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Project Apollo - NASSP => Project Apollo - NASSP News & Discussion => Topic started by: Vinny003 on January 12, 2016, 03:42:22 PM



Title: Gimbal lock and program alarms
Post by: Vinny003 on January 12, 2016, 03:42:22 PM
Hi, guys!

Question for you. How do I fix the gimbal lock situation in VAGC? Since I'm now using the VAGC, do I fix the program alarms on the DSKY, what verb/noun number to use to monitor the altitude, velocity, vertical speed, and what verb/noun number to use to monitor direction the spacecraft is pointing in on the DSKY? Thanks!

                  Cheers,
              Vincent


Title: Re: Gimbal lock and program alarms
Post by: indy91 on January 13, 2016, 08:36:34 AM
How do I fix the gimbal lock situation in VAGC?

You will find how to do this either here http://www.ibiblio.org/mscorbit/mscforum/index.php?topic=2839.msg22361#msg22361 or in one of the Excel flightplans under Errors and Failures.

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Since I'm now using the VAGC, do I fix the program alarms on the DSKY

That of course depends on the type of program alarm and the program in which it occurs. Usually you would press RSET first to make the PROG light go away and then follow the correct procedure for that specific program alarm.

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what verb/noun number to use to monitor the altitude, velocity, vertical speed

So, this isn't really something that the astronauts would do that often, but with creative use of the tools the AGC provides you can find out these values. These three numbers are displayed by noun 62. However, in orbit the values are only calculated for N62 when you run Program 47. P47 is usually used to monitor a thrusting maneuver that is not automatically done by the AGC, e.g. TLI or transposition and docking. In this case the procedure would be:

V37E 47E (to start program 47)
N62E (to display noun 62)

the displayed values are:
R1: inertial velocity in ft/s
R2: vertical velocity in ft/s
R3: altitude above the pad in 0.1 NM

Don't run P47 too long though, it doesn't calculate your trajectory very accurately. You will also find how to use P47 in the G&C Word Checklist.

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and what verb/noun number to use to monitor direction the spacecraft is pointing in on the DSKY?

That would be Verb 16 Noun 20 (V16N20E).


Title: Re: Gimbal lock and program alarms
Post by: Vinny003 on January 14, 2016, 05:43:57 AM
HI, indy91!

Great! Thanks for the explanation!

          Cheers,
       Vincent