Space shuttle reentry problems

[Matte]

Hi guys.
I'd like to know how do I have to put the nose of space shuttle while reentering.
It pitches down, but if I leave it I think I'm gonna burn.
If I try to keep it up, the vessel  rise altitude again 4 another semi-circle of orbit! Help me Please
ty

 
Title edited by moderator



Post Edited ( 11-22-04 19:54 )

[Aragörn]

Arg please If you wants an answer, doesn't write in capital letters.

For the re-entry od the shuttle, take an angle of -5° (I take this angle) because if u take a positive angle, you will go up
and take altitude.

[Aragörn]

In reallity i thinks the shuttle takes a positive angle but Orbiter doesn't manage that.

[SimFan]

but Orbiter doesn't manage that.

Ara, I'm afraid you're wrong.

In reallity i thinks the shuttle takes a positive angle

Yes, 40°. you've an automatic feature for doing this. Read the doc in shuttle addons

With Orbiter, you can follow what is told in these documents :

http://spaceflight.nasa.gov/shuttle/reference/shutref/events/entry/

http://www-pao.ksc.nasa.gov/kscpao/nasafact/pdf/landing.pdf

Pls, also read  tutorials in the Martin's main forum (unfortunatly, main ones on the subject have been hacked, so you'll
have to search in the main forum post for landing and shuttle



Post Edited ( 11-27-04 22:51 )

[DocHoliday]

The trick to it is that you set your periapsis so low, that even if your nose is positively pitched, you won't bounce off
the atmosphere.. If your periapsis is as low as you can get it.. rougly 6379, than you can increase the apoapsis, so
you get a steeper reentry angle.. if you come in too shallow, you bounce off, just like a flat stone bounces off
the water surface


Cheers,

[docks]

What is the steepest reentry angle that the space shuttle would survive in real life?  I mean if you come in at too
much of a angle, would'nt you simple burn up?

[Matte]

hi, here i am again.
now, i have all 3.6 shuttle fleet, and in this version there is a nice auto reentry angle pilot.
problem is that when i hit atmosphere, my plane start (as i can see in orbit MFD) going down, then up again a bit,
then down again, up a bit, down, up, down, till i arrive ground, with not precision, for those slopes.
know something?
ty

[Simonpro]

seems fairly normal, if my experiences with the space shuttle are anything to go by.

[Matte]

oh, so how can i calculate the precize reentry and landig slope??
how do u o?

[Simonpro]

you dont. you have to use your experience. it is impossible to compute a precise reentry profile if you are manually in
control of the craft - as human beings (especially in orbiter without the data available to the real shuttle crew) are
unable to hold the correct pitchs, rolls and yaws required for a precise entry. the nearest you can do in orbiter is have
an educated guess - which is still a good thing to have.

the easiest, and best, way to "compute" reentry angles is simply to try a load of different ones - see what works and
what doesnt. after all, you cant kill any shuttle crewpeople in orbiter - the entire point of it is to experiment!

[Matte]

you're right, but i don't think shuttle crew, after engine burn 4 reentry, start jumping on the atmosphere as on a
pillow...
i thought they put the ship up 40° and go down and down till Cape Canaveral is in sight, more or less... i think it
could directy be done with orbiter too.
try to think to Gemini, Mercury or Apollo reentry modules.
they go down, not start descent, then ascent, then descent again and so on...
sorry, my  porpouse is not to be noisy...i only want to understand

[Simonpro]

the shuttle crews have slightly more advanced ismulations of reentry to guide them than we do
to get you started do your deorbit burn over the indian ocean - make sure your PeD reaches about 6.350M
now wait until you reach 100km altitude then pitch up to 40degrees angle of attack (AoA). hold this and you should
end up somewhere near the cape.

[Matte]

ok
i'll try
my last try(the one with Atlantis carring a Progress ferry) ended 400 km from the cape...quite a
success...ahahahahahahah      ty

[SimFan]

You may want to try this :

http://orbit.m6.net/v2/read.asp?id=8231

[johnc]

I had the same problem with bouncing off the atmosphere. I think it was because I didn't have a deep enough Ped. BUt I found
a MFD that will take the shuttle down from orbit. It is called Otto, and I believe that I found it on AVSIM. The zip name is
: "jelair_-_otto_for_orbiter.zip"

Hope this helps.


Johnc

[jtiberius]

you have to fly S-turns to keep the descent rate around -100 m/s.
I always reach KSC with shuttle 3.6 no probs.
BTW PeD is 6370 from any Orbit.
Reentry burn occurs around 18.500 km to Base.
And I always try to stay at 30 km alt just before HAC.

regards
jitberius

[Matte]

ok, now i need a technical skill.

how to adjust trim manually?? when i deactivate auto-pitch 4 reentry, trim mantain at +1.00, and i want it at 0.00.
how to do?

[Orbiter Fan]

To adjust trim setting use Insert(Not on the NumPad!) to decrease trim setting and Delete(again not on the NumPad!)
to increase it.

[Matte]

i can't find those buttons on my keyboard. can u explain me better? my keyb. is in italian...maybe the name of keys is
different! ty

[SimFan]

[Matte]

i'm sorry 4 disturb i gave u! i saw now that it was explained in read-me...sorry

[MisterC]

Yes...

Just like jtiberius said, all is in S-turns...

In fact, you have to think differently to reentry your shuttle...

You must look at the vertical acceleration and vertical speed in mfd... Let the autopilot manage the AOA around 40° (B
key), and you control lift, so altitude, so DRAG, using the roll...

If you bank the shuttle, you decrease lift, preventing her from boucing back in space, and adjusting the bank angle,
you can control the vertical acceleration, thereby the vertical speed, thereby the altitude, thereby the drag, thereby
the speed, thereby the range, lol...

With a little experience, it's very feasable...

[Matte]

what do u mean with "S-Turns"???
i don't understand.........

[SimFan]

"S-Turns"

= Slalom turns.

Alternatly use 1 and 3 keys

That seems as dirty piloting, but provides very efficient braking, as when skiing.

A cleaner way is use of b]4[/b] and 6 keys.
The cleanest is use of b]1/4[/b] and 3/6 keys.
Both make the way longer, that reduces Hspeed in accordance to.

It's all explained here :

http://www-pao.ksc.nasa.gov/kscpao/nasafact/pdf/landing.pdf



Post Edited ( 11-23-04 14:36 )

[SimFan]

Btw, Matte, please be kind enough to reedit your heading post and title in lowercase letters (no capitals, except
when beginning a sentence or a people's name)

Thks