In this European Space Agency illustration, a satellite breaks up, adding to the growing population of orbital debris. Debris-clearing spacecraft the U.S., China and others have in the works could double as anti-satellite weapons. Credit: ESA

On June 18, President Trump directed the Pentagon to create a Space Force as the sixth branch of the armed forces. This directive instantly puts the Pentagon and Congress in overdrive. Those who loathe or love a Space Force “separate but equal” to the Air Force must think and act decisively and quickly. Regardless of whether the Space Force actually materializes, the deliberation of its pros and cons alone could finally spring us into action to deal with the overlooked looming threat of space Pearl Harbor.

To know whether we need a Space Force, we must start with current and future threats and how we plan to counter them. By the early 2020s, China will deploy specialized worker-bee spacecraft to clean up space debris and service existing satellites. The United States, Russia, and the European Union will do the same in a similar timeframe. My two papers in 2017 and 2018 explain how these spacecraft can readily be re-tasked to stalk and, at a moment’s notice, attack U.S. satellites from such close proximity that we will have no time to mount a defense, a situation that can facilitate a space Pearl Harbor.

This threat of a surprise attack has been discussed since 2001, when the Rumsfeld Commission sounded the alarm of a space Pearl Harbor, and in the ensuing years, many have cried wolf with similar concerns. Am I just the latest alarmist? After all, worker bees are slow flyers. Upon command to switch from peaceful mission to anti-satellite attack, these spacecraft would take days or even months to move within striking distance of our satellites. In theory, that time window would allow us to see them coming and to prepare a defense of our targeted satellites. Moreover, even if perchance these worker bees were to “sting” a few of our satellites, such pinpricks could hardly qualify as a space Pearl Harbor.

However, we must take into account the current lack of an international agreement or treaty, similar to the Law of the Sea, about the rights and responsibilities of nations with respect to their use of outer space. Currently, any country can command its spacecraft, including worker bees, to spend days during crisis or even months during peacetime in positions that tailgate or stalk any number of another country’s satellites simultaneously. If we were to block worker bees from sidling up to our satellites or negate their anti-satellite potency in order to prevent attack on our targeted satellites, we would be condemned as the aggressor, one who denies another country’s satellites freedom of passage or harms them.

Worse yet, there are still more reasons to fear the use of worker-bee spacecraft to effectuate a space Pearl Harbor.

  • Some experts envision that only dedicated sophisticated anti-satellite weapons are capable of producing a space Pearl Harbor and, since such weapons will not be ready in the 2020s, their threat is not nearly as urgent as that of de facto anti-satellite weapons from re-tasked worker bees. To boot, these de facto weapons are not only arriving soon but also effectively free, as all their costs can be attributed to peaceful functions.
  • Being authoritarian countries, China and Russia can easily and instantly divert these worker bees to attack satellites, while democratic countries cannot.
  • In crisis, China or Russia could divert all worker bees to attack mode. In fact, an outsized fleet of, say, 50-100 worker bees could lie in wait in peacetime, at the ready to mount a near-simultaneous attack of any size on our critical satellites.
  • Typical anti-satellite weapons generate space debris. They are not the weapons of choice for the attacker, because space debris would be detrimental to its own satellite operations as well. In contrast, a worker bee equipped with a robotic arm can disable a satellite by simple tactics like spray-painting the victim’s sensors or bending its antennae and solar panels with little space debris generated.
  • The risk of a space Pearl Harbor alone (i.e. without actually firing a shot) could be enough to deter U.S. intervention. Yet, the failure to intervene would destroy the U.S. alliance system, which is critical to our national security and interests.
  • The most serious concern about space Pearl Harbor is that such a worker-bee attack, like the Pearl Harbor in 1941, can leave the U.S. no choice but to be pushed into an otherwise avoidable war with untold casualties.

My two aforementioned papers proposed a two-part rule:

  • Prohibit satellites, regardless of aggressive or peaceful purposes, from positioning too close to more than an agreed threshold number of another country’s satellites
  • Authorize preemptive self-defense as a last resort countermeasure if a potential adversary’s satellites violate the threshold distance and number

Preferably, this rule would be adopted with an international treaty or agreement. In the absence of such an accord, however, the United States should still declare this to be our policy and observe it with as many as its allies and other countries that can be persuaded to join.

In sum, the threat of a space Pearl Harbor will be upon us by the early 2020s and the capability to threaten more and more satellites at the opening of a conflict with the U.S. will only grow with increasing capabilities and more placement of worker-bee spacecraft in space. We should seize the opportunity that President Trump’s Space Force directive offers to prevent worker bees from turning into killer bees.

Brian Chow is an independent policy analyst. This commentary is a companion to a recent piece about the connectivity of President Trump’s space policy and Chow’s latest study, The Trump self-defense doctrine for the new space era, appearing in SpaceNews on June 4. He can be reached at

Brian Chow (Ph.D. in physics, MBA with distinction, Ph.D. in finance) is an independent policy analyst with more than 170 publications.