BrianJ
Addon Developer
Hi,
just been messing about with the "Venera 9" add-on by 4throck (trying to check the lander re-entry profile at Venus: drag, max.G, timings, etc.)
It wasn't going very well (impossible to get the correct re-entry angle of 20.5deg, using historical timings and landing site target) - so I thought I'd check the Venus .cfg rotation parameters.
JPL Horizons can give the azimuth/elev for the Sun as seen from various sites on Venus, so I grabbed the data for the Venera 9 landing site at the time of the landing and 25 years later. Here it is....
Site Long, Latitude = 291.000000 E, 31.9999185 N
Changing the Venus .cfg SidRotOffset parameter to
gives a pretty good match for the JPL Horizons data - and also solves my re-entry angle problem for Venera 9.
It's about 22deg different to the default SidRotOffset value.
Anyone wanting to simulate historical missions to Venus may like to take note......
Cheers,
BrianJ
just been messing about with the "Venera 9" add-on by 4throck (trying to check the lander re-entry profile at Venus: drag, max.G, timings, etc.)
It wasn't going very well (impossible to get the correct re-entry angle of 20.5deg, using historical timings and landing site target) - so I thought I'd check the Venus .cfg rotation parameters.
JPL Horizons can give the azimuth/elev for the Sun as seen from various sites on Venus, so I grabbed the data for the Venera 9 landing site at the time of the landing and 25 years later. Here it is....
Site Long, Latitude = 291.000000 E, 31.9999185 N
Code:
Date__(UT)__HR:MN:SC.fff Azi_(a-appr)_Elev
***********************************************
$$SOE
1975-Oct-22 05:13:00.000 * 148.9915 53.6546
2000-Jun-01 00:00:00.000 * 153.8611 54.8522
$$EOEChanging the Venus .cfg SidRotOffset parameter to
Code:
SidRotOffset = -2.44It's about 22deg different to the default SidRotOffset value.
Anyone wanting to simulate historical missions to Venus may like to take note......
Cheers,
BrianJ
