Space Apps Challenge 2018

“ITERUM” Lunar Rover Mission

Background

The Moon may be the most accessible and realistic destination for most space agencies. However, there are still a couple of issues we need to solve of we're planning to go back. Those issues are:

-Moon dust

-Lunar debris

Although these two issues may seem that they have nothing in common, the ITERUM mission can solve them at the same time, by combining their components and aspects.

Introduction

When it comes to future space missions, planet Mars is usually the next destination where space agencies want to focus on. However, reaching Mars is not an easy achievable goal. A more accessible and realistic destination is the Moon, or Earth’s only natural and permanent satellite. While there are some ideas about building a colony on the Moon, there are still a couple of issues we need to solve before we actually start sending humans on the Moon to live there. According to me, one of the main issues is moon dust (lunar soil) and the other one is moon debris. While lunar debris may not be considered as such a great issue, it will be further explained about its use to conduct this research. As for lunar dust, if humans are planning of going back to the Moon, then we need to learn how to deal with lunar dust, as it can be a potential threat to astronauts and machines.

With this mission, I believe that these two issues can be solved at the same time, by combining their components and aspects. The lunar rover is planned to land to several Apollo missions landing sites, so it can examine some of the left, but still useable moon debris, to conduct research experiments.

For the moon dust (lunar soil), a team of scientists and astronauts will be able to study it “in situ”, that is, on the Moon itself. I believe that this is the best method because it is known, from previous experience, that the samples of moon dust that were brought back to Earth were useless when it mixed with oxygen and water vapor. That way, we can make a better and more detailed examination upon the moon dust, more specifically, its physical and chemical characteristics, its reactions with materials, natural or artificial, other metals, etc.

As for the moon debris, many people think that with the many missions on the Moon, humans have already begun to pollute the lunar surface as well. While the Apollo mission landing sites are the locations where most of the debris had been left, the Iterum lunar mission can revisit certain locations and use the lunar debris to conduct some research experiments that the lunar dust had. Namely, lunar dust is considered as a part of the lunar composition, or as a tenuous “atmosphere” of electrostatically-levitated dust. It is likely that the lunar debris is covered in lunar dust, so if we can send a research team on the previous Apollo landing sites, where the lunar debris is left, we can analyze the effects of lunar dust upon the materials of which parts of the lunar debris is made of.

That way, the lunar debris that we have left on the moon might not necessarily be viewed as useless debris anymore, but in a more optimistic and positive manner, as an important aspect of a scientific research to help humans understand the mysteries behind lunar dust, which will further lead to find a way to solve certain issues associated with it.

This may sound like a pretty simple mission, but it can provide very meaningful results. Still, in order for us to plan a lunar rover mission, there are many engineering and scientific aspects that need to be taken in consideration.

First of all, let us focus on some of the main engineering and technical aspects of the Iterum lunar mission;

Landing site and trajectory

It is essential to determine which Apollo missions landing sites the lunar rover is going to visit. Based on the amount and types of lunar debris, through astro-visualization, these are the considered locations:

Landing site (location A): Apollo 14 Landing location: -3,40˚ N, -17,23˚ E

Location B: Apollo 15 Landing location: 26,6˚ N, 3,39˚ E

Location C: Apollo 16 Landing location: -8,973˚ N, 15,31˚ E

Location D: Apollo 17 Landing location: 20,10˚ N, 30,46˚ E

Duration of the Iterum lunar mission

In order to find out how many days/hours it will take for the lunar rover to reach each location point and spend one Earth day on each location, we will need to know the distance between the location points in order to calculate the duration of the mission from the landing (there will be other calculations about the time that the spacecraft will reach the Moon from the Earth later).

Again, according to astro-visualization of the moon and the location sites of the Apollo mission, the distances between the required landing sites were calculated in km;

Point A (Apollo 14) to Point B (Apollo 15) = 1095 km

Point B (Apollo 15) to Point C (Apollo 16) = 1119 km

Point C (Apollo 16) to Point D (Apollo 17) = 995 km

All in total, the lunar rover is supposed to pass a trajectory of 3209 km. But if we want to know the amount of days/hours it will take the lunar rover to reach all location points, we will calculate by the formula:

t = s/v

t is the time,

s are the distance in kilometers that each location point has, and

v is the velocity by which the lunar rover is moving (average constant of 13 km/h),

Here are the calculations for each location point distance:

1.The distance between point A and point B is 1095 km, the average speed by which the lunar rover is moving is 13 km/h, then the time (in hours) is:

t = 1095km/13km/h

t = 84,2 h

2.The distance between point B and point C is 1119 km, the average speed by which the lunar rover is moving is 13 km/h, then the time (in hours) is:

t = 1119 km/13 km/h

t = 86,1 h

3.The distance between point C and point D is 995 km, the average speed by which the lunar rover is moving is 13 km/h, then the time (in hours) is:

t = 995km/13 km/h

t = 76,4 h

Now that we have the duration in hours that the lunar rover needs to reach each location point, let us calculate the total duration in days.

NOTE: There is one Earth day (24 h) added on each location, expected to be the time that the research team will spend in conducting experiments upon the lunar debris;

84,2 + 86,1 + 76,4 = 246, 7 hours.

246, 7 h : 24 h = 10 days and 6 hours

10 days and 6 hours + 4 days (or 96 hours) = 14 days and 6 hours.

The conclusion from these calculations is that the lunar rover (from the landing site) will need 14 days and 6 hours in total to complete the mission.

Calculating Earth’s escape velocity and the duration of the journey from the earth to the Moon

Escape velocity is the minimum speed needed for a free object to escape from the gravitational influence of a massive body. Escape velocity from Earth is about 11,2 km/s (40,000 km/h).

