An alien race decides to test the hability of humans to survive and engage into space travel, for whatever reason.

The planets

The aliens prepares a pair of Earth-like planets revolving around a common center of mass around a Sun-like star. The planets are very similar to Earth in mass, size and composition, and revolves around their common center of mass in almost-circular orbits, with a diamater that is twice the distance between Earth and Moon. They are not tidally locked one to the other. Lets call those planets Old Paradise and New Paradise.

Both planets are similar, and features plentiful food sources and fresh water readily usable for humans. The air is fresh. They also features a lot of natural mineral resources. The planet is covered by seas, grasslands and forests. It has plenty and diverse fauna and flora. However, dangerous or toxic bacteria and virus are absent. There is also no poisonous plants or animals. No animal or microorganism is able to live as an human parasite. No animal is more dangerous than what a dog would be. Those planets are almost like a paradise.

There are some glaciers, volcanos, deserts and very high mountains also on the planets, but those are very far from the equatorial grasslands. The climate is milder and more reliable than what is found on Earth, but there is still some danger from heavy rains, floods, landslides, lightnings and mineral toxicity. Earthquakes, tsunamis, tornados and typhoons are rare, much rarer than what happens in Earth, but they are still present and might happen occasionally.

The humans

The humans used in the experiment all speaks the same language. They are numbered in 100 millions. Those humans are men and women with Einstein-like intelligence, all very healthy, both physically and mentally, and aged in their mid-20s. They are also perfectly able to have children which would also be able to have children and so on.

Those people are scientists and engineers. They also feature genetic resistance against old-age illness, like pulmonary, brain or hearth diseases and cancers. Since there is no biologically pathogen available, this means that they would not naturally die before they lived beyond their 80s or 90s. However, even if nature is more forgiving than what happens in Earth, people still might die from falling off a cliff, drowning in the sea, being crushed in a cave or mine collapse, being poisoned by ingesting some dangerous mineral, being eletrocutted by incorrectly handling some machine and so on.

Many of those people have deep knowledge in physics, chemistry, math, biology, medicine, geology, engineering, economy, logistics, robotics, etc., each one to his/her own expertise. Those humans, collectivelly possesses the knowledge of everything relevant for them that humanity knows in 2015. I.E, there are a lot of people who know about how to create and study graphene and electronics, but they might not know or care about what would be the last musical hit here on Earth or what are the most recent memes being shared in facebook.

The objective

Are you curious why the planets are names Old Paradise and New Paradise? Well, first because those planets are like paradises. Second, because the aliens warned them that in 60 years, a huge bollide will strike Old Paradise and kill whoever is left there, transforming it in an inhospitable wasteland with unbreatable air, lava lakes and boiling acidic seas. All the 100 millions humans are then settled in an area of Old Paradise called Eden (more on that below). Their only hope is to be able to evacuate everyone to New Paradise, which will be spared and sustain human life for some more millions or billions years.

Those people are very smart and they all know that they must work together the best to be able to leave Old Paradise ASAP. Also they all have a deep desire to survive and to be able to successfully evacuate this planet on time. This makes those people all very willing to cooperate and survive, and are very altruistic one to the other. They are also workaholic. This also means that they are really interested in not wasting time and energy with wars, crimes, greed, disputes over natural resources, endless debates about politics, making money only for the sake of making more money, dedicating their knowledge to frivolous and uneeded purposes or to anything that may distract or divert them from their evacuation objective. However they might still be interested in playing games, have parties and have fun in order to enjoy their lifes and not getting too tired or depressed. On the other hand, since they know that Old Paradise is going to be destroyed and should be evacuated ASAP, there is little to no need to concern about environment and natural resources preservation or about pollution.

The Eden

The people are initially distributed in an area called Eden in Old Paradise, which features some grasslands, meadows, rivers, beaches, small mountains and small forests within a radius of something like 1500 km. This way, those people would be able to eventually contact everyone quickly enough while also being able to take food and water from the nature.

Initially, the aliens left everyone in the planet completely naked, barefoot and barehand, and there isn't anything artificial human-made or alien-made provided for them. All of what they can start to work out are plants, animals, stones, water, soil and rocks.

Also, in order to properly answer this question, you might also add watever animal, vegetal or mineral resources are present in Old Paradise, especially in the Eden area, as long as you don't add something that is not likely to be a creation of nature.

The question

Now the question: Is it possible that they might succeed to evacuate Old Paradise and sucessfully settle New Paradise with a minimal human life loss?

The humans have full knowledge of our current digital-age technology but are left only with stone age technology available. Are they able to bring everyone to New Paradise via space travel in 60 years, or they are all doomed to die when Old Paradise becomes a hell overnight?

Further, how would their technology evolve in the mean time from being naked with barehands and barefoot to achieving hability to perform mass-scale space travel?

If in the given scenario, they are simply unlikely to be able to reach their objectives in time, what are the minimal set of changes needed that would make at least something plausible that they would be able to leave Old Paradise en masse?