A Venus return mission is a mission which you leave Earth, land on Venus, liftoff, and come back. For a mission like this, a lot of fuel is needed.
Return Mission with part expansion[]
Rocket[]
The rocket used for this mission is a 3-stage rocket, weighing about 1,600 tons. It consists of:
- Six Titan Engines with a 3×3 array of 12×16 fuel tanks for the first stage, which will almost reach orbit.
- Three Frontier Engines and two stacked 12×16 fuel tanks for the second stage, which propels the rocket through space and lands on Venus.
- Three Frontier Engines, one 12×16 fuel tank, three Probes, one empty 12×8 fuel tank, and one 8-wide nose cone for the third stage, which returns to Earth.
A stack of a 12×8 fuel tank and one 8-wide nose cone is placed on both sides of the first stage. 8 side parachutes, 8 RCS thrusters, and large landing legs are on the second stage, while four side parachutes, 4 RCS thrusters, large landing legs, and two docking ports (large is best), with structual parts attached before the ports, are on each side of the third stage.
Mission[]
Launch[]
Set the throttle to 100%, and fire all first stage engines. For best results, the rocket needs to fly vertically until reaching 800 meters. At around 5 kilometres, when Max Q occurs, it is advised to throttle down to 80%, to reduce fuel waste from drag. After max q, the engines can throttle back to 100% and continue to tilt slowly, reaching an angle of 75 degrees at 15 kilometers altitude.
Turn off the engines when the apogee is above the Karman Line, and wait until the rocket reaches the apogee. After that, burn prograde until you gain an orbit completely above the Karman Line. The second stage needs to reach orbit with at least 90% fuel.
Coast to Venus[]
Click on Venus and press 'Navigate To'. Wait until Earth reaches 'Transfer Window', then if so, then wait until the rocket reaches 'Transfer Window'. If Earth is in the transfer window in the right time wait the transfer window to pop up on your rocket. (This could be done before launch.)
If the Delta-V value is above zero, burn prograde until it disappears; if it is below zero, burn retrograde until it disappears.
Once the number disappears, focus on Venus. Do a tiny burn to set the flight path to intersect Venus' atmosphere. Then, wait until the rocket is near the periapsis. Do another tiny burn to adjust the periapsis to 23 kilometers above Venus's sea level. When the rocket begins to enter the atmosphere, turn straight up. If it is still turning, turn the rocket with RCS thrusters. Repeat this until the rocket enters a collision course with Venus.
Once at Venus, slow down until the velocity is below 1.6 km/s. This will decrease chances of burning up into the atmosphere.
Venus landing[]
At 2.5 kilometers, deploy the second stage landing legs and parachutes (also deploy the top 2 on the third stage). Do a quick landing burn if necessary. The second stage should land with some fuel.
Return[]
Liftoff with 100% throttle. After reaching that speed, keep it there. The second stage will run out of fuel during this phase. Venus's atmosphere will slow down the rocket significantly until it it almost stabilizes. After passing around 7 kilometers, turn slowly, with efforts to reach low Venus orbit just above the atmosphere boundary.
The third stage will most likely not have enough fuel to return to Earth. This is normal. Send the same rocket on the same route; instead of getting it to land on Venus, get it into Venus orbit, and dock it with the main rocket. Transfer all of the backup rocket's fuel to the main rocket. Then, undock the backup rocket.
Set Earth as a target and wait until your rocket and Venus are both at the transfer window. Burn prograde until the Delta V indicator disappears, then focus on Earth. Set the perigee to 15 kilometers and turn retrograde.
When the rocket enters the atmosphere, keep the landing legs retracted and the rocket facing retrograde. Slow down if necessary to decrease chances of burning up. At around 2 kilometers, perform the landing burn, deploy the landing legs, and return safely to the Earth. If the third stage runs out of fuel before landing, deploy the parachutes. They will slow down the rocket to a safe speed.
Important notes[]
- Quicksave every once in a while, so you won't have to start all over if you make a mistake.
- The flight path will fluctuate when travelling from Earth to Venus and vice versa. Since this doesn't occur during time warp, time warping actually solves the minor problem.
- Make sure you don't impact anything at a velocity of over 12 m/s, as this will break the landing legs, and could cause further damage if it is on a greater speed (20+ m/s).
- If the rocket is greater than that speed, it cound be rendered unflyable.
