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Shuttle Questions Q and A
by
Terry Rocket
on 15 Oct, 2005 11:05
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#1
by
FransonUK
on 15 Oct, 2005 11:12
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Welcome to the site, and you bet. Good idea!
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#2
by
Terry Rocket
on 15 Oct, 2005 12:15
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Thanks!
Ok, this is basic, so please try to answer with basic answers otherwise I'll get stuck!
Q) Launches are very powerful and I've seen clips of the Astronauts been shaken around etc. Yet they have a pilot on board, so how does he/she fly the Shuttle whilst been shaken about, such as the roll which looks like it has to be just right?
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#3
by
Chris Bergin
on 15 Oct, 2005 13:13
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Terry Rocket - 15/10/2005 1:15 PM
Thanks!
Ok, this is basic, so please try to answer with basic answers otherwise I'll get stuck!
Q) Launches are very powerful and I've seen clips of the Astronauts been shaken around etc. Yet they have a pilot on board, so how does he/she fly the Shuttle whilst been shaken about, such as the roll which looks like it has to be just right?
Welcome to the site, Terry.
A) The pilot doesn't fly the Orbiter (the part of the Shuttle that added to the Solid Rocket Boosters and External Tank makes up the Shuttle) like a normal plane. The Orbiters are driven by flight computers and the astronauts pretty much just sit back and make any required corrections on assent, but it really is all down to the Orbiter. The main two astronauts on the Orbiter's flight deck are the Commander and the Pilot in the front two seats. They are used more on landing (after coming back through re-entry - which again the Orbiter flys herself through).
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#4
by
Terry Rocket
on 15 Oct, 2005 13:26
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Thanks!
Another one:
Q) Why are there sparks just before the main engines fire up? Is that what ignites the fuel? Just seems a bit dangerous!
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#5
by
WARPed
on 15 Oct, 2005 13:42
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I'm not an authority on the subject but if I remember correctly the spray of sparks below the SSME's is purely there to ensure any excess hydrogen that has escaped through the nozzles is burnt away. The engines are ignited by "Spark Ignitors" like a spark plug in the engine.
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#6
by
Flightstar
on 15 Oct, 2005 13:53
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Terry Rocket - 15/10/2005 8:26 AM
Q) Why are there sparks just before the main engines fire up? Is that what ignites the fuel? Just seems a bit dangerous!
Warped pretty much answered that exactly.
Here is a picture of the event that happens just shortly after T-10 seconds.
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#7
by
Terry Rocket
on 15 Oct, 2005 13:57
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Yes, that is the picture of what I was talking about. Thanks Flightstar and thanks Warped.
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#8
by
Flightstar
on 15 Oct, 2005 18:41
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You're welcome. Always feel free to ask any questions. We're happy to hear of the interest.
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#9
by
Tahii
on 15 Oct, 2005 22:39
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Terry Rocket - 16/10/2005 12:15 AM
Ok, this is basic, so please try to answer with basic answers otherwise I'll get stuck!
Welcome to the site. I am kind of in the same boat. Its good to see people who don't know something wanting to find an answer.
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#10
by
discovery_fan
on 16 Oct, 2005 16:48
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Ok - here is my - maybe stupid - question:
Afaik the orbiter is after Main Engine Cut Off not yet in an orbit, and has not the right speed to go into orbit (thats why the ET descends into the indian ocean, I think). To get to the orbit the Orbital Maneuvering Engines are fired, twice I think usually, first to get into an elliptic orbit and then into the final planned orbit (each time adding some couple of hundred kilometers/hour of speed).
Right?
When the Orbiter needs to go to a higher then usual orbit (maybe to deploy a spaceprobe or to catch the Hubble ST), does it simply fire the OMEs longer (additionally to having a lighter payload)? Or do the SSMEs burn longer as well and the orbiter with ET goes higher up?
Or another way to ask the question:
Is MECO (and ET seperation) allways at the same altitude or does it vary? If it does vary is there a possibility that the MECO is so late that the ET goes into a low orbit itself and circles the earth a couple of times or can that never happen?
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#11
by
Rocket Guy
on 16 Oct, 2005 17:36
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It's not the speed, it's the fact that after the SSMEs cut off, the orbit is too elliptical. The ET reenters quickly because this elliptical orbit plunges it back into the atmosphere on the other side of earth. The Shuttle would take the same route if it did not fire its OMS engines. In fact, that is what it would do if it were to do an "abort once around" emergency landing.
The Orbiter fires its OMS to circularize the orbit.
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#12
by
Orbiter Obvious
on 16 Oct, 2005 20:24
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Would it be ok to ask for some of the likes of MECO to be explained in the words those letters stand for?
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#13
by
Chris Bergin
on 16 Oct, 2005 20:32
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Orbiter Obvious - 16/10/2005 9:24 PM
Would it be ok to ask for some of the likes of MECO to be explained in the words those letters stand for?
