A while back, SpaceX set a new milestone by becoming the first private company in the history of space exploration to send humans into space. However, this milestone is only one amongst the many that it aims to overcome on its road to revolutionise the space exploration industry. As it turns out, this remarkable company has many projects up its sleeve spanning across the entire decade and beyond. Amongst all these missions, one of the most important and talked about is the Mars Mission. Since 2017 SpaceX has been working towards achieving this aspirational mission of landing the first humans on the surface of Mars by 2024 and thereby laying the foundation stones for the eventual colonisation of our red neighbour.
The mission infrastructure for this ginormous project is quite expectedly, pervasive. The mission architecture includes fully reusable launch vehicles like the Starship,on-orbit propellant tanks, rapid turnaround landing/launching mounts and local production of rocket fuel on the Martian surface via in-situ resource utilisation.
SpaceX’s first goal in this historic project will be to send two uncrewed cargo spaceships to Mars which would aim at confirming water resources, identifying hazards and setting up infrastructure for a life support system for future missions. Given the success of this launch, we will see the first manned mission to Mars, which will involve two crew and two cargo starships landing on the surface of Mars. Amongst others, the main objective of this mission will be to set up the infrastructure for the Mars base alpha. The first five starships are planned to stay on the Martian surface, though with the capability of returning to Earth on one of them will be
available. The initial crew of this mission will have to reside on Mars for about 26 months, thus making self-sustainability very important. This will be achieved with the help of in-situ resource utilisation (ISRU) on the Mars surface.
If all goes well, this program will lay the foundation for a colony on Mars which is the ultimate aim of this mission, thus making our dream of living on a planet other than ours a reality.
The Road to the Red Planet, however, is not going to be easy for SpaceX or Humanity in general. In the course of the next few articles, we will attempt to take a closer look at our red neighbour and try to highlight some of the key features of this program while also underlining some of the obstacles which might come in our way while reaching there.
Mars-What we know so far
In the earliest days of Mars observation, all that we knew about the planet was that it appeared to be a fiery red speck amidst the backdrop of the stars and followed a strange loop, unlike any other. Humans have come a long way since then, and our knowledge about our red neighbour has substantially broadened - all of it at the cost of decades of space exploration and research involving hundreds of scientists and engineers across the world. Still, there is so much more about the red planet that we are yet to know.
In 1877, Italian astronomer Giovanni Schiaparelli reported using a telescope to observe canali, or channels, on Mars thus leading to a lot of speculation regarding the existence of extraterrestrial life on the planet. These speculations, fueled by the pop culture and science fiction of the time, was able to capture the imagination of the public right up to the space age and the first Mars missions. However, Mariner missions launched in the latter half of the 20th century revealed that the Martian atmosphere was much thinner( mostly made up of carbon dioxide) than expected and it had a negligible magnetic field. These findings dashed the hopes of many who believed that there could be intelligent life on Mars. The Mariner 9 further revealed several of the surface features of the planet including river beds, vast canyon systems and large extinct volcanoes.
The Viking missions launched in the following years provided some crucial information about the plant, including the fact that the surface was made up of iron-rich clay, thus giving the planet its red colour. The mission also revealed that the permanent northern cap was made of water ice. Then came the groundbreaking discoveries made by the MGS spacecraft launched in 1970 which revealed features on the Martian surface which indicated the possibility of flowing water at or near the surface of the planet.
The Mars Express orbiter launched by ESA in 2003 provided evidence that Mars had a period when its surface had flowing liquid water. The twin rovers Spirit and Opportunity launched in the same year further affirmed the fact that Mars had water and a warmer and thicker atmosphere in the past. The MAVEN orbiter launched later in 2013 confirmed the fact that solar winds were responsible for stripping away the atmosphere of Mars over the years, which ultimately resulted in the present condition of the planet.
