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ExoMars lander

Okay, sounds like the signal lost was an experimental one and wasn't intended to be the primary method of determining whether the craft has been lost or not. That will come later. Hard to find out when exactly....
 
I wouldn't call it yet, but it doesn't look good.

Earth-based ground stations and Mars Express have not detected a signal from the lander. MRO should be able to detect the lander's transmitter, but it should take a couple of hours to acquire and read the signal.

On the other hand, there was a similar problem with the orbiter after the lander was launched. However, that passed and the last I heard was that the orbiter was in communication.

The lander runs entirely on battery power so it has a projected lifespan of a few days.
 
Seems that the signal was lost before it landed. Not looking good. They hope to know what went wrong by the morning.
 
The good news here is that the orbiter (TGO) seems to have hit its capture orbit successfully. The spacecraft carries by far the more important science payloads. The loss of the lander isn't that big a deal in terms of the science objectives. The bad news is that it was supposed to be a demonstration vehicle for the EDL (entry, descent and landing) of the 2020 rover. :( Hopefully much can be learned even from the failed attempt.

Pixel42 said:
They hope to know what went wrong by the morning.
Click to expand...

I understand that TGO will provide some additional telemetry from the lander in a little while.
 
Thank you for that clarification. I should have provided that to begin with but was in a bit of a rush and left it out. But yeah, even if the lander is lost, much science can still be done with the orbiter. Much like Philae.
 
I red that the lander is mostly Russian-made. Recent developments made me hugely skeptical of Russian technology - they can't even make a reliable ICBM any more, their newest Bulava missiles have a failure rate in excess of 50%, mostly due to poor quality control. Given the overall levels of hysteria coming from Russia lately I would say their space program is, if anything, worse.

Something can be learned from it immediately: don't rely on Russians for landers.

I hope the satellite works perfectly.

McHrozni
 
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This morning's report indicates that the heat shield worked well, the parachutes deployed, and there was controlled flight by the parachutes. However, the probe departed from expectations at the time when the parachute release was supposed to happen. A landing burn occurred, but was much much shorter than it should have been.
 
RussDill said:
This morning's report indicates that the heat shield worked well, the parachutes deployed, and there was controlled flight by the parachutes. However, the probe departed from expectations at the time when the parachute release was supposed to happen. A landing burn occurred, but was much much shorter than it should have been.
Click to expand...


I would surmise that Mars probably acquired a new crater very shortly after the burn ended!
 
Just a reminder: Landing on Mars is hard. Harder than on the Moon, for instance. The main problem being that there's an atmosphere that's thick enough to be a nuisance, but not thick enough to be useful.
 
elgarak said:
Just a reminder: Landing on Mars is hard. Harder than on the Moon, for instance. The main problem being that there's an atmosphere that's thick enough to be a nuisance, but not thick enough to be useful.
Click to expand...

Landing on Mars is harder than on the Moon, but its atmosphere is very useful indeed.

Yes, the atmosphere is too thin to decelerate a lander sufficiently for a soft touchdown, but spacecraft can shed much of their velocity just using atmospheric drag. The Mars Science Laboratory (Curiosity Rover), a vehicle with a mass of almost 1 ton, lost more than 90% of its velocity using drag and then even more employing parachutes. While even small vehicles, like Schiaparelli, need some retropropulsion for a soft landing, by the time it is employed, they are going very slowly.

Mars' atmosphere means that spacecraft can enter its orbit (using aerobraking) and even land (at least smaller vehicles) on it almost for free in terms of delta-v (a measure of the impulse and thus fuel required in spaceflight). This makes a big difference in how feasible Mars missions are, as less mass (fuel for Mars arrival) needs to be lifted off Earth and injected into transfer orbit to Mars.
 
Pianoro said:
Landing on Mars is harder than on the Moon, but its atmosphere is very useful indeed.
Click to expand...


Yes, Mars' atmosphere is useful in slowing down, but its low density is just enough to cause us to have to use a combination of retro burning, supersonic parachutes and landing thrusters to put a payload on the surface. If Mars had no atmosphere, it would be technically lot easier to land. Sure you would have to carry more fuel for the deceleration phase, but much of that would be made up in not requiring a heat shield or a complex system of ballistic/supersonic parachute deployments. The more complex a system is, the more difficult it is to build, and the more chance there is of something going wrong.

Mars' gravity is under 40% that of the Earth, and only 2.3 times that of the Moon; if Mars had no atmosphere, something as "simple" as the Lunar Module on a larger, stronger scale could land on Mars.

A good article here on the difficulties and limitations (MSL is about as big as we can achieve currently) and how they might be overcome
https://www.wired.com/2011/11/landing-on-mars/
 
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smartcooky said:
Yes, Mars' atmosphere is useful in slowing down, but its low density is just enough to cause us to have to use a combination of retro burning, supersonic parachutes and landing thrusters to put a payload on the surface. If Mars had no atmosphere, it would be technically lot easier to land. Sure you would have to carry more fuel for the deceleration phase, but much of that would be made up in not requiring a heat shield or a complex system of ballistic/supersonic parachute deployments. The more complex a system is, the more difficult it is to build, and the more chance there is of something going wrong.

