From the earth to the moon

Perhaps in this world nobody is as weird as Bill Stone: Exploring the deepest caves of the earth to train and prepare for traveling into the universe.

Stone is not an astronaut, he is a cave explorer who has explored the deepest and most dangerous caves on Earth. He wanted to prove that the cave is the best training for space exploration.

DepthX robot

With NASA's $ 5 million support budget, Stone is developing a robot called DepthX , which can become the most advanced self-propelled underwater vehicle ever. DepthX is a cave exploration robot, capable of navigating and moving in tight conditions and many obstacles. The mission of DepthX is in theory to seek life on Saturn's moon Europa. Even Stone did not dare to believe in this almost impossible task.

This month, DepthX will be tested for the first time, in the deepest cave in the world, Zacatón Cenote of Mexico. To achieve the ambition to conquer the universe, Stone needed to impress the wealthy investors, interested in the space universe. Therefore, this test must be spectacular and successful. Moreover, at age 54, Stone did not have much time.

Try comparing DepthX with two self-propelled vehicles that are currently exploring Mars and currently Spirit and Opportunity, we will see the difficult task of the Stone group. Despite being very successful in collecting data and images, these two self-propelled vehicles are still extremely sophisticated remote controls. The ground controllers will order Spirit and Opportunity to move based on the images of the surrounding scenery sent. Meanwhile DepthX is a fully self-propelled vehicle. It will be released into a new environment, and have to figure out where it is, where to go and what to do.

Many different technologies are combined to make the DepthX self-propelled vehicle capable of mapping and detecting life.(Photo: Popsci)

Basically, DepthX is a giant ball . Armed with 54 ultrasonic sensors, DepthX collects data from thousands of ultrasound waves every minute to create a detailed picture of the surrounding environment. DepthX not only draws a three-dimensional map of the surrounding scene, but also determines its location in this environment, using an inertial guide, accelerometer, depth gauge and Other sensors for positioning. All of these devices constitute the Synchronization and Mapping (Simultaneous Localization and Mapping - SLAM) component.

This is the first test of three-dimensional SLAM. Current self-propelled vehicles have a relatively narrow vision and can only be seen in front. DepthX is a cave exploration robot, which can encounter obstacles from any direction, so it must have a comprehensive perspective.

Dream

From a young age, Stone dreamed of flying into space. In 1989, Stone entered the last 60 of the 10,000 applicants to NASA astronauts.

At all physical, psychological and emotional tests, Stone is at the top. Later, he was called into an interview before a board of former astronauts. When Guy Bluford asked if he had any regrets in his life, Stone replied: " I want to have $ 2 billion to bring a private expedition team to the Moon ."

During the past 10 years, Stone has become a scholar about the universe . His daily work is the automation expert of the National Institute of Standards and Technology. In his spare time, he writes scientific articles such as life support equipment, jet propulsion and spacecraft design. His genius and cosmic passion is well known. In 1982, he was invited to a congressional council to review existing space station projects, and then a federal government committee to design a separate space station.

Equipped with 54 ultrasonic sensors, Bill Stone's self-propelled vehicle is a giant sphere that can create 3-D maps of the surrounding landscape.Maybe someday a similar robot will look for extraterrestrial life in the icy pits of Europa, a moon of Saturn.
Stone also wants to explore space: he is planning to lead a crew to the moon with private funding.

However, despite his scholarly knowledge, Stone's opinion in front of the astronaut's council showed pride and lack of restraint. Don Puddy, a senior expert at Johnson Space Center, told Stone: "It is unlikely that NASA will return to the Moon again."

Stone felt all hope and dreams of years gone by. He was laid off and did not get upset. He said that the agency's exploration department lacked courage. With the help of some scientists at NASA, he himself sought to contribute to the discovery of strange lands.

Planet Europa

Ever since Voyage 1 flew around Jupiter orbit in 1979, scientists have believed that one of the moons of this planet has water, and may have life. Although Europa is very cold (-2600F surface), and surrounded by a layer of ice more than 10 km, cosmologists still think that below it is a sea with more water than the total water in the great Positive Earth. Europa is considered the most likely place to live in the solar system. DepthX is a way to prove this.