Sometimes you'll see it mentioned, such as MECO, just got to look out for it and associate. However, here's a few reeled off (one's you might see a lot of around these parts) as reference.
STS = Space Transportation System
ET = External Tank
OV = Orbiter Vehicle (such as OV-103 is Discovery, 04 is Atlantis, O5 is Endeavour)
SRB = Solid Rocket Booster
OMS = Orbital Maneuvering System
RCS = Reaction Control System
MPL = Mobile Launch Platform (Rides on the Crawler Transporter, Shuttle Stack goes on top of the MLP).
VAB = Vehicle Assembly Building
MECO = Main Engine Cut Off
SSME = Space Shuttle Main Engine
MAF = Michoud Assembly Facility
MSFC = Marshall Space Flight Center
KSC = Kennedy Space Center
RLV = Reusable Launch Vehicle
LOX = Liquid Oxygen
LH2 = Liquid Hyrogen
ECO = Engine Cut Out (sensor)
If anymore pop into my head, or the question is asked, I'll edit and add here.
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#14
by
MKremer
on 16 Oct, 2005 20:40
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RLV = Reusable Launch Vehicle
and its counterpart:
ELV = Expendable Launch Vehicle
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#15
by
Orbiter Obvious
on 16 Oct, 2005 20:42
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Very cool thanks.
This site is great, but if I was to go to say three sites a day to get as much Shuttle news as possible, which other two would I go to?
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#16
by
Chris Bergin
on 16 Oct, 2005 20:48
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Orbiter Obvious - 16/10/2005 9:42 PM
Very cool thanks.
This site is great, but if I was to go to say three sites a day to get as much Shuttle news as possible, which other two would I go to?
For me, spaceref.com and spaceflightnow.com
We're getting to the stage where the forum (in my humble opinion) is going to be the best space flight forum around (expondentially getting busier and doesn't insist on the bulk of its posts being non-related to the site).
The news section of the site does its job but won't be where I want it till we've got 20 writers in the pool. We're aiming for that as we have a few good writers already active, but you'll see just next week how we're going to do this. There's a Langley story being finalised as we speak where the writer is actually involved in the program. This is the kind of reporting we are looking to have here....but it'll take time and won't be "in replacement of" the aforementioned sites. We want people to go to all space related sites. Our aim is that we're one of those sites you go to.
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#17
by
MKremer
on 16 Oct, 2005 20:58
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For me, spaceref.com and spaceflightnow.com
Agreed.
Spaceref.com stays pretty up-to-date on the latest NASA and space-related press releases and updates (in the right hand column).
And, during special events (launches, dockings, spacewalks, landings), Spaceflightnow.com's event Mission Status Centers are about the next best thing to watching a live feed.
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#18
by
Flightstar
on 17 Oct, 2005 00:23
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Ben - 16/10/2005 12:36 PM
It's not the speed, it's the fact that after the SSMEs cut off, the orbit is too elliptical. The ET reenters quickly because this elliptical orbit plunges it back into the atmosphere on the other side of earth. The Shuttle would take the same route if it did not fire its OMS engines. In fact, that is what it would do if it were to do an "abort once around" emergency landing.
The Orbiter fires its OMS to circularize the orbit.
Very well put.
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#19
by
Do Shuttles Dream
on 17 Oct, 2005 03:22
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Chris Bergin - 16/10/2005 3:32 PM
Orbiter Obvious - 16/10/2005 9:24 PM
Would it be ok to ask for some of the likes of MECO to be explained in the words those letters stand for?
Sometimes you'll see it mentioned, such as MECO, just got to look out for it and associate. However, here's a few reeled off (one's you might see a lot of around these parts) as reference.
STS = Space Transportation System
ET = External Tank
OV = Orbiter Vehicle (such as OV-103 is Discovery, 04 is Atlantis, O5 is Endeavour)
SRB = Solid Rocket Booster
OMS = Orbital Maneuvering System
RCS = Reaction Control System
MPL = Mobile Launch Platform (Rides on the Crawler Transporter, Shuttle Stack goes on top of the MLP).
VAB = Vehicle Assembly Building
MECO = Main Engine Cut Off
SSME = Space Shuttle Main Engine
MAF = Michoud Assembly Facility
MSFC = Marshall Space Flight Center
KSC = Kennedy Space Center
RLV = Reusable Launch Vehicle
LOX = Liquid Oxygen
LH2 = Liquid Hyrogen
ECO = Engine Cut Out (sensor)
If anymore pop into my head, or the question is asked, I'll edit and add here.
Thanks. Most message boards laugh you off the forum for not knowing all that.
) where questions could be asked for the experts on Shuttles. I don't know much and I'm sure there are others like me, so even if they are basic stuff, would that be ok?
) where questions could be asked for the experts on Shuttles. I don't know much and I'm sure there are others like me, so even if they are basic stuff, would that be ok?