DGIII alpha release available part 2 (closed)

[Wilko]

Just relaynig a idea from the M6 board.

agent036 wrote:

Sometimes it's nice to hook your DG to a bigger ship (like the vespuchi) and use it to scout the
moons of the outer planets. However you can't do this with the DG III without killing your crew. If
would be nice if you could purge the crew from the DG III while it was parked. Shut everything
down and then purge the crew. When you got to your destination planet you start all the life
support back up (you assume a crew member in a vacc suit turns it on) then wait awhile for it to
heat up and get back to full pressure. Then load your crew and off you go.

----

This isn't such a bad idea, but like Voyager next suggested, you can leave the hatch open and
everything is fine. But it might be neat to actually tell your crew to leave the DGIII and go into
whatever you are docked to, that way the crew status would drop dead (flatline or just blank
displays) and you wouldn't have to worry about the door status.

[DanSteph]

attractive this one...
see my reply here:
http://orbit.m6.net/v2/read.asp?id=13398


Dan

[MattNW]

The term APU (Auxiliary Power Unit) is a pretty general term. For aircraft it might be a small jet
turbine that supplies power in place of the main engines. For a ship it may even be a small diesel
or gasoline generator that supplies power.

The one on the Shuttle is a hydrazine catalyst reaction powered generator (been reading some of
the links I found in my search). This requires a seperate fuel tank of hydrazine that is pumped over
a catalyst material (Shell 405 catalyst) which causes a chemical reaction producing heat. The
pressure generated is driven through a turbine to create mechanical energy which on the shuttle
is used to power the hydraulic system. The same mechanical energy could concievably be used to
generate electricity also, which is, I assume is going on with the DG III.

Hydrazine isn't the only fuel however. I've also found references to a catalytic APU that powers
the steering mechanism in the Shuttle SRBs that uses helium for a fuel source (HEAPU:  
http://www1.msfc.nasa.gov/NEWSROOM/background/facts/heapu_techsumm.pdf  ). The reason
they use that is because hydrazine is highly toxic (why NASA cautioned people not to touch pieces
of the shuttles afer the Challenger and Columbia disasters) and the potential for damage great in
the SRB recovery process.

I guess we can also assume that there are other fuels that are suitable for a catalytic reaction. It
would be good if a catalyst can be found that uses hydrogen since that's what fuels most rockets.
It would reduce systems and weight since the APU is using a fuel source that is allready in place
on the space ship. Quick search for "Hydrogen Catalyst" produced about 96,000+ hits so there's
some scientific backing to the theory.

Pure wild speculation on my part:

There's also a possibility of a hybrid APU system that uses a hydrazine catalyst to generate heat
to rapidly heat hydrogen and use the results to drive the generator and/or hydraulics. This would
require a very small catalyst bed, just enough to make the heat for heating the hydrogen and
good hydrazine fuel efficiency. You could also assume that the hydrazine in this instance is only
needed to start the process and that superheated hydrogen can maintain a burn once it's started.

APU lifetime is also explainable. The info I posted dates back to the 1980s. The Shuttles are using
an improved APU at present with longer lifetime and improved performance (just how much
improvement I can't find). Further improvements in lubrication and regulation of RPMs would
greatly increase APU run/life time.

Since Dan doesn't want to rewrite all the code for the DG III. I'll will assume that this is the
technology used.

Have to remember that the Delta Glider is unrealistic at present anyway. No ship that size can
carry enough internal fuel to reach orbit much less the Moon or Mars so we have to assume that
between the Shuttle and the DG III there have been some pretty significant advancements in
technology.

[DanSteph]

Safe mode and EPU Done,

I will upload the new version with EPU and
vessel "Safe-Mode" (no one on board)
in a couple of hours. (I must leave home now)

To set Safe mode: (docked or landed only)
all button off appart:
-EPU
-bus rotator EPU
-Lifepack power button
-lifepack A button On

you get than a bell sound and a message:

To leave safe mode and board again the crew:
-start the APU (the only button allowed)

Notice that in safe mode you can't click
on anything you will get a warning sound
and a message "safe-mode, no one on board,
restart apu"

(new check-list available "10-Safe mode / unload crew")

!!! not uploaded now !!! watch for alpha 040125_rev1
in one or two hours.

