A mysterious Russian satellite has exhibited "very abnormal behavior" in its orbit, leading the Pentagon to worry that it may be some kind of weapon.

Weapons are banned from outer space by treaty, but it's believed that there are ways to weaponize lasers and electronic jamming devices to disable or destroy satellites.  China is believed to already have an advanced anti-satellite capability, with the U.S. nearly on par with the Chinese and Russia trailing in the race to develop this vital technology.

The media largely dismissed Trump's plan to develop a Space Force and make it a separate branch of the armed forces.  In fact, much of the press made fun of the notion.

But this satellite launched by Russia is a perfect example of why we need a Space Force and why it's no joke – especially to the Russians and Chinese.

BBC:

"[The satellite's] behaviour on-orbit was inconsistent with anything seen before from on-orbit inspection or space situational awareness capabilities, including other Russian inspection satellite activities," Ms Poblete told the conference on disarmament in Switzerland.

"Russian intentions with respect to this satellite are unclear and are obviously a very troubling development," she added, citing recent comments made by the commander of Russia's Space Forces, who said adopting "new prototypes of weapons" was a key objective for the force.

Ms Poblete said that the US had "serious concerns" that Russia was developing anti-satellite weapons.

Alexander Deyneko, a senior Russian diplomat, told the Reuters news agency that the comments were "the same unfounded, slanderous accusations based on suspicions, on suppositions and so on".

He called on the US to contribute to a Russian-Chinese treaty that seeks to prevent an arms race in space.

It's a little late for that.  In fact, for more than a decade, the three major nuclear powers have spent tens of billions of dollars to develop an anti-satellite capability.  It's an arms race that the U.S. simply cannot afford to lose, which is the major reason why the disparate elements located in all military services must be combined into a single command.

As for this particular satellite, a space-based satellite-killer would be an enormous advantage over trying to disable or destroy a satellite from the ground:

Space weapons may be designed to cause damage in more subtle ways than traditional weapons like guns, which could cause a lot of debris in orbit, explained Alexandra Stickings, a research analyst at the Royal United Services Institute.

"[Such weapons may include] lasers or microwave frequencies that could just stop [a satellite] working for a time, either disable it permanently without destroying it or disrupt it via jamming," she said.

But it was difficult to know what technology is available because so much information on space-based capabilities is classified, she added.

She also said it would be very difficult to prove that any event causing interference in space was an intentional, hostile action by a specific nation state.

For our enemies, targeting surveillance satellites during war is one thing.  But imagine the chaos if commercial communications satellites could be targeted.  There is much to protect as far as our space assets are concerned, and a Space Force is a large part of the answer.