My June Contest submission - Mission to Mercury!

[Rigel]

I've been working abroad for some time, so I'm sorry for being out of the forum for so long. Here's my submission for the Proficient flight.

This is my spaceship. No BP edition, no clipping, no cheats. A powerful first stage with two boosters; a high eficiency second stage; and the spaceship itself with two auxiliary fuel tanks, two solar pannels, and the cargo. Why the solar pannels? Because that makes my spaceship cooler. 904T, more than enough.

Welcome onboard flight 001 to Mercury. Weather at our destination is sunny, with a mild temperature of 350ºC. Please fasten your seat belts, and remember that smoking is strictly forbidden during this flight:


Ladies and Gentlemen, we're floating in space. Soon we'll use our second stage to get to Venus. When the window opens, we'll wait until Earth, Venus and the point of encounter are perfectly aligned, just like we'd do for a VEEGA maneuver. That way we'll maximize the gravity assist with Venus:


Ok, alignment confirmed. We are prepared to leave earth orbit. Ladies and gentlemen, please remain seated! We burn and detach our second stage. Mercury awaits us!


Now We're flying by Venus 42 km high above the surface. enjoy the views! This gravity assists puts our periapse near Mercury Orbit:


Half an orbit later, we get a transfer window towards Mercury. We ignite our engine and brake 300m/s to get an encounter. Now we've almost depleted our auxiliary fuel tanks:


Ladies and gentlemen, capitain's speaking. We're approaching Mercury and starting to brake. We detach our auxiliary tanks when they are depleted, and stabilize in a low Mercury Orbit. And we still have 32% of fuel left in our ship!


Cabin crew, prepare for landing. Now the lander separates and starts braking. We get a soft landing ver easily (applauses in the cabin)


Last maneuver: We don't need no more the two side engines we used for landing. So we reignite our engines at 30% thrust, and inmediately detach them so they separate in a ballistic trajectory that sends them some 200m away from the capsules:


Ladies and gentlemen, we've arrived in Mercury. Hope you enjoyed your flight with Rigel Airways!

 

[Rigel]

Rigel Airways, in an effort to make the Mercury trip affordable for everyone, has been optimizing our rockets to make them lighter, simpler, and cheaper. As a result, we have shrinked our spaceship down to 696T. Here's the report of our maiden flight:

Here's our new rocket. Same architecture, but the core stage now uses frontier engines. Also, the fuel tanks are smaller, and I've eliminated the two auxiliary tanks in the last stage and the RCS's in the lander:

This is the launch. We spend the first stage and the boosters to get into orbit:


Once again, we wait until the two planets and the point of encounter are aligned, then we burn most of our second stage to get a Venus flyby as low as possible:


The gravitational slingshop sends us to an eliptical orbit with a periapse near Mercury's. Less than a full orbit later, we find a transfer window to Mercury. We burn half of our remaining fuel to encounter Mercury:


Once in Mercury SOI, we deplete the fuel in our last stage to stabilize our ship in a low Mercury Orbit:


Time for landing. We detach the lander and start braking. This time we have less margin than in our first trip, as we start our landing from a higher orbit:


Dear passengers, we have made a soft landing in Mercury!!! Now we repeat the maneuver to get rid of the side engines: 30% throttle, then we detach then in a parabolic trajectory away from our capsules:


Mission accomplished! and we've saved more than 200T from our first trip to Mercury!

 

[Mooncrasher]

Looks like you have a good grasp of gravity assists with elliptical orbits!

 

[Rigel]

Looks like you have a good grasp of gravity assists with elliptical orbits!

Ha ha ha, Not really! I learnt the "three bodies alignment" trick in the VEEGA video tutorial. But for the rest of the flight, t's mostly a lottery: first try, I ran out of fuel before arriving; then I made it easily the next try with the same rocket.

Theory is good, but the result depends on the relative position between planets, now with the elliptical orbits

 

[Mooncrasher]

Indeed.
The feeling when you do a nice gravity assist and catch Mercury at its aphelion... rip. Hard way to learn.

 

[TtTOtW]

Ha ha ha, Not really! I learnt the "three bodies alignment" trick in the VEEGA video tutorial. But for the rest of the flight, t's mostly a lottery: first try, I ran out of fuel before arriving; then I made it easily the next try with the same rocket.

Theory is good, but the result depends on the relative position between planets, now with the elliptical orbits

Very happy to see value taken from my publications