Dan

[Dave]

>> Dave told me "fts" because there is more than one feet.... fts or ft ?


LOL....HEY, hey....Dan....you must be drinking too much coffee while coding the DG3!!!  See the
post below from earlier in this thread...look closely!


Author: canadave
Date:   01-23-04 15:19

Well, Dan, I'm not sure about the switch from feet to miles; I know for sure the switch wouldn't be
for at least 100,000 feet, maybe 150,000.

Abbreviations:
for feet (plural of "foot", i.e. "10,000 feet"): "ft"
for miles: "mi"

Not "mis" or "fts".

--Dave

[DanSteph]

Oups ! sorry Dave

My error , perhaps too much coding time ?


I ran into a bug when you save a situation where te DGIII don't have focus (CTD)
I have an idea of what is going wrong but I must test, change and test again.
This to say that the 040125_rv1 will be a bit late (it will perhaps
be the 040126_rev 1


Dan

[reekchaa]

My God... It's full of Posts!    this latest Thread filled up pretttty quick!  

Nice Tease on the alpha 040125_rev1 release(...A Whole Hour??? ) ... Sounds like a
great update... but I'm sure we can all chill out and wait until tomorrow.
'040126_rev 1' -- I covet thee!

[DanSteph]

pfeeew 300 line of code modified, it was an Orbiter's SDK bug I tried with the stock
DG it do the same bug (CTD)....  I had to implement my hown version of one stock
function of the SDK.

Anyway the 040125_rev1 is out

I hope I didn't added bug, I tested it seem to run fine
(well appart that I burned during the reentry due to the radiator still deployed )


Dan  -->

[darkvoid]

Hi Dan your new DGIII looks great...

But I'm having a problem... With the new DGIII I can't de-orbit...
The temperature rises a lot, and very fast @ 40º AOA
I've tried several configurations and manual or autopilot reentry but my ship always get burned.
With the "old" DGII I had no problem reentering!!

I'm I doing something wrong?

"Keep up the good work"



Post Edited (01-26-04 00:02)

[DanSteph]

Dark:

I mad several reentry without problem (even I'll tweak the reentry a bit
in the future)  watch the computer's 2nd display about your reentry angle
when you do your deorbiting burn the angle must be about 1.1° or  1.2°
then accelerate the time until your about 120km high and fire
the pro104spec40... after that just wait and set the autopilot off
when your at mach2.

Hope it help ?

Dan

[MattNW]

Only one other download when I clicked on the link. Now there's 33.

I did a complete system check on the ground. No problem at all. Ship went into "Safe Mode" just
fine and powered back up OK. Hey Dan you should be writing code for NASA.

Trip up to ISS went perfectly. Powered down into Safe Mode docked to ISS. Only thing I noticed
was that the radio kept playing ATC Chatter even when powered down.

Adding the EPU fixed a minor but annoying problem of having to reset all your breakers when
going from Gen 1 to Gen 2.



Darkvoid:

Getting ready to try a deorbit. I'll see if I burn up too.

[jgrillo2002]

Also the edit passenger config always gets screwed up with other fonts. please check

[Leemon]

I just tried the KSC fly-by scenario.  Awesome!  

I hovered to the end of the runway, turned around and floated to a gentle landing thanks to the
new hover autopilot.

Stupidly, I switched back to the runway camera and went to full thrust for a take-off without
checking that the DGIII wasn't in atmosperic flight mode.  Needless to say I screamed down the
runway but was unable to lift off.  The gear collapsed (taking out the hover engines also -- nice
touch!) but I managed to get airborne finally .  The damage smoke looks great!

A small bug, though.  I circled back to try a belly-landing.  I flared and landed successfully, but just
for kicks I tried the brake keys (. and ,) and the brakes still worked!    If it's not too much trouble,
maybe you can disable the wheel brakes when the gear collapses.

The DGIII keeps getting better and better.  I'm currently landed at Brighton Beach to pick up some
passengers for a return trip to earth.  The hover autopilot helped me make a beautiful precision
landing on Pad One from lunar orbit.

