Want to support the development of our crewed Spica rocket and crowdfunded space program while wearing some cool space merch? 🚀 Visit our store here: zazzle.co.uk/copsub

Most crewed rockets carry a system to pull the crew clear if something goes wrong, and right now we plan to fly without one. The reason is that we fear it would bring us bigger problems than it solves.

We measure almost everything we build, except the people following along. Take our six-minute anonymous survey and you're in the draw for a Remove Before Flight key ring. bit.ly/3TE6mdu #CopSub

We publish almost everything we do. Almost is doing real work in that sentence. Open development is the reason this program exists, and it is the reason people trust it.

Hardware can take 15 g. A person can take a fraction of that, and only lying down, facing the right way. Acceleration through the chest is survivable at levels that would grey you out instantly if you were sitting upright.

A person on board wants a hand on something. The reliability data does not agree. Automation does the same thing every time, does not panic, and does not need to see out of a window.

The capsule is a pressure vessel that happens to have a person inside it. One atmosphere on the inside, nothing on the outside, and a wall that has to hold that difference without complaint.

"Boy Scouts on steroids" That’s how one of our guests described us - we’ll take it! We are 100% crowdfunded and 100% volunteer-run. When you book our tour, you are stepping into a working workshop where real people are building rockets. Book your visit: bit.ly/3kLX7SK

Buying the part is faster, until the lead time comes back as 40 weeks. Off the shelf hardware is qualified, documented and someone else's problem when it fails.

Everything we have said so far is true for a satellite. Now put a person in it. Back us: bit.ly/4rtFgBZ

This failed engine test brings some *ahem* "warm" memories... We share many such less-and-more-successful memories during our weekly rocket factory tours, while showing you our latest rocket production in action. Dates and booking. 👉bit.ly/3kLX7SK

Every safety factor is mass, and every kilo of mass is altitude you do not get. On an uncrewed vehicle you can argue the margin down and accept that sometimes you lose the rocket.

A rocket tank has to be strong enough to survive the flight and light enough to make the flight worth taking. Those two requirements pull in opposite directions on every single millimetre of wall.

Our rocket "factory" is open for visits every weekend. You can watch our Spica rocket take shape and hear about all the success and failures from our previous tests and launches. Like the time this engine came apart during a static fire. 🚀Dates & booking: bit.ly/3kLX7SK

Wings look like the future. We are not building wings. A spaceplane gives you a gentle return and a runway at the end of it, which is genuinely better for the person inside.

Why is it taking so long? Because nobody sells the tools we need. At our scale you cannot buy a rocket welder, so we built one, and it took years. From outside it looked like nothing was happening, and it was us buying speed later. youtu.be/6V5lNKQXnB8 #CopSub