Program Background/Overview

Prepare for a long read: Recently, progress has picked up once again at Rainier Space & Launch Systems Division, after a period of relative inactivity in development. The in-development Endeavor rocketplane launch vehicle, Rainier's first space-related vehicle, has underwent a major design review, with a focus on making the vehicle as efficient as possible. This also coincided with the news of Boeing's cancellation of the DARPA/Boeing XS-1 Phantom Express, a low-cost launch vehicle that had rapid-launch, recovery, & re-usability capabilities. Rainier being the business opportunists they are, decided to re-focus & re-bid the Endeavor as a "rapid launch vehicle", which also gave birth to it's new designation, RLV. It's unconfirmed yet whether or not the Endeavor name will stick, as it's a different design now, but there aren't really anymore plans to develop the original Endeavor since the new RLV design is superior, so it may be still considered the Endeavor. It's basically meant to fulfill the role of the cancelled XS-1, except it will be commercially funded & commercially available, where the XS-1 was more of a military project.

Design Changes

The RLV employs a completely new canard-wing layout that utilizes smaller wings that are much more lighter & efficient than the previous wing-set up. All other components & internal systems including the Atmos engine were carried directly over from the Endeavor to minimize development costs.

Because of the lighter & more efficient structure of the vehicle, the RLV gained the capability to launch vertically, whereas the Atmos engine was too weak to lift off the original Endeavor design off the ground. Runway launches at this point have all but been abandoned for the RLV, and will instead be launched vertically from land or sea-based launch sites, or from the air on a mothership launch aircraft, such as Rainier's current Air Launch One 747-400BCF mothership aircraft. This greatly enhances the RLV's efficiency and flexibility for missions, as it doesn't have to waste fuel on conducting a horizontal runway take-off run.

Payload Capabilities

The RLV will launch CubeSats and SmallSats into orbits from 150km to 500km under $3 million per launch, with payload masses as little as 1kg to as much as 500kg, although 500kg is the absolute limit for the RLV. Recent simulations have shown the RLV can barely push a 500kg dummy boiler-plate to an orbital height of 150km, with only 1 out of 2 tests done with the 500kg weight being partially successful which resulted in a lopsided orbit. The 1 test that failed was due to fuel exhaustion before orbital speeds were reached. The previous 4 tests with 25kg weights were 100% successful at reaching an orbit of 150km. Rainier Aerospace is hoping the 747 air launches will increase the orbital insertion heights for the RLV beyond 150km and up to 300km at least, with the current default Atmos engine set-up. Rainier will look into any improvements that could be made for the Atmos engine to further improve efficiency. Rainier has also explored the possibility of switching to methalox fuel for the Atmos. A new rocket engine is also in development called the Phoenix, which will be an aerospike engine that is designed solely to use methalox, and to potentially replace the Atmos engines, although the Phoenix still has a long development road ahead before it can be implemented on space vehicles. So while the RLV's payload capabilities are relatively weak-sauce, especially in regards to orbital altitudes, there is potential that could greatly improve in the future.

Launch Methods & Launch Sites

The RLV will be capable of launching airborne from a mothership air-launch aircraft, or vertically from either land or sea-based launch platforms. The following is a list of locations where the RLV would be launched from:

[Vertical Land Launch] Kennedy Space Center - Cape Canaveral, FL
[Vertical Land Launch] Cape Canaveral Air Force Station - Cape Canaveral, FL
[Veritical Land Launch] Vandenberg AFB - Vandenberg, CA
[Vertical Land Launch] Pacific Spaceport Launch Complex - Kodiak Island, AK

[Horizontal Air Launch; Over Pacific] Grant County International Airport - Moses Lake, WA
[Horizontal Air Launch; Over Pacific] Vandenberg AFB - Vandenberg, CA
[Horizontal Air Launch; Over Pacific] Mojave Spaceport - Mojave, CA
[Horizontal Air Launch; Over Atlantic or Gulf of Mexico] Patrick AFB - Cape Canaveral, FL

[Vertical Sea Launch] Pacific Ocean - US West Coast (WA, OR, or CA coasts)
[Vertical Sea Launch] Atlantic Ocean - US East Coast (FL)

Recovery Methods

The RLV's default mode of recovery is gliding back to a runway, whether a runway at the launch site or at a separate airport. However from a vertical launch, this requires a boost back burn and will result in lower velocities & orbital insertion altitudes on the RLV's part, and will require more fuel from the OMV and higher risk of fuel depletion before the targeted orbital velocities & heights are reached. Completing using all of the RLV's fuel for orbital insertion without boost-back is an option, but the chances of it being able to glide back to a runway are non-existent unless there is one down-range, and Rainier wants to avoid ditching the RLV in the salty ocean at all costs since that would damage the vehicle and greatly degrade it's re-usability value. So, another mode of recovery Rainier is exploring, is one similar to what Rocket Lab will conduct; Air-catching of the launch vehicle via helicopter. Rainier conceptualizes having the RLV deploy a large parasail/paragliding wing that greatly decreases it's rate of descent & speed, and prolongs it being airborne to give the helicopter time to meet with the vehicle and catch it with a hook. Than the helicopter would either deliver it to a recovery vessel or back to the launch site/base depending on how far down-range the vehicle travels. Rainier would love to use the Bell-Boeing V-22 Osprey for this job, as it is capable of lifting the empty weight of the RLV and has the range & speed to easily catch it down-range, although it's not available for commercial/civilian use and the similar Leonardo AW609 doesn't have the ability to lift the empty weight of the RLV. So for now at least, the Boeing Vertol 234ER (civilian version of the CH-47 Chinook) would act as the retrieval helicopter. This method isn't confirmed but it's being explored. It's sort of a last-ditch option, as Rainier would prefer to have the vehicle land all by itself at a land-based runway without using other assets. After all that's why it has wings, so it can glide.

Conclusion

So that's the recent developments with Rainier Space & Launch Systems Division. So far the RLV looks highly promising, and may be Rainier's ticket to having a launch vehicle that is dirt cheap to launch and it is capable of rapid launch & recovery and become highly-reusable. The lessons learned from the RLV will be applied to future launch vehicles, especially the Eagle which will be re-designed like the Endeavor.

That's all for now, any tips or suggestions are welcomed. Strong tailwinds & happy flying!