General Question powering down Shuttle Atlantis?

[rocketdued]

is there a way to power down space shuttle atlantis after getting into orbit? i think that would be kind of cool to be able to power down and having to start it back up from dark and cold.

 

[Urwumpe]

is there a way to power down space shuttle atlantis after getting into orbit? i think that would be kind of cool to be able to power down and having to start it back up from dark and cold.

Like in the real thing - no.

In the real Shuttle you can completely power it down, but not up again, at least not without being docked to the ISS, so you can transfer electricity from the ISS to the Shuttle (The fuel cells need 1500W power for reaching operating temperature).

 

[N_Molson]

I don't know which add-on your are speaking of, but in real life you can't "power down" a Space Shuttle, since its power is generated by fuel cells, that can't be turned off (well, you can, but they can't be restarted without a strong power supply). It is why Shuttle missions have a limited duration of more or less 15 days, while a Soyuz, powered by solar panels, can spend 1 month on orbit.

 

[rocketdued]

powering down

ah ok. much like apollo13? close the fuel cells and your stuffed. :lol: ok. so i won't power it down.

 

[Urwumpe]

Also, in reality, you actually power more stuff up, once you are in orbit, than what you power down. In the first 2h50m of the mission, you launch and then reconfigure the whole inside of the Shuttle for being in orbit. Everything you don't need in orbit, is powered down. Two computers out of five are even shutdown in orbit. Only two GNC and one System Management computer are left, one of the Shutdown computers acts as hot spare for GNC, and is usually powered up during rendezvous and docking. Many navigation sensors are no longer needed until landing, and thus powered down. At the same time you power up such important stuff as the space toilet and the galley (the kitchen and sink of the Shuttle). The airlock is activated, the satellite antenna (Ku band antenna) as well. The star trackers can be used and are powered up...

The whole transition from launch configuration to orbit configuration is in a special checklist, the "Post insertion" checklist.

 

[rocketdued]

ohok

 

[garyw]

To add a little more context to Urwumpes postings - One of the issues that Discovery and Endeavour have when they uses SSPTS (Station to Shuttle Power Transfer System) is that the ISS can take on too much of the shuttles load. This can lead to problems with the fuel cells as they actually require a certain load to be placed on them or they hit problems.

I *believe* that the fuel cells need around a 30% load placed on them otherwise problems result.

 

[rocketdued]

oh ok. like chargeing a battery for too long?

 

[Urwumpe]

I *believe* that the fuel cells need around a 30% load placed on them otherwise problems result.

Not problems, they just become very ineffective and cool down until they are no longer producing electricity at all. Also you waste a lot of hydrogen for purging the fuel cells when they run at low power.

Also you need to remember that all drinking, cooking and washing water on-board the Shuttle comes from the fuel cells. That can also cause some trouble.

Don't know how this problem is prevented in actual operations, Shutting one fuel cell down could be a viable option when docked to the ISS.

 

[garyw]

Don't know how this problem is prevented in actual operations, Shutting one fuel cell down could be a viable option when docked to the ISS.

They don't shut down any fuel cells when docked. I do know that they have quite a lengthy checklist before SSPTS is activated so I can only guess that SSPTS is designed to only off-load a certain amount of the fuel cells work to prevent the fuel cell from running into trouble.

On the flip side, there is a document on the NASA website about running the shuttle from SSPTS for up to 90 days. This is in the case of severe damage to the rcc/tiles. At this point the fuel cells are largely a moot point because the shuttle will be undocked and dumped in the pacific.

 

[rocketdued]

i think im going to give up on this simulation. i have been trying for the last hour with the delta glider to get into space. and it's not doing what the directions say it's supposed to do. :compbash::WTF::ripped:

 

[garyw]

Then you are probably doing something wrong. Have you learnt how to read the orbit MFD screen yet?

 

[rocketdued]

been trying to. but appaerntly. it's not sticking with me. im not gonna say i have it yet. but i think i might finally have an orbit going here.

 

[Urwumpe]

Then you are probably doing something wrong. Have you learnt how to read the orbit MFD screen yet?

or learned to operate Surface MFD for seeing the relevant data...

rocketdued: How much do you actually know about spaceflight already?

 

[rocketdued]

the real thing nothing at all. as im not a nasa astronaught. but i got orbiter to be a virtual astronaught insted. i didn't know i needed to know rocket science for a game.

 

[orb]

Try this reading at NASA JPL, it's really what should help you: Basics of Space Flight.

 

[rocketdued]

:WTF: thats for real space flight? how does that relate to a game? it's good reading but thats not gonna help with a game:lol:

 

[orb]

:WTF: thats for real space flight? how does that relate to a game? it's good reading but thats not gonna help with a game:lol:

I don't understand your reaction. Orbiter is space flight simulator. If you want a game that has nothing to do with orbital mechanics, try some space shooter.

 

[rocketdued]

well im a flightsimulator 2004 cessna pilot. does that mean i have to know how to bulid a cessna and know every operation for it to be able to fly it? no. then why would i have to be a nasa rocket scientist to be able to fly a space flightsimulator?

 

[Urwumpe]

the real thing nothing at all. as im not a nasa astronaught. but i got orbiter to be a virtual astronaught insted. i didn't know i needed to know rocket science for a game.

Well, time to clean up some misconceptions for you.

1. There ain't no such thing as rocket science. What the layman calls rocket science is the sum of many different kinds of science, that not a single person on this planet has mastered all. The magic is just cooperation.
2. It is astronaut. I don't really have an idea what in Armstrongs name "Astronaughts" could be, but I have the feeling you mean the creepy stuff that appears on your windshield on Halloween.
3. You don't need to know mathematics, but it helps. Actually everything in spaceflight has very simple relations. It is like chess or go. Extremely simple rules, that become very complex if you have many of them apply at the same time.
4. What you really need to know, are Keplers three laws, because they are the basis of all what you will see in orbiters navigation, and have only little to do with actual math. It is only geometry.
5. And still it is just the start. All piloting in Orbiter is pretty much knowing different kinds of trajectories, selecting which trajectory brings you to your target, switching from your current trajectory to the new one. And guess what: Outside the influences of atmospheres or geology, every trajectory is an orbit.
6. Every change in trajectory is a maneuver. A maneuver must not be just one change in trajectory, many popular maneuvers consist of multiple trajectories. Getting from A to B in Orbiter means not getting from location A to location B, but actually getting from trajectory A to trajectory B (maybe with trajectories C, D, E, F, G, etc in between)
7. Most important maneuvers in Orbiter follow common patterns. A deorbit maneuver is rarely different between spacecraft, you will just aim for a different landing trajectory. Changing orbit planes has only few working maneuvers. Learn these patterns, from Orbiter or from real spaceflight.
8. This is called "Astrodynamics", it is the simpler part of what is called rocket science. The full magic of astrodynamics will NEVER happen to you in orbiter, since orbiter does already take the hardest task from you: Calculating where you actually currently are, and where you are going. You just need to open Orbit MFD to tell.
9. What no machine can really do for you, is deciding what trajectory is the best for your mission. That requires a lot of creativity and out of the box thinking.

Does this help?