A few years ago, The Center for Land Use Interpretation (CLUI) reported on the dozens of Photo calibration targets found in the USA. They are odd looking two dimensional targets with lots of lines on the of various sizes, used as part of the development of aerial photography. Mostly built in the 1950’s and 60’s as part of the US effort of the cold war.
At this point, just after the second world war, there was a huge push to get better information about the enemy. The military needed better aerial recconasance. This very problem lead to the development of the U-2 and the SR-71. As part of this, there needed to be methods of testing these planes with the big camera systems attached to them. This was before the development of digital photography, so resolution is much more difficult to test.
This is where the photo resolution markers came in. Much like an optometrist uses an eye chart, military aerial cameras used these giant markers. Defined in milspec MIL-STD-150A, they are generally 78ft x 53ft concrete or asphalt rectangles, with heavy black and white paint. The bars on it are sometimes called a tri-bar array, but they can come in all forms, such as white circles, squares, and checkered patterns.
The largest concentration of resolution targets is in the Mojave desert, around Edwards Air Force Base. This is the place most new planes were tested during this time, with the U-S, SR-71 and X-15 being just some of the planes tested there. There are a set of 15 targets over 20 miles, known as photo resolution road. There are also plenty of other resolution targets at aerial reconnaissance bases across the US, such as Travis AFB, Beaufort Marine Corps Base and Shaw Air Force Base.
As part of my degree I had to complete a project as part of the third year in the field of robotics and electronics. I chose to make a robotic platform, a simple idea that could be completed to a high quality with the right amount of effort. What is a robotic platform I hear you ask? well it essentially is a small buggy/rover that that moves around an assigned area completing simple jobs such as transporting goods, picking up parcels or any job that needs a moving vehicle. Usually autonomous, and very expensive, the majority of systems are very application specific. Some simple systems without any sort of control system can cost tens of thousands of pounds, and are not easy for the average employee to operate. Tackling the problem of expensive, application specific robotic platforms was the basis of my project.
Named the Semi Autonomous Robotic Platform, the idea was very simple, make a modular system, with building blocks that could be easily interchanged, and didn’t cost the world. These modules were things like motor controllers, sensors and power systems. If a user had a working platform built from this system, it would take minimal effort to swap out any of these modules to bigger motors or better sensors. This means a user can make a robot and only buy the bits they need, and even make their own modules, as long as they fit to the standard written as part of the project.
In most robotic systems, mainly to keep costs cheap, there is one controller that controls everything. This idea makes sense for small integrated systems that don’t need to change, but doesn’t really work when systems need to be dynamic. For instance, say you decide that your DC motors driving your robot aren’t giving you the control you want. You source some stepper motors, but this means completely changing the motor controller and therefore the software that controls it. Because one controller is in charge of everything, the software for the whole system needs to be re-written, and re-tested. That small change could have affected any of the other systems that that controller is in charge of. Make a change that breaks something important, you could set back a project weeks. This shows how painful a setup like this can be, especially when it starts to become a complex robot. Add on top of that the potential for computer intensive algorithms being used on the robot, like route planning or SLAM, and that controller suddenly has a lot to do. My system design separates these jobs out to a selection of individual controllers, such as a system specifically for motor control, or power systems. These controllers can deal with the nitty gritty hardware, and leave the master controller to orchestrate a higher level version of control.
The added benefit of separating out all these jobs means that multiple engineers can work on the same robot, at the same time on different areas and not be worried about breaking the other person’s design. The system specification defines how the modules interact in terms of communication speeds/type, the way to alert other modules and how those communications are scheduled. The master controller (shown in the system block diagram in green) schedules all these communications and decides which modules need specific information. Warnings, control signals and user inputs are all calculated and scheduled, then communicated to and from the required modules. A power system doesn’t care that a user has pressed a button to scroll through an LCD screen, and the master controller means it doesn’t see it.
