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View Full Version : Opportunity is Ready Descend Into Victoria Crater



Fraser
2007-Jun-28, 05:29 PM
NASA's Opportunity rover has been tentatively checking out the rim of Victoria Crater, gathering as much science as it can before going down inside. Mission controllers announced today that they've got all the data they need, and they're ready to push the rover over the edge, and send it on a potentially one-way journey down into the crater. ...

Read the full blog entry (http://www.universetoday.com/2007/06/28/opportunity-is-ready-descend-into-victoria-crater/)

Doctor Know
2007-Jun-29, 03:57 AM
I'm so jazzed by the robustness and longevity of these rovers. I'd love to know how many miles or kilometers they've each managed to stray from their original landing sites.

antoniseb
2007-Jun-29, 02:52 PM
I'd love to know how many miles or kilometers they've each managed to stray from their original landing sites.

If you follow Opportunities zig-zag path and add it all up, it's coming up on having gone 11 km. Spirit has gone perhaps 7 km.

crosscountry
2007-Jun-29, 03:04 PM
wow. we could have sent men there and back by now.



I'm not downplaying the significance of the rovers. They are fantastic machine and do their job well along with the men and women working them.

Just an oddity that in the time we've been on Mars humans could have sent a mission, walked farther (much farther), returned the samples for more analysis, and returned themselves.



the total cost would have been more, but so would the knowledge. How may robot missions will it take to cost one manned mission? And how many robot missions will it take to get even a fraction of the data a manned mission could?

cost wise - in the longer run - manned missions might win out. Then all the data too ;)

antoniseb
2007-Jun-29, 03:20 PM
How may robot missions will it take to cost one manned mission? And how many robot missions will it take to get even a fraction of the data a manned mission could?

That's hard to say. I've heard that a manned mission would cost about a trillion dollars, and these two rovers were 250 million each, so you could send 4000 rovers for the cost of one manned mission (if such a calculation were that simple). But the fact is that each rover that we send will either be capable of more, or cost less, or both. In the twenty or thirty years it would take to build and send a manned mission, we will probably develop robotic capabilities that will continue to cut into the advantage you imagine a manned mission would have, without the risk to the health and lives that the voyagers would be exposed to.

crosscountry
2007-Jun-29, 03:47 PM
That's hard to say. I've heard that a manned mission would cost about a trillion dollars, and these two rovers were 250 million each, so you could send 4000 rovers for the cost of one manned mission (if such a calculation were that simple). But the fact is that each rover that we send will either be capable of more, or cost less, or both. In the twenty or thirty years it would take to build and send a manned mission, we will probably develop robotic capabilities that will continue to cut into the advantage you imagine a manned mission would have, without the risk to the health and lives that the voyagers would be exposed to.

thing is that the price of the two rovers keeps increasing. the initial cost was only 250 million each, but what is the continual cost? after years it adds up. we're still paying all those scientists to live on martian time and think up neat ways to keep the two rolling.

that trillion dollars sounds high, and probably includes incidentals not figured into the rover totals.

antoniseb
2007-Jun-29, 04:29 PM
thing is that the price of the two rovers keeps increasing. the initial cost was only 250 million each, but what is the continual cost? after years it adds up.

I think the $250 million included one year of all the scientists moving them and doing research with the data received, so yes, the cost has gone up some above that.

that trillion dollars sounds high, and probably includes incidentals not figured into the rover totals.
Like what? Like water purification, or climate control, or three years worth of food, or the fuel to accelerate the massive shell required to protect the crew from cosmic rays, or the crew training, or psychological testing, or some other non-essential thing that wasn't figured into the rover cost?

Mansie
2007-Jun-29, 05:35 PM
I think that one of the most important and significant achievements of the Rover missions (other than the collection of scientific data), is its demonstration that using a locally available resource (in this case solar power) has allowed the mission to continue for such an extraordinarily long time.

The Rovers longevity has highlighted the possibilities, and I'm sure future missions will be designed to exploit this. In my view, the success of the rovers makes a manned mission less likely - although of course I'd be delighted to see a manned mission ASAP!

John Mendenhall
2007-Jun-29, 05:42 PM
I really llike manned exploration, but the robots get better and better. The advantage to rpbotic exploration is that we are not endangering human lives, indeed, when we eventually send people, we should have a much better idea of what to expect, and how to do it safely. Or if we should do it at all. If Mars is not terraformable or will not support a colony, is it worth it to go there?

RUF
2007-Jun-30, 11:39 PM
Remember, a human mission to Mars may well require 9 months travel time there, 9 months back, and perhaps 9 months on the surface to make it all worthwile. I can't begin to calculate the costs.

Nick4
2007-Jul-01, 06:17 AM
If the rovers go over the edge do they plan on destroying them by doing that or do they think that they will survive the fall.

Hamlet
2007-Jul-01, 11:29 PM
If the rovers go over the edge do they plan on destroying them by doing that or do they think that they will survive the fall.

They are not dropping Opportunity over an edge and letting it fall. The folks at JPL have identified an incline down into Victoria Crater that they think is within the capability of the rover to traverse. There is always the possibility that something may happen to strand the rover in the crater, but the mission is being planned with every intention to come back out again.

crosscountry
2007-Jul-02, 08:09 AM
wish them luck

Ivan Viehoff
2007-Jul-03, 06:37 PM
Remember, a human mission to Mars may well require 9 months travel time there, 9 months back, and perhaps 9 months on the surface to make it all worthwile. I can't begin to calculate the costs.
Wernher von Braun sized a Mars mission back in 1952, summary here: http://www.astronautix.com/craft/vonn1952.htm
The basic parameters must remain roughly true today. In the von Braun mission:

1000 launches from earth in a reusable vehicle to assemble everything in earth orbit for the mission.
Various non-resusable cargo loads sent independently to Mars.
Return vehicle and payload put in orbit around Mars.
Humans puts onto the surface in a 200 tonne lander, which will then take off again to join their return vehicle.