In 2011 NASA launched the Curiosity rover which for the first time drilled into the martian rocks and revealed their composition, which consisted of Sulphur, Nitrogen, Oxygen, Carbon among other life-forming chemical ingredients. It also found out that
the radiation levels on the surface were comparable to those experienced by astronauts in the ISS.
In addition to these, there have been several other missions aimed towards increasing our knowledge about our neighbour, the Perseverance rover being the latest iteration. All these missions are symbolic of humanity’s resolve to know the unknown. There are several missions planned for the coming years, the most crucial of them being the manned Mars Missions. These missions will be undoubtedly the toughest in humankind’s history as they would require a very vast and sophisticated infrastructure both on Earth and Mars for its sustainability and success. However, one thing is for sure; no matter how daunting and intimidating the task might seem, our ingenuity and curiosity will surely help us find a way through!
Time Window of Mars Programme
2020 has been quite a disappointing year for many people a pandemic, a blast, and whatnot, but it does have its perks. 2020 is being called the year of Mars, owing to the large number of missions planned.
| NAME OF MISSION | LAUNCH DATE |
| Emirates Mars Mission | 19 July 2020 |
| Mars 2020 | 30 July 2020 |
| Tianwen I | 23 July 2020 |
Credits: ESA - What is a 'launch window'?
*Launch Dates are sourced from Wikipedia and can be subject to change
The above mentioned are just a few missions but all of them were launched towards the end of July. The reason for this is that the Launch Period for the Mars missions is mid-July to August.
The Launch Period is a set of particular days during which the vessel must be launched to reach its destination. A term that is generally confused with this is Launch Window, it refers to the time during the day when the launch must occur to reach its destination.
Launch Period - Days of the year when launch must happen.
Launch Window - Time of the day during which launch must occur.
When it comes to space missions, timing is key.
If the spacecraft intends to rendezvous with another spacecraft, a planet, or other points in space, the launch must be carefully timed so that the orbits overlap at some point in the future. If the weather is bad or a malfunction occurs during a launch window, the mission must be postponed until the next launch window appropriate for the flight.
In case some of you are wondering why we don’t just launch when Mars is closest to us, we found a piece from ESA that words it together better than we ever could.
“But why did we need a launch window for Mars Express? If we are going to send a mission to a planet, why not just launch the rocket at any time, find where Mars is in the sky, point the rocket at it and travel there?
Imagine the Solar System as an athletics race track. If you were watching the 400 metres race from the centre of the track and wanted to intercept one of the runners taking part, one way would be to simply chase the runner you wish to stop. If you were fast enough, you might eventually catch up but only after expending a lot of energy and travelling a long way.
A much better way to intercept your athlete is simply to walk across the centre to the other side of the circular track. It is a much shorter distance and you use a lot less energy and time getting there.”
The launch period is calculated by taking a lot of features into account, but the most important feature being Fuel Consumption. We generally launch the vessel such that it reaches its destination while consuming the least fuel. So a direct journey along a straight line to mars is not very fuel-efficient
So we take the help of gravity and take an elliptical orbit to the destination, this may take a longer time but saves quite a lot of fuel.
There are a lot of ways to construct the elliptical transfer orbit but the most famous one is Hohmann transfer orbit. (it is debated if it is the most fuel-efficient transfer available)
Now, the journey takes almost 0.70 years, now we need to make sure that when the orbit of the vessel intersects with the orbit of Mars, the planet must be at the point in its orbit. This is where the calculation of the launch period comes into play. We launch the vessel when Earth and Mars are aligned in the proper manner.
In order for the launched vessel and Mars to intersect in the destination. We must launch when Mars is 44.44 deg away from Earth. (Calculations are in previous link)
This occurs from mid-July to August every 26 months.
This probably explains the Launch Period but does not explain the Launch Window.
While explaining the transfer orbit on a piece of paper we neglect one aspect of the orbit, the inclination. So we require the Orbital plane of the vessel and Mars to be coplanar for them to intersect. This is timed by the Launch Window, it occurs when the launch site is inclined with the plane of the required object.