ahead of me. Hence, when accelerating (to circularize the orbit) with the OMS-2 burn, I nearly "run" into the ET. Any thoughts?

 

[Urwumpe]

Thanks Don! However, if I am right, plus Z means FORWARD (along the longitudinal axis of the Orbiter) and plus X means UPWARDS. But there is no translational component in it, is there?

Wrong. +X means forward, +Z means upwards. and it is both translational. Rotational axis would be Pitch, Yaw and Roll.

 

[David413]

Thanks Don! However, if I am right, plus Z means FORWARD (along the longitudinal axis of the Orbiter) and plus X means UPWARDS. But there is no translational component in it, is there?

Not sure what I am doing wrong in the Orbiter simulation, but I exactly do that, thrust forward and up and do the pitch up (for the ET photos) and still, when reaching the time for the OMS-2 burn, the ET is always floating pretty close to my (Shuttle's) velocity vector a few hundred feet ahead of me. Hence, when accelerating (to circularize the orbit) with the OMS-2 burn, I nearly "run" into the ET. Any thoughts?

In the actual Shuttle coordinates, a +Z translation is downwards, and a +X translation is forward.

Are you manually entering orbit or allowing the Shuttle Fleet autopilot to fly the ascent? The reason I ask is that the separation burn at ET sep should put you well above the tank so that by OMS2 the tank is below and in front of you.

 

[FordPrefect]

Ah shoot, sorry for that. Of course it is translational... :facepalm:

And sorry, I was thinking with the Apollo spacecraft coordinate system.
What I meant with translational actually is, they do not perform a burn "sideways", in order to get out of the orbital path of the ET!?

 

[garyw]

Sounds like there is some confusion between the two different co-ordinate systems used in Orbiter and the shuttle world. They are different (left handed and right handed I believe?)

a +X translation (into the VV) would mean that the shuttle is slightly higher and slightly slower than the ET which would make sense. When STS-134 was originally going to launch two weeks ago we in the UK were looking forward to seeing the ET and Shuttle fly overhead. The ET would have been just slightly in front of the shuttle.