The government developed the technology to create a portal that connects our universe with another universe, in which the laws of physics were slightly different, unknown to the government this had resulted in an almost identical world, except a small change in the nature of gravity has resulted in all the macroscopic phenomena being scaled up by a factor of 200, hence their is another earth filled with a society very similar to our own, although not quite as advanced, however this earth has a radius 200 times large, and instead of people being about 1.8 meters tall, they're about 360 meters tall. On the other hand all the microscopic phenomena are pretty much identical, atoms, molecules and even cells are the same size, and behave in the same way. Overall if you where to switch the minds of someone in this world with someone from our own neither would even realize they were in a different universe until hey had cause to observe the relative scale of microscopic phenomena. But the government doesn't yet know anything about where the portal opens, other than that it reliably opens in the same location, just above a flat surface, with a 1g gravitational field. Attempts to send through a drone however failed with the drone being destroyed by the portal, however a solution has been finally found animal based organic matter can pass through safely given its part of a living animal, further other matter that is fully contained with in a living animal is protected from the damaging effect of the portal. Hence the only way to explore this new location is to send people through but their are several problem with this they can't carry any thing externally on their bodies not even clothing, and they have no idea what the environment is where the portal opens. But this dosen't stop the government they come up with the solution of augmentation, using top secret technology they are able to make volunteers virtually indestructible using a nanite base implant computer, and several special organs to produce several types of nanites, including combat nantie for the immune system, repair nanite to repair any damage, etc. along with generic modification to make their skin tougher and bones stronger. These augmented people could survive and entire skyscraper falling on them, or being submerged in a pool of boiling Hydrofluoric acid for an entire week, they could sit inside a nuclear reactor with out worrying about the heat or radiation, and lounge in the arctic with out worrying about the cold. But the best upgrade of all is a cold fusion generator which can generate power by fusing 4 x H-1 in to He-4 as a direct reaction, and second one able to carry out the alpha ladder and triple alpha fusion, this allows them to extract hydrogen from water, ammonia, and hydrocarbons for provider for all their bodies energy needs, allowing them to even survive exposure to vacuum, with a supply of a mere milligram of water a week. The problem with the augmentation process is it will kill anyone over the age of 19. But once augmented said person would be indestructible even to the unknown giants in the other world. Given the danger of the mission it was decide to seek out pairs of volunteers aged 16 to 19, who were in a committed relationship, to avoid possible problem from isolation on their mission. These teams would be sent through the portal to one of several identified locations the portal would be opened again up to 12 times every 744 hours at the same location for them to return, and keep open each time for 1 minute only as they didn't want to risk something unexpected coming through the volunteers implant computers would keep tract of the location and when the next opening would be, any team that missed 12 check-ins would be assumed lost and no further recovery attempts made, if all the teams failure to make their check-ins the project would be abandoned and the portal destroyed.
The only question that remains is just who the teams will be, where they come out and what would happen to them in this strange world were they were completely indestructible yet the size of Lego figurines compare to the Giants of this new world, and thus also unable to do anything to effectively harm them either, but remain completely at their mercy owing to their tiny size.