Engineers working with the promising new Uranus Orbiter and Probe mission have come up with a technical solution that would easily put the vehicle into orbit around the solar system’s seventh planet. They plan to use aerodynamic braking.
Flight to Uranus
So far, Uranus has not been studied in detail by any spacecraft orbiting it. Only migratory missions were involved. But this could soon change with the implementation of the Uranus Orbiter and Probe (UOP) program that NASA scientists are currently developing.
The reason why in the Saturn system the Cassini spacecraft worked 20 years ago, and on Uranus a similar mission is still on paper, is due to certain consequences of the distance of this planet from the Sun. It now takes 13 years to fly there, which is already a challenge in itself for the spacecraft.
At the same time, the duration of this journey could already be shortened by simply accelerating the probe to a higher speed. However, we should not forget that at the end point we still have to slow it down to orbital velocity, and we have to spend fuel for that too.
And this fuel also needs to be accelerated during the initial phase of flight. If we try to accelerate the spacecraft to higher speeds, the mass of payloads that can be delivered to Uranus’ orbit quickly decreases.
Aerodynamic braking
To get out of this situation, engineers developing the UOP mission suggest using a long-known method — aerodynamic braking. Its point is that the trajectory of the spacecraft is laid out in such a way that it simply flies into the upper, most rarefied layers of the planet’s atmosphere, and during the time it moves in them, the force of friction reduces its speed.
The advantages of this method are well known and have already been tested during the realization of the Curiosity rover mission. Thanks to this maneuver, it is indeed possible to drop speed and enter orbit around the planet with virtually no fuel consumption at all. The saved mass can be used to increase the flight speed, or to increase the number of instruments on board.
However, this does not mean that the method has no disadvantages. During aerodynamic braking, the kinetic energy of the vehicle is converted to thermal energy. That is why it should be equipped with a heat-resistant shield made of ablative material. Even so, the risk of losing the vehicle due to thermo-mechanical stresses remains.
Opportunities and challenges
However, even that doesn’t end all the problems with UOP. After all, a heat shield alone is not enough for it to survive aerodynamic braking. It is also necessary to design the rest of the vehicle in such a way that it survives the temporary re-entry into the atmosphere of Uranus.
On the other hand, the application of aerodynamic braking may give the UOP mission new opportunities. After all, some scientific instruments will be able to operate during this maneuver and get some really unique data.
In addition, the main obstacle to realizing UOP is very, very earthy. Funding for NASA science projects is being cut. The mission to Uranus is one of the highest priorities, but even it may fall victim to a lack of money.
According to phys.org