- If the rocket has more than 20% fuel during atmospheric entry, try burning the excess fuel. The third stage engines consume fuel pretty quickly.
- Heat shields must be used on atmospheric entry to avoid burning up into the atmosphere. If you cannot afford it, use the No Heat Damage cheat
Return mission without part expansion[]
If you are using the free version of the game, parts as Titan Engines are not available, but there is still a mean to achieve a Venus return mission without them, and even without activating Cheat expansion.
Rockets[]
This requires 3 different rockets and 7 launches with 6 earth orbit rendez-vous, to put in orbit a Venus ascent stage, a Venus descent stage and 6 tugs able to provide additional engines and fuel to reach Venus low orbit and get back to earth. The tugs and descent stage are almost the same, the only difference is that the tugs don't have landing legs.
Ascent stage[]
It is composed of the ascent stage itself, and a booster to put it in earth orbit for rendez-vous and docking to the descent stage launched separately.
From top to bottom, the ascent is made of: parachute, capsule, heat shield, separator, 15t tank with 2 docking ports and 2 RCS on it, Valiant engine, separator, 15t tank, valiant engine, separator, 15t tank, Hawk engine, separator, docking port to provide the connection with descent stage.
The ascent stage booster is made of a center core with a Hawk engine, 15t and 20t tanks connected to ascent stage with a separator, 2 side separators with two 20t, one 15t tanks and a Hawk engine, and two other side separators connected to two 20t tanks and a Hawk engine. Since center stage have less fuel than side ones, it shall be shutdown at 90% in order to be re-ignited when the others are jettison out of fuel.
Descent stage[]
As the ascent stage, it is composed of the descent stage itself and a booster to reach low earth orbit. As the bottom engine don't have to be connected with a docking port, as for the ascent stage, its engine is used to reach earth orbit.
The descent stage itself is composed of, from top to bottom: docking port, probe, 2 times three 20t tanks horizontally put side to side with 2 docking ports at the top and 2 RCS at connection of these 2 groups of three, a 15 t below the center tank with a Hank engine and inverted U shaped structure supporting 2 landing legs, use staging to ease simultaneous deployment of them both. As they are too small to touch ground if mounted above a Hawk engine, a inverted U shaped structure is necessary to lower their mounting point. Be careful to create a U larger than the tank to allow the stage separation between descent stage and its booster.
The booster of the descent stage uses the most powerful first stage which can possibly made without extension : horizontally align 7 Hawk engines, which should take almost all blueprint area width, use staging to ease simultaneous ignition, stack two 20t tanks on each of them, and one additional 20t tank on each of the 2 outermost. Put a separator atop the five center tanks, and Hawk engines on them, also use staging to ease simultaneous ignition. Add a 20t and a 5t tanks on each of these second stage Hawk engines, except the center one which has only a 20t tank because a 5t tank cannot fit below the separator connecting the booster to the descent stage.
Tug[]
The Tug is the same rocket as the descent stage with its booster, except that it has no U shaped structure and landing legs, but two additional 10t tanks at this place.
As the descent stage have docking port on both its left and right sides, 3 side by side tugs can be connected on these docking ports, using the top docking port of the center tug of them 3 to connect them to the side docking port at the top of the descent stage.
Mission[]
The mission first requires to put on circular 50km earth orbit and dock : the ascent stage, descent stage and 5 tugs.
Spacecraft assembly in earth orbit[]
Each launch should be managed the same way (except that ascent stage has an additional cut-off of its center Hawk engine between 90% of its tank and 0% of the other first stage tanks) ;
- Ignite all lower engines at 100% and wait 2000m altitude
- Pitch to 5° at 2000m, 30° at 5000m and 45° at 10000m and jettison stages when empty with immediate ignition of the upper stage
- Cut off engine when apogee is at 40km
- Once at 30km, pitch to 90° in order to let the rocket be horizontal related to ground and re-ignit the engine at 100% thrust. It should barely raise the apogee but extend the orbit to make it goes around the earth. Reduce trust when the orbit goes around earth to prevent the perigee to rise above 49km, and stop the engine when the perigee has increased up to 49 km. Perform engine burn facing moving direction or opposite direction when passing by perigee and apogee to circularise orbit to 49.5km.
