Meadville Space Center
Welcome,
Guest
. Please
login
or
register
.
May 21, 2013, 07:09:50 PM
1 Hour
1 Day
1 Week
1 Month
Forever
Login with username, password and session length
Search:
Advanced search
Project Apollo - NASSP 6.4.3 released!
http://nassp.sf.net
20010
Posts in
1929
Topics by
2250
Members
Latest Member:
mikegk
Meadville Space Center
Project Apollo - NASSP
Project Apollo - NASSP Development
(Moderators:
movieman
,
Tschachim
,
Swatch
,
lassombra
)
RDV SPREADSHEET
« previous
next »
Pages:
[
1
]
2
3
4
Author
Topic: RDV SPREADSHEET (Read 2619 times)
Christophe
Project Team Member
Hero Member
Posts: 1072
RDV SPREADSHEET
«
on:
August 11, 2011, 05:22:19 PM »
Hi Apollo fans!
I'm very happy to introduce the first version of a new spreadsheet dedicated to the calculations of phasing and coelliptic rendezvous orbits and maneuvers.
Here in the attach is a zip file that contains
- An excell file: the calculator
- A word file: The user manual including 2 tutorials.
I hope that this may help to improve your virtual space flights.
This is the very early version.
I'm already working on additionnal features and improvements.
Feel free to post criticism, comments, suggestion or questions here in this thread.
Enjoy your flights
Christophe
RDV_1.0.zip
(1832.37 KB - downloaded 41 times.)
«
Last Edit: August 11, 2011, 05:56:00 PM by Christophe
»
Logged
eddievhfan1984
Full Member
Posts: 231
Re: RDV SPREADSHEET
«
Reply #1 on:
August 11, 2011, 08:19:09 PM »
You left the workbook password protected; I can't paste SV data straight from Orbiter to the spreadsheet.
EDIT: There's a bum cell in the service worksheet, F4, with a formula that reads as "=REF!B12" that appears to cascade throughout the sheet, messing up the calculations. What should go there instead?
«
Last Edit: August 11, 2011, 11:58:10 PM by eddievhfan1984
»
Logged
meik84
Project Team Member
Sr. Member
Posts: 299
Re: RDV SPREADSHEET
«
Reply #2 on:
August 12, 2011, 12:03:26 PM »
Quote
There's a bum cell in the service worksheet, F4, with a formula that reads as "=REF!B12" that appears to cascade throughout the sheet, messing up the calculations. What should go there instead?
I guess 'service' should go there -B12 on 'rendezvous' does not contain anything sensible.
Although, this does not fix the problem. There's something wrong in the other cells, too.
Anyway, one question that comes up to me as practician: in how far does this sheet help me? It shows that it's obviously possible to calculate those burns, but it doesn't provide me the data I actually need to
do
the burns -or am I missing something?
Logged
Christophe
Project Team Member
Hero Member
Posts: 1072
Re: RDV SPREADSHEET
«
Reply #3 on:
August 12, 2011, 02:51:35 PM »
Oops!
Sorry guys, it seemes that I messed up my mind with the protected cells.
Things shouls be OK now in the current 1.1 version.
I erased the #REF!B12 cell to avoid confusion. This doesn’t affect the spreadsheet since this cell is not use anymore. It's from a very old beta while this one was part of a non released EOCA.
Quote from: meik84 on August 12, 2011, 12:03:26 PM
Anyway, one question that comes up to me as practician: in how far does this sheet help me? It shows that it's obviously possible to calculate those burns, but it doesn't provide me the data I actually need to
do
the burns -or am I missing something?
Yes I admit this is not clear at all.
For the moment, you may proceed like this:
After each maneuver, between each strip, is a medium grey line with orbit parameter: Pe, Ap and T and the relative LOA angle.
From the strip itself you got the GET of the burn too.
This is the minimum required to allow you to insert in IMFD to get the delta V's in LVLH for the use of AGC/LGC.
By the way, once the rendezvous sequence has begun, CSI, CDH, TPI and TPF should be made only with the AGC, with no refer to any other software anymore. As it was done in real since these maneuvers may occur on the lunar far side and/or time does not permit real time computation from ground.
Nevertheless, I already began the work for a third tab into the spreadsheet where all the maneuvers parameters and setting for both entry in AGC/LGC and IMFD will be summarized in a more friendly and practical way
May be I should have include that feature before the first release.
I was too impatient.
Sorry for that.
Anyway, thanks for the report and I hope this version works properly
Regards
Christophe
RDV_1.1.zip
(1831.73 KB - downloaded 22 times.)