It is all completely beyond belief as something that is realistic to attempt for within the foreseeable future trajectory of technology. We have enough problems operating the space shuttle on earth to imagine we could do something similar from the Martian surface without any ground crew to leave behind. The cost of achieving the above is so unsupportable in any kind of future until we develop entirely new, massively cheaper, ways of getting large payloads into space. Such developments would require advances in science and technology so large that they would be indistinguishable from magic to present day people (to make the famous quote). So it's centuries, not decades, away.

aurora
2007-Jul-03, 09:10 PM
Just an oddity that in the time we've been on Mars humans could have sent a mission, walked farther (much farther), returned the samples for more analysis, and returned themselves.


Well, the robots can last a lot longer. So they can gather and return data for years, as these two rovers have so adequately demonstrated.

It isn't as important that they move quickly, if they can last a long time.

Noclevername
2007-Jul-03, 09:22 PM
Wernher von Braun sized a Mars mission back in 1952, summary here: http://www.astronautix.com/craft/vonn1952.htm
The basic parameters must remain roughly true today. In the von Braun mission:

1000 launches from earth in a reusable vehicle to assemble everything in earth orbit for the mission.
Various non-resusable cargo loads sent independently to Mars.
Return vehicle and payload put in orbit around Mars.
Humans puts onto the surface in a 200 tonne lander, which will then take off again to join their return vehicle.

It is all completely beyond belief as something that is realistic to attempt for within the foreseeable future trajectory of technology. We have enough problems operating the space shuttle on earth to imagine we could do something similar from the Martian surface without any ground crew to leave behind. The cost of achieving the above is so unsupportable in any kind of future until we develop entirely new, massively cheaper, ways of getting large payloads into space. Such developments would require advances in science and technology so large that they would be indistinguishable from magic to present day people (to make the famous quote). So it's centuries, not decades, away.


It's currently being planned with present and near-future technology. A lot of engineering is involved, but no magic. There are many other scenarios for a returnable manned Mars mission besides the Von Braun one you describe. For example, why 1000 launches? Why a reusable (expensive) cargo launcher?


The basic parameters must remain roughly true today.

Why not use different parameters?

crosscountry
2007-Jul-04, 08:30 AM
Why not use different parameters?



Because Mars is still dangerous and the same distance as before.



the only thing we can change is technology, the parameters don't go anywhere.

Ivan Viehoff
2007-Jul-04, 11:27 AM
There are many other scenarios for a returnable manned Mars mission besides the Von Braun one you describe.
Do you have references for them so I can see if they differ in the essentials from what von Braun said?

The basic problem is this.
(1) You need to get onto the Martian surface an object that can lift off and put into Martian orbit all the people you put there in the first place, which includes enough people to prepare and operate this launcher. Since this is Mars with high gravity and an atmosphere, this is not the the small lunar VTOL lander we put on the moon, it is a large air/spacecraft.
(2) You need to have in Martian orbit enough payload to contain a vehicle and fuel to take everyone back home (unless they are suicide scientists). The take-off vehicle will lift off from Mars and meet it and transfer the people to the return vehicle. (The alternative is to put everything on the surface, but that is obviously even harder).
(3) You need to get all of the above to Mars in the first place.
(4) Since all of the above, together with the fuel to move it, is far too large to launch in one go off the earth, you have to take it up in pieces into earth orbit, where you assemble it.

That much was obvious to me before I knew of the von Braun estimate.

Sure we quibble with von Braun's details. But as an order of magnitude estimate of what the basic parameters are, can you actually present something that shows he was way out?

crosscountry
2007-Jul-05, 05:53 PM
Do you have references for them so I can see if they differ in the essentials from what von Braun said?

The basic problem is this.
(1) You need to get onto the Martian surface an object that can lift off and put into Martian orbit all the people you put there in the first place, which includes enough people to prepare and operate this launcher. Since this is Mars with high gravity and an atmosphere, this is not the the small lunar VTOL lander we put on the moon, it is a large air/spacecraft.
(2) You need to have in Martian orbit enough payload to contain a vehicle and fuel to take everyone back home (unless they are suicide scientists). The take-off vehicle will lift off from Mars and meet it and transfer the people to the return vehicle. (The alternative is to put everything on the surface, but that is obviously even harder).
(3) You need to get all of the above to Mars in the first place.
(4) Since all of the above, together with the fuel to move it, is far too large to launch in one go off the earth, you have to take it up in pieces into earth orbit, where you assemble it.

That much was obvious to me before I knew of the von Braun estimate.

Sure we quibble with von Braun's details. But as an order of magnitude estimate of what the basic parameters are, can you actually present something that shows he was way out?


sure, all those things are true... well if we cannot make fuel on Mars. Also the astronauts can leave mars with much less than they came since they have to dock with a mother ship anyway.

lastly the return mother ship could leave in advance and be parked in Martian orbit long before the astronauts ever leave earth. That saves trying to take two loads of fuel at one time in effect saving tons of fuel.


the astronauts could dock with the return mother ship before landing to make sure of proper orbit. Also supplies could be picked up at that time for landing.

there are many ways to simplify things.