NASA's defense program against asteroids aimed at increasing the impact

space

He's planning the first ever event to drop a course, but funding is pending

The Trump administration has proposed to triple the budget of NASA's Global Defense Coordination Office from $ 60 million to $ 150 million, while humanity fears that humankind is unpredictable but unthinkable: an asteroid.

The White House has also recently released a new strategy and plan of action for the preparation of near-Earth objects to mobilize a host of organizations that can contribute to the prevention of such disasters.

History continues below

Lindley Johnson, a former Air Force officer who is the space agency's global defense officer, is at the center of these efforts, which include plans for the first-ever event to topple an asteroid if one of the more than 25,000 asteroids that have a height of 140 meters or more are proving to be a real threat.

But this test, scheduled for 2022, risks being delayed if NASA's credits for the 2019 fiscal year are included, as expected, in a continuing resolution – which means that the agency will have to operate at NASA's current new budget spending levels.

Johnson, who published for the first time in 1994 an article on the threat of the asteroid as an air force major, described a recent two kiloton meteor strike in Greenland as a "cosmic awakening". .

He explained to POLITICO how the global defense mission had evolved. how much more NASA has learned; and the various ways in which an important near-Earth asteroid could theoretically be diverted as it was heading towards us – that is, if we had enough notice of it.

This transcript has been changed for length and clarity.

NASA has been addressing this issue for two decades. What's different now?

I think one of the reasons you see more interest and activity here is due to NASA's efforts over the last two decades to better understand what exists – asteroids and comets in our solar system . on the occasion impact. Thirty years ago, there may have been only a handful of astronomers who thought that there was a danger. This is because no one has really looked at what exists. Since there was a dawn in the minds of people: "Well, you know, there are still a lot of things from the formation of the solar system and a lot of asteroids and comets that could get into the internal solar system on the orbit of Mars and still impacts the Earth.

There is nothing that prevents this from happening and if there is a large population of asteroids entering the orbit of Mars, it could still to have a significant impact. [here] In the future.

Tell us how this mission began two decades ago.

The initial charge was to try to find an asteroid larger than one kilometer (two-thirds of a mile) to see how many of them were in close orbit to the Sun.

Twenty years ago, projections indicated that there could be up to 2,000. And our survey work in the early 2000s showed that this figure is only about half . There are just under 1,000 near Earth asteroids that we have discovered in our investigations – and we believe that we have about 96 or 97% of the population discovering the asteroid population of one. kilometer. Of course, that's something we would not want to be touched with. An impact of one kilometer or larger object would have significant global effects and would constitute a global catastrophe.

By further studying the problem, we examined the effects of an impact, even on an object of more than 100 meters. If it were to have an impact near an agglomeration, it would be a disaster on a scale larger than anything we tried to do in our history. The threshold we wanted to search was reduced to 140 meters, according to a study sponsored by NASA. It would be an existential threat to national well-being. Its effects would have a significant impact on our society and on a nation as a whole.

So, if the threshold of 140 meters is the threshold, I imagine that it increases the population of these asteroids?

There are nearly 950 objects more than one kilometer in size in orbits near Earth and we believe that the population of [asteroids] 140 meters or more is about 25,000. To date, we have found 8,303 asteroids over 140 meters in size that are now in our catalog. But in light of what we have found and statistical studies, we estimate that the overall number is close to 25,000. How might the effects be due to the impact of an object of relatively small size and 100 meters, which has attracted increased interest and interest, let's find out what is really going on and think about what we would do if it was on an impact trajectory.

They are all asteroids about 30 million kilometers from Earth's orbit. It's a relatively small distance when you think of a solar system ladder. We have to find them before we can do anything about them. If we do not know they are coming, there is no chance of preventing an impact. And the more time between detection and impact, the better our chances of doing something.

How does NASA build this image?

None of the observatories we use to try to detect these things are actually observatories of NASA. Our program funds observatories operated and operated by US universities and space institutes. The University of Arizona is one of the largest, the other is the University of Hawaii. We are also working with the US Air Force. We have also set up an international asteroid warning network with counterparts in Europe, Japanese and even assets in Russia and China. They bring observations to the Minor Planet Center, which is the central node of the International Astronomical Union for world observations on asteroids and comets.

