In the first episode of Terra Nova, it's mentioned that Terra Nova is able to communicate with the future. However, it was established earlier that going through the time schism is a one-way trip, and that you go to the past of a parallel Earth. So they shouldn't be able to send messages back through, nor can they leave time capsules with messages inside to communicate with the future. So how are they able to send messages back to the future?
The IMBD FAQ page for Terra Nova has the following -
How can the commander communicate with the alternate 2149 if it's a one way portal and in a different timeline?
According to creator Craig Silverstein, the commander can communicate with the people in 2149 only while the portal is open . Only while it is open can he order more supplies, communicate info back and forth. The main drawback with this is that if he orders medical supplies, he has to wait till the next opening to get them.
(So, does this mean the trip isn't really 'one-way'?)
It's a massive plot hole.
There's no way for them to know.
Even if they did have some sort of inter-dimensional communication device that was time delivered 85 million years later -- there is no way to tell the future that was what they needed and have it sent back to Terra Nova in the first place so they can set it up.
In fact, there is no way for the future to even know where/when these probes and people are being sent.
Essentially, the first team had to have been sent over blind. But there's no way for them to tell anyone what they found and what supplies they need because it was a one-way ticket.
So, every single transport sent over was sent over not knowing what was on the other side of the rift, if anything at all. In fact, they can't even be sure they weren't sending these people into a rift that simply killed them.
There is no reason the temporal anomaly could not transmit radio waves back and forth across the cross-time region. This could potentially explain how communication is done in a fashion similar to radio transmissions across wormhole horizons in the Stargate franchise. Energy would not have the same limitations matter would have crossing between universes.
Please notice the way they discovered --the so called-- "Terra Nova":
First they lost the discovery satellite, then they followed up the signals and they then determined that where their satellite landed (or crashed) was not a different planet, but the earth in past (but in different time stream).
That means that the anomaly through which this satellite passed is permanent, so they can track down signals from it.
In my humble opinion, that explains everything.
Also, as shown in the last episode, Mira has a communication device and she receives commands from her peers in future.
Don't be silly. The two parties, the future and the past can easily agree on scribbling something on some stones or, more probable, some techy solution they have in Terra Nova, and the recipients (the future) could read/watch it. So, ask a question on a (metaphorical) stone, get a reply back with the next recruit.
I was asking the same question too. Perhaps it could be like the time rift in Julian May's Pliocene Saga. In those books, people can pass through a rift in time to 6 million years earlier safely but they cannot return; if they stay in the time rift when it "recycles" they return to their present and take on an age of 6 million years and rematerialize as fossils or ash. Some substances like amber and platinum can be sent back without being destroyed. Perhaps this could be the same idea behind the Terra Nova portal?
There's no reason to assume the anomaly itself does not allow bidirectional travel. When the portal to the past was shown in the pilot, it was in a building with two extremely large circular buildings on either side of the portal building, giving the impression it was between two cyclotrons or something similar.
There were one or two comments that indicated the original anomaly itself was small and the implication is that it takes massive amounts of energy to open the gateway so people can be sent through (and note they are sent through one at a time, indicating there are either safety issues or that the more mass that goes through, the more of a strain on the system it is).
So there's no reason to assume it takes high amounts of energy to access the anomaly, it just takes high amounts of energy to send large chunks of matter through it. So radio waves and possibly even tiny pieces of media might be quite feasible for Terra Nova to send back to the future in the timestream from which they came.
(But that also raises the question -- just as there was originally only two stargates, but eventually it was found the original gate could access other gates, is it possible that one could access other timestreams through that same anomaly?)