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Author Topic: DG-III Competition 'From KSC to ISS'  (Read 13384 times)

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Matt

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23 May 2004, 15:06:10
Hi,
I would like to compare some figures. Here are my values concerning the trip below:

Date =Oct 29, 2023
DG-III earth scenario 'KSC departure to ISS'


15:50   Engage full thrust
   - Rotate at 580 km/h
   - Gear up
   - Climbangel: 30°

15:51   Program Autopilot 'CP03S40'
   Engage Autopilot 'Ascent'
   Engage Turbo pump

16:01   Achieving orbit (Ecc=0)
   Alt: 214,3 km
   Speed: 27.000km/h
   Fuel: Main 40,4% / RCS 95,5%
   
   - Aligning orbit not neccessary (Rinc: 5.37°) -
   
16:03   Starting 'synchronize orbit' maneuver...
   
   Three turns 'to match' neccessary...

23:10   Starting break maneuver
   ...hmm, ISS far away - seems to be not my best trip ;-)

23:20   First correction maneuver (speed & direction)

23:21   Tune ISS Transponder & Dock frequencies

23:25   Some more correction maneuvers 'to catch the station'

00:09       ...yes, not brillant, i know,  ISS in sight

00:15   Switch MFD to docking mode
                'Corridor' is on

00:16      Open docking cone

00:16      Fine tuning...

00:23   Docking complete!
   Fuel: Main 22,1 % / RCS 91,6%
                Paxe alive

Well, 8 hours 43 minutes... anybody faster?
How fast from ISS to MIR? Anyone should set a benchmark :-)

Matt


Offline McBrain

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Reply #1 - 23 May 2004, 19:43:13
Here is mine:

Start date: Oct 29, 2023
DG-III earth scenario 'KSC departure to ISS'

15:51
-take off

15:52
-ascent autopilot/turbo pump engaged
-begin ascent with heading 42° / Mach 1.0

15:53
-flight control: RCS

15:54
-auto air intake closed

15:55
-altitude: 100km  speed: 1.600km/s

15:57
-speed: 3.000km/s

16:02
-orbit reached
-target RInc. 3.4°

16:17
-target aligned to RInc. 0.01°

16:49
-intercept Dv reached
-predicted interception with target: 2 orbits

19:00
-speed correction

21:11
-braking maneuver

21:22
-target in sight

21:30
-docking ports alignment

21:31
-opening nosecone

21:34
-docked!
-fuel: main: 90% RCS: 88.9%

total time: 5 hours and 43 minutes

note: I used high fuel configuration.


Cheers,

McBrain

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Offline freespace2dotcom

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Reply #2 - 23 May 2004, 23:10:15
Ok, first off, I just *had* to load my little special config to get the specs I wanted.
That killed a few seconds. I ran with just one person, the payload, realistic fuel, and my precious markV engine. (more
power = more fun!) I'm also writing this as it happens, so read it like it's happening.

Date of start: Same as you guys
Same scenario too. (duh ;) )


15:50:30

Engaged full thrust *AND* turbo pump at same time
Rotated at just under 200 M/S
going straght up. ( >85 degree ascent)
Autopilot isn't used due to limitations of freedom of choice of target altitude.

15:53:17

lowering nose from high angle to 40 degrees
Current altitute is 57.71 kilometers.

15:54:30

leveled the horizon. Rising a tad faster than expected

15:56:09

Reached desired altitude of about 164 Kilometers. Only at speed of 2600 M/S
Raising nose to prevent fall, but no more altitude gain is planned.
planned tragectory is somewhat.. off. better than expected though.
tilted nose slightly to the left to lower Rinc before course correction becomes costly

15:57:15

tilted nose back to the right to original position.
nose at about 23 degrees above the horizon. but lowering gradually as speed increases.
speed at 3684 M/S

16:00:42

Reached orbit! (ecc .0002)
altitute is 165.7 Kilometers
Speed is 7504 M/S.
Fuel:  Main 2420 KG, RCS 596.6 KG
ISS Rinc is at an amazing 2.4 degrees. (I got lucky)
Plane adjustment still planned. (I always do it for good measure)
Beginning to fine tune orbit...

by 16:04:30 I had...

Ecc lowered to 0.
Distance to ISS is learned to be 4460 KM away.
Dyn Pressure is at 0.0006 Pa. No threat of a firey death, eh?
(At least as long as I keep an eye on it, but no worries)
70% of the RCS fuel was put into the main fuel tank, to roughly make equal percentage in both tanks.

16:14:43

It's time to adjust orbital plane now. (Edit: adjusted orbit to 0.02 degrees after burn)
Distance to ISS is now at 4187 KM. (getting there)
No orbital decay is noticed. Surprised me just a tad.
Time to arrival is estimated at 2.72 hours based on time taken to get the disance covered so far. I know this to be a
relatively bad number to judge by, but it's nice to know.

