What were some direct Mercury Hohmann transfer windows/dates?

[Grant Exploit]

I am creating 2 spaceflight-related alternate histories which would include missions directly launched to Mercury. However, there has never been a direct mission to Mercury (all of them have used gravity assists), preventing me from using an existing launch and the synodic period to calculate their launch dates (the only method I know how to use). So, does anyone know any optimal launch dates for direct Mercury transfers?

[satnet]

There is a site called the cosmic train schedule (http://clowder.net/hop/railroad/sched.html). It has Hohmann transfers for a number of bodies including Earth to Mercury.

If you want to work from first principles you might look at http://www.braeunig.us/space/interpl.htm, since alexmoon's launch window planner used it as a guide.

[DAL59]

On 9/22/2018 at 12:58 AM, satnet said:

There is a site called the cosmic train schedule (http://clowder.net/hop/railroad/sched.html). It has Hohmann transfers for a number of bodies including Earth to Mercury.

If you want to work from first principles you might look at http://www.braeunig.us/space/interpl.htm, since alexmoon's launch window planner used it as a guide.

If you remove the stuff after the .net, you get to a website with an interesting design.  http://clowder.net/

On 9/21/2018 at 11:22 PM, Grant Exploit said:

I am creating 2 spaceflight-related alternate histories which would include missions directly launched to Mercury. However, there has never been a direct mission to Mercury (all of them have used gravity assists), preventing me from using an existing launch and the synodic period to calculate their launch dates (the only method I know how to use). So, does anyone know any optimal launch dates for direct Mercury transfers?

Another more versatile website is https://trajbrowser.arc.nasa.gov/traj_browser.php