Agera-Class Spaceplane

## Agera-Class

Regera awaiting the rollout of the Agera from the OPF after OST-018. A Pegasus IV carrying a communication satellite is on the launchpad.

## Performance

### Engines

10x- S3 KS-25 "Vectors" LF1x- S3 KS-25x4 "Mammoth" LF

### deltaV

4598 m/s

The Agera-Class Spaceplane is the workhorse and primary LKO launch vehicle of the KASA fleet. The Agera is a first generation Spaceplane and SSTO. As such, its capabilities are very limited compared to later space planes.

The *Agera-Class* was a 12 year project developed by KAAB's Vålnad Verks Aerospace Division to replace the Explorer-Class Shuttle.

There are 3 spaceplanes currently in service, the Agera, Regera, and the new Gemera.

## Overview

The Agera-class is a reusable series of 2 Orbital Rated SSTO Space planes. A first generation SSTO, the Agera-class is a rocket engine based design.

The lack of efficiency and other optimizations scene in later SSTO's negated the Agera to be only rated for Kerbin Orbit Payloads. However, the Agera's great safety track record, low cost to launch, and superb lifting capabilities made it a go to LKO launch System for KASA.

A prominent advantage the Agera's have over the previous Explorer-Class is the optional crew. The Ageras can be piloted autonomous or by a crew.

## Early History

After the loss of the shuttle *Enterprise,*  KASA opened a proposal for a Spaceplane replacement for the ageing shuttle fleet. While the Enterprise's crew had been saved by a subsequent launch of the Discovery, the risk for future issues was deemed to high.

The subsequent OVX Program received several proposals. After a lengthy decision process, KAAB's proposal was ultimately selected for further developments.

KAAB's original proposal was the result of an early in house SSTO Study called "Project Mjölnir", lead by head engineer Jesko Von Kerman.

KAAB's proposal was for a 3 hull fuselage, with a Boxwing design. The proposal included a 10m long cargo bay, matching the capacity of the Shuttle. A secondary deployment cargo area at the tail of the craft was designed to launch small rovers on the surface of Mun/Minmus.

The promise of a Minmus capable of SSTO led to the selection of the KAAB proposal.

## CCX

The CCX was a non-orbital structural model for atmospheric tests. The CCX flew only twice, before a structural failure caused the wing to fall off. The CCX spun out of control, and slammed into the ocean.

However, during the earlier test flights, the CCX was found to be woefully under powered and sluggish to fly. The result led to the Minmus aspirations to be shelved, as a Minmus capable flight would require a full redesign of the vehicle.

The later Agera had a dramatically different and much more powerful engine structure. The overall fuselage was refined but stayed similar to the CCX.

## Service History

The Agera would roll off the assembly line 12 years after the program had been announced. After another close call concerning the near loss of the Challenger, the shuttle was completely retired. The untimely retirement of the Explorers left KASA was left without a Kerbal-rated rocket.

To bridge the void until Agera was flight ready, KASA contracted Kerbal flights to Azovka Space Industries, to be launched on the antiquated Lyra Family Rocket. The Agera marked the return to KASA Kerbal flight capability, and a return to space planes.

The Agera featured an extended 7.5m long payload bay, as opposed to the CCX's 2.5m payload bay

The Regera would roll off the assembly line a year later. The Regera was originally built as a cargo only variant, with the crew area of the Agera replaced by an extended cargo bay 15m long.

### **Block I**

The Block I was the original design of the Agera. Heavily based on the CCX prototype, the Block I differed from the CCX in the replacement of the aft payload bay with a KS-25x4 Mammoth engine, and 2 engine clusters of 4 individual KS-25 Vectors on the lateral 3.75m fuel tanks.

The Block I used Monopropellant for orbital maneuvers, along with a host of individual RCS thrusters. The structural integrity of the Block I was not fantastic, and returning space craft required lengthy repairs to make them flight worthy again.

The Block I Agera flew 3 times, while the Block I Regera flew only once. As such, the Block I did not receive crew certification, and did not fly with a crew.

In fact, neither craft launched with cargo. A dummy payload of 4t was loaded into Regera, but this was ejected shortly after the retrograde burn to allow it to burn up.

