Solar sail reaches Mars in 26 days

Scientists have calculated how quickly a spacecraft with a solar sail made of a new aerographite material can get to different places in our star system. It will take 26 days to reach Mars, and several years to reach the heliopause.

Solar sail. Source: phys.org

Advantages of solar sail

The journal Acta Astronautica recently published an article by scientists who analyzed how quickly it was possible to get to Mars and the heliopause using solar sails made of a new material called aerographite.

The solar sail is an extremely thin film of mirror material that is stretched over a large frame. Light also has an impulse, therefore, the energy of the collision of photons with this spacecraft can be used to accelerate the vehicle. In practice, this has been proven in the last few decades with missions like LightSail and LightSail2.

Now the solar sail seems to be the most promising technology for delivering a payload of up to several kilograms to distant planets. Such a weight may seem ridiculous compared to the tens of tons that the most powerful carriers put into space. However, in this case, speed is much more important.

Flight to Mars

The fact that the solar sail can be faster than chemical engines has been known for a long time. But the time it takes for it to get to certain points in the Solar System has been established by scientists in a new study. They were mainly interested in two locations: Mars, as the most interesting planet for research, and the heliosphere, a conditional boundary where the pressure of the solar wind is aligned with the action of the interstellar medium.

Scientists have prepared two scenarios for each of them. The first one assumes that the solar sail vehicle will be launched directly from the polar orbit of the Earth. In the second case, it will first be delivered to a certain point, which is located inside the Earth’s orbit at a distance of 0.6 AU.

The pressure of solar radiation on the sail will be much greater there, and it will accelerate faster. The spacecraft is calculated to have a weight of 1000 g, 720 of which falls on the sail, which at the same time has an area of 140 m2.

How fast is the solar sail

The launch to Mars from the polar orbit of the Earth is proposed to be carried out when it is in opposition to our planet, that is, exactly behind it. Calculations show that in this case, the flight to it will take only 26 days, compared to 7–9 months, which are usually necessary for chemical rockets.

In the case of the sail deployment point inside the Earth’s orbit, the journey to Mars takes 126 days, and 103 of those days the probe will fly to Mars with chemical engines. This is not very fast, but in the case of a trip to the heliosphere, such a scheme justifies itself.

After all, if you fly to the borders of the Solar System from the polar orbit of the Earth, then acceleration to the maximum speed takes two years. And the spacecraft will reach its final goal only in 5.3 years. In the case of traveling through the 0.6 AU mark to the Sun, the sail will first have to fly to it for the same 103 days as in the case of Mars.

But then the spacecraft will accelerate to the maximum speed for only 300 days. And it will reach the heliosphere in 4.2 years. That is, for flights to distant bodies of the Solar System, this scheme fits perfectly.

According to phys.org

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