Project ORCHID

"We're not exactly like those artificial gods from the earlier generations. More like demigods. And I'll be damned if that usually isn't good enough."

- Edward Buck

The SPARTAN-IV Augmentation Program is the formal name for the biochemical and surgical augmentation procedures performed on the Spartan-IV supersoldiers. As with the recruitment methodology of the SPARTAN-IV program, the scope of their augmentations hearkens back to the ORION Project's less extensive physical enhancement moreso than the decidedly more superhuman Spartan-IIs and Spartan-IIIs, although several new procedures are utilized.

Background
Like their forebears, nascent Spartan-IVs undergo a series of procedures to enhance their physical capabilities. The augmentations are performed through a combination of chemical injections (like those of the Spartan-IIIs) and invasive surgical implants (like those of the Spartan-IIs). The technology used in the two preceding SPARTAN programs necessitated that the candidates meet exceedingly strict genetic qualifications as well as the application of the enhancements on preteens to avoid the catastrophic failure rates produced by the augmentation of adult subjects in the ORION Project. By the time the SPARTAN-IV program was initiated the technology had advanced to the point that some of the previously dangerous procedures could be performed safely on adults and without stringent genetic requirements. Due to the subjects' bodies no longer being in developing stages as well as their lack of genetic requirements, the process must be carefully custom-tailored for each individual.

Augmentations
While the enhancements have not been described in detail, they incorporate technologies originating from the prior SPARTAN programs as well as completely new additions. However, because the Spartan-IVs' performance-enhancing physical augmentations do not produce results as effective as those of their predecessors, they are forced to rely more heavily on their GEN2 Mjolnir armor to compensate.

Experimental phase
A series of additional augmentations were included in the earliest, prototypical phase of the program. These enhancements would have made the Spartans significantly stronger and more resistant to injury, the goal being that they could operate without Mjolnir armor. However, these procedures proved to have an unacceptable casualty rate, killing or crippling nine of the ten initial candidates: The sole survivor, Ilsa Zane, was rendered mentally unstable. Demonstrating the effectiveness of these experimental enhancements, Zane was able to engage a Mjolnir-armored Sarah Palmer in hand-to-hand combat without the use of any protective equipment and survived Palmer violently driving her head into a metal bulkhead face-first, as well as her subsequent prolonged exposure to the vacuum of space.

Procedure
The SPARTAN-IV augmentation procedures (at least at the onset of the program) take three weeks to perform, with recovery and subsequent training usually lasting several months. It took about two days for the first team of Spartan-IVs to relearn how to walk again following their augmentations. Significant disorientation was in evidence during their initial training exercises.

The augmentation procedures are conducted in a dedicated Spartan-IV facility on Mars and are considered quite painful. Approximately two dozen candidates were augmented and conditioned at any given time during the second Spartan-IV class.

Effects
Reflecting on her augmentations, Sarah Palmer stated that the synthetic cardiac weave allows her to "outrun a horse". The enhancements performed on the lungs potentially allow a Spartan-IV to breathe methane for around an hour. Nutrition-wise, it is also said that a Spartan could eat a raw tree and retain the equivalent of six meals' worth of calories in terms of energy. According to Edward Buck, the ocular implants enable him to see in the dark and read the fine print on release forms "from across the room". The subject's hearing is also greatly improved.

However, the decision to augment adults as opposed to preteens comes at the cost of performance: the results of the Spartan-IVs' physical augmentations are not as effective as those of the preceding generations. To compensate for this shortcoming, the GEN2 Mjolnir armor worn by the Spartan-IVs is designed to multiply the wearer's strength and speed significantly more than first-generation suits. At least in theory, this makes a Spartan-IV clad in GEN2 armor equal to a GEN1-wearing Spartan-II in terms of strength and speed, but the Spartan-IV would be at a considerable disadvantage without armor. The physical disparity between a Spartan-IV and a Spartan-II has been compared to that between an elite-level athlete and a "near-supernatural monster". Spartan Edward Buck also compared the Spartan-IVs to demigods while respectively likening the Spartan-IIs and Spartan-IIIs to the Titans and gods of Greek mythology.

Spartan-IVs must follow a rigid set of guidelines to maintain their physical fitness and health. These include undergoing regular medical examinations, including physiological scans, reviews and treatment before and after each mission. A Spartan-IV is expected to perform at optimum capacity with a minimum of 2 1/2 hours of sleep per 48-hour cycle; for cryosleep, standard UNSC practices apply. They are also instructed to follow standard UNSC physical training practices. Due to their augmented physiques, however, they are provided their own, custom-built gym equipment. Official meals are specifically prepared to meet the caloric, nutritional and medicinal needs of each individual Spartan. These personal needs are measured based on activity data recorded by the Spartan's individual physiometer. Ancillary medications may be provided to ensure the Spartan's well-being and to reduce risk of potential implant rejections.

Performance
Training performance of the initial Spartan-IV unit in 2553 was decidedly underwhelming, something that was acknowledged by their recruiter, Spartan-III Jun-A266. Part of this may be attributed to their still-ongoing acclimatization to their enhancements, as well as the group not having worked together before, though all of them came from military backgrounds. The majority of the first batch of Spartan-IVs were incapacitated by their unaugmented Marine training opponents, who outnumbered them ten to one, and their lack of coordination resulted in SPARTAN-IV program head, Commander Musa-096, personally chastising them about the importance of teamwork (a lesson the Spartan-IIs learned in their first days of training at the age of six). However, several Spartan-IVs of this group later distinguished themselves in live combat during the New Colonial Alliance's attempted takeover of.

Later combat performance also shows marked improvement to the training sessions of the initial group. During a 2555 mission to Talitsa, Spartan Edward Buck fought Spartan defector Michael Crespo in hand-to-hand combat and shattered the faceplate of the latter's GEN2 Mjolnir armor by pummeling it repeatedly. Spartan Kojo Agu killed multiple Insurrectionists by throwing rocks at them before procuring a weapon from the fallen rebels during the same mission. Agu subsequently assaulted a rebel stronghold single-handedly, eliminating numerous rebel combatants.

During the Requiem campaign, Spartan Gabriel Thorne was able to fight five Sangheili in close-quarters combat and successfully kill them before being subdued by two other Sangheili. Thorne later fought Gek 'Lhar (who had previously killed several Spartans) in hand-to-hand combat and held the upper hand for a majority of the brawl, before having a boulder smashed on his chest and unprotected head, dazing him. Later during the Requiem campaign, Spartan Paul DeMarco was able to defeat multiple Sangheili and a Promethean Knight in close-quarters combat. During the Battle of Ealen IV, Spartan Naiya Ray defeated a Sangheili Warrior in close-quarters combat. While on a War Games simulation marathon, Sarah Palmer fought and killed a Hunter with her bare hands.

List of appearances

 * Halo 4
 * Infinity Briefing Packet
 * Halo: Initiation
 * Halo: New Blood