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Project Apollo Beta 7.0 released!
http://nassp.sf.net/wiki/Installation
25068 Posts in 2094 Topics by 2266 Members
Latest Member: twa517
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1  Project Apollo - NASSP / Support & Bugs / Re: LV GUID Light on: June 29, 2017, 12:33:00 PM
What I don't get is that Apollo 8 works smoothly. It shouldn't -or does the LM do some things we don't anticipate here?
2  Project Apollo - NASSP / Support & Bugs / Re: LV GUID Light on: June 27, 2017, 11:35:54 AM
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Also, I think the issue might be a navigation problem after all.
Guess so, too. According to the attached lvlog, the LVDC thinks that it reaches the required terminal velocity. Interestingly, the CMC thinks that it is in a perfectly 100 x 100 nm orbit, too.
3  Project Apollo - NASSP / Support & Bugs / Re: LV GUID Light on: June 27, 2017, 08:52:16 AM
Well, 11 doesn't work out well either. I don't get a 100 nm x 100 nm orbit, but something around 65 x 100, so that you partially re-enter during LEO. Not good.
4  Project Apollo - NASSP / Project Apollo - NASSP Development / Re: V8 Release Work Thread on: March 16, 2017, 08:59:55 AM
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The solution here was supposed to be to hold the Saturn down by attaching it to the launch pad vehicle, and sever the attachment at launch time.
At least it should solve the problem with the touchdown points: define 3 wide apart points for the pad, give the pad a lot of mass and attach the Saturn to it. Should give the whole assembly the stability of an elephant...
5  Project Apollo - NASSP / Project Apollo - NASSP Development / Re: V8 Release Work Thread on: February 25, 2017, 10:55:10 AM
Am I just thinking wrong, but why don't we do it the simple way? a = F/m, or total force vector divided by current vehicle mass. This should give us the acceleration directly, without any dvel or something. Of course, this will only work if GetForceVector works with docked vehicles.
6  Project Apollo - NASSP / Project Apollo - NASSP Development / Re: V8 Release Work Thread on: February 24, 2017, 04:09:48 PM
AFAIK, the weight vector stuff was a work-around for Orbiter 2006, as GetForceVector didn't work for docked vehicles in 2006. See here-> http://www.ibiblio.org/mscorbit/mscforum/index.php?topic=2127.msg21910#msg21910
7  Project Apollo - NASSP / Project Apollo - NASSP Development / Re: What needs done? on: February 20, 2017, 08:50:04 AM
I have no idea from where our entry pattern derives. On the other side, I haven't found one LEO pattern in any doc I came along. They always talked about the non-exit and 3500 NM pattern. I for myself doubt that an earth entry pattern ever existed. Any lunar mission could've ended up in a LEO mission, and then the 'lunar' entry patterns had to be used for a LEO entry. And why develop separate patterns for not even a handfull of missions? Apollo was about going to the moon, not LEO.
8  Project Apollo - NASSP / Project Apollo - NASSP Development / Re: What needs done? on: February 20, 2017, 07:57:21 AM
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Not the range, the inertial velocity.
Right. The range integrator operates only when in ENTRY and .05g or when in TEST 4 and the 10s timer runs.  One should read the block diagramm correctly. Bangs Head
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so you first have to go through Test Mode 5 before reentry, if scroll and range integrator are supposed to be synchronized.
Yep, that's one of the nice gotchas of the EMS. Happy
You are not going to change the fps/pixel scaling of the scroll, right? I'd try to grab the 3500 NM pattern from the AOH, then.
9  Project Apollo - NASSP / Project Apollo - NASSP Development / Re: What needs done? on: February 19, 2017, 03:19:05 PM
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I'll implement this, if someone wants to fix the scroll.
