Thread by @CassandraSteer

The amazing @LauraEGrego now speaking #spacethreatsOEWG on behalf of the Union of Concerned Scientists.

Space based weapons that target Earth directly are easy to identify, and right now only hypothetical. Therefore not the greatest threat, and shouldn't be the focus of the #spacethreatsOEWG

While space is a place, orbit is a condition. Speed in orbit is 30 times that of a jet plane, which takes enormous amount of energy. Rockets are mostly made up of fuel. It's expensive and energetically difficult to put something in space so it needs to be worthwhile

Also takes a lot of energy to return an object to Earth, including some kind of fuel or propulsion. Therefore extraordinary expense of Earth targeting space weapons is hard to justify when other means are possible. This is why we haven't seen them developed

An average satellite designed for another purpose can't easily be re-purposed. Can't target with accuracy, hard to direct to Earth

Laser systems in space sound exciting but they also require ongoing high energy source, making them unviable as weapons

Objects in orbit are moving fast and passing over the Earth constantly, so their effectiveness as an Earth targeting weapon isn't practical since you can't respond at a specific time and place.

Biggest issue for Space based, Earth targeting weapons is their vulnerability. Easy to identify difficult to protect, highly expensive. Militarily useless. This is also why space based missile defence has never been developed, even in testing mode.

Space is most useful militarily for observing, navigating and communicating. Any target intent of a Space based Earth targeting weapon could be achieved by other (terrestrial) means. No lasting advantage, so remote possibility of them being a real threat