Race To Design Atomic-Armed Rockets To Destroy Planet-Killer Asteroids

A White House science advisor recently joined forces with space agency leaders worldwide to devise a planet-saving defense to a massive asteroid determined to be on a precise collision course with Earth: the high-stakes summit was convened in response to a simulated crisis, but as part of preparations for real-life threats to the globe predicted for the future.

Millions of lives were at stake in the simulation, as government heads raced to decide whether or not to rocket nuclear warheads to deflect the asteroid or completely disintegrate it. Physicists and engineers, weapons specialists and aerospace titans were all called on to develop – at lightning speed – spacecraft entrusted to stave off the cosmic strike.

Jan Osburg, a leading American planetary defense expert who helped set up the simulation, tells me in an interview that if a “planet-killer” asteroid or comet is found to be just months away from destroying the Earth, “the best approach is to use a nuclear device – the physics is clear.”

If a 10-kilometer comet or asteroid struck the Earth, it could rival the destructive power of a nuclear war, igniting wildfires that crisscross continents, triggering violent earthquakes and tsunamis, and annihilating most of the planet’s living species.

Yet there is no way to be certain exactly when the next potential “extinction event” collision could appear.

The last asteroid-triggered apocalypse swiftly ended the 150-million-year reign of the mega-dinosaurs and pterosaurs, and a similarly sized comet could be just as catastrophic, Osburg says.

“People say the dinosaurs didn’t have a space program – or astronomers to track asteroids – that’s what killed them,” he muses.

While astronomers at NASA and the European Space Agency have been mapping the giant asteroids that crisscross Earth’s orbit, he says, comets are much more difficult to track and therefore might present a more ominous looming danger.

“Due to their high speed relative to Earth, impactors have a great amount of kinetic energy,” Osburg states in the mesmerizing “Planetary Defense Decisionmaker Guide: What Leaders Around the World Should Know—and What They Can Do—If an Asteroid or Comet Threatens to Hit Earth” that he drafted for the International Academy of Astronautics’ latest Planetary Defense Conference, staged at the UN’s Vienna International Center.

“The energy set free by an impact can be compared to that of a nuclear weapon, and is often measured in the same units (kilotons or megatons of TNT equivalent).”

Comets tend to be larger than asteroids, and have a much higher impact velocity. “Many comets are only detected less than a year before they cross the Earth’s orbit,” he adds, “which would leave little time for comprehensive terrestrial preparedness.”

A 10-kilometer comet or asteroid – rivaling the gargantuan impactor that struck during the Age of the Dinosaurs – might end the short-lived reign of Homo sapiens.

“It is critical to the long-term survival of our civilization to prevent such major impacts,” Osburg says. “This is the task of Planetary Defense.”

Alongside its proposed nuclear-tipped spacecraft, NASA is also exploring gentler asteroid deflection strategies, including the use of “kinetic impactors” or “gravity tractors,” to nudge Near Earth Objects off an impact trajectory with the globe, but these technologies can require years or even decades to deflect an incoming threat, Osburg says.

During the simulated face-off with the asteroid – determined to measure nearly one kilometer in diameter with a 100-percent probability of striking Earth – defense planners mapped out alternate responses, but discovered a kinetic impactor attempt to deflect the threat would require “over 1200 successful launches” to prevent a collision with Earth, Osburg stated in the same guide.

In contrast, he added, just one “successful launch of a nuclear explosive device (NED) would fully deflect the object away from Earth.”

If a more massive cosmic impactor – measuring 5-10 kilometers – were discovered to be on a trajectory to smash into the globe just months into the future, leading planetary defense experts planet-wide say the only chance to save the Earth would be by destroying the threat with powerful nuclear weapons.

That consensus has led the White House, acting in concert with the Department of Defense, NASA and the National Nuclear Security Administration, to formulate an interim Near Earth Object (NEO) strategy and action plan.

“NEOs greater than 140 meters have the potential to inflict severe damage to entire regions or continents,” the White House warned in a report on developing defenses to an incoming asteroid or comet. “Such objects would strike Earth with a minimum energy of over 60 megatons of TNT, which is more than the most powerful nuclear device ever tested.”

