Pallas

Ulysses was a robotic space probe whose primary mission was to orbit the Sun and study it at all latitudes. Ulysses was put to orbit using "gravity assist" of Jupiter through a long adventurous journey. It was launched in 1990 and stayed in operation until 2008.

The Solar Orbiter is a Sun-observing probe which will also perform close observations of the polar regions of the Sun. It performed two gravity-assist maneuvers around Venus and one around Earth to alter the spacecraft's trajectory. It was launched on 2020 and planned to operate until 2030.

Pallas is a dwarf planet which orbits the Sun every 1,680 days (4.60 years), coming as close as 2.13 AU and reaching as far as 3.41 AU from the Sun. Pallas is about 513.0 kilometers in diameter. It completes a rotation on its axis every 7.81 hours.

With an orbital inclination of 34.8°, Pallas's orbit is unusually highly inclined to the plane of the asteroid belt. The high inclination of the orbit of Pallas results in the possibility of close conjunctions to stars that other solar objects always pass at great angular distance. This resulted in Pallas passing Sirius on 9 October 2022, only 8.5 arcminutes southwards, while no planet can get closer than 30 degrees to Sirius.

The summary of all of these is, a space telescope deployed on Pallas can be used to observe our solar system and beyond from a perspective no other satellite could achieve. There are no complex and time-consuming gravity assists needed to go beyond the solar plane. Just land an explorer with a telescope on Pallas while it crosses the solar plane. Much lower gravity of the dwarf planet would allow a smaller and lighter lander stage. Additionally, its relatively small diameter allows the moving space telescope to be positioned on the extremes of Pallas. Placing the explorer on the sun opposing pole would allow deep space exploration like James Webb telescope. Moving to the other extreme would make it a solar probe.

Ceres

Dwarf planet Ceres is the largest object in the asteroid belt between Mars and Jupiter, and it's the only dwarf planet located in the inner solar system. NASA spacecraft Dawn approached Ceres for its orbital mission in 2015. Dawn found Ceres's surface to be a mixture of water, ice, and hydrated minerals such as carbonates and clay. Ceres is one of the few places in our solar system where scientists would like to search for possible signs of life. Ceres has something a lot of other planets don't: water.

From an average distance of 413 million km., it takes sunlight 22 minutes to travel from the Sun to Ceres. Ceres takes 1,682 Earth days, or 4.6 Earth years, to make one trip around the Sun. As Ceres orbits the Sun, it completes one rotation every 9 hours, making its day length one of the shortest in the solar system. Ceres' axis of rotation is tilted just 4 degrees with respect to the plane of its orbit around the Sun. That means it spins nearly perfectly upright and doesn't experience seasons like other more tilted planets do.

Ceres is more similar to the terrestrial planets (Mercury, Venus, Earth, and Mars) than its asteroid neighbors, but it is much less dense. One of the similarities is a layered interior, but Ceres' layers aren’t as clearly defined. Ceres probably has a solid core and a mantle made of water ice. In fact, Ceres could be composed of as much as 25 percent water. If that is correct, Ceres has more water than Earth does. Ceres' crust is rocky and dusty with large salt deposits.

Ceres is covered in countless small, young craters. The lack of craters might be due to layers of ice just below the surface. Within some of Ceres' craters, there are regions that are always in shadow. It's possible that without direct sunlight, these "cold traps" could have water ice in them for long periods of time.

Ceres has a very thin atmosphere, and there is evidence it contains water vapor.

I guess this is enough information to justify a mission to Ceres compared to searching for water on Mars.

The Asteroid Belt

In my previous articles, I proposed a planetary rocket. It would be used to explore our solar system further. After making some research, I concluded that conducting preliminary research on protoplanets in the asteroid belt would be more beneficial for the humanity compared to researches conducted on Mars. Protoplanet exploration requires slightly more powerful rockets compared to Mars missions like the one I proposed earlier.

The asteroid belt is full of space bodies with different characteristics. With a distance between Mars and Jupiter, lots of scientific research can be conducted. The asteroids have way less gravity compared to the planets and their moons. As a result, safely landing on them does not require big and heavy landing stages. Additionally, their way smaller surface area allows thorough exploration of the space body.

Only Mercury, Venus, Mars and the moons of the outer planets allow surface exploration. Mercury is very hot. Venus is also very hot and have a very chaotic and dense atmosphere. The moons of the outer planets are very distant from Earth. That leaves Mars and the asteroid belt as a feasible research zone.

Some of the protoplanets in the asteroid belt have interesting properties well forth exploring for.

1 Ceres, 2 Pallas, 4 Vesta

The Fourth Stage

Since the beginning of space exploration, humanity could only send surface explorers to Mars with few exceptions. Main reason for that is the time it takes for a payload to reach the planets. We need to increase the payload’s average speed during its long voyage. In my planetary rocket design, I dedicated the fourth stage for that. This stage needs to generate high thrust like the previous stages.

An option can be to have a liquid methane engine to generate high thrust. For this task, a highly efficient but small engine can be developed. As a result, the thrust would be generated over a longer duration and the rocket would not be stressed by high g-forces.

