We learn a little history behind the Orbital Defense Grid in A-Next #2 when Mainframe off-handedly mentions the Orbital Defense Grid was erected years prior when the government was convinced by the events of the mysterious 'Skrull Incident'. We also learn in Last Planet Standing #2 that Reed Richards helped design the Orbital Defense Grid.
It's worth mentioning that on occasion the Orbital Defense Grid seems to be referred to using different names and there is also one instance where the speaker may, in fact be referring to an entirely different satellite. The only potential reference to appear in either Fantastic Five series comes from Fantastic Five (vol. 1) #1 when Johnny Storm mentions having downloaded images from the team's 'new Safeguard Satellite'. However, aside from this one example, I believe all other mentions to defensive satellites protecting the Earth are referring to the Orbital Defense Grid.
With all of that out of the way, let's take a look at the various appearances and mentions of the Orbital Defense Grid throughout the MC2. The Orbital Defense Grid first appears to in A-Next #2 when it detects the approach of a Kree spacecraft and fires upon it, resulting in the craft splitting into two before crashing into the Washington National Park.
Following the return of hero spider-powers, May 'Mayday' Parker and her father visit the Fantastic Five for a full check-up. The check-up is interrupted when Lyja spots an alien vessel on long-range space scanners. Lyja calculates the unidentified alien spacecraft will be within range of the planet's Orbital Defense Grid. The team sets out to determine the alien's intentions and potentially avoid a misunderstanding (Spider-Girl #34).
The Fantastic Five are again involved when the Orbital Defense Grid destroys the meteor swarm concealing Apox the Omega Skrull on his approach to Earth. However, the Grid isn't powerful enough to prevent the Skrull from reaching the Fantastic Five Headquarters on his mission to destroy the team (Spider-Girl #46).
The Orbital Defense Grid detected the Skrull High Command's coherent energy beam as it passed on it's way to restore the Power Cosmic to Apox the Omega Skrull so that he could play a part in their revenge plans against the Fantastic Five (Spider-Girl #86).
In Last Planet Standing #2 we not only learn that Reed Richards helped design the Orbital Defense Grid but we also see it's destruction when the latest Herald of Galactus Dominas the Wavemaster uses his phenomenal power upon his approach to Earth.
The destruction of the Orbital Defense Grid is referenced in Avengers Next #1 by American Dream when she mentions Mainframe being called to Washington to consult on a 'new Space Defense Program'. The situation is also referenced by Nova and Earth Sentry when they recall their near deaths during the events of Last Planet Standing (Avengers Next #2). Notably, on both occasions Nova doesn't use the term 'Orbital Defense Grid', instead calling it 'Earth's Satellite Defense Program' in Last Planet Standing #2 and 'Space Defense Perimeter' in Avengers Next #2. Perhaps these are colloquialisms, as we see the likes of the more formal and intelligent Reed Richards, Mainframe and Vision use the term 'Orbital Defense Grid'.
This is the last time the Earth's Orbital Defense Grid is mentioned or seen in the MC2. It's unclear whether Mainframe's meeting in Washington yielded productive plans for a new and improved Orbital Defense Grid and related program. In the meantime, the MC2's Earth remains just a little more vulnerable.
I like the idea of an Earth that's frequently combated alien incursions and invasions developing a defense, particularly because it shows the veteran heroes are competent and didn't leave the world defenseless in their absence. It's a nice plot device.
Until I figure out a way to expand the 'Skrull Incident' into a full post, I remain
frogoat