- Once on 49.5km circular orbit, and rendezvous target on 50km circular orbit, you just have to wait the two spacecraft to be side by side to start the rendez-vous with RCS engines and dock. Speed up time a lot to see the two spacecraft getting closer to each other: clic on the target spacecraft and select "Focus", this will make the the time speed up creates a kind of "snail" view of the rocket approaching the targeted spacecraft, making easier the detection of the moment to slow down time to not miss closest position between rocket and targeted spacecraft.
Following this procedure, ascent stage booster should reach circular 50km orbit with few percent of fuel in its lower center stage, and descent stage and tugs with approximately 80% of fuel in their higher stage, which should by just for the mission.
Trip to Venus low orbit[]
Use the navigation features of the game to know when to start engine to enter transfer orbit to Venus, extensively use time speeding to reach required space position for transfer. In order to reach the required ~700m/s for Venus transfer in a signle burn, ignite the engines before reaching the transfert window starting point. If required speed is not reached with one burn, wait an entire orbit to start an additional burn when back at "Transfer window" point of the orbit. Once outside earth influence sphere, zoom on Venus and perform a burn at 0,1% trust to lower the flyby altitude of Venus to 80km.
Venus powdered descent and landing[]
Transfer fuel from outermost tugs to innermost ones during trip to Venus and jettison them in order to save fuel by not having to slow them done during Venus orbit insertion which will be done with 3 tugs only.
Speed up time until the spacecraft is at this 80 km from Venus and start the three engines facing moving direction at 100% trust to lower the perigee to 52km, also undock the thee empty tugs at the beginning of this burn to jettison them. At 52km, Ignite again the three engines facing moving direction to circularise orbit at 52km.
As the descent stage with the ascent stage docked on top of it is pretty tall regarding its landing legs, it is mandatory to land on almost perfectly flat area on Venus. Use Quicksave to be able to perform several Venus descent tries until a flat enough landing site is reached. A wide flat enough region exits near Atalanta Planitia:
Before the flyby of Atalenta open the landing legs, make the descent stage engine face moving direction (represented by a white arrow), undocked the descent stage and ignite its engine at 100% trust. From this moment, continuously pitch the rocket to keep the burning engine facing moving direction as close as possible (to save fuel). When entering Venus atmosphere, landing legs temperature should rise to approximatly 240°C, without reaching 300°C otherwise they would be destroyed. When the landing legs temperature has cooled down to 150° after exceeding 200°C, cut-off the descent engine and pith the rocket vertically. Use a Quicksave at this point in case you don't manage to land on a flat spot. Wait the altitude to be 10 times the speed to ignite again the engine at 100%, at approximately 700m, and from this, try to perform short burns at 100% to keep the speed ten times smaller than the altitude, until touching the ground. Try to not pitch the rocket because Venus atmosphere has cancelled horizontal speed and pitching would increase it and required to pitch again to cancel it before landing.
Return to Venus low orbit[]
Once landed, use the ascent stage to get the capsule back to orbit and rendezvous with the 3 tugs leaved there:
Ignite the lower ascent stage engine at 100%, jettison this stage and ignite the upper one at 100% when it run out of fuel, and again for the third stage. Keep the trajectory perfectly vertical up to 14km altitude, in order to get out of dense atmosphere as quick as possible. Don't worry if speed decrease, it will increase again later. Once above 14 km, pitch the rocket a little bit above horizontal. Cut off the engine when the apogee is at 40km, and use the same technique as the one described for earth orbit rendez-vous to reach and dock to the three tugs waiting on 50km circular orbit.
Trip back to earth and atmosphere reentry[]
To get back to earth, click on earth and select "Navigate to" in order to see when starting the return orbit burn. Speed up a lot to make earth and Venus reach the necessary position to start the burn (spacecraft should be at "Transfer" point espace). Before burn, transfer fuel between tugs to empty two of them, and undock them at the beginning of the burn to save weight. Keep the engine align with moving direction during the burn and do it at 100% trust. Once outside Venus influence, put the engine facing moving direction and perform a 0.1% trust bien when zoomed on earth to make the trajectory enter earth atmosphere and flyby at 10km to ensure atmospheric reentry. Speed up time until the spacecraft is close to earth atmosphere. At this point, separate the capsule, move the spacecraft away from it with the RCS and pitch the capsule to make its head shield facing moving direction and pitch it during the atmosphere reentry to keep it this way. At 1000m of altitude, open the parachute. The capsule will land softly, click on Recover, and you will get the 3 Venus achievements.