PTN interviews Escape Dynamics on the future of space technology

Escape Dynamics is developing a radically different approach to space launch: The team is developing the first single-stage-to-orbit spaceplane designed for full and rapid reusability, to dramatically reduce the cost of reaching orbit and beyond. PlanetTech News interviews them on the future of space technology:
Please tell us briefly what is Escape Dynamics and how did it get started? What’s the big idea?
We started the company with the vision of opening space for large scale commercial, social and scientific exploration and with the fundamental belief that affordable, sustainable aerospace transportation is possible. The primary challenge we decided to address is fundamental inefficiency of chemical rockets which prevents affordable access to space. We asked the question: are there technologies and propulsion systems that can be 10x more efficient than chemical rockets. We’ve been thinking about this a lot and eventually converged on external propulsion.
The big idea behind the company is that new electromagnetically powered propulsion systems that dramatically surpass chemical rockets are possible. There is no need to limit space access to chemical combustion – there is a better way. In the external propulsion system developed at Escape Dynamics, energy necessary for propulsion is coming from a ground-based array of microwave antennas and is delivered to a moving vehicle via a microwave beam. The microwave beam tracks the vehicle as it accelerates into orbit and is absorbed in a heat exchanger on the belly of the vehicle. Hydrogen from an onboard tank flows through the heat exchanger and is heated with microwaves before it is exhausted through the nozzle, creating thrust with efficiency far surpassing the maximum efficiency of chemical rockets.
Basically, by using external microwave energy we are able to eliminate the need for combustion and dramatically increase efficiency. In rockets efficiency is often quantified through specific impulse, Isp, which is proportional to the exhaust velocity of the gas. Chemical rockets max out at around 460 seconds of Isp and many of the rockets used today operate at around 340-380 seconds. This fundamental inefficiency leads to a very unfavorable ratio of propellant mass to useful (structure + payload) mass. In chemical rockets the ratio is around 90/10 and this make it extremely hard for chemical rockets to achieve reusability. Because of this unfavorable ratio, chemical rockets used today are flying as multi-stage systems, making reusability even harder.
In our external propulsion system specific impulse will be above 750 seconds leading to propellant to useful mass ratio around 70/30. This is a transformative change in efficiency and the one that is required for full and rapid reusability and for single-stage-to-orbit, airplane-like operation.

Here is the video describing our concept:

A short story of the founding days
When I (Dmitriy Tseliakhovich) was the first year Ph.D. student at Caltech I met an amazing visionary entrepreneur and a legendary aviator, Richard F. Schaden, who was at that time searching for an opportunity to transform aerospace industry and enable sustainable travel in the atmosphere and beyond. Richard and I immediately resonated and he became the main investor and partner in Escape Dynamics. A lot of the initial ideas of the business and technology originated from the early discussions between Richard, myself, Andy Lee and Shaun Maguire who has become an invaluable adviser to the company and is a big part of Escape Dynamics right now. The company
would not be possible without other co-founders, including Andy Lee who has been the rock behind our operations from the very beginning and Laetitia Garriott who joined our founding team and has been absolutely instrumental to the growth and development of the company.
What has been the journey of the company up to this point?
After an initial period of mainly theoretical development, we started to grow the team and build the lab and the hardware in Broomfield in late 2012/ early 2013. The most extraordinary thing that happened during that period is that the idea and the passion of the founders attracted the most remarkable engineers to join us and start contributing their ideas and hard work to the effort. We were extremely fortunate to have attracted experts from MIT and Caltech as well as the most remarkable group of engineers and manufacturing experts from other places.
From the start we decided to focus on the most challenging and demanding aspects of external propulsion: high power microwave generation and wireless energy transfer. We designed and built a 100kW microwave source designed for continuous operation, something that only a few companies in the world are able to do. The challenges of HPM are easy to comprehend if one thinks of the fact that we are taking all of the energy required to power a flying vehicle and compressing it into a device the size of a small SUV: 100kW is more than enough to power a small airplane, but now that energy is compressed into a small device staying on the ground.
We also developed wireless energy transfer systems and thrusters to convert microwave energy into thrust. This summer we demonstrate a thruster operating with efficiency above chemical rockets and showed the complete sequence of external propulsion system, drawing the electricity from the electric grid, conversion of electricity into microwaves, guiding microwaves into the antenna, beaming microwave energy wirelessly to the thruster and conversion of the energy into highly efficient thrust.
Here are two technology demonstration videos:
1. Technology Overview Video: 

