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NASA
Course: NASA > Unit 3
Lesson 1: Mars: Modern exploration- Satellites 101
- GAME: Cruise to Mars
- INTERACT: Exploring orbits
- Mariner 4
- Mariner 9
- Viking mission
- Mars global surveyor
- Dry ice experiment
- Pathfinder
- Mars odyssey
- Mars express
- Martian methane
- Spirit & Opportunity
- Mars reconnaissance orbiter
- Modern discoveries
- INTERACT: Features of Mars
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Satellites 101
The space age
On October 4, 1957, the course of space exploration was forever changed, when the Soviet Union successfully launched Sputnik I. The world's first artificial satellite was about the size of a beach ball (58 cm.or 22.8 inches in diameter), weighed only 83.6 kilograms and took about 98 minutes to orbit the Earth on its elliptical path. While the Sputnik launch was a single event, it marked the start of the space age and the space race between the United States and the U.S.S.R.
Shortly thereafter, with the U.S. launch of Explorer 1 and subsequent missions, it was suddenly possible to send human-made instruments into space that could travel distant worlds. One key element was figuring how and exactly when to launch a satellite so that it would reach Mars in the minimum amount of time and with the least amount of power.
Video: How do you get to Mars?
At first, we had the technological knowledge to design “flyby” missions that would simply travel by Mars, taking pictures and collecting other data on their way past. For example: here is an animation of an asteroid briefly entering and exiting the Sun's orbit.
To get a detailed, long-term, global views of Mars, we needed to design techniques that allowed a spacecraft to be captured into orbit around Mars by approaching the planet at the correct position, velocity, and heading. Failure would result in either a flyby or a crash landing! To place the spacecraft in orbit, you need a balance between the forward movement of the spacecraft and the gravity of the planet. If forward motion is too great, you get a flyby; if gravity has a stronger effect, you get a collision. When you have a balance, the spacecraft establishes a circular or elliptical path around the planet.
For example, here is an asteroid which has the correct velocity and heading such that it is captured by the Sun's gravity.
After that, it’s a matter of designing cameras and other instruments, a power system, a communications system, and other spacecraft systems, to make the desired discoveries and send the data back to Earth.
Alright, let’s go to Mars!
Want to join the conversation?
i have question that does earthquakes come on other planets?(54 votes)
While they aren't technically 'earth'quakes, yes, other bodies have quakes. The Moon has moonquakes, Mars has marsquakes. Basically, if there is any geologic activity on a body, it will likely have quakes.(85 votes)
how is earth and mars alike?(9 votes)
Earth and Mars are alike in many ways. Mars is a planet, has water ice, is a rocky planet, and is in the edge of the habitable zone (or Goldilocks zone) in the solar system. There are also differences, for instance, its thin atmosphere and low greenhouse effect. Also it has low air pressure, no current life, (we don't know of any Martians) Mars has lower mass, and that it is in a colder environment (region) than the Earth(1 vote)
how long doe it take to build a space craft?(5 votes)
Building a new spaceship can take 4-10 years depending on its complexity and the resources of the manufacturer.(6 votes)
how do you know if mars is aligned with earth and the right timing of deploying the satellite?(4 votes)
Hundreds of years ago, astronomers watched Mars through telescopes and figured out its orbit around the Sun. It is relatively easy for computers now to use that orbital data to predict where Mars will be at any given point in time, and figure out when to do the transfer burn from Earth to Mars.(4 votes)
In Wich manner ,the Mars magnetic field is arranged(4 votes)
After all the preparations are made and the vessel is set off into space, how is the going to prepare itself for collision or even landing? Also, how long after landing can everyone onboard survive for?(3 votes)
The space craft will probably use parachutes and/or jets of gas to slow its descent enough to land without damage. And it depends on how much food and water is packed into the ship to determine how long people will survive for, along with the kinds of equipment they brought with them, and what it does, and how long it can function before breaking down.(3 votes)
After releasing CO2 into the air to heat mars and melt the water, plants will grow right? so, how long might it take to create a mesosphere and everything below it?(3 votes)
It's not that simple, Mars would probably need a magnetic field to keep it's atmosphere, and some people think is not even able to retain an atmosphere due to it's low gravity. Also importing that much CO2 would take a very (very very very very) long time. And then to get a proper, thick atmosphere would take even longer.(3 votes)
did a rover find water on Mars or not(2 votes)- Yes, a lander did find water on Mars. Here's a link to an article about it: https://www.nasa.gov/mission_pages/phoenix/news/phoenix-20080731.html(4 votes)
- Would we terraform the moon or mars first?
(tarreform means settle on or colonize)(2 votes)- the Moon would be impossible to terraform, so if we were trying to terraform a planet/moon, then it would be mars.(3 votes)
How hard is it to get out of Mars' atmosphere? My teacher told me that once you get in, you can hardly get out, but we saw a clip from NASA's website where the astronauts were going to Mars. The first half of the video was shot from inside the shuttle while the they were rocketing to Mars, and the other half shows them coming back to Earth in the shuttle, but in order to get back to Earth, they would have to get out of the atmosphere of Mars, but that leads back to what my teacher told us, that once you get into that atmosphere, you can't get out, but I believe it may be a struggle to get out of Mars' atmosphere, but not impossible.(3 votes)
It is easier for a rocket to get from Mars surface to orbit than it is to get from Earth surface to orbit, as Mars gravity is about 38% that of Earth's. And the rocket taking off from Mars will be a lot lighter than the one launched from Earth as it has to carry only enough fuel to get from Mars to Earth, whereas the one taking off from Earth has to carry enough fuel to get from Earth to Mars and back.(1 vote)
