Cortex 2 is One Serious 3D Printed Experimental Rocket

Rocketry is wild, and [Foaly] is sharing build and design details of the Cortex 2 mini rocket which is entirely 3D printed. Don’t let that fool you into thinking it is in any way a gimmick; the Cortex 2 is a serious piece of engineering with some fascinating development.

Cortex 1 was launched as part of C’Space, an event allowing students to launch experimental rockets. Stuffed with sensors and entirely 3D printed, Cortex 1 flew well, but the parachute failed to deploy mainly due to an imperfectly bonded assembly. The hatch was recovered, but the rocket was lost. Lessons were learned, and Cortex 2 was drafted up before the end of the event.

Some of the changes included tweaking the shape and reducing weight, and the refinements also led to reducing the number of fins from four to three. The fins for Cortex 2 are also reinforced with carbon fiber inserts and are bolted on to the main body.

Here’s an interesting details: apparently keeping the original fins would result in a rocket that was “overstable”. We didn’t really realize that was a thing. The results of overstabilizing are similar to a PID loop where gain is too high, and overcorrection results in oscillations instead of a nice stable trajectory.

Cortex 2 uses a different rocket motor from its predecessor, which led to another interesting design issue. The new motor is similar to hobby solid rocket motors where a small explosive charge at the top of the motor blows some time after the fuel is gone. This charge is meant to eject a parachute, but the Cortex 2 is not designed to use this method, and so the gasses must be vented. [Foaly] was understandably not enthusiastic about venting hot gasses through the mostly-PLA rocket body. Instead, a cylindrical cartridge was designed that both encases the motor and redirects any gasses from the explosive charge out the rear of the rocket. That cartridge was SLA printed out of what looks to us like Formlabs’ High Tempurature Resin.

Finally, to address the reasons Cortex 1 crashed, the hatch and parachute were redesigned for better reliability. A servo takes care of activating the system, and a couple of reverse-polarity magnets assist in ensuring the hatch blows clear. There’s even a small servo that takes care of retracting the launch guide.

The rocket is only half built so far, but looks absolutely fantastic and we can’t wait to see more. It’s clear [Foaly] has a lot of experience and knowledge. After all, [Foaly] did convert a Makerbot printer into a CNC circuitboard engraver.

An Englishman’s Home Is His (Drone-Defended) Castle

Retiring to the garden for a few reflective puffs on the meerschaum and a quick shufti through the Racing Post, and the peace of the afternoon is shattered by the buzz of a drone in the old airspace,what! What’s a chap to do, let loose with both barrels of the finest birdshot from the trusty twelve-bore? Or build a missile battery cunningly concealed in a dovecote? The latter is what [secretbatcave] did to protect his little slice of England, and while we’re not sure of its efficacy we’re still pretty taken with it. After all, who wouldn’t want a useless garden accoutrement that conceals a fearsome 21st century defence system?

The basic shell of the dovecote is made from laser cut ply, in the shape of an innocuous miniature house. The roof is in two sliding sections which glide apart upon servo-controlled drawer runners, and concealed within is the rocket launcher itself on a counterweighted arm to lift it through the opening. The (toy) rocket itelf is aimed with a camera pan/tilt mechanism,and the whole is under the control of a Raspberry Pi

It’s understood that this is a rather tongue-in-cheek project, and the chances of any multirotors falling out of the sky are somewhat remote. But it does serve also to bring a bit of light back onto a theme Hackaday have touched upon in previous years, that of the sometimes uneasy relationship between drone and public.

Travel to Mercury on Ion Power

Star Trek — as much as we love it — was guilty sometimes of a bit of hyperbole and more than its share of inconsistency. In some episodes, ion drives were advanced technology and in others they were obsolete. Make up your mind!

The ESA-JAXA BepiColombo probe is on its way to Mercury riding on four ion thrusters developed by a company called QinetiQ. But unlike the ion drive featured in the infamous “Spock’s Brain” episode, BepiColombo will take over seven years to get to Mercury. That’s because these ion drives are real.

The craft is actually two spacecraft in one with two different Mercury missions. The Mercury planetary orbiter will study the surface while the magnetosphere orbiter will study the little planet’s magnetic field. Check out a video about the mission, below. The second video shows [Neil Wallace] talking about how the ion propulsion — also known as solar electric engines — differ from traditional chemical thrusters.

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Rocket Science With The Other SpaceX

When you say that something’s not rocket science you mean that it’s not as hard to understand or do as it may seem. The implication is that rocket science is something which is hard and best left to the likes of SpaceX or NASA. But that’s not the hacker spirit.