What would be the options to divert a person considered a threat?

There have been several studies on what we can do for mitigation. The most reliable methods are essentially based on a simple principle. We just need to change the speed of the asteroid by a fraction of a percent. If we do it well in advance, the orbital mechanics of an asteroid orbiting the sun will change its orbit from a dangerous orbit to a benign orbit. So, we must either add or cut a few inches per second of the asteroid.

A 2010 National Research Council study has looked at this issue and given the current technology, there are at least three techniques that seem viable. Some are very simple in principle. The first is only a kinetic impact. Just insert a spacecraft at the right speed and in the right angle to transmit that force to cause a gear change of about one inch per second.

So we set out on a mission to demonstrate this technique and to determine if we really understood everything we thought we were doing about it to make sure it would be a viable answer to the search for an asteroid on a trajectory. 'impact. The double asteroid redirection test is in our budget request for the 2019 exercise – a significant increase in the planetary defense program. A good part of this is to pass the redirection test to the launch pad in the summer of 2021 to meet the double asteroid in October 2022. We will show the ability of a kinetic impactor to change this moon's orbit. around the primary asteroid.

What budget increase are we talking about?

For the overall proposed planetary defense program, the budget is $ 150 million for Exercise 19, of which $ 98 million for the two asteroid redirection test.
The whole program goes from about $ 60 million to $ 150 million. It allows us to embark on space capabilities and to demonstrate deviation techniques and to start working on spatial sensing and characterization capabilities.

What are other potentially viable ways to treat a threatening asteroid?

The second is what is called a gravity tractor. The premise is that you place a spaceship next to an asteroid and that mutual gravitational attraction between the spacecraft and the asteroid will slowly pull this asteroid off its trajectory. 39; impact. If it is a large asteroid, the relative mass of the asteroid to the spacecraft is an important factor here. If it is a very large asteroid of one kilometer, it will not have much effect. But the most common impactors will be those measuring 100 meters or less. So now, the mass of the spacecraft is becoming more of a factor and can have more effect on gradually pulling on this asteroid and changing its speed.

Another idea came up while we were looking at it: "What if you could increase the weight of the spacecraft after it arrives, that is to say, go down and pick up a big block of tens of tons on the surface of the spacecraft? asteroid and put that in the arms of the spaceship. This was going to be part of the asteroid redirection mission in the last administration, but this program failed to cross the transition. So now we do not have that in our program yet. We are still interested in this technique and perhaps a future demonstration of the planetary defense program could it be the demonstration of a gravity tractor.

The other viable option?

The third, of course, if we like to talk about everyone and that's the nuclear option. Not like in the movies "Armageddon" or "Deep Impact". We believe that the most effective technique would be to have a nuclear explosion several hundred meters from the surface of the asteroid. Nuclear radiation causes the surface of the asteroid to overheat and exert a force on the asteroid in the opposite direction.

So, nuking to the asteroid itself would not work.

Blow it to pieces and then you have a lot of comrades in your head. You have not changed the direction. You have just broken it up into pieces, some of which can be processed by Earth's atmosphere but perhaps not all.

What is the importance of the recent strategy and plan of action?

This allows all the agencies that have a piece of cake to know what the problem is, what can be done so that this particular agency can contribute to the capacity of the country to tackle this problem. NASA, of course, has been working for 20 years now and we have been working for about eight years with the Federal Emergency Management Agency on emergency response preparedness if NASA were to find an asteroid on a trajectory in the future. Impact for the US territory. How could we work together to protect as many citizens and infrastructure as possible?

Which agencies could do more?

The Air Force certainly does, but could do more. They certainly have a role to play in detecting, tracking and characterizing – creating a more complete picture of situational awareness in space to take into account not only artificial objects but also natural objects. If we enter a scenario where we need lifting and rapid development capabilities, we will have to use Air Force resources to help us.

So, what is the best asteroid movie?

I'm the real Bruce Willis. Do not seem so disappointed.

Hollywood is entertainment and fantasy. I must say that the movie "Deep Impact" is probably better than "Armageddon". "Deep Impact" actually had science. "Armageddon" was pure fantasy. My favorite movie, which had an impact on the asteroids, is' Meteor ', in the' 70s. It played Natalie Wood and Sean Connery who played me.