Voyager wins $16.5 million DARPA contract to give solid-fueled rockets variable thrust
The space station startup Voyager Technologies announced today that DARPA has awarded it a $16.5 million contract to develop a technology for use by all solid-fueled rocket manufacturers that will allow those rockets to have variable thrust while firing.
Until now, once you light a solid-fueled rocket motor (SRM) it works like a firecracker, burning at the same high thrust until it runs out of fuel. The goal is to introduce ways to change that thrust along the way, if need be.
During the 20-month contract, Voyager will combine its expertise with complex system modeling and controls with the propellant and manufacturing specialized to develop and validate proof-of-concept systems, culminating in tailorable SRM hot-fire demonstrations.
The program also focuses on manufacturing scalability and post-manufacturing control architectures, including the integration of structural health monitoring systems to support real-time health monitoring and performance. These activities are intended to prepare the technology for rapid industrial transition across multiple weapon systems, enabling flexible weapons procurement and large-scale production and stockpiling.
The vagueness in this description likely comes from two reasons. First, the technology is likely difficult and still uncertain. Two, when developed this technology is certainly going to be classified, since solid-fueled rockets are used extensively by the War Department in missiles. It will be made available to multiple American manufacturers, but only to them.
Whether this technology can become operational in less than two years remains a large question. We shall see. Nonetheless, as a company Voyager continues to expand its reach, diversifying its effort beyond its Starlab space station.
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Significant words from announcement: “… to advance the development of a new propellant-embedded control technology that gives solid rocket motors (SRMs) tailorable, post-manufacturing thrust control…”
“Propellant-embedded”, eh? Sounds like a way to control propellant burn rate at run-time! Perhaps selectable at firing, as opposed modulated during flight?
The operative word in this article is “post-manufacturing”, since solids do commonly vary thrust, but only in a fixed pattern set when the motor is built. The ability to change that pattern at will right before launch would confer a major military advantage. My guess is that would not mean much for space launch, though.
Cloudy,
Yes, while it’s useful for some tasks, it doesn’t address the challenges SRBs have for cheap, rapid reuse, or offer anything measurably superior. Liquid boosters can already vary their thrust on demand.
The hillbilly engineer in me envisions positioning a Traeger pellet feeder in between the solid fuel and the rocket nozzle.
I am hoping this technology is a way to prevent back-engineering of ordnance.
A Sidewinder got stuck in a MiG’s tailpipe, and came right back at us as the Atoll.
If propellant grain can run right up into a warhead’s explosive–it should go off at the end of the burn.
Joe Barnard of BPS.space came up with a method to “throttle” solid rocket motors for his model rocket landing projects:
https://www.youtube.com/watch?v=8sksiYfkses
Voyager?
Seriously?
This sounds like a total waste of money.
The only way to control the burn is to control the mix.
Any powder that sits for a long time will settle and compact into a hard block. Especially if it is subject to vibrations.
Do they plan on grinding it up and blowing it into the chamber. Very dangerous.
Or do they plan on keeping the components separate and blow them both into the chamber? A little safer.
Voyager used a rubber solid and a liquid oxidizer. The rubber kept burning slowly the whole time.
And in fact one time fell off the wall and blocked the chamber causing an explosion. Or a RUD as the space folks like to call it.
Propellant embedded control technology? Pretty vague.
Seems to exclude hybrid motors where oxidizer injection could be varied to result in thrust variability.
How does this different from Pintle nozzle implementations which have been around for 25+ years? The adjustment of the throat area allows for thrust variability. It has been used with a little success. It is mechanically complex. Maybe seeks to reduce pintle mechanical complexity?
Theoretically, some sort of liquid injection at the throat could do the same thing but to my knowledge never been done beyond laboratory demonstrations,
DARPA has been chasing this for 20 years.
At a propulsion conference in Huntsville back in 2000, there was a pintle throat presentation for throttling solids. When the pintle opened up, pressure dropped and burning slowed for throttle down. When the pintle closed some, pressure increased and it throttled up. All a function of pressure changing the burn rate. Long since lost the paper from that one.
Pintle throat implementation seems to be most successful for smaller SRMs. Thinking like Hellfire with its Northrop Grumman (formerly: Thiokol) M120E1 SRM.
The pintle mechanism takes much more of a beating the higher the thrust and the longer duration the burn. Been chased for a while for bigger SRMs. Can think of a lot of uses in both SAM and land attack missions, if a more reliable method of thrust variability could be demonstrated.
Pintle engines were the talk of the town then….