2. UAV Tracking and Energy Uplink to a moving UAV: 

Currently, what do you perceive as your biggest challenges?
Right now, after we have built the key individual components of the system, the primary technical challenges are integration and scaling. Making everything work in concert in a system like this is an exciting challenge of control, dynamics and real time system analysis. Energy needs to keep continuously flowing from the storage system into an array of microwave sources, microwaves need to be measured and adjusted in real time as the beam is travelling towards antennas, antennas need to synchronously move in order to track the vehicle and the vehicle needs to be able to dynamically regulate the thrust to conform to the pre-designed trajectory.
Do you intend to build your own launch vehicles or will you license your technology for others to use?
External prolusion systems and SSTO spaceplanes do not exist today, so we do need to develop our own spaceplanes. This is both a challenge and an opportunity as it allows us to start from scratch and design the most efficient spaceplane possible using the latest and most advanced simulation tools, materials, and manufacturing approaches. However, we are certainly not planning on doing it all alone. There is tremendous expertise at NASA and at commercial companies that we plan on leveraging through contracting and through partnerships. Many of the important components we need for the vehicle are available or can be jointly developed by working with experts outside of EDI. We are only focused on technologies that do not exist today or cannot be acquired at reasonable price/quality.
What are the plans (timeline) for the future of Escape Dynamics?
We are currently focused on the next generation of tests. The goal is to take the system into the field and do power beaming over 100’s of meters with the energy converted into thrust by a prototype of a flight capable engine. We are also designing new high power energy transfer systems and are looking forward to testing megawatt-scale power beaming. After that the next step will be flight test starting with megawatts of power and very small thrust and going into the flight of suborbital vehicles with 10s of megawatts.
Are others working on similar projects in competition with you? What do you make of SpaceX’s highly publicized attempts at reusability? Do you see this as a competing vision for the next generation of launch technology?
I believe that the space is a remarkable frontier that can unite people and focus various parties on a common goal. The opportunities enabled by reusable single-stage-to-orbit spaceplane are big enough for everyone to focus on making it happen rather than on competing on who gets there first.
I think SpaceX is the shining star for both the aerospace industry and for our civilization. They are building large reusable chemical rockets that will reduce the cost of space access and enable launch of heavy payloads necessary for making life multi-planetary. We are building a different system – a compact reusable single-stage-to-orbit spaceplane that will allow a much broader scope of businesses to access space affordably and do a wide range of things in orbit. I believe that our effort is complementary to the effort of SpaceX’s team. I also believe that it is absolutely critical to be working on technologies that go beyond chemical rockets, and EDI is one of only a few companies focused on that. We need to and can find better, more efficient ways to propel vehicles both in the atmosphere and outside of the atmosphere.
In your opinion, what will the space technology scene look like in 10 and 20 years time?
I believe in 10-20 years the following breakthroughs will appear and become reality:
1. It will be possible to board a spaceplane in a hangar, taxi to the launch pad, fly into orbit and return back to the spaceport a few hours later. Spaceflight will be done in a way similar to airplane operation today.
2. Large scale chemical rockets will reach reusability and SpaceX will be able to launch vast quantities of cargo into orbit.
3. In 20 years we will see the beginning of a colony on Mars and there will be a permanent settlement in Earth orbit – similar to the ISS today, but commercial and on a scale of thousands of people.
4. There will be suborbital point-to-point flights with time between New York and Sydney reduced to under 60 minutes.
5. New propulsion system for both aircraft and space launch systems will be fully developed and operational; there will be no new engines burning fossil fuels in 20 years.
6. The entire planet will be capture in real-time high resolution video from orbit and the high speed internet from orbit will be available to the entire population of our planet.