The new millennium has seen the number of missions of humans traveling to space increase in leaps and bounds. One notable method used in human missions to space is the space probe. A space probe can be defined as a robotic spacecraft that goes beyond the earth space. We have seen them traveling to the moon and beyond the interplanetary space. A space probe will flyby, orbit and eventually land on the intended planetary body.
A good example of a space probe is Voyager 1, which started its journey back on September 5, 1977. Voyager 1 was launched by NASA to study the outer solar system. As we speak, it is 11.7 billion miles from Earth and is zipping at 61,000 km/h. Voyager 1 has discovered many things including volcanic eruptions in Jupiter. Also, it has sent pictures of a dark spot on Neptune and possible liquid on Saturn’s moon, just to mention few.
To understand some of the tech challenges that emerge during the building of a space probe, let’s look at some missions that did not turn out well:
The Orbiting Carbon Observatory
This was a mission by NASA that did not succeed. The mission was to look at how carbon dioxide moved through the atmosphere. It failed to touch the orbit because the containing satellite could not separate from the rocket. In the process, the whole assembly crashed into the ocean.
The DART spacecraft
This spacecraft was to dock on another satellite and provide maintenance. The mission was to autonomously navigate towards an existing communication satellite. The mission failed because the computer controlling this satellite miscalculated the distance between the two satellites, which made it bump into the other satellite causing it to burn all of its fuel. In the end, it crashed into the ocean.
This spacecraft was designed to fly in the upper atmosphere. Its mission was to conduct some atmospheric research. This craft didn’t make it after 30 minutes as it hit a powerful wind shear.
This spacecraft was designed for the scientist to study the original composition of the solar system. The spacecraft went into space to fetch solar wind so that scientists could study actual pieces of the sun. The problem arose when the satellite was on its way back since it was too delicate to land. NASA engineers jumped on helicopters to catch the capsules but it did not work. The spacecraft landed in a desert thanks to the hard materials that it was made of. It was built with strong wafers which enabled NASA to collect a few samples from the crash scene.
The necessary technology needed for a space probe to work properly
The proper propulsion
A space probe travels long distances, which is why it needs a proper propulsion system that enables it to maintain its course in precision. The service modules must have multiple engines with specific functions in case one fails, there is a back-up. For instance, the Orion spacecraft has about 33 engines.
Besides its propulsion, fuel is another vital component since it enables the spacecraft to travel long distance. They should also have backups in case the main engine fails.
The ability to resist heat
The spacecraft should be designed with materials able to counter-attack heat. As we all know, space probes travel at high speed. This process eventually generates heat as hot as lava. The material should have an advanced heat shield like the Orion spacecraft, for example, which uses AVCOAT, that enables it to endure heat up to 5000 degrees Fahrenheit.
Protection against radiation
A space probe travels beyond the earth’s magnetic shield, which poses a high risk of being hit by a solar storm that can eventually shut down computers. In this case, even if the space probe’s material is radiation resistant, there should be backup computers just in case one fails.
Communication and navigation
They do travel beyond the global positioning systems (GPS) and hence needs space communication network. Tracking and data relay will only work if there’s a space network that will communicate with near earth objects.
Fuel for the space probe
As we all know, here on earth we burn fuel to get energy but things are different for the space probe since they spent years on space. Carrying fuels like gas, coal, wood or oil would be an unrealistic task since the spacecraft would have to be huge, the size of the Asian continent.
One of the alternatives that have been used is solar panels. However, these panels need to be directed towards the sun. If the panel is in deep space, maybe behind the moon or another planet, it will not generate electricity. The solar panel is only applicable when the mission is in direct line of sight to the sun.
One of the more advanced means of energy for a spacecraft is the Radioisotope. These forms generate heat by the decay of the radioactive material. The material itself is tiny, almost the size of a golf ball, and can supply energy for decades.
Collecting and sending information
For the mission to be successful there has to be a channel of communication from space probe and earth. Special tools are designed for communication. For instance, NASA spacecraft are equipped with special antennae. These antennae receive and send information using a Radio signal. The radio signal is carried by powerful radio dishes that signal command. In most case, NASA uses DEEP SPACE NETWORK to send a signal to spacecraft.
Landing on a different atmosphere
For the space probe to land smoothly on a surface, it needs to slow down from orbital speed. Re-entry on earth is made possible using the parachutes but landing on the moon landing is different because it has no atmosphere. As a solution, a rocket has been used in the past to drag the space probe all the way down to the Moon surface.
Mars, on the other hand, has a very thin atmosphere which does not offer much resistance to a slow space probe. In such cases, NASA uses;
- Airbags which bounce when they reach the surface for soft landing.
- Rockets. When the space probe is near the surface, a rocket engine is fired to slow it down.
- Aero-shell. The shell is heatproof and encloses the fragile space probe inside.
- Parachute. They are released once the spacecraft is past high temperatures.
- Supersonic Inflatable Aerodynamic Decelerator. It can be used to land a larger payload on the surface.
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