Although there are no plans to officially land on Europa, NASA has drafted a three-stage space ship plan. Phase one, the ship will land on Europa surface and in the second stage, a robot shaped like a pendulum will be released. This robot has a nuclear reactor that generates heat at the top, which will melt the thick ice to the bottom of the ocean. At the third stage, one or more robots like DepthX will be released.

From here, DepthX will conduct cautious expeditions, several hundred meters each, map the surroundings and use visual and chemical monitoring systems to track the trail of life. . Periodically, DepthX will return to the pendulum robot to transmit the collected information to Earth.

If the DepthX test succeeds, Stone will achieve its goal of attracting $ 100 million private funding to design another robot, which can land on Earth's Moon to find signs of water. If the ice on the Moon is thick enough, Stone will move closer to his ultimate goal of reaching the Shackleton Crater, right in the middle of the Moon's southernmost tip.

From the pit to the sky

Shackleton Crater is about 1km deep, and about 10km across, most of it is submerged in eternal darkness. Ice comets often collide with the Moon and in the deep bottom of Shackleton can accumulate thick layers of ice.

In the universe, ice is more precious than gold. Scientists can melt ice to get drinking water, extract oxygen to breathe and use oxygen in combination with hydrogen as a fuel for missiles. Stone also wants to go further. According to him, it is possible to transport ice from the Moon to space stations outside Earth's orbit for sale.

The biggest obstacle to space travel is a huge amount of fuel to escape Earth's attraction. But if you set up a fuel station on the Moon, the cost of taking a space ship into space can be reduced by 75%. Stone estimates that within a few years, based on the Moon, it could earn $ 1 billion a year.

To equip his cave expeditions, Stone has focused on groups of comrades of more than 100 people and has found millions of dollars in grants. In order to survive many weeks in dangerous, unfamiliar environments, and often lacking in air, Stone faces challenges similar to those of space astronauts and has built devices. complex support for exploration work.

Because underground caves are often flooded, Stone has designed a kind of recyclable carbon dioxide vapor for re-use, allowing divers to live more than 24 hours underwater . This type of boiler can be fully adapted for use in space. There are caves that don't have any water at all. Stone is making a device to recycle urine into drinking water, which is useful when landing on Shackleton for the first time.

In the cave as on the Moon, outside help cannot be expected. The explorer must manage on his own. What Stone has gathered from cave expeditions does not show what he will do but how he will do this.

Although NASA rejected all of his offers, Stone was not discouraged. He hopes private investors will be willing to lend money to support his project. His chance was actually lower than the ability to win American Powerball lottery, but he still hoped that someday, he would have enough money to take a crew of 12 - 18 people to the Moon to build a base.

NASA hopes to use a similar robot DepthX to explore Europa, an icy moon of Saturn .Astrophysicists have long suspected that Europa's ice moon has liquid water - and it is likely that there is life outside of Earth.A robot like DepthX can be launched into space on a probe, landing on the icy surface of Europa in a bullet-shaped base station and able to generate heat, which is then released into the lane. icy, mysterious water below.One or more such robots will be smart enough to determine the direction to maximize the chance of detecting life.

DepthX tested the versatility of a fully autonomous underwater vehicle that could move in tight environments like caves .When completed, the DepthX does not need to be remotely controlled or pre-programmed, it will assess the surroundings in real time using 54 ultrasonic sensors (A) by the ultrasonic emitters ( B) control, together with an inertial guide, accelerometer and depth measuring devices.A Doppler speed recorder (C) monitors the vehicle's travel speed.This information is passed on to computers (D and E), from which the robot will draw a 3-D map of the surrounding environment and determine the next direction.To avoid blind spots, sensors are placed across the surface of this circular omnidirectional robot.

When determining the direction, DepthX will move by using 6 thrusters (F) to move, hover and find the path correctly.This system follows the redundancy principle - there are two vertical thrusters and four horizontal thrusters.If there is an engine that does not work, the other one will replace.A floating computer (G) controls valves, pumps and compressed air to push water out of the system.The goal is to achieve balanced buoyancy and to avoid wasting energy.Two battery towers (H) (also following the redundancy principle, preventing a broken tower), generated from lithium-ion battery blocks with energy that can operate 30 electric cars.

Leaf