### **Block II**

The Block II was a minor upgrade over the Block I- Block II consisted of structural reinforcement of the wings, with additional internal struts added to stiffen the wings. Externally, both space planes remained more or less identical to the Block I.

The largest change was the expansion of the 3.75m lateral fuel tanks. A 2m extension was added on both sides right in next to the payload bay.

The Agera also received the unique addition of a set of ladders to allow for disembarkation from the top of the craft.

The first flight of the Block II Regera, consisting of the first actual payload of a communications satellite resulted in a stunning failure. Upon release, the Regera was not able to maneuver away from the Communications Satellite, resulting in the satellite smashing into the central rudder of the Regera.

The comm satellite was completely destroyed in the process.

Fearing the rudder's ceramic tiles to be damaged, and the craft would burn up upon reentry like the *Enterprise* had years earlier. KASA launched a manned mission on-board an ASI Lyra II rocket with replacement tiles.

The crew docked to the front of the Regera, and EVA'd to the rear of the Regera. The crew found and replaced 5 damaged tiles, before returning and reentering the atmosphere separately from the Regera. The Regera remained in orbit for another 8 days, allowing the adhesive to fully cure.

The Regera managed to reenter and landed without issue.

Due to the failure of the Regera, the Agera would not launch with a crew. Agera would make the first successful launch of a small dummy payload of 6t.

Agera would launch another 6 times, but the failure of the Regera eventually led to another update.

### **Block III**

The Block III refit was the first extensive overhaul to the design of the Agera. The Block III update resulted in the addition of a dozen more RCS thrusters to allow for more nimble maneuvering in LKO. The Block III also included RCS thrust along the center mammoth engine cluster to allow for RCS maneuvering towards

stations.

Another large update to the space planes was the lengthening of the central fuel tank. The Agera and Regera both received had 5m of fuel tank added right behind the payload bay, adding 28t to the fully fueled weight of the craft.

The front landing gear was also strengthened to handle this weight.

The Agera flew 4 times, and made the first successful payload delivery to space. A small 2t communications satellite was finally launched in LKO.

The Regera flew 3 times, assembling the Intrepid NDSP in LKO. During the post flight inspection of the Regera, micro cracks were discovered in the structure of the wings. A result of added stress from the additional 68t of fuel on takeoff. By this time, Agera had flown 14 times, while Regera had flown 5 times.

While the Agera did not show any cracks, it was recommended it receive a wing replacement to avoid a catastrophic failure on takeoff.

Faced with an expensive repair, and due to the continued unsatisfactory performance of the space planes, the Agera Program was nearly scrapped. In a desperate attempt to save the space planes, KAAB elected to propose an extensive refit of both craft at no cost to KASA.

With millions of credits already invested in the development of the Agera, and with no replacement system in the works, KASA agreed.

### **Block IV**

The Block IV was the second massive overhaul. The Block IV upgrade saw the conversion of the forward 7.5m of the of the Regera be converted into a crew compartment mirroring the Agera.

The Agera received extensive structural changes. The wings were completely removed and replaced with ones with a completely redesigned internal structure 6x stronger then the previous wing. The 4xKS-25 Mammoth Cluster was modified to allow for the installation of 2 additional KS-25 Vectors.

The Orbital Maneuvering System was completely overhauled. The monopropellant system was removed, and replaced with liquid fuel powered "Vernor" engines. These new engines were much more powerful then the previous RCS system, and increased the speed of orbital maneuvers.

With the newly useless RCS propellant tanks, on the Agera they were converted into an additional 2.5m of cargo bay. While on the Regera, the propellant tanks, as well as the first 2.5m of the payload bay, were converted into a crew compartment with life support systems.

This finally gave the Ageras a payload bay identical in size to the preceding Explorer Shuttle.

The space planes entire electrical system and guidance was completely overhauled. The remote guidance unit was replaced with a newer more powerful version, and moved inboard and mounted right behind the cabin. Additionally, a 4k charge battery was added. The solar panels were removed, and replaced with 2 large fuel cells.

The Agera would be the first completed due to delays in the conversion of the Regera.

