Any day now, the non-profit Aeronautics and Cosmonautics Romanian Association (ARCA) will launch a high-altitude balloon with a rocket tied to the bottom from a ship in the Black Sea.
Actually its three rockets tied in what one reader creatively describes as “nunchuck staging”. When the balloon reaches altitude, the first of the string of rockets will fire, carrying a small probe on a short suborbital trip. If all goes well, this proof-of-concept mission will pave the way for a launch balloon-based moon launch.
It’s an unusual, some might argue slightly crazy, approach to rocketeering. But Bogdan Sburlea, ARCA’s Project Manager, thinks it will work. He graciously agreed to answer some questions about this unorthodox proof-of-concept rocket, known as Helen.
How are you planning on attaching the Helen’s stages together? Will you use cable? Rope?
We will use cables of different diameters, the cable from the balloon to the first stage being the thickest.
How will you separate each stage when it has finished firing?
Actually, the separation will not take place after the previous stage finished firing. We will have about two seconds of simultaneous firing for stage one and two and later on for stage two and three. There are two reasons. The first is to avoid chaotic tensions in the cables. Firing the next stage before the previous stage shuts down means that there will be no moment in time when the tension in the cable becomes zero. The second reason is to avoid a collision between the stages.
Yes, the previous stage will become unstable during these few moments and will alter its trajectory. It will be enough to avoid a collision with the next stage. For separation, we use a pneumatic system for stages two and 3.
Are you worried that pendulum motion (swinging from side-to-side) might cause the rocket to become unstable?
This is not a concern for us, we modelled it and it works. If we are talking about the risks, that’s a different story. There are associated risks with many critical activities, but we hope that we covered everything.
How high do you hope the rocket will carry the test vehicle? Will it go into orbit?
No, it will not. This is just a test. We need to check the launch from the water, the usage of world’s largest solar balloon, not to mention the stabilization method and the strange position of the stages. We’ve got enough things to test; reaching orbit is not an objective for this launch.
How much have you spent developing the Helen? Who is paying?
We decided not to disclose the budget for the moment. There are many sources for the current budget, sponsorships and donations.
Do you have popular support in Romania?
Yes, we do. Many people are interested in what we do.
What will you do if the launch fails?
We will continue. Did SpaceX quit after the first failure? Or after the second failure?
Do you really think it will work?
Yes, we do. We have a huge advantage by being a small, private company: we can afford to test this.
When do you hope to get to the moon?
Before Google Lunar X Prize ends. We will do our best.
If you haven’t seen it already (and chances are if you’re a regular reader, you have), here’s a video showing the Helen’s flight plan:
Credit:ARCA