Flight Question getting into orbit?

[Urwumpe]

cause i bet you 5 dollars that every one of you on this forum was new to orbiter at one time just like me.

You would have won the bet. Just like I would win the bet that you have been born or water is wet.

But still: It is a sign of poor piloting skills, if you blame Orbiter, the MFDs or an not existing autopilot for your problems, especially after many people explained you in the "talk slowly for the noobs" mode, that you simply act extremely ignorant. You are quick to blame everything for not being like inside your favorite flight sim game, or that orbiters physics are not like you expect them to be. Of course they are not, they are based on real physics, not your personal preferences.

Even more, it wouldn't work differently. For making a spacecraft fly in Orbiter like in your favorite starwars movie, you need to wrap a lot of code around it and waste a lot of energy in Orbiter for fighting all the forces and potentials that would make you fly in a different direction.

Everybody started with poor piloting skills. I am sure even martins started with them. I can't even tell how often I missed by burn targets in the beginning and needed to restart. I needed 5 days until I docked on the ISS. Despite having had all the theory in advance at an university. All the theory is one thing, applying it properly the other. But you don't even care about the theory yet, you are still often defending that things should be like for aircraft.

And nobody even dared complaining about spaceflight being no pony club.

You crash, burn up, get stranded in space. And you simply start again. You will NEVER really stop making errors. It is a simulation game, and you want challenges. And challenges mean risks. The difference between a noob and a pro is eventually just, that the pro has accidents, that the noob can only dream of. In the beginning your most exciting failure might be just crashing into the moon because you failed checking your transfer trajectory. Later you can post for the 20th time how hot a miscalculation in a Saturn aerobraking can get. But for doing that, you need to get there, first.

So. You expect all to be easy. AP always means autopilot, right? And for flying higher in space, you simply raise your nose.

But you NEVER really asked, what is expected from you.

 

[Rtyh-12]

So what you need is just someone to explain the Orbit MFD? Well, I don't think so, but if you want, I can help. The grey circle is the Earth/Mars/Zorblug's Moon/whatever you're orbiting. The green line is your path. You want it to be as round as possible to get into orbit. Then, there are the parameters. You don't need to learn all of them. What you need to remember are the parameters Ecc, PeA, ApA, PeT and ApT.
Ecc is the eccentricity of the orbit. You don't need to remember the formula, just remember that the larger the number, the more elongated your orbit is. You want it to be very close to zero. (0.01 will do for now)
PeA is the altitude of the lowest point of your orbit, the periapsis.
ApA is the altitude of the highest point of your orbit, the apoapsis.
PeT is the time in seconds you need to wait until you get at periapsis.
ApT is the time in seconds you need to wait until you get at apoapsis.

And that's about it. Hope this helps! It's not so hard after you get used to it, you know...

Edit: Urwumpe posted before me and I can only say that I agree. Don't give up, though! You'll be a pro one day! Unless you give up, of course...

 

[rocketdued]

a space shuttle is NOT!!! an aircraft. no it won't handle the same as my cessna. but my cessna dose not weigh a million pounds either dose it? and im not trying to go to saturn:lol: im trying to go to the international space station with the DELTA GLIDER!!! just like you pepole told me to do. you all said NOT!!! to start with space shuttle atlantis. did you not? ok so i did try with the deltaglider and i made it into orbit JUST LIKE I SAID!!!

 

[Urwumpe]

i have listend to the pepole here and read the orbiter help on the orbit mfd.

Ok, lets assume you did read the in-game help. Did you really understand it, or did you just look at the pages until the letters blurred out.

Did you already discover "Orbiter.pdf" in the "/docs" folder?

Lets make the typical "Of course I did read the manual" test: Which key do you need to press for undocking?

 

[rocketdued]

So what you need is just someone to explain the Orbit MFD? Well, I don't think so, but if you want, I can help. The grey circle is the Earth/Mars/Zorblug's Moon/whatever you're orbiting. The green line is your path. You want it to be as round as possible to get into orbit. Then, there are the parameters. You don't need to learn all of them. What you need to remember are the parameters Ecc, PeA, ApA, PeT and ApT.
Ecc is the eccentricity of the orbit. You don't need to remember the formula, just remember that the larger the number, the more elongated your orbit is. You want it to be very close to zero. (0.01 will do for now)
PeA is the altitude of the lowest point of your orbit, the periapsis.
ApA is the altitude of the highest point of your orbit, the apoapsis.
PeT is the time in seconds you need to wait until you get at periapsis.
ApT is the time in seconds you need to wait until you get at apoapsis.

And that's about it. Hope this helps! It's not so hard after you get used to it, you know...

Edit: Urwumpe posted before me and I can only say that I agree. Don't give up, though! You'll be a pro one day! Unless you give up, of course...

ok. finally thank you. thats what im having troulbe maintaing. is the apr's the pea,s the apt's and pet's. thats what im having trouble with getting into space is easy now. it's just the trouble of being able to match my numbers with that of the international space station. i don't expect to be a pro in 10 minutes.

---------- Post added at 01:36 PM ---------- Previous post was at 01:35 PM ----------

yes i understood most of it. but like i said it's just that matter of understanding that apt's the apr's and the pet's and the per's

 

[garyw]

it's just the trouble of being able to match my numbers with that of the international space station. i don't expect to be a pro in 10 minutes.

You don't want to match your numbers to that of the ISS. If you do you'll be stationary relative to the ISS and won't be able to close in for docking.

Question though - Are you plane aligned with the ISS?

For docking what I do is make my orbit lower than the ISS. This allows me to close in on the ISS. around 500KM I raise one part of my orbit to be a few KM below the ISS and then raise the other part of my orbit to match that of the ISS. This puts the PER and APR points to the same as the ISS and let's me close in on the ISS at quite a slow speed for docking.

