Seamus McLaughlin, 35, and 37-year-old Gary McDaid are accused of conspiring to cause explosions, possession of mortars and a pipebomb, and possession of a van for terrorist purposes.
Senior police say they prevented "mass fatalities" when the bombs were found inside a van on Sunday night, just minutes before they were due to be launched at Derry's Strand Road station.
Creggan men McLaughlin, from Eastway and McDaid, of Glenowen Park, were arrested at the scene after police intercepted a van and motorbike.
Inside the white Citroen Berlingo van, police uncovered four mortar bombs, which contained a substantial amount of explosives.
The bombs were ready to be fired through a hole cut in the van's roof. Two timer devices with toggle switches marked A and B had been placed inside a plastic lunchbox.
A mobile phone, described by police as a dissident republican "operational phone" was seized from the dashboard of the van.
A bomb had also been attached to a petrol container, and police believe the device would have been used to destroy any forensic evidence within the van once the mortars were fired.
At Londonderry Magistrates' Court on Wednesday, the two defendants smiled and waved at supporters who had packed the courthouse.
The court heard that McLaughlin, who was driving the van, was wearing rubber gloves and several layers of clothing when he was arrested.
District Judge Barney McElholm described the accused's purpose as "nefarious insofar as he had gloves on and forensic covers over his shoes".
McDaid had two crash helmets for the motorbike, which police believe was to be used as a getaway vehicle.
He was stopped close to the van after being spotted driving erratically with the lights off. McDaid told police he had been on his way to get petrol, despite having no cash. Then he said the second helmet was for his drug dealer.
There is a very, very strong circumstantial case that both were involved in something extremely serious.
Detective Constable Funston said both men had been subjected to extensive interviews at Antrim Serious Crime Suite, and McLaughlin refused to speak.
She objected to bail, describing both men as "active and prominent members of a dissident republican grouping".
"Police have serious concerns that if released on bail they would re-engage with other dissident republicans in order to continue on with their murderous and cowardly campaign targeting police, prison officers and security forces.
"Given the serious nature of the offences, police have serious concerns they would not answer bail or appear for their potential trial," she added.
But a solicitor for McDaid said there was no forensic evidence linking his client to the alleged offences. He said his client still lives with his mother and has strong links to the city.
"He has lived in Derry all his life. He has no ties outside the jurisdiction. That would negate against any flight risk," explained Dermot Walker.
Paddy McDermott, speaking on behalf of McLaughlin, requested bail because of the considerable time before any trial comes before the court.
"He will comply with any conditions," he said.
However, District Judge Barney McElholm said there was a real risk the men would leave the jurisdiction if released on bail.
"The fear of further offences is a very real one. People who are committed to these sorts of mindless, pointless terrorism which is going to achieve absolutely nothing are hell-bent on pursuing that activity. They cause needless suffering to families.
"People who are that way inclined are not likely to give up their activities
"On those grounds bail is refused. Both are remanded in custody," he said.
They are due to appear again later this month.