16:41:10

Well, I screwed up my last plane change and I wound up with a less than perfect orbit. I've corrected this entirely, but I'm just a tad higher at 165.8 KM now. I'm far too lazy to correct this because it's so small a change.
Now it's time for the next plane change. This time I'll get a Rinc with the ISS to 0 for sure! (edit: I sure did)
distance to ISS is at 3804 KM.
Now preparing the instruments for the burn to the ISS's altitude in a few hours.

19:33:14

Distance to ISS is now 540 KM.
Current altitude is the same. still NO orbital degrading. Big surprise from me.
Transfer MFD says my burn to get to ISS's altitude at the time it gets there is coming up soon. Preparing complete.

19:37:45

Burn complete! If my calculations are correct, then all I need to do now is do another burn when I get to ISS altitude
to keep me at that height and the ISS should even be in visual range (if I'm lucky, but it seems to be on my side
today, so..)

20:17:20

35 KM away from ISS. A tad further tan planned. I would have gotten closer if I wanted to, but that would require
killing more time, And I wanna beat you guys. ;) Adjusting relative velocity to catch up with the ISS

20:20:24

Funny Time, not intentional. If it was, I'd go for 20:20:20.
19 KM away from the ISS. It's now a visible pixel or so on my monitor. But visible nontheless. Approaching the ISS at a
relative speed of 110 M/S. pumping up the speed to 300. (yeah, I'm reckless)

20:21:20 slowed back down to 90 M/S and continuing to slow. only 1.5 KM away and closing fast! *DAMN* my
recklessness!

20:22:25

going at 34 M/S and only 495 Meters left. Looks like I'm beating Mcbrain. hehehe. Opening the nosecone...

20:22:47

used the retro thrusters to stop that puppy and used the translation trusters to cancel out that accursed upward
force the retro thrusters create... going at about 4 M/S and 153 Meters away.. using RCS thrusters to align with a
docking port and close in.  

20:25:28.

Docked! I had bad luck aligning myself, but I'm satisfied with my performance.
I beat mcbrain by a bit over an hour. *does a victory dance*
Total time of 4 hours, 34 minutes, and 58 seconds.
fuel remaining. Main 23.5%, RCS 28.7%.

To close, I will say that this run was not my best, and I could have easily gotten a better time if I wasn't weighted
down by the payload. The two important things in this scenario are getting into orbit as fast as you can, and STAY
LOW to catch up. I stayed low for as long as I could. I could have also went even lower if I had dared to. 160 KM is
lower than my normal flights, but I have tried chasing down the ISS at far lower in the past. One time I was so low
that I needed to adjust my orbit with the rcs thrusters every 25 second or so to keep me from going further down
and causing more friction. in mcbrain's case he was bogged down by all the fuel he had. so he couldn't get into orbit
as quickly as he possibly could. I burned all mine up during my ascent. so anyway.. Any challengers to my title?

(If you beat my time, I'm allowed another go at it.)



Post Edited ( 05-23-04 23:26 )


Offline Zamzara

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Reply #3 - 29 May 2004, 18:03:53
October 29th 2023, KSC

16:21 Launched from runway. Not fuel optimal, but will result in a faster rendezvous at the expense of a larger plane change.

16:25 Passed 100km.

16.31 MECO at 157km, with orbit of 391km x -18km

16:50 Plane change 1, rInc=0.25º

16:52 Orbit adjustment 1 to set up rendezvous, dT=32s

17:04 Plane change 2, rInc=0.00º

17:47 Orbit adjustment 2, dT=0.04s

18:54 Interception with ISS at 400m, velocity match.

18:56 Commenced docking run to port 2.

18:57 Capture

Total time: 2 hours 36 min



Offline freespace2dotcom

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Reply #4 - 29 May 2004, 18:12:56
oh, a hot-shot, eh? well, when I get around to it, I'll take you on. but right now, I'm more interested in skinning ;)
until then, look forward to it.



Offline Cracker

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Reply #5 - 29 May 2004, 21:03:31
Take off on the morning of February 25, just as ISS is crossing the isthmus of Panama. Com set to 131.3, hard dock in
27 minutes, 45 seconds.

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Offline Cracker

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Reply #6 - 29 May 2004, 21:04:46
Oops, Feb. 25, 2004.

