Jodrell Bank Telescope Gets No Signal From Beagle

tipiyano writes "Continuing the story of Beagle 2 from earlier today it seems like the hope for Beagle 2 surviving the landing at Mars is reducing as the Jodrell Bank telescope didn't receive any signal from Beagle. In the words of a mission manager, 'I wasn't too worried about the missed link with Odyssey, but it starts getting serious if Jodrell Bank cannot get a signal either'."

Re:When wil they learn?

[applemasker]

Try 1 for 1, not counting Beagle or the current Spirit and Opportunity probes.

The other failures did not involve airbags - Mars Observer was an orbiter that went silent some kind of problem with the thrusters is suspected to be the cause, but we'll never know for sure; Mars Climate Orbiter got crispy over the metric/imperial units mixup during aerobraking/orbit insertion; and Mars Polar Lander did, in fact, attempt a Viking-like powered descent and it's theorized that when the landing legs deployed and locked, they incorrectly signaled the guidance system that the craft had landed, and the engine cut off too early, and it fell from a height of some 50m.

Next time, test it first!

[mekkab]

From This guy from MetaFilter [metafilter.com]: It probably will fail.

The balloons used to cushion the fall were never tested. The original balloons failed testing and they didn't have time to test the replacements.


Wow! Sounds like the way to run a space program.

5 watts...Crazy

[MrFreezeBU]

From the article, Beagle is only broadcasting a 5 watt signal. Quick calculation..5 watts power output with a free space path loss of ~200db means that the amount of power reaching the Lovell dish is roughly 1/5x10^-66 of a watt.. I'm blown away that they are able to pick that out of the backgound noise at all.

Links
Free Space path loss [planet.nl]
[huizen.deds.nl]
Nifty WLAN link calculator

Re:Wow...

[jagilbertvt]

ESA not NASA this time...

Re:5 watts...Crazy

[OOGG_THE_CAVEMAN]

OOGG want correct calculation.

5 watt = +7 dBW (dB REFERRED WATT. 0 dBW BE 1 WATT)

200 dB PATH LOSS reduce power -193 dBW.

= 5 * 10^-20 WATT.

OOGG NOT FIND GOOD INFO ON ANTENNA, FREQUENCY OF BEAGLE RF. NO FREQUENCY INFO MEAN OOGG NOT CHECK FREE SPACE LOSS CALCULATION)

Re:5 watts...Crazy

[Kyro]

from the Beagle2 [beagle2.com] site:

Communication frequency:

Forward (Earth - Mars): 437MHz

Return (Mars - Earth) 401MHz

Re:Next time, test it first!

[fname]

OK, I found a reference [bbc.co.uk] to this at the BBC website. Sounds like they tested them to some degree, but maybe not as much as they would have liked. If that's the case, they probably figured the airbags would work and assigned it a risk rating (baseline/low/low-medium/medium) and continued. Since Mars missions have a very narrow launch window, they likely needed to make a decision whether to delay the mission for 2+ years, or to launch without a complete testing regimen. If that's what happened, it's a tough call, not necessarily an indictment of the program management.

Re:When wil they learn?

[mOoZik]

It's really a weight issue. Beagle 2 is 68 Kilograms. The Viking landers were around 576 Kilograms, around 200 pounds of which was fuel. Beagle 2 was also done on a shoestring budget, which would have made it impossible to build and test custom engines (perhaps hydrazine monopropellant, as used on the Vikings). Furthermore, launch cost would have been increased as a result of the weight, not to mention further complicating the design of the Mars Express, upon which Beagle 2 hitched the ride. Again, we still don't know what happened, so to assume that the lander was damaged due to the bounces is pretty ridiculous. It could have been a million other single-point failures, as the lander had absolutely no redundancy whatsoever.

Re:Suggestion: Venus

[PinkyGigglebrain]

The atmospheric pressure on Mars is about the same as being 21 miles above the surface of Earth, IIRC. At that pressure you are effectivly in a vacume as far as things like humans are concerned.

Venus on the other hand has an atmospheric pressure of about 90ATM, or aprox. 1305LPS per square inch, thats more pressure than being under 2900 feet of water. Making a probe that can withstand that is not difficult, we do it all the time in marine exploration. The killer is the heat, once the probe is on the surface it starts to heat up to the 400C of the surounding air, the solder melts, resisters change values, basicly the probe gets roasted. The Russian probes that made it to the surface had been cooled to well below 0C before they where dropped. No cooling system yet devised can maintain a 400C tempature differance, all cooling works by "pumping heat" from one place to the next.

As pointed out the upper atmospher of Venus is much cooler, a simple hot air baloon could stay aloft for months if it had a nuclear heater to keep it floating.

Re:When wil they learn?

[golgotha007]

I speculate they're heavy and they're complicated, but they seemed to work pretty well on the Vikings and the Russian-built Venera.

the Venera project by the Soviets was used for landings on Venus by method of protective hemispheric shells, three parachutes, a disk-shaped drag brake, and a compressible, metal, doughnut-shaped, landing cushion.

Venera didn't use retro rocket thrusters.

Oi you git! Beagle 2 is British!

[reality-bytes]

Thanks a lot matey, we'll remember that - Try to remember that the Beagle 2 is British and the British are Europeans.