The one on the cover is not confirmed to be a Spartan, dude.

You're wrong, Fish. The Spartan-1 project was made of the finest soldiers the UNSC had to offer, and modofied their bodies to make them faster, smarter, stronger, etc. They never recieved the Mjolnir Mark IV, V, or VI. For everyone else, The Spartans first were in black combat jump suits, until the Mjolnir Mark IV was released. It lacked shields, but could withstand a small amount of plasma fire, nothing serious as we saw with Sam when his armor took damage. The Mjolnir Mark V was released for the surviving Spartan II's just days before The Fall of Reach. This armor was equipped with shields, but the shields were not as strong as they needed to be. When John-117 and the other surviving Spartans returned to Earth, the Mjolnir Mark VI was issued to them. The shield was stronger, and would recharge faster, making the Spartans deadlier in combat against the Covenant. So in conclusion, for anyone still wondering, that was probably the Mjolnir Mark IV, but could have been the Mark V. The Fall of Reach wasn't the only battle taking place in UNSC space at the time, and there's a chance that not all Spartans were onboard the Pillar of Autumn when the Covenant entered Reach's system.

Reply to Jason EL -

Damn, I guess it's the Spartan II's then, but I still think those guys are Ackerson's Spartan III's. I wonder if they, Ensemble Studios, got a hold of the Halo Bible.

spartan I's were regular soldiers that they put in the armor.  didnt work out so well and several of them convulsed to death b/c the armor moved their arms so fast that they broke, etc.  the spartan II's were john and them and had enhancements and graduated into usign the suits and MC was the first to test it w/deflecting the rocket cause his reactions are so good

WRONG redhead3031.

The Spartan 1.0s project involved taking the elite of the UNSC Marines and making them even better. They were given special training, chemical enhancements, but nothing like what the SPARTAN-IIs go through. The Spartan Is were fully grown adults who consentually undertook the training.

 The Twos are taken from their parents before they are even teenagers and put through surgeries, gene therapy, neural tweaks, etc.

((My source is the ILoveBees audio files. Yes, they are official))