The Helios Missions Paper

The Helios Missions Paper

By AlatarRhys



In which we discuss the topic of a manned mission to Venus and how such a mission could be completed.


Time to Venus: ~100-120 days

Aerobrake at Venus: Max 1 Week

Orbital and Possible Ground Operations at Venus: ~1 Week- 1 Month

Trip Home: 100-150 days

Lunar Assist and Earth Orbit: 1 week

Mission Time:  221-315 days


Our mission calls for a launch to the spacecraft in either a Dragon or an Orion spacecraft. We then use the moon for a slingshot maneuver to help us on our path to Venus. After a travel time of around 100-120 days we will arrive at Venus where we Aerobrake into a high orbit that we slowly lower to a stable orbit of 400km*400km. From here we can take a few paths and options.


  1. The first choice we could make is to complete orbital operations for the duration of this mission. We would likely use this path for our first mission. While we will not do any form of descent on this mission profile we will gain valuable data from orbit. We could release cubesats to assist with future missions as well as being able to possibly be able to capture and return old spacecraft and probes to Earth. We may be able to pull this off on our first mission however it would be recommended as a secondary objective. 
  2. The second option would be to do a small entry into Venus’ atmosphere. This would likely take the form of a small space plane (Aether) that could dive into Venus’ upper layers of clouds and then return to orbit. While this would be dangerous it would allow us to do research into the upper atmosphere which would be very beneficial to future missions. This would be recommended for either mission 2 or 3 to Venus and would be done before any deeper missions would take place. The space plane would be as light as we could make it. Most of the mass of this spacecraft would be taken up by the science experiments as well as a molten-lead cooling system. This system would be the basis for any missions. If done right the force of disconnecting from the mothership would allow us a slow dive into the upper edges of the atmosphere. Once we started to heat up the cooling system would engage and lighten us for the trip back up that could be completed with minimal amounts of fuel. We could use the data we recovered to make it feasible for future missions to go deeper.
  3. The third and final mission option for now is a deep dive to the surface of Venus. This mission would be the hardest of all missions so far. We would have to begin with a flight of our space plane Aether. Albeit a larger more powerful one that could withstand a flight to deeper depths. We would strip away most scientific equipment for this flight to allow for a larger coolant system as well as more propellant. We will call this version “Aether RS-2”. Once Aether RS-2 had gotten below the lower cloud layer we could use radar scanning on the craft to find a suitable landing site for our landing craft. The landing craft would be rather simple. We could descend by parachute to our desired landing site using RCS and thrusters only when needed for fine tuning. If needed we can slow down our craft near touchdown with thrusters. We will need large heat shields and safety mechanisms to use the atmosphere to its fullest potential on our descent. On launch we can use a sort of weather balloon filled with either Helium or perhaps even oxygen. Once this lifts us and our ascent module section of the spacecraft above the clouds we can use onboard thrusters to make it into orbit. From here we will rendezvous with the main craft with our samples and data. This mission will not have any rovers likely. I also must point out that ground communications will be provided by cubesats launched on prior missions or if needed a high beam laser communication from the groundship. As we will not carry all of the descent spacecraft to orbit it will be easier to get our crew up from the surface. If the lower descent stage is designed well we can even count on it being able to stay on the surface and operate for a time after we have left to bring in more long term data. 


After one of these 3 missions has been completed we can start to head home. Our astronauts can use the time on their trip home to do research on our findings and other work we may want done. Our arrival at Earth will be completed by either a Moon gravity assist to capture or an aerobrake though the Moon gravity capture is a better option as if we choose this method we will have time to abort to moon orbit and the Lunar Gateway station if needed. Our second abort would be to the ISS and if all goes well we park in LEO before descending to land on earth. Our craft in orbit will remain there where it can store extra samples we couldn’t bring home in the landing craft as well as where it can be refueled and refurbished for future missions.



Of Craft Design


Our mission will consist of at minimum 3 new crafts with 2 variants of one of these crafts as well as up to 3 existing crafts. 

These crafts will be:

  1. New:
    1. Hestia: Our main Craft. It will take care of supporting the crew throughout most of the mission. It will have thruster blocks, crew quarters and living spaces, docking ports, and labs.
    2. Aether and Aether RS-2: These are the light and heavy respectively space planes to take us down into the Venus atmosphere. Aether will be designed for high altitude operations only and will have a full science suite. Aether RS-2 will have little scientific equipment but will have a radar sensor and will be designed to duck below the clouds to find a good landing site. Both of these crafts will have a Molten-Lead coolant system (discussed below) to keep them cool while on their mission.
    3. Hephaestus: Hephaestus is our lander. It must be the best pressure and heat resistant craft of the mission as it will take the crew down to the surface and the lower stage will be left behind as a temporary scientific surface station until it succumbs to Venus.
  2. Existing:
    1. Orion: For crew transfers to and from Hestia.
    2. Boeing CST-100 Starliner: For crew transfers to and from Hestia.
    3. SpaceX Dragon: For crew transfers to and from Hestia.