Now, if I can just figure out how to get back to Earth safely!  (I hope the passengers didn't hear
that.)

Lee

[MattNW]

I'm getting the same thing on reentry. I tried it with a reentry angle of 1.12 and even .75 and was
crispy critters both times. I finally made it down when I used an angle of 1.20 exactly but it was
one exciting ride and I pulled about 3Gs.



http://www.savepic.com/freepicturehosting/is.php?i=63899&img=Reentry_3.jpg



http://www.savepic.com/freepicturehosting/is.php?i=63900&img=Reentry.jpg



http://www.savepic.com/freepicturehosting/is.php?i=63901&img=Reentry_2.jpg

[spets]

ah, so it's not just my re-entry procedure that's crap :P

I think a futuristic ship could have *slightly* higher re-entry tolerances.

[Wilko]

:D This means I have way too much time on my hands... made possible by the hover autopilot :D

http://atlas.walagata.com/w/wilko/dockedearth.JPG

[spets]

slight bug found:

when taking off with open canopy (just for kicks) I lose all atmospheric presure at around 120m..
everyone dies.

passenger aircraft generally descend below 12,000 feet or 3,600 meters when they experience
depressurization.

I am just going to assume you don't want to model the complete air equations of the earth's
atmosphere either, do ya?

[MattNW]

It isn't the reentry tolerances. Those are just fine but it seems that a "standard" reentry is a lot
more violent now than it was in previous versions of the DG. I've used the same methods with
earlier versions and reentered pulling only 1.3G. Reentry seems a lot more sensative to your angle
now also. Before, anything in the range Dan mentioned above ("1.1° or 1.2°") would give you a
decent reentry. I just barely made it using exactly 1.20°.

[ptwickler]

Hey,

Every time I try to ascend using autopilot and my target heading is too great, more than 40 or so
degrees from my take-off heading, I loose too much altitude and hit the ground. BLAMMO! Am I
doing something wrong?


I'm flying 040215rev1.

ptwickler



Post Edited (01-26-04 05:33)

[Wilko]

ptwickler:

If you are taking off on a runway, then make sure you are using the normal ATM mode, which
automatically sets the controls to elevrons etc. If you are taking off from a pad, make sure you are
using RCS for the first few moments before gaining speed, otherwise the DG cannot make the
proper turns etc.

Try turning to the correct heading (for ISS its 42 degrees) before activating the ascent program.
That way it doesn't fiddle around with changing your heading automatically (and usually
unefficiently).

--

Re-entires are a real problem for me, but then again in the DGII they were also, but back then as
far as I know you coudn't burn up on re-entry either, so you could pretty much do any angle you
felt like. Plus you have to remember, the DG is quite a small little spaceship and although it is
made for re-entires, it doesn't look like it has much protection at all. Then again in the future they
might have better materials to absorb heat... the debate continues

[ENS2018]

About the re-entries.  I managed to not burn up using an angle of about 1.12, then set the
autopilot to 40 degrees.  From their it was just a matter of making turns and keeping the general
bank angle.

Another thing any of you may want to consider is to think a few steps ahead, if you're VAcc is
going deep into the negative, bring the nose down (or something) to slow it down.  Becase, as
your VSpeed downward increases, so will your heat.  Once you have that process down, it's just a
matter of slowing down using retro-thrust, air-brakes, or S-Turns (whichever is most appropriate).

The only problem I had was that I did a final approach into the Cape, and ended up needing to
use the engines a lot more than I'm used to.  Maybe it's just me, or the new version or orbiter, but
the DGIII seems a bit heavier than it used to be.  I was unable to maintain a good glide speed
and couldn't figure out why - so I just pushed the throttle a bit, go within 30k of Runway 15, and
glided in for a soft touchdown.

I hope my advice about re-entries helps, sorry in advance if it doesn't - it may just take practice, I
only started to survive it after about 4 failed attempts.  

Oh, almost forgot.  Dan, great job with this.  I started from "Landed KCS" mission, went to safe,
came out, and launched to ISS.  At ISS I filled up with Fuel and topped off the O2 and went to Mir.  
Then back down to KCS, I didn't encounter anything eventful.  I really like the new HUD, though, I
like that the PeD is given in MSL, it really works great.

