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.
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.
Every year at Supercon there is a critical mass of awesome people, and last year Sophi Kravitz was able to sneak away from the festivities for this interview with Katherine Scott. Kat was a judge for the 2017 Hackaday Prize. She specializes in computer vision, robotics, and manufacturing and was the image analytics team lead at Planet Labs when this interview was filmed.
You’re going to chuckle at the beginning of the video as Kat and Sophi recount the kind of highjinks going on at the con. In the hardware hacking area there were impromptu experiments in melting aluminum with gallium, and one of the afternoon’s organized workshop combined wood and high voltage to create lichtenberg figures. Does anyone else smell burning? Don’t forget to grab your 2018 Hackaday Superconference tickets and join in the fun this year!
Below you’ll find the interview which dives into Kat’s work with satellite imaging.
Space elevators belong to that class of technology that we all want to see become a reality within our lifetimes, but deep-down doubt we’ll ever get to witness firsthand. Like cold fusion, or faster than light travel, we understand the principles that should make these concepts possible, but they’re so far beyond our technical understanding that they might as well be fantasy.
Except, maybe not. When Japan Aerospace Exploration Agency (JAXA) launches their seventh Kounotori H-II Transfer Vehicle towards the International Space Station, riding along with the experiments and supplies for the astronauts, will be a very special pair of CubeSats. They make up the world’s first practical test of space elevator technology, and with any luck, will be one of many small steps that precedes the giant leap which access to space at a fraction of the cost will be.
Of course, they won’t be testing a fully functional space elevator; even the most aggressive of timelines put us a few decades out from that. This will simply be a small scale test of some of the concepts that are central to building a space elevator, as we need to learn to crawl before we can walk. But even if we aren’t around to see the first practical space elevator make it to the top, at least we can say we were there on the ground floor.
French Defense Minister Florence Parly took a page out of Little Red Riding Hood when she recently called out a Russian satellite for having “big ears”. While she stopped short of giving any concrete details, it was a rare and not terribly veiled accusation that Russia is using their Luch-Olymp spacecraft to perform orbital espionage.
Luch satellite conceptual drawing from NASA
At a speech in Toulouse, Parly was quoted as saying: “It got close. A bit too close. So close that one really could believe that it was trying to capture our communications.” and “this little Stars Wars didn’t happen a long time ago in a galaxy far away. It happened a year ago, 36,000 kilometers above our heads.”
The target of this potential act of space piracy is the Athena-Fidus satellite, a joint venture between France and Italy to provide secure communication for the military and emergency services of both countries. Launched in 2014, it provides 3 Gbit/s throughput via the Ka-band for mobile receivers on the ground and in drones.
This isn’t the first time Russia’s Luch class of vehicles has been the subject of scrutiny. In 2015 it was reported that one such craft maneuvered to within 10 kilometers of the Intelsat 7 and Intelsat 901 geostationary communications satellites, prompting classified meetings at the United States Defense Department. As geostationary satellites orbit the Earth at 3.07 km/s, a 10 km approach is exceptionally dangerous. Even a slight miscalculation could cause an impact within seconds.
Could Stealth Satellites Be In Our Future?
Much to the chagrin of shadowy spy agencies everywhere, this sort of orbital cat and mouse is easily detectable from the ground. When spy planes became easy to detect using radar, the next step was to evade that detection. Are we on a path to satellites that are transparent to radar?
Gregory Charvat, author of Small and Short-Range Radar Systems and occasional contributor here at Hackaday, tells us that building a stealth satellite is no easy task. “Just like how we had to re-invent the aircraft to make the first stealth aircraft, to make a stealth satellite one would have to fundamentally re-invent the satellite as we know it today.”
Likening it to the immense cost and effort it took to develop stealth aircraft like the Lockheed F-117 Nighthawk, Gregory says developing a satellite which could hide from radar would likely be more trouble than it’s worth for most applications. Space is already hard enough. “Maintaining that special shape that reflects radar away from your aircraft and including all of these essential peripherals is a big challenge” Gregory says, which results in “compromise and high maintenance costs.”
Beyond attempting to eavesdrop on communications, military insiders say that these close passes by Luch satellites could also be “dry-runs” for anti-satellite operations; either by using a directed energy weapon to disable the target spacecraft, or simply running into it. With events like these, and the commitment by the United States to establish a Space Force in the coming years, efforts to militarize space seem to be on the rise.
Over the past few decades, numerous space probes sent to the far-flung reaches of the Solar System have fallen silent. These failures weren’t due to communications problems, probes flying into scientifically implausible anomalies, or little green men snatching up the robotic scouts we’ve sent out into the Solar System. No, these space probes have failed simply because engineers on Earth can’t point them. If you lose attitude control, you lose the ability to point a transmitter at Earth. If you’re managing a space telescope, losing the ability to point a spacecraft turns a valuable piece of scientific equipment into a worthless, spinning pile of junk.
The reasons for these failures is difficult to pin down, but now a few people have an idea. Failures of the Kepler, Dawn, Hayabusa, and FUSE space probes were due to failures of the reaction wheels in the spacecraft. These failures, in turn, were caused by space weather. Specifically, coronal mass ejections from the Sun. How did this research come about, and what does it mean for future missions to deep space?
I recently saw Apollo 13 again — this time with the score played live by the Houston Symphony. What a crazy coincidence that thirteen has long been considered an unlucky number and that Apollo 13 would be the one we almost lost. However, Apollo 12 almost became a disaster which — after the ordeal with flight 13 — was largely forgotten.
When all was said and done, Apollo 12 would result in a second manned moon landing in November 1969, just four months after Apollo 11. Commanded by Pete Conrad, Alan Bean accompanied Conrad to the surface while Richard Gordon, Jr. kept the getaway vehicle running. But less than a minute after launch something happened that could have been a disaster. Lightning struck the vehicle.
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.
[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.