The existing craft do not need explanation. I will go in-depth about the other crafts and their features.



A Deeper Dive


We will start with Hestia. Without her this mission could not happen. She will provide life support systems, CO2 scrubbers, radiation shielding, supplies stores, propulsion systems, laboratories, and living space for the crew. It will have a large heat shield to allow for the required aerobraking, and will have 0-2 docking ports depending on what mission configuration we are flying in. This craft will have to be very safe to allow our astronauts to feel comfortable the entire mission. It will be mostly solar powered and will have heat radiators for when needed. Other than this it is a fairly normal spacecraft. When not in a burn our craft will be turned so that we may spin it up to create some artificial gravity for the crew. They will still require exercise constantly to stay healthy so we will provide this equipment.


Next up is the Aether. Aether will be a spaceplane designed to take 1-2 astronauts below the atmosphere of Venus. It will function much like a spacecraft in Aerobrake around a planet. It will start by detaching from Hestia with the crew on board. After a short burn which will put its pericythe at approximately 45km above the surface, it will orient itself forward and use a very Space Shuttle-like entry profile. At about 55km up, while still taking in massive amounts of data and atmospheric samples, it will fire its engines to pull it out of its dive and rocket it back up to orbit. It should be able to catch Hestia within 1-2 orbits and redock. In order to cool the spacecraft in the Atmosphere, heat will be fed into a block of lead. As the lead absorbs the energy it will become molten and be ejected out the back of the craft. When no longer needed the remaining lead will also be ejected to make the trip back to orbit lighter. On the first mission the Aether flight would likely be done autonomously to ensure it functions as planned before putting human life in jeopardy.


Lastly is the daring lander Hephaestus. This lander would enter the atmosphere much like a traditional spacecraft. At about 50 kilometers or 1 atmosphere of pressure the drogue chute would deploy followed soon after by the main pair of chutes. The heat shield would still be held onto to keep the craft protected by the intense heat. It is likely that after Main Chute Deploy the crew could exit their seats and do scientific measurements as the craft slowly descended through the thick atmosphere. The advantage of such a thick atmosphere is that it allows for the EDL process to take much longer. After a while the crew would strap back into their seats and touch down softly on their landing gear which would extend from the heat shield. At this point ground work would take place for as long as the lead on board allowed the craft to stay cool. It is unlikely at this time that a Spacewalk would be possible as the technology just isn’t there at this time. When the crew is ready to go home they will separate from the heat shield and landing platform. This platform will remain on the ground producing data until it dies from the heat and pressure. The ascent vehicle as it is now called will rise up on a weather balloon like device to around 55 kilometers. It could remain here for some time if needed continuing its work; however, when it is ready to go home it will ignite a high efficiency upper stage engine to take it back to orbit and reconnect with Hestia. From here the craft will head home to Earth.



Closing Remarks

At this time many aspects of the Helios Mission are not possible. However within the next decade we could see the technology come about that would allow for the mission to be a success. All parts of the mission would have to be tested autonomously before Human lives were put at risk. The safety of our crew is the top priority. The cost of these missions would be immense but if we did it right, launched on exactly the minimum rocket for our mission, and reused segments of the craft, We could bring the cost down drastically. More content will be put out about these proposed missions over time however being that this first paper took over a year to fully flush out and figure out it may be a good while before the next one.



Next Steps

The Next steps for this likely involve deeper dives into each of the 3 crafts. This will include Delta V, more talks about specific systems, safety factors, and whatever else seems important. Note that at this time not all parts have been precisely tested in simulations and math to see if they will work. It is likely massive redesigns are still to come for all parts. However this is a start and a point to build from. 


Thank You for your time in reading this. We are aware not all parts are perfect. We would request you be kind in your discussions with us. We enjoy making this content however when everything we put out gets us shredded by people who think that we are wrong in every way for their own reason, it is really discouraging. As Peter Beck, Chief Engineer of Rocket Lab says, “Everyone told us this is impossible. And we did it.”





The Helios Missions Paper
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