Logged
eddievhfan1984
Full Member
Posts: 231
Re: RDV SPREADSHEET
«
Reply #4 on:
August 12, 2011, 04:15:07 PM »
Still got issues, sending some screenshots to demonstrate.
spreadsheet 1.png
(159.28 KB, 1280x800 - viewed 63 times.)
spreadsheet 2.png
(157.31 KB, 1280x800 - viewed 37 times.)
spreadsheet 3.png
(150.18 KB, 1280x800 - viewed 31 times.)
Logged
meik84
Project Team Member
Sr. Member
Posts: 299
Re: RDV SPREADSHEET
«
Reply #5 on:
August 13, 2011, 12:21:07 AM »
I guess the multi-language support of excel is flawed somehow -it doesn't understand 'EST.PAIR' for one example.
Logged
Christophe
Project Team Member
Hero Member
Posts: 1072
Re: RDV SPREADSHEET
«
Reply #6 on:
August 13, 2011, 01:27:20 AM »
Quote from: eddievhfan1984 on August 12, 2011, 04:15:07 PM
Still got issues, sending some screenshots to demonstrate.
Pictures indicate you're running excel in compatibility mode.
Which version do you use? Mine is from Office 2003.
The "EST.PAIR" function means 'IS EVEN" in english.
I guess 2 possibles sources of problem:
- Your version doesn't know that function: In this case may be you may try to get it from the CD. I know that the defaut istallation sometimes doesn't include all the features. I experienced that too and solved the problem by adding the missing from the CD.
- As meik84 pointed out, it's a problem of language support. I'm going to see if I can do something with the option setting.
I've seen that the file has been loaded 6 times.
Does anyone else experience same troubles?
Logged
Christophe
Project Team Member
Hero Member
Posts: 1072
Re: RDV SPREADSHEET
«
Reply #7 on:
August 13, 2011, 01:45:46 AM »
Still don't figure out what's wrong with language compatibility.
Meanwhile, since I've seen a problem with the characters size in the picture, I reduced it in the attached file. I additionnaly modified the settting to allow you to change format without any password.
RDV_1.15.xls
(458.5 KB - downloaded 12 times.)
Logged
meik84
Project Team Member
Sr. Member
Posts: 299
Re: RDV SPREADSHEET
«
Reply #8 on:
August 13, 2011, 07:50:09 AM »
After changing 'EST.PAIR' to 'ISTGERADE' (I'm german
) and reseting one of the circular references, it's finally working now. But I've got a problem: I followed your Apollo 7 example and get a insertion dV of 118,64 fps -far to high in my opinion. Could you have a look at it and tell me what I did wrong, please?
Edit: belay that. A look at the mission report shows that they even needed 204.1 fps for the first maneuver.
RDV_1.15.xls
(458.5 KB - downloaded 10 times.)
«
Last Edit: August 13, 2011, 09:29:19 AM by meik84
»
Logged
Christophe
Project Team Member
Hero Member
Posts: 1072
Re: RDV SPREADSHEET
«
Reply #9 on:
August 13, 2011, 12:04:13 PM »
OK, I did not expect such compatibility problems!!!
Meik84: I’ve downloaded your file and even with a reset back to "EST.PAIR" for my French Excel, I'm unable to avoid crash into the circular reference.
As far as I can see your wrong delta V INSERTION has probably something to do with the language incompatibility since I suspect some iteration failure.
I'm now convinced that the first thing to do is to fix that problem.
As far as the mission report data is concerned I've noticed significant differences in these data and the spreadsheet solutions.
2 explanations: the original orbit doesn't match exactly the real one and/or the nonspherical gravity field perturbation as greater effect on the burn data than expected.
This later is the more probable. I remember NASA itself had to do a second phasing burn to correct the unexpected SIVB orbit decay (greater aerodynamic drag than expected) and finally performed the NCC2 burn which was planned as a nominally 0 deltaV. So, even the NASA didn't anticipate these dispersions very well.
Logged
Christophe
Project Team Member
Hero Member
Posts: 1072
Re: RDV SPREADSHEET
«
Reply #10 on:
August 13, 2011, 12:16:15 PM »
Meik84, please try this one.
I've replaced the "EST.PAIR"/"ISTGERADE" function with something else.
If you could get the right result than the tuto it would be a good news.
RDV_1.16.xls
(458.5 KB - downloaded 14 times.)
