about the "pathfinder"?

Question

why is that the pathfinder landed on mars using parachutes and airbags? there is no gravity there and even though with a fraction of gravity it doesn´t need parachutes to land. parachutes are to use the air as a way to help soften the fall, there is no air there.
what made it land upright? it had a drill too to make holes on rocks and send info to earth. there was no obstacles on its path either and it landed on a flat surface. what if it had landed crashing a small rock and placing it sideways or upside down?
I really don´t believe on this fantasy space craft. do you?
thanks for your answers, and again, greetings from México !

Answer 1

I hope my answer to your previous question will help clear some of this up. But to continue:

> ...parachutes are to use the air as a way to help soften the fall, there is no air there...

You're right about the purpose of parachutes, but you're wrong about Mars. There IS a little bit of air there. The parachutes were not used in the same way we use parachutes on earth, though (that is, the lander did not reach the ground with the parachutes). The main purpose of the Martian parachutes was to create friction to subtract a lot of velocity. When the parachutes opened, the craft was still traveling faster than the speed of sound. Such a speed would have ripped the parachutes to shreds, if the air were as thick as on earth. But on Mars, all it did was create sufficient friction to slow the craft down to a few tens of feet per second.

But (because of the thin air) this slow speed was still too fast for a soft landing. For this reason, the parachutes were eventually cut loose, and rockets and airbags were used for the final landing.

> ...what made it land upright?

See my answer to your other question. The designers folded it into a tetrahedral (pyramid) shape, with doors that would push it over into an upright position in case it landed on its side. The Pathfinder actually DID land upright, but that was just coincidence; it might have landed on any of three other sides instead.

>...what if it had landed crashing a small rock...

The airbags were tested on laboratories on earth, to make sure they would not tear if they hit small rocks.

>...and placing it sideways or upside down?

See above: The "unfolding" mechanism pushes it into an upright position.

>...I really don´t believe on this fantasy space craft. do you?

It is an amazing accomplishment, but true.

Answer 2

I think you really need to do some research, you don't seem to know much about what you're asking.

Of course there is gravity on Mars - it's more massive than the moon, and has a surface gravity about a third that of Earth. There is gravity on any sizeable object (even the asteroids and comets have some gravity.

Of course there is an atmosphere on Mars - it doesn't have much oxygen, and it's thinner than on Earth but it's there.
So the only way to land softly on Mars would be either using rockets (and since there were no pilots it would have been dangerous to try that from Earth) or parachutes and airbags (which have been used on Earth before for unmanned objects).

It landed at an angle, but it had a stabilizer program and hydraulic jacks onboard (plus a pretty sophisticated computer) that helped to level the lander.

There were obstacles that the rover had to navigate around - rocks, soft soils, craters. That's why some of the control of the rover was remote from Earth, using the telecast images from the rover's camera to guide them. It only moved a few meters a day to make sure things were safe.

And now I wonder if you're trying to start some kind of "conspiracy theory" claiming we didn't land on Mars - everyone is tired of the "we never landed on the moon" one, so this is a new one.

Answer 3

Actually, Mars has a thin atmosphere. With Pathfinder's velocity, it was moving fast enough to make use of the parachute it carried. Mars' gravity is about 38% that of Earth, so that also helped in landing.

The space craft had airbags all over every surface (withtout them inflated, the lander looked like a pyramid), and when it finally stopped bouncing, it opened up - the way it opened set the craft upright.

Answer 4

ya,there is no air.but the spacecraft is travelling at a good speed right.
The spacecraft is entering the atmosphere at 12,000 miles per hour.So,if it lands at the martian surface at this speed,then the spacecraft will get damaged.There is a martian surface,even if no air is there in Martian atmosphere.So,NASA wanted to cut down the speed of spacecraft from 12,ooo to 12 miles per hour.How will they do it??
By parachutes.
After cutting down the speed to 12 miles per hour,air bags are used to cushion the landing.These air bags are inflated before touching the surface.This is done coz,after landing,the spacecraft will bounce at the surface due to the impact.In order to prevent the spacecraft inside from damaging,air bags are used.
The rover, protected by its lander structure and airbags, could bounce up to four or five stories high and roll as far as 1 kilometer (0.6 miles) across the martian surface before it comes to a complete stop.
I dont have idea about what made it land upright.


But I will explain how NASA's latest rover Spirit landed.

About 14 minutes after Spirit hits the ground and four minutes after it stops bouncing and rolling, transmission of tones resumes from the rover's low-gain X-band antenna. If the rover lands with its base petal down, this antenna will be near the top of the bundle and in a position that may be favorable to sending a signal to Earth. Its transmission of tones ends 150 seconds later. The lander, however, may not be in this orientation. Therefore, beginning about three minutes later, another low-gain X-band antenna, this one mounted on the lander's base petal, transmits tones for 150 seconds as well.

Immediately after landing, the rover will go through a series of critical deployments for 80 minutes or longer, depending on which base petal it lands. The lander will retract its airbags, deploy its lander petals and solar arrays, and raise its panoramic camera mast.


greetings from India....

Answer 5

"I really don´t believe on this fantasy space craft. do you?"

. . . fantasy? Oh great, first the flat earth loonies got people doubting Apollo, now it's Pathfinder. What's next?!?

Answer 6

anything which just drops on it's own weight can not be called a pathfinder at the first place.

Answer 7

i am given to understand that one seat is available for travel to Mars. R u ready? there u can find the answer to ur Q.