While NASA has made progress in tracking the largest asteroids along the periphery of the Earth’s orbit, “There is still some chance that large comets from the outer solar system could appear and impact the Earth with warning times as short as a few months.”

“Multiple technologies may be suitable for preventing NEO impacts that are predicted well in advance,” the White House stated, “while disruption via nuclear explosive device may be the only feasible option for NEOs that are very large or come with short warning time.”

The president called for the development of rapid-response asteroid reconnaissance and “disruption,” or destruction mission plans, and for the launch of demo flights to test these technologies.

In light of U.S. treaty obligations, the presidential directive added, demo mission “spacecraft would contain all systems necessary to carry and safely employ a nuclear explosive device, but would carry a mass simulator with appropriate interfaces in place of an actual nuclear device.”

There are two UN treaties the United States has joined that present complications to launching a spacecraft equipped with nuclear warheads – even one whose sole purpose is saving the peoples of the Earth, and the entire biosphere, from a cataclysmic cosmic impact, says Osburg, who is also a scholar at RAND, one of the top defense think tanks in the U.S.

The Outer Space Treaty of 1967 prohibits stationing nuclear weapons in orbit, or anywhere across the celestial realm, while the Partial Test-Ban Treaty of 1963 prohibits the detonation of nuclear bombs in space.

Yet those treaties were forged to ward off another threat to the human race – a fiery nuclear war between the Cold War superpowers – before astronomers realized the scope of the dangers posed by gigantic asteroids and comets, and before physicists discovered these weapons of mass destruction might be transformed into wondrous deus ex machina saviors of the planet.

Rather than embark on a complicated quest to amend these treaties, Osburg tells me, there appears to be a short-cut to obtaining authorization for a planetary defense sortie with nuclear arms – or tests leading up to an asteroid disruption mission – via the United Nations.

His co-author on a vanguard study outlining the potential to shield the globe from NEO impacts via repurposed atomic arms, Professor Frans von der Dunk, agrees.

One of the leading space law scholars in the U.S., Professor von der Dunk says that notwithstanding the existing treaty bans on lofting atomic weapons into space, the United Nations Security Council could issue a special dispensation for a nuclear-armed mission to protect the planet from an approaching comet or asteroid.

If at least nine of the Security Council’s 15 representatives backed the mission, it could be rapidly launched, with the two nuclear accords remaining in effect.

“If there is a real threat to humanity and civilization by an asteroid,” he tells me in an interview, the nuclear powers that also operate advanced launchers will likely rush to perfect weaponized spacecraft to protect the globe.

The UN Security Council is the right venue to seek authorization for a planetary defense operation that includes nuclear explosive devices, Osburg says, but “we shouldn’t bet on a last-minute approval.”

“Ideally there would be a resolution by the Security Council ahead of time,” he adds, that would preemptively approve the launch of specially designed spacecraft outfitted with multiple warheads to test out their effectiveness against a speeding asteroid – one that does not threaten the Earth.

“It would be good to test it multiple times,” he says.

It is only now, in the 2020s, that humanity has developed the array of hyper-technologies – including super-rockets that can be speedily assembled – that could power the launch of a quick-fire response to an approaching comet, Osburg says.

He lauds the recent liftoff of Blue Origin’s massive New Glenn launcher, which could one day speed a quiver of nuclear arrows to shoot down an asteroid, and the ongoing test flights of SpaceX’s Starship, the most powerful spacecraft ever developed on this planet.

With its potential to supercharge the planetary defense missions of the future, Osburg says, “Everyone should keep their fingers crossed that Starship is successful.”

Meanwhile Jared Isaacman, the billionaire space pilot who has already led two groundbreaking orbital flights to test out technologies that will one day aid the first astronauts to touch down on Mars, told me in an earlier interview that it’s vital to create a second branch of a spacefaring civilization on the Red Planet.

At that point, he says, the twin planets could act as mutually protective guardians, ready to come to the other orb’s defense if it is threatened by a Doomsday event like the asteroid strike that wiped out all but the winged dinosaurs.

Hailing Isaacman’s being nominated to lead the American space agency, Jan Osburg says: “It’s important to have someone heading NASA who understands the threat of asteroids and extinction events.”