Logged
meik84
Project Team Member
Sr. Member
Posts: 299
Re: RDV SPREADSHEET
«
Reply #11 on:
August 13, 2011, 12:27:42 PM »
Quote
I’ve downloaded your file and even with a reset back to "EST.PAIR" for my French Excel, I'm unable to avoid crash into the circular reference.
Really? Mine (the 1.15 I modified) is working fine now.
Just tried it with one of my Ap7 scenarios shortly after sep and got reasonable (and very close to the mission report) data. If I could just get the data from the sheet in IMFD...
Oh, and just for your info: the SIVB is doing some sort of maneuver shortly after sep. Maybe some of the booster guys (Tschachim?!) can tell more about that...
Quote
Meik84, please try this one.
I've replaced the "EST.PAIR"/"ISTGERADE" function with something else.
Have a look at R40 and R41. It's still there.
Logged
Christophe
Project Team Member
Hero Member
Posts: 1072
Re: RDV SPREADSHEET
«
Reply #12 on:
August 13, 2011, 12:50:00 PM »
Quote from: meik84 on August 13, 2011, 12:27:42 PM
Have a look at R40 and R41. It's still there.
Seems like you know my spreadsheet better than me
This is fixed in the attach 1.17.
anyway, if things go right with your scn, it's a pretty good news.
The SIVB vented fuel left just after insertion isn't it?
RDV_1.17.xls
(458.5 KB - downloaded 13 times.)
Logged
meik84
Project Team Member
Sr. Member
Posts: 299
Re: RDV SPREADSHEET
«
Reply #13 on:
August 13, 2011, 01:11:45 PM »
Quote
Seems like you know my spreadsheet better than me
Oh, the '#NAME?' errors just stroke my eye when I opened it. The rest was a job for the search function.
Quote
This is fixed in the attach 1.17.
..and works fine.
Quote
The SIVB vented fuel left just after insertion isn't it?
Yes, at 01:31:00 or so. No problem, as you are still attached to it. But shortly before phasing at 03:20:00 it is doing some sort of maneuver. I don't know if it's just 'putting it's nose in the wind' or if it does something propulsive.
Anyway, not very convenient so close to phasing.
Logged
Christophe
Project Team Member
Hero Member
Posts: 1072
Re: RDV SPREADSHEET
«
Reply #14 on:
August 13, 2011, 01:26:22 PM »
Quote from: meik84 on August 13, 2011, 01:11:45 PM
and works fine.
Good!
Since I know this function is unusable I won’t use it anymore and that’s all.
Now I can start the work for improvement, to make your life easier with the transfer to IMFD.
Quote from: meik84 on August 13, 2011, 01:11:45 PM
Yes, at 01:31:00 or so. No problem, as you are still attached to it. But shortly before phasing at 03:20:00 it is doing some sort of maneuver. I don't know if it's just 'putting it's nose in the wind' or if it does something propulsive.
Anyway, not very convenient so close to phasing.
Oh yes it remind me that I’ve read something like this. I think you’re right; it was an attitude turn to minimize drag to reduce orbit decay. Seems that it was not a great success since the orbit decayed more rapidly than expected.
BTW I don’t know exactly how orbiter takes this effect into account. Is our SIVB affected by that too?
«
Last Edit: August 13, 2011, 01:39:06 PM by Christophe
»
Logged
Pages:
[
1
]
2
3
4
« previous
next »
Jump to:
Please select a destination:
-----------------------------
Meadville Space Center
-----------------------------
=> NEW MEMBER REGISTRATION
=> Site News
=> Project News
=> Orbiter
=> Off Topic
=> Rob Conley's Blog
-----------------------------
Project Apollo - NASSP
-----------------------------
=> Project Apollo - NASSP News & Discussion
===> News & Announcements
===> Support & Bugs
=> Project Apollo - NASSP Development
===> Planning
===> Programming
===> Modeling
===> Sounds
-----------------------------
Project Mercury
-----------------------------
=> Discussion & Help
=> Development
===> Planning
===> Programming
=> Mecury Mission Control
-----------------------------
Project Gemini
-----------------------------
=> Discussion & Help
=> Development
===> Programming
===> Modelling
===> Sounds
===> Planning
-----------------------------
Orbiter Mars Direct
-----------------------------
=> Planning
===> General News
=> Development
===> Programming
===> Modelling
===> Sounds
-----------------------------
General Projects
-----------------------------
=> The After Columbia Project
===> Sprint
===> Greenstar
===> Cyanstar
===> Bluestar
===> Mars Challenger
-----------------------------
Sol 2018
-----------------------------
=> Planning
Loading...