Later,
Tony

P.S.
Has anyone else noticed the difference in the aerodynamic handeling of glide charecteristics?  It
just seems a lot different - not DGIII, just Orbiter in general.

[Hoverboy]

^About the gliding characteristics, the DG3 does seem heavier than it used to.  I usualy end up
breaking the langing gear and having to use the engines a bit.  Other than that it all seems to be
fine.  Nice work Dan!

[MattNW]

ptwickler

I used to have the exact same problem with the early version of DG II in the older Orbiter build. I
found that if you help it around with a little rudder it'll get to the right heading. That problem has
gone away for me since the latest Orbiter release, now I'm having a heck of a time with reentry
which never was a problem before.

Is it just me or is this DG III developing a personality.




ENS2018

I haven't tried checking my vertical acceleration. I was just trying it using the standard method in
the DG II Docs (unpowered Shuttle like reentry). I'll try adjusting vert. accel. some time tomorrow
and see if that helps. Either way though you can see from the screen shots that the ship is
reentering a lot more violently now than it ever did before. That last reentry that worked for me
was at a angle of 1.20° and I pulled 3 Gs. That never happened before from ISS using the same
procedure (reentries usually were around 1.3 G). Something is definately different. It might be
some of the aerodynamic properties that changed from DG II to DG III.

Yes. the DG feels a lot heavier since the latest Orbiter build. My guess is that it's the atmosphere
model. The redeeming fact however is that it allows for realistic aircraft behavior ie. Altitude vs
Airspeed. If you need more airspeed then bleed off a little altitude if you need altitude or want to
hold on to some, you have to pay with some airspeed. If you are coming up short then keep a
little more altitude so you can extend your glide.

[darkvoid]

I've tried 8 more times reentry angle between 1.10º and 1.20º with AOA of 40º.

I was only able to stay below 2600ºC once. The "panel top temperature" seems to be the
problem. It always burns the ship at around 50km.

[DanSteph]

Darkvoid


Strange I make the reentry fine almost all the time starting from iss
scenary and taking 1.20° reentry angle do you start also from iss ?
what is your speed when you start the reentry and what is your Epd ?

Anyway I'm not satisfied with the reentry code yet I'll tune it again.

Jgrillo

Strange ? no one reported any font screewing it's a simple
 windows MFC application and so there is no special font code... do
you have an picture of your desk with the passenger name problem ?
(sent it by mail if you can't host a picture)


For the sound screwed up it seem to me that your sound card have
some trouble with Directx and is unable to comply with the directx
buffer... if there is no new driver available for you, well....

Leemon

"Brake" with no landing gear bug added to my "todo bug" list

Now, if I can just figure out how to get back to Earth safely!
(I hope the passengers didn't hear
that.)


LOL


Wilko

http://atlas.walagata.com/w/wilko/dockedearth.JPG

Amazing picture, I'm the 1st one to try unusual things
to check all possible bug (and for fun) but I didn't
think to do that

Spets

when taking off with open canopy (just for kicks) I lose all
atmospheric presure at around 120m..
everyone dies.

Ooops ! I cleared a bug and added another, I didn't thought about
this case.  Added on my "todo bug" list



ptwickler

When you take off take care to climb at least to 250 meter with
at least a speed of 200 m/s before engaging the autopilot...



To All

I wasn't satisfied with the way the stock DG handle atmospheric
flight and reentry but I tought there where right and well done so I
was a bit shy to modify it.
But now I think they are in fact completely screwed and there was not
much attention payed to testing.

There is far too much drag at low altitude so you have to maintain an obsoneous
angle of descent to maintain speed and at high altitude during reentry there is about
no drag if you maintain 0° AOA... (and there was NO drag at all added for a 40° AOA
this is already modified)

Now that I think the stock DG is wrong in it's handling I wont be ashamed
to modify it completely... so ---> TODO list


Thanks for feedback it's always a pleasure to ear DGIII flying adventure
I have even more motivation when I hear them.

Back to duty (too much snow here I had pain to go to work so I took one day holliday


Dan