 

[Rtyh-12]

Well, one more thing you need to watch out for. The MFD will by default display not ApA and PeA, but ApR and PeR. Those are WAY different stuff: the ones with A are the altitudes, while the ones with R are the distances from the center of the Earth. So, if you're seeing ApR and PeR, then press the DST MFD button.

And I'd recommend checking that the projection is set to SHP, not ECL or EQU. That is the projection reference plane. It should be Ship, not Ecliptic or Equatorial. Otherwise, your orbit looks different, although it isn't, and it's confusing.

 

[rocketdued]

yes sir pretty close. now from what i have read in the manual. the planes can't be more then 5 degrees apart other wise it's like be on the other side of the world. and i did have them at 4 degrees at one point it was just a matter of catching up to the iss. but i didn't make it as life got in the way of practice. :lol:

---------- Post added at 01:56 PM ---------- Previous post was at 01:52 PM ----------

oh ok. now see the help for the scanrio said just leave the right mfd on orbit. i don't think it said to hit the dst button. because i did notice when id go to the orbit mfd and have a look that it said i was already at 6,731 km and i havn't left the ground. :lol: so i will try that. cause i know the grey line represents the earth and the green line is my space shuttle for exapmle. and the yellow is the space station. i just have to keep from buzzing past my target orbit.

 

[Wally]

Is the real shuttle always performing an OMS-1 and OMS-2 burn when going to ISS? I remember hearing the calls "OMS not required" coming from the shuttle to Houston during first stages of flight. Did I hear it wrong or that call is for something unrelated to OMS engines?

 

[rocketdued]

no sir you heard right. in the tutorial i tried for the space shuttle to iss. it said we'll do a manual oms_2 burn.

 

[Wally]

So "OMS is not required" call refers to OMS-2 burn and OMS-1 burn is always executed?

 

[rocketdued]

thats the way i understand it yes.

 

[Urwumpe]

So "OMS is not required" call refers to OMS-2 burn and OMS-1 burn is always executed?

No. OMS-2 is always executed, OMS-1 can be omitted. In NASA logic, OMS-1 is always taking place right after ET separation, approximately at the first apogee passage. It lifts the Shuttle from the (approximately) AOA trajectory, to a transfer orbit to the target orbit.

If the Shuttle does a direct ascent launch trajectory, in which it aims for the first apogee being at the target orbit, OMS-1 is only required if there had been a large error to the planned trajectory, for example by a under-speed MECO (which can have many reasons). It would then be used for correcting what the SSMEs failed to deliver. If it is not needed, you simply skip this part of the checklist and go on right with the preparations for OMS-2.

But OMS-1 still exists on the paper, even if it is usually not executed then.

 

[rocketdued]

yeah but the ssme's rarely fail don't they? i think it would be like 1 in 100 chance that they fail nasa gets it right. most of the time.:lol:

 

[Rtyh-12]

yes sir pretty close. now from what i have read in the manual. the planes can't be more then 5 degrees apart other wise it's like be on the other side of the world. and i did have them at 4 degrees at one point it was just a matter of catching up to the iss. but i didn't make it as life got in the way of practice. :lol:

These two pictures should explain to you how to use the Align Planes MFD and the Sync Orbit MFD to make docking easy.

This should help you do the rendezvous. That means that you'll get quite close to the ISS. To do the docking, use the Docking MFD. If you need help for that, just ask!:thumbup:

 

[rocketdued]

let me correct that. they do fail. look what happend to the challenger back in 1986

---------- Post added at 02:53 PM ---------- Previous post was at 02:52 PM ----------

yes sir thats what i had. i just need practice on getting my numbers right on it.

 

[Urwumpe]

yeah but the ssme's rarely fail don't they? i think it would be like 1 in 100 chance that they fail nasa gets it right. most of the time.:lol:

Still no reason to assume that OMS-1 is never needed.

There is a famous real example of a underspeed MECO caused by a leak in the hydrogen system. Was a pretty dangerous situation, since it caught the people on surprise and could have resulted in an engine explosion if it happened earlier (before the engines had already been throttled down to 69% thrust).

There was a video with the mission control communication about it, but I can't find it.

---------- Post added at 04:01 PM ---------- Previous post was at 04:01 PM ----------

let me correct that. they do fail. look what happend to the challenger back in 1986

Was an O-Ring failure and no engine failure.

 

[rocketdued]

yes sir it was an o ring that failed. and of course there was no engine failure. the whole vehicle blew up before it could have an engine failure:facepalm:

---------- Post added at 03:07 PM ---------- Previous post was at 03:04 PM ----------

the only nasa space craft having an engine failure was apollo 13. they lost engine #5. but ain't you a little fftopic: Urwumpe

 

[garyw]

let me correct that. they do fail. look what happend to the challenger back in 1986

STS-51F had the only SSME failure in Shuttle flight history. The abort modes worked and Challenger safely reached orbit but I don't think you are referring that to that particular flight.

Now back to Orbiter, If you've aligned planes correctly you should see a single line in map MFD with two crosses on it. That means that you are in the same plane as the ISS. You align planes via the Align Planes MFD and you will need to burn either normal and anti-normal.

There are other methods for plane alignment burns but this will get you started. Personally I always go for 0.0° I normally get into orbit with 0.3 to 0.5° out of plane with my target.

 

[Urwumpe]

the only nasa space craft having an engine failure was apollo 13. they lost engine #5. but ain't you a little fftopic: Urwumpe

And a few Space Shuttle missions. See above. Also many engine failures on the Shuttle are caught before lift-off, by a RSLS abort. *

I didn't go off-topic, you started it yourself.

*Also, it was Engine #5 on the second stage of the Saturn V. It had a few more engines onboard.