While remaining steadfast in their belief that the Beagle 2 lander survived its journey to Mars, project officials said this morning that the best shot at hearing from the craft won't occur before January 4.

Multiple attempts to detect signals from the lander using NASA's Mars Odyssey spacecraft orbiting the planet and the Jodrell Bank radio telescope in England have been unsuccessful since Beagle's Christmas morning touchdown.

"Odyssey and Jodrell Bank were not our primary communications routes," Colin Pillinger, the Beagle 2 lead scientist, told reporters at a news conference today. "The difficulty with using Odyssey and Jodrell is we can only search for Beagle at the times which have already been predicted that Beagle is able to talk to the spacecraft or could be on-air so that the telescope could look for it."

Future hopes are pinned on January 4 when two events are scheduled to occur -- the lander is expected to begin a new signal transmission mode and the Mars Express orbiter arrives on scene.

"We need to get Beagle 2 into a period when it can broadcast for a much longer period. This will happen around the 4th of January after the spacecraft has experienced a sufficient number of communication failures to switch to automatic transmission mode," Pillinger said.

"What we now are hoping to do, and what we (believe) is the best chance for communication with Mars, is to wait until Mars Express is available for use. Mars Express is, afterall, our primary route of communication -- it is the one that we spent the most of our time over the past three or four years testing. So we have to consider it the best way of talking to Beagle 2."

Mars Express carried Beagle on the seven-month cruise from Earth to the Red Planet before deploying the lander last week for a six-day solo trek to the Martian surface. The communications compatibility between the two craft was tested prior to launch -- unlike the Odyssey and Jodrell links that were never rehearsed.

Mars Express successfully entered Martian orbit on Christmas. But it is currently in an extremely elongated orbit that carries the probe well away from the planet. It will perform an engine firing next week to reach a much tighter orbit around Mars -- and then it can begin searching for Beagle.

"Mars Express is on a long pass well out into deep space. The reason we are doing that is to get away from Mars gravity in order to change the orbit. At the moment, we are in the equatorial plane of Mars, and we go very far way in order to turn the orbit into being over the poles of Mars," explained David Southwood, director of science for the European Space Agency.

"We have to take this long trip out into space to do this maneuver....That is the reason, in fact, that we have to wait until Mars Express is in the right place (to communicate with Beagle).

"We always knew this would be a very difficult wait, knowing that Beagle was down on the surface and that we couldn't use our regular communications system -- a communications system that has been planned all along. So Colin and his people put in place the alternatives that we have been trying -- the cooperation with the Americans to use the Mars Odyssey spacecraft as a communications link and using the big ground-based telescope, Jodrell Bank, in Cheshire, England. These are so-to-speak backups but they were there because we were aware that the media, and indeed everybody, would want to know as soon as possible how Beagle was.

"The procedures next are on the 30th of December, Mars Express will get as far as it's going to get from Mars and that is when we will fire the motors to put us into the polar orbit that will bring us back, much better able to survey the surface of Mars....The first time that we will be back at Mars is January 4, sometime in the morning around 10 o'clock, and then will be our first opportunity to really communicate with Beagle the way we expected. That is going to be something we all are working toward in our side of the house to make sure everything is set and we have done everything possible to listen to Beagle then."

Southwood was asked by a reporter how confident he was that a Beagle signal would be received by Mars Express on January 4.

"It is a very hard question. Clearly, I would feel so much more confident if we've got a signal now. I don't actually really want to put a number on it except that we haven't played all of our cards and we will then be using a system (the Mars Express-Beagle link) we absolutely know, having been tested and we fully understand.

"Let's put it the other way. If we don't get signals next week, then I will be really worried. At the moment, I am frustrated rather than worried. At the moment, it's a problem of just knowing I've got to wait a few more days...But I certainly haven't written off Beagle at this point in time, none of the team has."

As the next days pass while waiting for Mars Express to become available for Beagle, engineers and scientists are devising options to send commands to the lander to resolve potential problems that could explain the lack of signals to date. The first occurred on the recent Odyssey overflight when "blind commands" were sent to instruct Beagle to reset its onboard clock. Officials had thought that possibly Beagle's clock was bumped out of sync, thereby causing the lander to miss the pre-programmed communications sessions.

It is not known whether Beagle received the clock reset command, officials said.

Other options being examined include telling the lander to re-start the solar array deployment sequence in case the panels are stuck in a partially-unfurled position, which could block its transmitting antenna.

"What we are going to do until January 4 is to try and look at some other possibilities that we might be able to achieve with Jodrell and Odyssey," Pillinger said. "But really and truly we are waiting for January 4 for a really big attempt with Mars Express."

The radio telescope at Stanford University in the U.S. will be used starting tonight, adding more search time and greater sensitivity to hear Beagle 100 million miles away. And officials said that other radio telescopes around the world have expressed support in joining the hunt if needed.

Meanwhile, Southwood reported that the Mars Express orbiter is working just fine.

"Mars Express -- so far, so good. Everything has gone well with the mothership. The baby we believe is down on the surface, and the mother is very anxious to get in touch with the baby again."

The orbiter mission will go on with or without Beagle, spending a couple of years studying the geology of Mars and looking for clues about past water on the planet. But no one is ready to give up on Beagle.

"We want the icing on the cake. We want the full mission," Southwood said.