The Block IV Agera finally matched the performance figures, and reliability KASA needed. During the first orbital flight, the Agera exceeded all expectations and requirements. The thrust was so powerful on takeoff, the Agera was forced to throttle down even at the AoA of 85 degrees.

With the success of the Agera, KASA finally gave the go ahead for a manned payload mission. The first mission of the Agera was the delivery of a hallway module to the new Terranova Space Station. Agera would deliver the Hallway Alfa to the the Space Station, performing the first orbital rendezvous by the class.

The Agera would make 4 more deliveries to the station. During the 3rd mission, the Agera would perform the first orbital docking when it docked with TSS. During the fourth mission, Agera would perform the first crewed mission to the TSS.

While the Agera was highly successful, gained led to further optimizations to the Regera. This would become Block V.

### **Block V**

Block V is a series of optimizations initially made to the Regera. The performance of the Agera led to the 5m central fuel tank added during the Block III update being removed. The Vernor engines location were optimized and more were added to the outboard fuel tanks for increased maneuverability.

The ladder that surrounded the side of the cabin were removed, and a ladder and entry hatch was added to the bottom of the craft. Finally, the Block I era parachutes were replaced and optimized. Upon several landings, the Agera's parachutes had tangled in themselves.

The Regera would return to service, while Agera would undergo the refit.

### **Block VI**

Block VI was a second massive overhaul of the Agera-Spaceplane fleet. Started as an internal VVA engineering report, Block VI sought to increase the efficiency of the Agera fleet. One of the largest issues with Block V was a tiny cargo bay and low passenger capacity.

The Block VI saw an entire central fuel tank to be converted into cargo bay space, with existing cargo bay being turned into a crew compartment. The Block VI increased crew capacity to 32, with a 7.5m expansion of overall cargo bay. In effect, the rear of the cargo bay was shifted 15m back towards the engines.

Despite the reduction of fuel, the Block VI had identical capabilities of payload and orbital range.

Additional refinements were made to the flight computer's Orbital Maneuvering System to better increase orbital maneuvering efficiency, and larger canards.

Due to the high risk nature of the complete overhaul, KASA ordered the construction of a Block VI prototype. This would become called the Gemera, constructed out of spares and STA-004. An unflown Structural Test Article

## Proposed Variants

After the conversion of the Regera to the Block III Agera specification, KAAB proposed 2 other variants of the Agera-class.

### Carrera

The Carrera was a proposed interplanetary variant of the Agera, with 3 nuclear engines located on the back of the vehicle. This variant would have the cargo bay inverted to face towards the ground, with a small drill and ore processing to allow for refueling. The leftover space could be used for a small rover.

The Carrera was proposed to fulfill the original promise of a Mun/Minmus capable SSTO. However, the Carrera would be heavily limited and could not deliver any substantial payload to Minmus. Additionally, the craft would require a large amount of time to refuel enough to take off from Minmus.

### Sierra

The Sierra was a proposed variant of the Agera with an integrated science suite fitted into the payload bay. The laboratories would have the space for 4 kerbalnaut's to perform science experiments in LKO and return the samples to the surface.

The Sierra was cancelled, as KASA determined they could just fit a payload like that into the Agera with minimal modification.

## Structural Test Articles

After the completion of the Block V upgrades to both crafts, KAAB was desperate to further expand the Agera's capabilities especially as issue's arose with the Miura-Class Spaceplane. KAAB constructed 4 disposable Structural Test Articles (STA) to further optimize the Agera-Class.

These were essentially a rocket version of the Agera-Class, with the same fuel tanks and engines, but with the wings, gear, crew cabin and other spaceplane hardware removed.

Another huge addition was the lateral tanks were modified to act as boosters, that fed into the central tank. This was only explored on the last two STAs. The first STA-001 was a static fire version only.

The two other STAs, STA-002 and STA-003 both completed one flight. The final STA- STA-004 was never flown and later used to construct the Gemera.

Taking off from KAAB's Facility at the Dessert Spaceport, both arc'd over the south sea. Both had to cut engines early to avoid reaching Kerbin-Escape Velocity. Both reached an altitude of over 300,000km.

While the STA's did not ultimately result in any design changes in the Agera's like originally planned, they had a huge impact on changing the Agera's launch profile.