Rocket science with BPS.Space[Joe Barnard] recently had an unsuccessful flight of his Falcon Heavy’s second stage and gives a very clear explanation of what went wrong using those two simple concepts along with the thrust, which in this case is just the force applied to the moment arm.

And no, you didn’t miss a big happening with SpaceX. His Falcon Heavy is a homebrew one using model rocket solid boosters. Mind you, it is a little more advanced than that as he’s implemented thrust vectoring by controlling the engine’s direction using servo motors.

And therein lies the problem. The second stage’s inertia is so small and the moment arm so short that even a small misalignment in the thrust vectoring results in a big effect on the moment arm causing the vehicle to deviate from the desired path. You can see this in the first video below. Another issue he discusses is the high drag, but we’ll leave that to the second video below which contains his explanation and some chart analysis.

So yeah, maybe rocket science is rocket science. But there’s no better way to get your feet wet then to get out there and get building.

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The Largest Aircraft Ever Built Will Soon Launch Rockets To Space

Deep in the mojave, the largest aircraft ever made will soon be making test flights. This is the Stratolaunch, and it’s measured the largest to ever fly based on wingspan. The Stratolaunch was constructed out of two 747s, and is designed for a single purpose: as a mobile launch platform for orbital rockets.

There are a couple of ways to measure the size of an aircraft. The AN-225 Mriya has the highest payload capacity, but only one of those was ever built (though that might change soon). The Spruce Goose was formerly the largest aircraft by wingspan, but it only flew once, and only in ground effect. The Stratolaunch is in another category entirely. This is an aircraft that contains some of the largest composite structures on the planet. Not only can you park a school bus between the fuselages of the Stratolaunch, you can strap that school bus to the plane and carry it up to 30,000 feet.

But why build this astonishing aircraft? The reasons go back more than a decade, and the end result is a spaceplane.

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Build Your Own Two-Stage Water Rockets

Water rockets are one of the most fun and exciting science-adjacent activities one can take part in during the summer, and are popular with children and adults alike. Designs range from a bike pump with a cork in a bottle, up to significantly more advanced hardware. [Air.command]’s two-stage water rocket definitely fits into the latter category.

The build is initially somewhat confronting in its complexity, but after a thorough read-through the operating principles become clear. It’s an all-mechanical setup which relies on the weight of the upper stage and the initial acceleration of the rocket to keep the two stages coupled. It’s only when the first stage stops delivering thrust that a spring forces the two stages apart, and the upper stage rockets ever higher.

Parts-wise, everything is fairly accessible – with pieces cribbed from garden hose fittings, retractable pens and other household ephemera. It’s not the easiest thing to put together, but with perseverance and some tweaking and tuning, it’s definitely achievable for the home gamer, with no advanced tools or techniques required.

Now that you’ve got a two-stage rocket under construction, you might want to consider upgrading your launchpad. Video after the break.

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Delta Clipper: A 1990s Reusable Single-Stage To Orbit Spaceship Prototype

With all the talk of SpaceX and Blue Origin sending rockets to orbit and vertically landing part or all of them back on Earth for reuse you’d think that they were the first to try it. Nothing can be further from the truth. Back in the 1990s, a small team backed by McDonnell Douglas and the US government vertically launched and landed versions of a rocket called the Delta Clipper. It didn’t go to orbit but it did perform some extraordinary feats.

Origin Of The Delta Clipper

DC-XAThe Delta Clipper was an unmanned demonstrator launch vehicle flown from 1993 to 1996 for testing vertical takeoff and landing (VTOL) single-stage to orbit (SSTO) technology. For anyone who watched SpaceX testing VTOL with its Grasshopper vehicle in 2012/13, the Delta Clipper’s maneuvers would look very familiar.

Initially, it was funded by the Strategic Defence Initiative Organization (SDIO). Many may remember SDI as “Star Wars”, the proposed defence system against ballistic missiles which had political traction during the 1980s up to the end of the Cold War.

Ultimately, the SDIO wanted a suborbital recoverable rocket capable of carrying a 3,000 lb payload to an altitude of 284 miles (457 km), which is around the altitude of the International Space Station. It also had to return with a soft landing to a precise location and be able to fly again in three to seven days. Part of the goal was to have a means of rapidly replacing military satellites should there be a national emergency.

The plan was to start with an “X” subscale vehicle which would demonstrate vertical takeoff and landing and do so again in three to seven days. A “Y” orbital prototype would follow that. In August 1991, McDonnell-Douglas won the contract for the “X” version and the possible future “Y” one. The following is the story of that vehicle and its amazing feats.

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