Another option would be to use ion thrusters. However, a special engine needs to be developed to generate enough thrust for the heavy rocket. The gasses used in ion thrusters are quite expensive and supplying large volumes to satisfy the thrust requirement can be quite expensive. Additionally, ion thrusters require electricity for the thrust. While travelling away from the sun, not much electricity can be generated and protruding solar panels may not be reliable.

My proposal is a rocket stage filled with dry ice and Plutonium 238 heated nozzles. The idea is to convert small portions of dry ice into carbon dioxide and eject it from a tiny nozzle. The details are shown on the diagram. A Pu 238 tube with tiny holes on its sides would be used to heat the dry ice and pressurize it to generate thrust. The tube would be initially covered by an insulator low melting plastic that leaves no residue. This shield would prevent the dry ice from premature melting. The delay is the duration for the lower stages to complete their duties. Once the insulation melts away by the heat of the isotope, the rocket would start generating thrust. This is a much simpler and reliable design compared to the rest. Utilizing heat generated by radioactive decay gives the stage high ISP. The carbon dioxide gas would be exhausted from a tiny hole to accumulate higher pressure inside. This also increase the duration of the thrust generated.

The stage would be covered by a detachable heat shield. This shield would keep the dry ice cold during the atmospheric escape. Once the rocket is in LEO, the shield would be released to reduce weight. The released shield would than burn away in the atmosphere.

This simple stage can be cascaded to generate even more thrust.

Five Stages of a Planetary Rocket

The planetary space missions are the most complex and energy intense missions of all. By planetary missions I mean deploying a probe or explorer on the surface of a planet. Due to limitations of current rockets, only small probes and rovers could be send. With a purpose build rocket, we can explore our solar system better.

As a starting point, an economical rocket family can be developed. It would be configurable to suit missions. As a single rocket, it would be able to deploy LEO and geostationary satellites with its first stage recovered. Most probably a rocket with a maximum diameter of 5 meters would be enough for the task.

It’s not economical to recover stages beyond the first stage. As a result, the upper stages should be optimized for single use only. The objective of the second stage would be to put upper stages into low Earth orbit. LEO and geostationary missions would only have two stages.

In order to deploy heavy payload to the moon, at least three first stage rockets would be strapped together. The second stage would be a single rocket, so as the third stage.

Ideally, the first three stages of the rocket would utilize liquid methane engines with optimized nozzles. Utilizing the same engine in all three stages lower the costs and increase the reliability of the rocket while you can perfect a single engine compared to multiple ones.

The fourth stage would be used to accelerate the upper stages further to reduce the time to reach the planets. Ion thrusters can be an option. I also would like to propose a simple dry ice thruster powered by Pu 238 (details on my next article).

The fifth stage is a question mark. It would be used to safely descent the payload to the surface of the planet. It would be fired after many months of space travel. I don’t know if a liquid methane engine can be cold started in such a circumstance.

The Forgotten Stages of Rocketry

I have recently proposed a Mars Research Base. An adequate rocket is required to implement it. The rocket should have five stages. The first one can be a reusable heavy lift rocket. The second one would put the upper stages into LEO. The third one would free the upper stages from Earth’s gravity. The fourth one would guide the upper stages during the long journey to Mars. The fifth one which carries the payload would be used to descend the payload safely on Mars.

Almost every spaceflight company on Earth is working on their reusable first stage. Some even try to reuse the second stage as well. However, the upper stages get almost no attention. “The chain is only as strong as its weakest link”

Companies claim that they would conquer Mars with their two stage rockets. I give no chance to such designs. Even the government agencies are in the same mindset. The physics of rocketry has not changed since the Apollo program. An efficient rocket needs to get rid of its additional weight during it journey in space. That’s the reason we have stages.

On my next articles I would like to detail the upper stages of a high payload planetary rocket which are omitted by the others.

The Analyst

In recent years, I started to see more and more poorly designed product and services. I attribute the problem to poorly executed cost cutting measures and too much reliance on AI. The company's profit comes from the service they provide and the products they sell. Poor services and products result in reduced profits which intensifies the company’s cost cutting measures. In my opinion, the last place a company should cut costs should be the development of products and services. If this department is under employed and lower salary subpar employees are hired, then the company should prepare itself for bankruptcy or takeover.

From my observations, I conclude that the key role within a company is The Analyst. When analyses are made correctly which includes finding the alternative solutions, the success is inevitable. The complex engineering calculations and coding can be delegated to AI. However, it requires proper analysis which is a human task.

Analysis requires knowledge of many subjects. Good analyst doesn’t need to excel in any of them. However, need to be able to combine these knowledges whenever necessary. A good analyst should be able to ask the right questions to gather information which would guide him/her during his/her inductive reasoning, like Sherlock Holmes. When a company bases its products or services on successfully conducted analysis, the company would easily differentiate itself from the competition.

Previously, this role was assumed by non-engineers. AI has taken over most of the engineering tasks. As a result, new engineers should be taught to be good analysts who can look at the world from a wider perspective.

Better analysis solves more problems instead of creating new ones. This is beneficial for the societies that struggle in ever increasing number of problems.