CNN had been given an exclusive interview with the senior officials who run it, though the front door is as close as we're permitted to get.
Just weeks before a major national holiday widely thought to be a target date for the reclusive nation's first rocket and satellite blast-off in nearly three years, two senior directors of the National Aeronautical Development Association (NADA) tell us a launch is "imminent" and final preparations are underway to send rockets and "multiple satellites" into space.
They insist their purpose is peaceful space exploration. The scientists also express "outrage" at ongoing speculation they are secretly operating a ballistic missile development program.
We park on the street nearby, a main thoroughfare busy with vehicle and bicycle traffic, and walk up a small hill to the General Satellite Control Center. We pass two separate guard posts, where our identities are carefully checked against a list of approved visitors. Arranging access for a foreign news crew was exceedingly difficult, we are told, as there is great suspicion about the motives of reporters from "hostile" nations. The government says we're the first outside media allowed inside the complex.
But the two checkpoints are all the security we see -- no heavy barriers, no barbed wire or visible armed presence. It all seems very low key for access to what North Korea calls the heart of its supreme leader Kim Jong Un's ambitious plan to make his country a space superpower. Some international observers have speculated the satellite control center is actually a military facility, but its appearance, at least on the surface, suggests otherwise.
We're greeted by two of the program's top scientists dressed in smart, newly designed uniforms, a row of brass buttons down the front of their jackets, and a smart military cap.
On the left side of their jackets they wear a red pin with the portraits of the two former leaders Kim Il Sung and his son Kim Jong Il, on the other, the logo of NADA. Both the acronym and the logo bear a striking similarity to those of NASA, its counterpart in the land of its great enemy the United States.
Hyon Gwang Il is the director of scientific development at NADA, and Kim Gun Song is in charge of the Satellite Control Center.
The facility was inspected in May by the Supreme Leader himself, an event marked by a plaque on the front of the building. Plaques are posted at all sites visited by Kim, who is often seen on state-controlled media conducting "field inspections" across the country.
"Following the instructions of Marshall Kim Jong Un we scientists here are working very hard, you can't imagine how hard, to develop in the shortest possible time, multi-functional, highly reliable Earth observation satellites. We are trying to show to the world how patriotic we are and how creative we are as scientists," Hyon said.
Parking lot meeting
Instead of going into the building, the scientists suggest we sit down in the mostly empty parking lot in front of the main building where tables, chairs, and bottles of water are laid out. It's a warm day and the sun is blazing, but the air-conditioned interior of the building is off limits to us. They invite two other scientists to join the conversation, which lasted more than one hour and revealed insights into the passion and motivation of these North Korean scientists.
We asked what's been happening at NADA headquarters in recent weeks, and asked if a satellite launch is imminent.
"In recent weeks we have been making a lot of progress in many different areas. We are updating our satellite launch site in order to carry a better satellite on a more reliable basis. Finally we have finished the work of perfecting the control system of launching the satellites into outer space. And again we have nearly finished our important work of controlling the satellites which would be launched into orbit," Hyon said.
The scientists tell us NADA has prepared multiple satellites and they are in the "final stages of perfecting all operations." One particular area of focus is interlocking the satellite orbit with other systems.
After an embarrassing failure early in 2012 -- a previous rocket had blown up just after takeoff in April -- they claimed to have placed Kwangmyongsong 3-2, an Earth observation satellite, in orbit in December. But most outside observers stated the device had been placed into a wobbly Earth orbit, unable to transmit information, essentially becoming "space junk."
The scientists tell us the KMS 3-2 satellite was functional earlier this year, while acknowledging "problems with communication and data transmission."
The secretive state had claimed two previous satellite successes in 1998 and 2009, though no one outside of the country was ever able to detect them.
The scientists claim they have learned from those previous launches and their technology is constantly improving. They insist their work not a threat to opposing nations, most notably the U.S.
"The satellites we are going to launch imminently are Earth observation satellites. We believe those satellites will be of much benefit to the national economy in general and improving the people's living standards in particular," said Kim Gun Song.
Space power dream
There's been much speculation internationally that NADA will carry out its next launch in the coming weeks. Scientists would not reveal a specific launch date or timeframe, saying there are a variety of factors that must align before a launch occurs. However, they did claim the launch is "imminent."
"We have got our own schedule we have got our own program of launching our peaceful satellites. We have achieved some good progress in our work," Hyon said. "Our ultimate goal is to turn the DPRK into a major space power."
The scientists say they're not aiming to launch satellites on any particular date, despite the hype surrounding the upcoming Party Foundation Day on October 10. A countdown sign to the major national anniversary is posted at NADA's front gate.
"I think what is very wrong about those people when they try to understand the DPRK's space program is that they seem to think that we are about to launch a satellite on a particular festival day, on a particular anniversary or on a major holiday. The launch of a satellite itself, it's a very hard and difficult procedure. It's a concentration of all important elements of science and technology, specially cutting edge science. This important scientific work is not something that you must implement on a particular day," Hyon added.
Hyon acknowledged that Americans and others around the world may be concerned about the upcoming launch but said those fears are not justified.
"Why on Earth would we have any intention to drop nuclear missiles on the heads of people throughout the world, including of course the people of the United States?"
But just this month, North Korea's own state media said it's "fully ready" to use nuclear weapons "at any time." That bombastic rhetoric triggered a harsh warning from U.S. Secretary of State John Kerry.
Kerry warned of "severe consequences"
if North Korea does not refrain from "its irresponsible provocations that aggravate regional concerns."
North Korea is already under severe sanctions for its nuclear program. But the cash-strapped country continues investing heavily in its space agency, even as wealthier nations cut back.
Scientists get perks like special housing and their own vacation resort -- even as their nation faces food and electricity shortages.
"Our will and determination will not change," Hyon said. "Our space program, especially our satellite launches, are not diplomatic bargains, they should not be seen as diplomatic leverage."
The scientists pledged to continue what they call "important scientific and technological work," that they claim will improve the living standards of North Korea's 24 million citizens.
The U.N. World Food Program says 18 million North Koreans -- 70% of the population -- are "food insecure," or highly vulnerable to food shortages.
Threats of imminent war and nuclear destruction are aimed at the U.S. from North Korea all the time. Many analysts believe North Korea could well possess a nuclear weapon capable of being mounted on a missile and able to reach some parts of the U.S. But they continue to doubt its reliability and accuracy.
North Korea certainly does have a missile development program. It has been producing its own short and medium range ballistic missiles since the 1980s. It now claims to have perfected intercontinental ballistic missiles, able to reach as far as the mainland United States.
But is the satellite program genuine or merely a cover for a military program? Both use similar rocket technology. And why else would an impoverished country like North Korea spend so much on what some would call an unaffordable luxury? It is a question these exasperated scientists are tired of hearing.
They say their new facility features a meeting room where international scientists can sit down together and talk about space programs. They've even constructed a press center for international journalists to work. But both sit empty, as the scientists and their work remain isolated. Hostilities between the regime and much of the outside world severely limits communication and travel to and from the isolated nation, greatly restricting their ability to share information with outside scientists.
"We are developing satellite technology, we are exploring outer space, not because we are in a very good position, well off economically. We still have a lot of economic problems. Even today we are tightening our belts to survive and to improve. All the same, we are investing a lot into this space program. We will continue, regardless of what people say," said Kim Gun Song.
He said the "real threat" is from the United States and other world powers, which have huge budgets and the ability to use outer space for military purposes.
One thing is clear: North Korea is determined to catch up in the space race, encouraging scientists to work feverishly.