Pay with bank transfer

In order to donate via bank transfer, we will send our bank account details to your email. Please enter your email address here:

DEAR COPENHAGEN SUBORBITALS GUESTS, We'll get right to it: We need your help to run Copenhagen Suborbitals. This is a 100% non-profit project driven by sheer joy and hard work. We survive on donations averaging about $10, that we use to pay for raw materials, tools, our workshop, electricity and most importantly, rocket fuel. The entire CS team are unpaid volunteers, building rockets in our spare time. If this project brings you joy, please donate to keep it running. Thank you.

This is an update on our next generation of rocket engines, the BMP100, which will propel our manned Spica rocket above the edge of space. Here we discuss our current progress on the engine design after our initial design project called BPM100 in 100 days.

Make a donation

Help us continue building rockets with a one time donation

Published by Rasmus Agdestein on


Sune Peitersen · 23rd February 2019 at 11:37 am

Hi CS,
by switching to swirl injectors you seem to take on an additional year-long development project. I understand from the video that you expect “an extra few percent” thrust from the swirl injector design. Your current plans seem to be a 20x engine scale-up from 5 kN to 100kN. Why did you choose to go with the swirl injector instead of scaling up the existing engine by a factor (say) 22 and accept a few per cent loss?
– Sune

    Thomas Pedersen · 25th February 2019 at 8:58 pm

    It should not be a year long process at all. I firmly believe that switching to swirlers is overall the fastest way to go.

    Producing a showerhead injector in BPM100 size is tricky. The margin for error is very small, it does not take much error during production before you have to start all over again.

    In that sense the swirlers are optimized for rapid CNC manufacture on the type of CNC lathe that is auto fed with a round bar of rough material. The machining time per element is a few minutes. The tricky part is the silver soldering but we have some pretty good ideas on how to go by that. I promise we will make some very cool videos of that whole process.

    The current plan is to get the first elements in production this week and hopefully start testing soldering next week.

Comments are closed.