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Nov 21 2017

Ascension Program to Take Rocketry to the Next Level

We’ve learned a lot over this past year with the Progenitor program, mostly that we still have much more to learn when it comes to building and flying rockets. The only way we’re going to get that additional knowledge is by trying and the time has come to try to establish a permanent presence in space. The Ascension program will aim for the goal of placing a probe into orbit next year!

What’s In a Name?

Rockets go up, and going upwards can also be referred to as ascending, which is probably the first thing that would come to someone’s mind when seeing a rocket program called Ascension. There’s a double-meaning here though, because the word ascension can mean more than simply going up, but also reaching a new level or higher position. We are indeed aiming above what has been achieved before and even though we can already send rockets higher than the altitudes we would initially aim to orbit at, staying up there is a whole new level of technology and knowledge. Speaking of technology…

Getting to Orbit

We already have the power to reach orbit. Based on the performance of the Progeny Mk5 Block I we’ve calculated the Block II has enough Δv to insert into a very eccentric orbit with a perikee 20-50km outside of the atmosphere. This would be horribly complex to achieve however because the Mk5 lacks the ability to control its flight path other than to coast between burns and let its nose fall to flatten out the trajectory. The timing would need to be very precise and well-calculated, especially since none of the engines can be lit more than once and only one can be throttled.

The Ascension program will feature fins with the ability to adjust their deflection during flight in order to control the trajectory of the rocket, based largely upon what has been learned from control surfaces in the Genesis program. In order to handle the high-stress of supersonic flight they will need to be large and well-built, necessitating that Ascension rockets will be bigger than our current Progeny rockets. We are planning for a 1.25m core, which will also allow for larger payloads to be placed atop.

The rocket core will contain pressurized tanks of liquid fuel and oxidizer to power a dual-start lift engine, which will allow for additional control during the ascent phase through its ability to throttle down to as low as 10% thrust so we can aim for various orbital insertion altitudes. The lifter engine will be chosen at the start of 2018 – several companies have spent the past year building and testing various engines for us to award a contract to. Should the core not be enough for heavier payloads, we plan to use the USI 0.625m SRBs in a 2, 3 or 4 configuration to add additional boost, given that we are currently using less than half of their total power for Progeny rockets.

Control of the rocket will be via a computer system based off the M-315 used on the Progeny rockets, sporting dual modular redundancy thanks to the increased size of the 1.25m core atop which it will sit.

We do not have an estimate of payload capacity at this time.

Operating in Orbit

As if reaching orbit isn’t hard enough, there are various issues that need to be addressed once we get there. The most important one will be power, because unlike the Progeny rockets these craft will not be coming back on their own if they run out of juice before we tell them to retard their orbit back into the atmosphere to eventually be dragged back down and recovered (or allowed to burn up, depending on the mission). So far we have been able to rely on batteries to power our spacecraft on short sub-orbital flights but spending hours or days or longer in orbit with batteries would reduce the payload mass available for scientific instruments.

Our reliance on keothermal power has not led to any real progress in energy technology useful for spaceflight, like kerbolar power. We hope to have kerbolar panels to test out sometime in 2018 but the tech is still very nascent. Progress has been made readying radioactive isotope thermoelectric generators using the Kuudite mined from Sheltered Rock (described in our Extremis program brief) but no one is really eager to place radioactive materials on an unproven rocket. For now, orbital satellites will be limited in their ability to operate in space for extended periods of time, although our own Research & Development section has been working to give us bigger batteries that weigh less and store more energy.

Control in orbit extends beyond mere communication, as once the rocket engine shuts down it will only be able to restart once for a de-orbit burn – but it will be facing the wrong way! To allow the rocket to maneuver in zero-G and to also help make sure fuel gets to the engine for a restart, a reaction control system will use a small supply of monopropellant onboard to reorient the rocket. The fixed nozzles will be placed around the ends of rocket core to increase torque and will not be powerful enough to use as maneuvering thrusters during ascent.

While we can easily send and receive signals from low orbit, our time to do so while the spacecraft is within sight is limited due to the number of ground stations being just us along the equator, which would be the easiest trajectory to launch into. Arekibo and ATN central will not be capable of relaying signals as part of the Deep Space Network until late 2018 and early 2019, respectively. This will require a good deal of advanced operational planning to ensure that we can be in touch with the spacecraft often enough to tell it to get back down out of orbit before its power runs out.

We Can Build It!

As all the pieces continue to come together, we are targeting a series of launches to begin by the end of Q1 2018, which will feature just the core stage carrying a cargo bay for instruments capped off with a nose cone parachute and a decoupler to drop the engine and fuel tanks once re-entry is complete. After the engine has been selected we will reveal the rocket blueprint. Many more details of the program will be covered also in the coming months. Everyone here at the KSA is excited and ready to take the next step in space exploration!