Spider-Man's webbing requires air to become adhesive, as discussed here. Yet in the latest Spider-Man comic he manages to use his magnetic webbing in a vacuum. How much 'air' does he need? Was the vacuum from opening to space not 'hard'?
My guess here is two-fold:
- Magnetic webbing provides a force by which to assist in the propelling (rather pulling) of webs to an intended target, and
- The targets on which he uses his magnetic webbing (octobot zombies) contain magnetic material.
From Food for Thought: The Empty Calories of Amazing Spider-Man #681, Spider-Man says:
I switched to my magnetic web cartridges. If I aim it right, it should attach to the octobots on all the crew.
For a while Spider-Man had cosmic powers. This came from an alien symbiote that replaced his red suit. (The suit that became Venom after it was rejected but that is an answer to a different question)
The alien suit meant Spider-Man no longer required webshooters or cartridges to produce webbing. It also provided Spider-Man with some special abilities that allowed him to travel through space and use his powers.