By 10 April, 2021 - 10:20pm
The Perseverance robot, who has been in Jezero Crater for more than a month, is not alone. He carries with him a small helicopter, dubbed Ingenuity . Until now it has been hung under the chassis, folded to take up as little space as possible and hidden by a cover that protects it from dust and rocks raised during landing
Wanted Martian, Dead or Alive 'Perseverance' - Successfully land the largest mission to Mars in
history These weeks have been dedicated to testing and calibrating the cameras and mechanisms on board, a long and complicated task. It has moved about a hundred meters, looking for a flat place to deposit the helicopter, a heliport . You have discarded the shield and disconnected the cables that connect you to the helicopter. Then, Perseverance has released the jaws that hold him, allowing him to unfold his four fragile legs and fall to the ground. The vehicle will then reverse and pull out to a safe distance, leaving Ingenuity free to allow the sun to charge its batteries. And you will have all the air of Mars at your disposal so that you can take the first flight, which NASA plans to be tomorrow, Monday at 3.30 in the morning , US East Coast time, 9.30 in the morning, peninsular time. Spanish. Here are some answers about this novel way of exploring the red planet:
Why a helicopter on Mars?
Ingenuity is just a proof of concept, an engineering essay. He is not assigned science or exploration assignments. It is just a matter of demonstrating that it can fly in an environment as hostile and unfamiliar as the Martian atmosphere.
Does it work like a conventional helicopter?
Generally speaking, yes. It uses a double counter-rotating rotor: some blades turn to the right and others to the left so that their movement is compensated and the reaction does not make the entire vehicle spin. That is why it does not need a tail rotor. In that sense, it is more like a drone than a helicopter.
Will it be able to move in the thin atmosphere of Mars?
That is what we are trying to verify. The density of the air is barely one hundredth of that of the Earth, equivalent to that which exists here at an altitude of 30,000 meters. No conventional aircraft reaches them. And much less a helicopter, whose operational ceiling (landing and taking off) is well below 8,000.
In the future, other models may understand more complex orders. 'Ingenuity' is just an obedient robot but without a lot of lights.
To get up, Ingenuity's rotors have to spin at a crazy 2,400 revolutions per minute, almost like the blades on a mixer and five times faster than in a conventional helicopter. It is such a precarious situation that flights are planned for just before local noon, when it is estimated that the density of the air will have gained a few thousandths and can offer a little more lift.
Why has that design been adopted and not the typical quadcopter drone?
For a very simple reason: it did not fit. To rise in the thin Martian air, Ingenuity needs very large blades, more than a meter in diameter, although their weight (on Mars) is less than a kilo. They are not collapsible and fit very tightly under Perseverance's belly. A quadcopter could not be accommodated there
Has it been tested on the ground?
As far as possible. In large part, its design is based on mathematical models of what is known of the Martian atmosphere and climatology. The prototype has flown inside a vacuum chamber, but at the cost of lightening its weight to simulate less gravity (on Mars it weighs just over half a kilo, compared to almost two kilos on Earth). For this reason, the tests were carried out only with the propulsion system and the landing gear; the control electronics and batteries remained on the ground, connected to the helicopter by a cable. So testing under real conditions can only take place on Mars.
Is it autonomous?
It has to be. Radio signals take more than ten minutes to reach Mars. Such a delay makes it impossible to control a helicopter - or almost any other type of vehicle - from here.
Now, in that case, autonomous does not mean "smart." Ingenuity flights are planned in advance. Instructions for takeoff, altitude, and route are stored in its memory long before the flight begins. And he must follow them as best as possible. Its decision-making capacity is limited to correcting deviations due, for example, to gusts of wind.
In the future, other models may be able to understand more complex orders, such as "go to that rock avoiding overhangs on the ground" (something that Perseverance does know how to do - up to a point -). Ingenuity is just an obedient robot but without many lights.
Does it have a flight computer on board?
Yes. It is a commercial unit, much like the one you probably equip the cell phone you carry in your pocket. And there is no excess memory: 2 gigabytes of RAM and 32 of ROM, which corresponds to a low-end phone. Of course, it has a lot more battery and, in addition, a small panel of solar cells to recharge it together with some heaters to protect them from the frigid Martian night.
Perhaps this can give you an idea of the power that your mobile contains: in Ingenuity , that The processor controls two inertial navigation units, an inclinometer, a laser altimeter, and two television cameras. All, commercial products. If you're interested, you can get an identical gyro sensor for less than 600 euros and an altimeter for 150.
Illustration of 'Ingenuity' work on Mars, with 'Perseverance' in the background.A
P This is the first time an interplanetary spacecraft has used Linux as an operating system. It is programmed in JPL's own language called “F-prime”, suitable for flight control applications. If you are a computer buff, you probably don't know it. But it is available for download on the Internet, with sources, tutorials and all the details.
Will it transmit images?
Yes. Directly to Perseverance and from there, to Earth. One of its cameras, in black and white, points vertically downwards. It offers a modest quality, like the VGA of our old computers. The helicopter estimates its speed by comparing the speed at which the terrain features (or its own shadow) are moving in successive images. The other high-definition camera looks straight ahead at an oblique angle. It is the one that promises more spectacular views, with a quality superior to 4K
What autonomy does it have?
Ninety seconds of flight. Its small electric batteries do not give for more. In that time it will be able to reach a maximum ceiling of ten meters and move away at most 300 meters.
The first flight will be limited to a vertical rise up to about three meters, it will turn on itself as if exploring the horizon and it will land again. Nothing spectacular. On subsequent attempts he will have to go higher and further.
Will you accompany 'Perseverance' in his exploration of the crater?
No. Perseverance has its own set of experiments and the helicopter, a last minute stowaway, is not one of them. The flight team has been given about a month for its tests. In total, five flights are planned. Then, Ingenuity will land more or less where it is now and Perseverance will go off to do his things, leaving him abandoned, although his equipment is still in perfect condition.
Rafael Clemente is an industrial engineer and was the founder and first director of the Museu de la Ciència de Barcelona (current CosmoCaixa). He is the author of 'A small step for [a] man' (Dome Books).
newsletter Source: Elpais