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Offline DocHoliday

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Reply #7 - 30 May 2004, 00:36:51
Hey Cracker, do you have any kind of calculus to back up this kind of direct approach??? I'd like to set up some kind of
an Excel model, so you could calculate it and do it every time accuratelly! The main factor I guess we need to
measure is the angular distance of the ISS to your launch site, assuming it is passing right overhead.


~~~

"Mood is a matter of choice. I choose to have fun!" -Vidmarism No 15

Offline McBrain

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Reply #8 - 30 May 2004, 00:47:47
Hey, Doc!
I think you don't need to calculate the distance of the ISS to the Cape before launch.
Just guess and try, and keep the distance in mind. Then, after orbit insertation, get the distance
to the ISS and then add or subtract (add if ISS is further forward) it from the launch distance.
Then try again, and tada! Of course you should use the same autopilot prog everytime.

But, this is just my opinion. I haven't  tested it, so it might not work. But I will test it after I have woke up
in just a few hours! :) I'll go to bed now...


Cheers,

McBrain

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Offline Cracker

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Reply #9 - 30 May 2004, 01:26:18
Doc, I basically eyeballed it, using the docking HUD. I took off with full turbo, turned onto 42 degrees, pitch up to 70
or so just as ISS crosses the coast. When you pick it up on the docking HUD, steer using the deltaV and null it out,
then keep turbo engaged until 250 or so Km away, 2.5 or so Km/sec. approch speed, pitch over, full turbo. Voila.
Throttle to a stop next to ISS, dock. Too much fun. It took a few tries to get the timing right.

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Offline Cracker

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Reply #10 - 30 May 2004, 01:28:35
Doc, this is VERY BEAUTIFUL using the StationV add-on. 16-20 minutes to intercept, usually passing over the Azores.

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Offline DanSteph

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Reply #11 - 30 May 2004, 02:06:02
27 mn ? 8o 8o 8o :applause:

What about to edit the autopilot to get the same altitude than the iss at top of ascent
than launch and see how much delta time you have in advance or late....
Than perhaps it would just be a matter to launch at the exact time
to be able to knock at the door at top of ascent ? Would be really neat
to see the thrust stop, autopilot disengage and have iss only a few km aways
And this at each launch without worrying too much, THAT would be a real futuristic trip :)

Dan



Post Edited ( 05-30-04 02:07 )


Offline Cracker

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Reply #12 - 30 May 2004, 02:09:49
Dan, I just tried it again, gear up 5 minutes BEFORE ISS crosses the coast, hard dock in 16 minutes. This is just TOO
MUCH FUN. Full throttle, seat-of-the-pants manual flying at it's L.E.O. best, many thanks to you and the good doctor
for allowing me to experience this.

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Offline Cracker

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Reply #13 - 30 May 2004, 02:13:00
On the last try, I overshot ISS by a wee bit, went by at about 3 Km, 700 Km/sec., full throttle. I doubt if NASA/ESA
would approve such an approach.
A few more tries, I think a few minutes can be shaved off by a skillful hotrod pilot. Not me, of course.

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Offline DanSteph

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Reply #14 - 30 May 2004, 02:28:35
Quote
Cracker wrote:
I doubt if NASA/ESA would approve such an approach.


old NASA/ESA perhaps but NAESA directive 893.3 dated october 2025 recommend
straight aproach to save time and fuel... :)

If you write down your pitch at each altitude you would be able
to make your custom "bang in the goal" autopilot.

For recall the autopilot ascent is located in sound/deltagliderIII/prog/pro903spec.txt
copy it to pro906spec.txt for example, edit pitch and alt into it and call it with PRO906SPEC42.

If you do one send it to me I'll put it for download as well as the proc to get the iss
in less than 1/2 hours in the faq, with credit to you of course.

And congrat, perhaps your may reduce the time a bit but I think your near
the absolute best time with 16 minutes. :wor:

Dan



Post Edited ( 05-30-04 02:32 )


Offline Cracker

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Reply #15 - 30 May 2004, 02:35:18
Dan, isn't that a lot to ask an old man to do? Write down numbers while yanking joystick? :pfff:

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Offline freespace2dotcom

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Reply #16 - 30 May 2004, 02:38:09
That would be what "Control-P" is for. ;)



Offline Cracker

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Reply #17 - 30 May 2004, 02:39:03
I really wish I could capture the flight to a video, but a 20 minute video would be huge, and I don't currently have
capture software. Is there a way to record the control dynamics of a flight in real time?

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Offline DanSteph

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Reply #18 - 30 May 2004, 02:49:34
mhhhh a "record ascent MFD" would be nice... if I had time to do it.

Dan


Offline freespace2dotcom

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Reply #19 - 30 May 2004, 02:52:11
Isn't the "custom MFD" similar to that? it doesn't log the info though...



Post Edited ( 05-30-04 02:52 )


Offline DanSteph

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Reply #20 - 30 May 2004, 02:59:10
Sure there is one, I forgeted it: "flight data" perhaps ?

Dan


Offline freespace2dotcom

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Reply #21 - 30 May 2004, 03:13:13


Isn't this what you wanted to know? you have to activate it in the orbiter module menu. (customMFD)



Post Edited ( 05-30-04 03:17 )


Offline Cracker

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Reply #22 - 30 May 2004, 03:16:09
Hmmm, I might give that a try. Almost like work, though, and I do that 75 hours a week......
:wonder:

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Offline McBrain

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Reply #23 - 30 May 2004, 09:38:20
75 hours of work a week?????


Cheers,

McBrain

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In a world without walls and fences, who needs windows and gates?

Offline Cracker

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Reply #24 - 30 May 2004, 10:26:08
Well, usually 5x14, plus 8 on Saturday, so, I underestimated by 3. Sick, isn't it? That's what it's like to be involved in
heavy construction. Almost 30 years now.......:fool:
Cracker


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