The above video shows how the robot moves with its mecanum wheels, and how it can easy move around environments. I will explain the more technical parts of the project in a later post, but this simple idea became a very heavy hardware based project, rather than the software project it started as. I learnt about mechanical design, PCB design and good techniques associated with electronic design. For these reasons, the robot won the “Best Project” award for 2017. Thank you to: Cubik Innovation for help with electronic design, and providing PCBs, VEX Robotics for donating the wheels, and Altium Designer for providing their electronic design software. I would not have been able to produce the robot I did without them.
At 17:10 UTC on the 9th of March 2018, Arianespace launched its second rocket of the year from Guiana Space Center at Kourou. Designated VS18, the Soyuz rocket launched four O3b Satellites into orbit more than 3 years after the last O3b launch. Controlled by a Russian ground crew from the Soyuz Launch Complex (ELS) near Sinnamary, there was a 33 minute delay to the start because of bad weather. The Soyuz used was a Soyuz 2-1b/Fregat placing the satellite in Medium Earth Orbit (MEO).
A somewhat complex launch, the first ascent lasted 9 minutes and 23 seconds placing the launcher in a sub orbital trajectory. After separation the Fregat performed a 4 minute burn to reach 160 x 205 km x 5.16 deg parking orbit. Coasting for 8 minutes, the Fregat performed its second burn for 8 minutes and 36 seconds to enter a 190 x 7,869 km x 3.88 deg transfer orbit. Then after a coast of 1 hour and 21 minutes to the apogee, the Fregat fired for its third and final time for 5 minutes and 6 seconds, to enter its 7,830 km x 0.04 deg insertion orbit.
After the third burn, the satellites were release two at a time, with opposite satellites released at the same time. The first were released 2 hours into launch, and the second set 22 minutes later after a short firing of the Altitude Control System. The rocket then performed 2 more burns to lower its orbit to 200 km below the O3b release point. This was a disposable orbit, intended so that it will not interfere with working satellites.
The Ka band satellites are the fourth set of O3b to be sent up, making the total constellation 16. Arianespace intend to launch the next set of four in 2019. “The new Ka-band satellites will join the existing O3b constellation to deliver high-speed connectivity to people and businesses in the growing mobility, fixed data and government markets,” Arianespace officials said in a statement. It was reported that the launch was a success, and the Luxembourg based satellite operator SES Networks now have control of the O3b’s.
The second launch of the year, Arianespace delayed the launch from the original March 6th launch date. This was postponed to conduct extra checks, likely inspired by the partial failure of the Ariane V earlier this year. On January 25th the company lost contact with the upper stage of the rocket. The 3 satellites on board did reach orbit despite the anomaly, but Arianespace have been quiet on the condition of them.
In the late 1950’s, there were three people who were at the epicenter of a huge breakthrough in the world of electronics, the invention of the Integrated Circuit (IC). Jack Kilby of Texas Instruments, Kurt Lehovec of Sprague Electric Company, and Robert Noyce of Fairchild Semiconductor. In August 1959, Fairchild Semiconductor Director of R&D, Robert Noyce asked Jay Last to begin development on the first Integrated Circuit. They developed a flip-flop with four transistors and five resistors using a modified Direct Coupled Transistor Logic. Named the type “F” Flip-Flop, the die was etched to fit into a round TO-18 packaged, previously used for transistors. Under the name Micrologic, the “F” type was announced to the public in March 1961 via a press conference in New York and a photograph in LIFE magazine. Then in October, 5 new circuits were released, the type “G” gate function, a half adder, and a half shift register.
These first few integrated circuits were relatively slow, and only replaced a handful of components, while being sold for many times the price of a discrete transistor. The only applications that could afford the high prices were Aerospace and Military systems. The low power consumption and small size outweighed the price drawbacks, and allowed for new and more complex designs. In 1961, Jack Kilby’s colleague Harvey Craygon built a “molecular electronic computer” as a demonstration for the US Air Force to show that 587 Texas Instruments IC’s could replace 8,500 discrete components (like transistors and resistors) that performed the same function. In 1961, the most significant use of Fairchild Micrologic devices were in the Apollo Guidance Computer (AGC). It was designed by MIT and used 4,000 type “G” three input NOR gates. Over the Apollo project, over 200,000 units were purchased by NASA. The very early versions were $1000 each ($8000 today) but over the years prices fell to $20-$30 each. The AGC was the largest single user of IC’s through 1965.
