SpaceRyde, a Canadian microsat launcher, completes field trial of rocket carrier | Hacker News Reader

SpaceRyde, a Canadian microsat launcher, completes field trial of rocket carrier

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38 pointsmuunbo32 comments

The technology is described well on their web site: https://www.spaceryde.com/technology

"A stratospheric balloon takes satellites in a custom-designed, ultra-light rocket to high altitude, where it is launched in near vacuum conditions, avoiding the stress and costs of high speed travel through dense layers of the atmosphere."

The common term for this is Rockoon: https://en.wikipedia.org/wiki/Rockoon

Disclaimer: I am an Avionics Specialist at SpaceRyde. Ask questions!

Could you explain what is going on in this video? Are you building a microsat launcher that gets sent off while hanging from a helicopter?

> enable accurate launch of the rocket from the balloon in the stratosphere. Even though Silverthrone is designed for launch from a balloon, its control capabilities were put to test in harsher conditions of the heavy downwash of the helicopter, to ensure it is ready for rocket launch.

Seems like this is testing the hardware that will be elevated using a balloon. The helicopter isn't part of launch plans.

Ah, so it's a tweak for sneaking the rocket beyond those thickest layers of air, interesting. My initial impression was that it might be just a clever idea to forego the need for a dedicated rocket launch pad.

Why not both? :)

A launch pad gives you the capacity for far larger rockets and payloads.

A high altitude start only allows you to tweak your rocket nozzles for minor efficiency gains.

I believe it's similar to this: https://en.wikipedia.org/wiki/Air-launch-to-orbit

The idea is to get the rocket as high as possible using conventional vehicles, which should make it easier for the rocket to reach orbit.

It was proposed as a way of launching rockets from countries that don't have access to the best spots on the planet.

I've followed ARCASpace with interest for a while, although it looks like nothing came out of it, sadly:

https://en.wikipedia.org/wiki/ARCAspace

https://en.wikipedia.org/wiki/IAR_111

https://en.wikipedia.org/wiki/Haas_(rocket)

Only problem is that altitude is the least important component of orbital space flight.

To each orbit you need to achieve roughly Mach 30 in the correct inclination, and above the bulk of the atmosphere. If your rocket can achieve Mach 30 you don’t need an altitude boost from a balloon, if your rocket can’t hit Mach 30 the balloon won’t help.

But hitting air isn't a small problem either, or is it?

It is, but it also takes time to reach those velocities. Every orbital rocket that I am aware of has a period called MaxQ, where it has to throttle back to avoid exceeding air pressure limits. But it only occurs in lower dense atmosphere and usually ends in a few seconds.

So balloon drop from high altitude avoids having MaxQ issues at all, so no throttling required (which could also make rocket engines simpler). But all the other drawbacks make air drop only useful for the tiniest of orbital payloads.

In the video, we show a flight test of our system hanging from a helicopter - however, our actual launches will happen while hanging from a high altitude balloon, not a helicopter. The helicopter test gives us a way to test the performance of our yaw control system (to point the rocket along a desired heading) without having to do a full blown balloon launch.

Awesome! Thanks for being here to answer questions, I've got a few for ya.

The big quad thing is just to ensure heading stability? Does that imply that the rocket lights and drops at roughly the same time so there's no chance for it to tumble out of it's desired orientation? Are you going to blast all the props immediately before launch to get it to swing into a more vertical position? How much control authority do you actually have with the air so thin up there?

Hi, great questions! 1) Yes you're right - the 'big quad thing', a.k.a rocket carrier a.k.a gondola, stabilizes the heading of the rocket. 2) It does not necessarily imply that, but yes that would be a great way to do it so that the rocket control system doesn't need to correct for the tumble. 3) There are multiple ways to pitch up the rocket, and you are right that one of them is to use the props. Alternatives are to have thrusters on the rocket or have gimballing on the rocket nozzle. All are viable approaches. 4) This is a complex question as we have many variables to play with, such as choice of launch altitude, size and design of propellers, etc.

I have a question: So this is intended to maintain heading prior to launch (my friends who previously did balloon launch were doing something similar), and you intend to launch from baloons at a height where there's very little air .... how are the props going to work without air?

If balloon remains buoyant it means there's air.

It's rarified but shouldn't be impossible to compensate with propeller rpm.

So there's not "no air" but rather just low pressure. The props can be designed to work at certain high altitudes, although they will be less effective at higher altitudes. But this only means that it takes longer to change the yaw of the gondola to the desired heading.

yeah but hanging it from a helicopter is not a test of that

Am I correct in thinking that the launch will be basically horizontal once the assembly has enough altitude?

Most likely, yes, but it's not necessarily the case. We could pitch the rocket up slightly if it helps to achieve a specific target trajectory.

What's the expected maximum payload weight and size? What's the expected maximum altitude? Tried searching for that info on the website but didn't seem to be able to find it at a glance (?)

Does it need to be carried by a manned helicopter? How high can you launch?

The helicopter flight was a test of our gondola's ability to control the heading of the rocket. Our actual launches are not on a helicopter but rather on a high altitude balloon, which allows us to go up and launch from the stratosphere.

Are you hiring software developers in the Ottawa area?

Hi! We are not currently hiring in Ottawa, only in Vaughan (close to Toronto): https://www.spaceryde.com/careers. Let your friends know!

Hydrogen or helium balloons?

And why did you chose that one over the other?

We have no specific preference for hydrogen vs helium balloons at the moment

Elon Musk once discussed why air launch from planes was not a good idea, and his criticisms apply to Rockoons as well.

“seems like...you're high up there and so surely that's good and you're going at...0.7 or 0.8 Mach and you've got some speed and altitude, you can use a higher expansion ratio on the nozzle, doesn't all that add up to a meaningful improvement in payload to orbit?

"The answer is no, it does not, unfortunately. It's quite a small improvement. It's maybe a 5% improvement in payload to orbit...and then you've got this humungous plane to deal with. Which is just like having a stage. From SpaceX's standpoint, would it make more sense to have a gigantic plane or to increase the size of the first stage by five percent? Uhh, I'll take option two.

"And then, once you get beyond a certain scale, you just can't make the plane big enough. When you drop...the rocket, you have the slight problem that you're not going the right direction. If you look at what Orbital Sciences did with Pegasus, they have a delta wing to do the turn maneuver but then you've got this big wing that's added a bunch of mass and you've able to mostly, but not entirely, convert your horizontal velocity into vertical velocity, or mostly vertical velocity, and the net is really not great.”

For SpaceRyde the extra height is a trivial benefit given that the velocity of reaching orbiting is the key part, altitude is a free byproduct of that velocity. The real benefit is being able to use a more efficient nozzle.

By not having to throttle for MaxQ, with a vacuum optimized nozzle, at most balloon launch adds 10%, at the cost of substantial size and payload limits.

One benefit of SpaceRyde over plane launch is the rocket can launch at a better orientation, not requiring the added weight/complexity of wings like Pegasus.

But the problem is that SpaceRyde lacks the single major benefits of airplane launch, the ability to launch almost regardless of weather by flying around it, and in a mission specific latitude that can be reached in flight from a home launch base. SoaceRyde is not launching in inclement weather, though it can be launched in different latitudes.

It’s sole advantage is going to be cost over other air launch systems (should be way less complex) and other ground launched small sat providers but is unlikely to be able to serve more than the tiniest payload sizes.