If you had the opportunity to simulate your treasured flight to Uranus or Neptune, then what would it look like?
Would you begin to explore the unattractive surface of the satellite of Uranus Miranda? Or maybe the strange and massive rings of Neptune? Or the amazing interaction of these planets with the solar wind?
But why choose a single goal, if you can do everything at once?
Recently, planetologists have designed a hypothetical flight to one of the giant ice planets of our solar system. They figured out what a dream spaceship should be like flying to Uranus, taking into account the latest innovations and the most advanced technologies.
“We wanted to come up with technologies that really expand horizons,” said Mark Hofstadter, senior fellow at the Jet Propulsion Laboratory and the California Institute of Technology in Pasadena. “To think that they will appear in 10 years is no madness.” Hofstadter is the author of an internal study of the Jet Propulsion Laboratory, which he spoke about on December 11 at the autumn meeting of the American Geophysical Union.
Some innovations are the natural embodiment of existing technologies. Hofstadter talks about small and light equipment and computer chips. If you use the most advanced systems, you can reduce weight and free up a lot of space on board the spacecraft. “A rocket can launch a certain mass into space,” he says, “and therefore, every kilogram of construction saved makes it possible to supply additional scientific instruments.”
Nuclear ion engine
In the dream spaceship there are two technologies that have proven themselves in space, which in combination gave a completely new engine, called the electric power plant on radioisotopes (ESUR).
The spaceship works just like any other machine. The battery provides energy to power the on-board systems and start the engine. Fuel passes through the engine, where a chemical reaction occurs and a reactive force appears, causing the ship to move.
In a dream spaceship, the battery receives energy from the radioactive decay of plutonium, which is the preferred source of energy when flying in the outer part of the solar system, where there is little sunlight. Voyager 1, Voyager 2, Cassini and New Horions had a radioisotope source of energy, but used hydrazine fuel in a chemical engine that quickly delivered them to the far corners of the solar system.
In an ion engine, xenon gas is used as fuel. Xenon is ionized. The electric field accelerates xenon ions, and it leaves the spacecraft in the form of exhaust gas. Deep Space 1 and Don used exactly this type of engine on the spacecraft, but they received energy from large solar panels, which work best in the inner part of the solar system, where most space flights take place.
Xenon gas is very stable. The spacecraft can transport it in large quantities in a container under pressure. This allows you to increase the duration of the flight. “ESUR gives us the opportunity to explore all areas of the giant ice system: rings, satellites, and even the magnetosphere surrounding them,” said Hofstadter. “We can fly wherever we want.” We can spend there as much time as we need. It gives us wonderful freedom of action. ”
A dream spaceship with an ESUR installed on it can fly past the rings, moons and the planet itself 10 times slower than an apparatus with a conventional chemical combustion engine. Moving at low speed, the dream ship can take clear high-resolution pictures with a large exposure. But to take full advantage of the ion engine, the spacecraft needs on-board navigation automation.
“We don’t know exactly where the satellite of Uranus is located, or where the spacecraft is located [relative to this moon],” said Hofstadter. Most of the satellites of this planet are visible only from afar, and details about their sizes and orbits are unknown. “Because of this uncertainty, one should always keep a decent distance from the object you are considering so as not to crash into it,” he added.
“But if you are sure that the spacecraft will see the satellite’s location using the camera and adjust its orbit, then you can get close to the satellite and not crash into it,” the scientist noted. “You can come much closer than when you are preparing a flight from Earth, because in this case the communication delay is more than five hours.”
Autonomous navigation equipment of this level on spacecraft did not exist before. NASA’s Curiosity all-terrain vehicle has a limited ability to plot a trajectory between two points. And the OSIRIS-Rex interplanetary station will be able to detect hazards and stop sampling.
The dream ship will be more like an unmanned vehicle. For example, he will know that he will have to fly the satellite of Uranus to Ophelia. He himself will prepare for himself a low flight path above the surface in order to visit interesting places, such as chaos territory. And this ship will maneuver, flying around unexpected obstacles such as sharp cliffs and rocks. If he misses something interesting, he will have enough fuel to make another pass.
Trio of Lander
Having received additional space thanks to compact electronics, as well as the ability to fly slowly and low above the surface, which will be provided by ESMS and an autonomous navigation system, the dream ship will be able to take onboard the descent vehicles, which can be easily dropped onto the surface of Uranus’ satellites.
“We designed a flight with three small descent vehicles that can be planted on any of the satellites,” said Hofstadter. The sizes, shape and capabilities of these devices can be anything from simple cameras to a complete set of devices to measure gravity, soil composition and even seismicity.
The dream spaceship will be able to explore all 27 satellites of Uranus, starting with the largest Titania and ending with the smallest Cupid, whose diameter is only 18 kilometers. Then the team will be able to decide how best to use the descent vehicles.
“We don’t have to decide in advance which satellites to plant them on,” said Hofstadter. “We can wait until we get there.” We can land all the devices on one satellite, creating a small seismic network to search for lunar earthquakes and study its insides. Or maybe we will decide that it is better to land these devices on three different satellites. ”
Icing on the cake
Scientists conducting internal research acknowledge that incorporating all these innovative technologies in one flight is simply unrealistic. It will be very risky and expensive, says Hofstadter. Moreover, the equipment tested in space, which was used on board the Cassini, New Horizons and Juno, may well make fascinating scientific discoveries on the ice giants. And innovation will complement this equipment.
At the moment, NASA is not preparing for flights to Uranus and Neptune. In 2017, Hofstadter and his colleagues insisted that it was necessary to fly to one of the ice giants, and now they hope that the technologies of the future will inspire someone to develop a proposal for such a flight.
“It’s almost like icing on a cake,” he said. “We said that if you apply new technologies, you can do a lot of new things, and this will ensure great scientific success.”