Which ship will we fly to Mars?
SpaceX, a private aerospace company, is working hard on a very ambitious project: its final goal is to be populated by Mars people. To do this, employees are developing a reusable launch system called Starship.
This is a complex of a 67-meter launch vehicle and a 54-meter spacecraft that will refuel in low-Earth orbit to deliver 100 passengers and more than 100 tons of cargo to Mars at the same time.
Recently, Elon Musk spoke about two radical changes in the design of Starship. The first concerns the material: the ship is made of stainless steel alloys instead of carbon fiber – this is a way to reduce costs (67 times) and quickly build a system. Another company, General Dynamics, was already trying to launch a steel rocket, but it creased under its own weight even at the start. Musk notes that his team intends to use advanced steel of a different composition.
SpaceX will also try to make the spaceship not burn in the atmospheres of the Earth and Mars, that is, become reusable.
What is the revolution?
Instead of relying on thousands of heavy ceramic tiles to protect the spaceship from heat, as NASA did with its space shuttle, the company plans to make the spacecraft “bleed out” with some kind of liquid (water, methane, or something else) tiny pores. This will allow it to cool.
Theoretically, if you put a liquid between the steel skin of a starship and the heated plasma generated by passing through atmospheric gases, it would be possible to prevent the destruction of the ship.
the rocket will look like liquid silver:
To date, the largest vehicle that NASA was able to land on Mars, has become a solid Curiosity ship. According to agency engineer Walt Engelund, the landing of a robot the size of a car and a ship the size of a building filled with people are two completely different stories and the second will be about 100 times more complicated.
Steel and so strong, why cool the ship?
The spaceship will enter the atmospheres of Mars and Earth, presumably at a speed of 30.5 thousand kilometers per hour. In this case, the nose of the ship may be exposed to temperatures of about 1480 degrees Celsius. By itself, the steel melts at a temperature of 1400-1500 degrees, so the ship will need to be cooled.
The team decided to abandon conventional thermal protection tiles in order to save mass and avoid the risk that a damaged or lost tile could jeopardize the entire heat shield. Instead, the spaceship will “sweat” with water or methane (this issue has not yet been resolved) from tiny holes in its steel shell and the liquid layer will carry with it the burning heat of atmospheric gases. This is an absolute innovation of his company – such an idea has never been implemented before.
Now SpaceX is testing a new material for resistance to high temperatures, but there is still a lot of work to be done before it can certify the idea of a new heat shield.