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This article will explain how to build a rocket that can go to Venus and possibly back. Building Venus rockets should be done after building building Mars rockets and Moon rockets. A tutorial for how to get to Venus can be found here.
Rocket[]
The rocket is very similar to a Moon/Mars rocket, but with heat shields and less parachutes. For usual missions, it is recommended to have at least 2 or 3 stages for a rocket to land or explore Venus.
It is recommended a rocket to Venus would consist of at least six stages in a landing and return mission if refueling mid-mission is not considered.
First and second stages[]
These need to be powerful enough to send the entire rocket to low Earth orbit. The Titan/Hawk engine can be the first stage engine to lift up the entire rocket up to the Kármán line, and the same engines mentioned earlier or Frontier engines can bring the rocket to LEO. Boosters may be necessary if the rocket has a low thrust.
Third stage[]
This stage and/or the previous stage will execute the transfer burn to Venus, alongside with deep space maneuvers if required, then a retrograde burn to enter Venus orbit and start aerobraking. Entering its atmosphere is the biggest challenge of this mission. It requires a strong or multiple heat shields and a protective fairing to protect the rocket from the harsh environment outside it. Venus's atmosphere is enough to destroy rockets passing through its atmosphere, with or without a heat shield. The rocket must go to orbit before landing to decrease velocity during entry, and this in turn can decrease the heating effects. If this stage runs out of fuel before the entry into Venus's atmosphere, the rocket can aerobrake in the upper layers of Venus's atmosphere. The first pass into the atmosphere must make the rocket go into a highly elliptical orbit of Venus, with its periapsis going through its atmosphere. The next several passes will slowly lower the apoapsis until it goes though the atmosphere and make the rocket land on the surface. This method is effective and safe, because the atmosphere at that height is thin enough to not cause a rocket to burn up upon atmospheric entry.
Landing on Venus is one of the most challenging steps because of the rough terrain. A rocket must land in a flat zone (e.g. Atalanta Planitia) and carry at least one parachute.
Fourth, fifth, and sixth stages[]
Similar to the first two stages, the fourth and most, if not all of the fifth stage will bring the rocket to the orbit. It may not be necessary to use heavy-lift engines like the Titan Engine as the remaining stage is much lighter than the entire rocket. The Hawk Engine on the fourth stage will lift the rocket off the ground and push it through the lower part of the Venusian atmosphere. Boosters may be required so that the rocket can go faster through the atmosphere. The fifth stage will power the rest of the ascent to space and make it to low Venus orbit. The sixth and final stage (or the previous stage) will do the trans-terrestrial injection and land the capsule/probe back on Earth safely.
Tips[]
Refueling[]
It may be worthy to refuel the rocket's second and/or later stages with a helping vehicle or a space station. This can increase the fuel margin for the later stages, improving the likelihood of mission success.
Fine-tuning the trajectory[]
Fine-tuning the rocket's trajectory can ease the difficulty of visiting Venus.
Aerodynamics[]
Both Earth and Venus have atmospheres (30 and 40 km respectively), have thick atmospheres (Venus's atmosphere is denser) and rather high gravitational acceleration (9.81 and 8.87 m/s2 respectively), making it challenging to get to orbit. Improving the aerodynamics and increasing the TWR of the return stage of the rocket can ease the process. Parachutes on earth will slow down a rocket to around 5 to 9 m/s, while on Venus it will slow down from 0.5 to 3 m/s, depending on weight.
Streamlining the rocket[]
Try making the rocket a stretched "A"-shape, rather than "V", "H", or "I" shaped. This can reduce the aerodynamic drag so that it is easier to reach orbit.
Increase aerodynamic effectiveness[]
Adding fairings to cover your lander or payload will reduce the rocket's drag. Triangular nose cones can be used on boosters to improve aerodynamics and save fuel for the mission.
Optimizing TWR[]
TWR is the thrust-to-weight-ratio of a rocket. It is determined by , where m is the mass of the rocket, t is the thrust of the rocket, and g is the gravity of the planet the rocket is in (Earth or Venus). If the TWR is higher than 1.1, it can lift off of the ground. A higher TWR usually indicates the rocket can go further than with a lower TWR.
It is quite difficult to increase the number of engines due to limited building space and aesthetics. Instead, it is simpler to optimize weight. Find out any unnecessary parts in your rocket (e.g. extra structural parts) and remove them. This can reduce the workload of the engines.
Other[]
- Bring more fuel than needed to allow recoveries from accidents or fails.
- Using parachutes instead of executing retrorocket burns to land can save fuel and the overall mission complexity.
- Dump unnecessary weights to reduce fuel required. They include unused parts and empty stages.
Gallery[]
Real life rockets[]
Rockets that have launched or will launch probes to Venus.
- Molniya-M
- Atlas-Agena (Carried Mariner 2 and 5)
- Proton-K/Blok-D (Carried Venera missions)
- Atlas-Centaur (Pioneer Venus)
- Space Shuttle (Magellan and Galileo (Galileo used a gravity assist of Venus)
- Titan IV (Cassini (Gravity assist of Venus))
- Soyuz-FG/Fregat (Carried Venus Express)
- H-IIA (Carried Akatsuki)
- Delta II (MESSENGER)
- GSLV (Shukrayaan-1)
See also[]
| Rocket construction |
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| Suborbital rockets • Orbital rockets • Reusable rockets • Moon rockets • Mars rockets • Venus rockets • Mercury rockets • Jupiter rockets |