The formula to calculate the escape velocity is:

Ve = √ 2GM/ R

G is the gravitational constant, which is 6.673 x 10^–11

M is the mass if the Earth, which is 5,97 x 10^ 24 kg

R is the radius if the Earth, which is 6.3781×10⁶ m

Ve = √ 2 x 6.673 x 10^–11 x 5,97 x 10^ 24 kg / 6378100

= √ 2 x 6,6726 x 5,9742x10^24-11 / 6378100

=√ 79,73x10^13 / 6378100

=√ 125005879,5

= 11180,6 m/s

Now, if we want to convert m/s to mph, then 1118,60 m/s = 250102.8991 mph, which is enough because it takes for a spacecraft to travel at a speed faster than 25,000 mph just to escape Earth’s gravity.

After we have calculated the Ve from the Earth, it is assumed that the spacecraft, on its way to the Moon, travels at an average speed (of course which is less than the speed for the escape velocity). An average constant by which the spacecraft is supposed to travel is 10,000 mph.

Knowing that the distance between the Earth and the Moon is 238,855 miles, we can convert the 10,000 mph in years, so we can make out just how long will it take for the spacecraft to reach the Moon.

Since 1 mph = 8760 miles per year, 10,000 mph = 88 million years per year.

Distance to the Moon = 238,855 miles/ 88 million miles = 2 days and 17 hours.

So, according to these calculations, the journey of the spacecraft from the Earth to the Moon is approximately considered to be 2 days and 17 hours.

Level of force due to gravity between the Earth and the Moon

Before we move on to the details about lunar dust and lunar debris, let’s consider the gravitational force that the spacecraft has to overcome to reach the Moon. We can do that by comparing the Earth’s gravity and the Moon’s gravity and calculate the level of force due to gravity:

F = Gm1m2/r2

F is the force due to gravity,

G is the universal gravitational constant

m1 is the mass of the first object (in our case, the mass of the Earth)

m2 is the mass of the second object (in our case, the mass of the Moon),

r is the distance between the centers of the two object (in our case, the distance between the Earth and the Moon).

10^-11 x 10^24 x 10^22 = 10^24+22-11 = 10^35

F = 6,673 x 5,972 x 7,35

= 292,9 x 10^35 kg / 384 400 000 m

= 292,9 x 10^35/384,4 x 10^6

= 0,76 x 10^26 N.

Second of all, let us focus on some of the main scientific aspects of the Iterum lunar mission;

In order to that, we must determine some questions that are crucial if we want to understand the real purpose of the mission, such as scientific goals, creating a team of astronauts and scientists, needed instruments and research methods, type of lunar rover, etc.

1.What are the scientific goals of the Iterum lunar mission? What do we want to learn?

-The scientific goals of the Iterum lunar mission are simple, yet very effective. By sending a lunar rover to revisit some of the previous Apollo landing sites, the team can analyze the moon dust “in situ” for more precise results, which will provide us with better information about moon dust, thus inspiring many scientists to think of a way to handle it considering future lunar missions. Plus, after so many years, we get to see in what state we’ve left our Moon and make most of the artificial lunar debris useful by observing how effects the moon dust has upon artificial materials and metals, especially during a long period of time.

2.Why are the landing sites of Apollo 14,15,16 and 17 only chosen for the Iterum lunar mission?

- According to the catalogue of manmade material left on the Moon by previous space missions, it is a well known fact that the Apollo missions had a much bigger part in polluting the Moon compared to any other mission, no matter the country. According to my calculations, here is the percentage which shows how much certain countries have contributed in the lunar pollution:

USA: 96,2% ; SSSR: 2,70% ; Japan: 0,62% ; India: 0,24% ; China: 0,12% ; ESA: 0,12%

* Note: From the listed countries in the chart, only the ESA is not a state but the European Space Agency;

And after reviewing all the manmade material left on these locations, there are some potential objects that can contribute in conducting a successful research upon the moon dust, also due to the fact that most of the lunar debris is left on these locations, with the Apollo 14 landing site having 120 objects, the Apollo 15 landing site having 153 objects, the Apollo 16 landing site having 182 objects, and the Apollo 17 landing site having 172 object, all which with a variety of materials can be helpful observation items for the research.

For instance, on the Apollo 14 landing site (-3,40˚ N, -17,23˚ E) there are some instruments such as a Lunar Portable Magnetometer, a radioisotope thermoelectric generator, etc.

3. Who will be included in the ITERUM team?

-When planning a lunar mission, especially for research purposes, a team is a very relevant aspect to consider. Since the main scientific goal of the mission is to conduct experiments upon the moon dust, its physical and chemical characteristics, and more importantly, the effects it has upon the overall lunar debris materials, it is assumed that the team should consist of scientists who are experts in their field. In order to determine the professional aspects that the scientists should be qualified, we must first see the known traits of moon dust. Since moon dust originates from meteorite impacts, which throw up and briefly melt lunar rock, the ITERUM team will consist of four Lunar researches, each an expert in his own field;

-Lunar geochronologist (to study the moon dust’s geological past)

-Lunar petrologist ( to study the condition of moon rocks and how moon dust effects them)

-Lunar chemist (to study the chemical traits of moon dust and its effect upon various lunar debris materials and metals.

-Planetary-Lunar physicist ( to use magnets in a filter to collect moon dust, since moon dust is magnetic).

Resources:

https://moon.nasa.gov/

https://eyes.nasa.gov/eyes-on-the-solar-system.html

https://moontrek.jpl.nasa.gov/