Well, if you are at it Wink, here what I corrected those days:
- the dV/ EMS SET sw moves the scroll in the wrong direction when EMS FUNC is in V0 SET: inc means scrolling to the right, dec means scrolling to the left
- implemented a real range integrator
- consequently, when moving the scroll in V0 SET, the range changes, too, as the impulses from the SET sw are also fed to the range integrator
- decimal point and last digit blanked when EMS FUNC - ENTRY

Regarding the test pattern: the real ones also had this 'doorstep' at the end, however this will only work when the scroll moves a little to the left when switching to TEST 5. I can't see from the schematics how that was done. Confused
10  Project Apollo - NASSP / Project Apollo - NASSP Development / Re: What needs done? on: February 19, 2017, 10:40:23 AM
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I tried to implement using the biased accelerometer and the range integrator for the EMS tests, but it didn't end up at the proper place on the pattern.
I came along something similiar when I gave the EMS a general overhaul (maybe the code has survived somewhere on my HD): the test range you dial in can't be right. You should dial in 58 NM (=107416 m). EMS test 4 applies a 9 g (=88,26 m/s) for 10 s. Initial velocity 37000 fps (=11277.6 m/s). (a/2)*t + v0*t= (-88,26/2)*10 + 11277.6*10 =  108363 m or 58.5 NM. Confused
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All the others thrusters seem to be only a show effect without imparting a thrust right now.
Well, at least the numbers are here now and I don't have to dig them out again. Wink
11  Project Apollo - NASSP / Project Apollo - NASSP Development / Re: What needs done? on: February 19, 2017, 10:02:31 AM
Hmm...we'd also need the 3500 NM exit pattern, at this moment we only have the non-exit. Does anybody rember from where we got it? Simple copy & paste from the AOH?
12  Project Apollo - NASSP / Project Apollo - NASSP Development / Re: What needs done? on: February 19, 2017, 08:52:13 AM
The LVDC uses the solid ullage rockets of the SIVB after orbit insertion and before restart instead of the APS ullage thrusters.
As we talk about the solid rockets: some of them have wrong thrust and/or ISP settings, and all draw their fuel from the main tank. I had the numbers looked up some time ago, maybe I'll find them.
I also had an EMS scroll with the correct numbers of entry test patterns and DV test instructions. Maybe I'll find it, too.
Edit:
Found them Happy.
Thrust, ISP and prop mass per rocket (!):
SIB retro: haven't found them, yet Edit: 155 kN, 1931 m/s, 122 kg (SIB retro and SII retro are the same type)
SIC retro: 337 kN, 1520 m/s, 120 kg
SII ullage: 102 kN, 2516 m/s, 152 kg
SII retro: 155 kN, 1931 m/s, 122 kg
SIVB ullage: 15 kN, 2150 m/s, 27 kg

Also found them EMS scroll, shall I post it?
13  Project Apollo - NASSP / Support & Bugs / Re: Apollo 8 Beta Testing Bugs on: February 16, 2017, 04:26:20 PM
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Maybe this is a CSM-103 only thing with special sensors on that bus.
I guess the FQR (flight qualification recorder -not to be confused with the DSE) was on the noness bus. AFAIK they wanted more data from the SPS when in deep space.
14  Project Apollo - NASSP / Planning / Re: Documentation on: February 04, 2017, 03:26:41 PM
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CSM/LM Spacecraft Operational Data Book Volume I CSM Data Book Part I Constraints and Performance
This thing is incredible. Shocked 1500 pages with figures you always wanted (or didn't want) to know. Sort of a 'Apollo Numbers Bible' (no religious offense intended) Wink.
15  Project Apollo - NASSP / Support & Bugs / Re: Apollo 8 Beta Testing Bugs on: January 21, 2017, 08:25:34 AM
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I usually get around 150 pitch at 0.05G on the Lunar Entry PAD.
Me too. CMC steers for about 157, so the error needle never moves down. Which could lead somebody who follows the checklist by the letter to the assumption that the CMC is no go.
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Can you give me a source on that? I can't find this in the AOH or checklists...
AOH Vol. 2, p. 4-544 states that 'On position is momentarily'. CSM 104 sys handbook p. 464 shows a little downpointing arrow on the switch, indicating that it is springloaded to down. A toggle switch wouldn't make sense; those are squib valves. Once they have been fired they remain open, whether there is voltage on them or not.
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