Mars' gravity is under 40% that of the Earth, and only 2.3 times that of the Moon; if Mars had no atmosphere, something as "simple" as the Lunar Module on a larger, stronger scale could land on Mars.
Click to expand...

Sure, landing on Mars is more complex than landing on the Moon. However, if Mars had no atmosphere, landing, while more simple, would require a lot more fuel. It would take about 6 tons of fuel alone to place 900 kg (mass of Curiosity) from Mars transfer orbit to the surface. That doesn't include the mass of the engines and supporting infrastructure.

MSL's supporting infrastructure (aeroshell, parachutes, skycrane, propulsion, etc.) was only about 2.4 tons.

For a manned mission, these differences become very significant. NASA's current Human Mars Exploration Design Reference places 40 tons on the surface of Mars using a combination of drag and retropropulsion. The supporting infrastructure would be about 70 tons. For an all-propulsion landing 270 tons of fuel would be required, plus engines, supporting infrastructure, etc. In fact, NASA estimates in their design references that an all-propulsion landing would require about 8 tons of total mass for every ton put on the surface.

This doesn't mean that EDL on Mars using atmospheric drag would be easy, but the existence of the atmosphere is also a big advantage for Mars exploration.

Furthermore, a Mars mission that brought enough fuel to shed all its velocity using propulsion would probably not find negotiating the atmosphere particularly difficult. Mars landings are hard, because we are taking advantage of its atmosphere, not just because it is there.
 
McHrozni said:
I red that the lander is mostly Russian-made. Recent developments made me hugely skeptical of Russian technology - they can't even make a reliable ICBM any more, their newest Bulava missiles have a failure rate in excess of 50%, mostly due to poor quality control. Given the overall levels of hysteria coming from Russia lately I would say their space program is, if anything, worse.

Something can be learned from it immediately: don't rely on Russians for landers.

I hope the satellite works perfectly.

McHrozni
Click to expand...

The lander was actually Italian built: https://en.wikipedia.org/wiki/Schiaparelli_EDM_lander

The Russians provided the launcher and a couple of instruments on the TGO. And also the battery for the lander.

Moral of the story? If you are offered a choice between a Lada and a Lamborghini, take the Lada.
 
Well? ... At least there will be more equipment to salvage parts from, next time Matt Damon, gets left behind.
 
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Pianoro said:
Landing on Mars is harder than on the Moon, but its atmosphere is very useful indeed.

Yes, the atmosphere is too thin to decelerate a lander sufficiently for a soft touchdown, but spacecraft can shed much of their velocity just using atmospheric drag. The Mars Science Laboratory (Curiosity Rover), a vehicle with a mass of almost 1 ton, lost more than 90% of its velocity using drag and then even more employing parachutes. While even small vehicles, like Schiaparelli, need some retropropulsion for a soft landing, by the time it is employed, they are going very slowly.

Mars' atmosphere means that spacecraft can enter its orbit (using aerobraking) and even land (at least smaller vehicles) on it almost for free in terms of delta-v (a measure of the impulse and thus fuel required in spaceflight). This makes a big difference in how feasible Mars missions are, as less mass (fuel for Mars arrival) needs to be lifted off Earth and injected into transfer orbit to Mars.
Click to expand...

Yeah, I simplified probably a bit too much for compactness. The point is that there's no single scheme that alone solves the problem. You have to deal with the atmosphere, and can use it to a certain degree, but you still have to employ some other means to get all the way down safely.

The thing that always pops into my mind are the old Wernher von Braun plans for going to Mars. He never bothered to think about the landing too much, because, at the time, it was thought the atmosphere was thick enough to use plane-like wings all the way down.
 
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jonesdave116 said:
The lander was actually Italian built: https://en.wikipedia.org/wiki/Schiaparelli_EDM_lander

The Russians provided the launcher and a couple of instruments on the TGO. And also the battery for the lander.

Moral of the story? If you are offered a choice between a Lada and a Lamborghini, take the Lada.
Click to expand...

Klimax said:
Because it will be much cheaper failure?

:D
Click to expand...
Because for the price of a Lamborghini you can deploy a whole whack of Lada's, and at least one of the Russian boxes will probably work.;)
 
elgarak said:
Yeah, I simplified probably a bit too much for compactness. The point is that there's no single scheme that alone solves the problem. You have to deal with the atmosphere, and can use it to a certain degree, but you still have to employ some other means to get all the way down safely.

The thing that always pops into my mind are the old Wernher von Braun plans for going to Mars. He never bothered to think about the landing too much, because, at the time, it was thought the atmosphere was thick enough to use plane-like wings all the way down.
Click to expand...

So a Twin Otter (DHC6) would be ideal?:D
They've been known to land on Arctic tundra,,,,, runways, runways, we don't need no stinkin' runways.
https://upload.wikimedia.org/wikipedia/commons/2/20/WinAir_De_Havilland_Canada_DHC-6-300_Twin_Otter_Breidenstein.jpg
 
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