Note that although Fairchild designed and owned the type “G” device, they were mostly made by Raytheon and Philco Ford under licence from Fairchild. Over this time many semiconductor manufacturers such as Texas Instruments, Raytheon and Philco Ford were also making large scale silicon production for other military equipment. These included the LGM-30 Minuteman ballistic missiles, and a series of chips for space satellites. This major investment from the government and the military kick started the development of the increasingly complex semiconductor, and eventually forced the prices low enough for non military applications. The processes improved and by the end of the Apollo program, hundreds of transistors could be fitted into an IC, and more complex circuits were being made. Eventually the costs of adding more transistors to a circuit got extremely low, with the difficulty being the quality of manufacturing. It could be argued that NASA and the Pentagon paved the way for silicon device production as we know it today.
At 05:33 UTC on March 6th 2018 SpaceX launched it’s 50th Falcon 9 mission. The version 1.2 Falcon 9, with a brand new “Block 4” variant booster B1044, lifted off from Cape Canaveral Space Launch Complex 40. On board, inside the type 1 fairing was Spain’s Hispasat 30W-6. Weighing in at 6,092kg, being the size of a bus and being launched into geosynchronous transfer orbit, it’s the biggest challenge that the Falcon 9 has come up against.
Falcon 9 flight 50 launches tonight, carrying Hispasat for Spain. At 6 metric tons and almost the size of a city bus, it will be the largest geostationary satellite we’ve ever flown.
The First stage if the Falcon 9 fired for about 2 minutes and 35 seconds before releasing and plummeting back towards the Atlantic ocean. The initial plan was top land the “type 4” first stage on the autonomous drone ship “Of Course I Still Love you” in the Atlantic. Landing legs and titanium steering grid fins were attached and went up with the rocket. There was already speculation, due to the large payload and the orbit attempted, whether the Falcon 9 would have enough fuel left to attempt the reentry and landing procedure. Unfortunately it was not possible to find out whether the F9-51 mission would have made a landing because the autonomous drone ship was kept in port because of high sea conditions. The rocket still went through the entire reentry and landing procedure, as mentioned on the livestream, but ended up in the Atlantic.
almost 9 minutes in, the second stage with the payload achieved a Low Earth Orbit, and “parked” until T+26 min 36s where they first crossed the equator. This second burn lasted 55 seconds to accelerate the ss/Loral-built satellite into a Geosynchronous Transfer Orbit. The Hispasat 30W-6 will fire its four SPT-100 plasma thrusters to gradually raise itself to Geosynchronous Orbit positioned 30 degrees West (clue in the name). Hispasat 30W-6 is designed to provide broadband services in Europe and Northwest Africa.
This is the fourth all-expendable Falcon 9 launch in the past 5 years, and the first time a “type 4” stage has been expended on it’s first flight. Both of the stages of the F9-51 rocket were tested at SpaceX Rocket Test Facility in McGregor, TX during October/November 2017. They have been at Cape Canaveral since January 2018, and were stacked ,loaded with propellant and tested (first stage only) at the Cape at SLC 40 on February 20, 2018. The Launch was initially planned for February 25th, but was shelved by SpaceX to investigate payload fairing pressurisation issues.
At 22:02 UTC on March 1st 2018 the Second Atlas V launch of 2018 fired the 5,192kg GOES-S satellite into orbit. Launching from Space Launch Complex 41 at Cape Canaveral, FL, the AV-077 (the launch designation) was an Atlas V in 541 configuration. GOES-S, an A2100 series satellite built by Lockheed Martin, was separated 3.5 hours into the mission into a 8,215km x 35,286km x 9.52 deg Geosynchronous Transfer Orbit (GTO).
The second of a new generation of weather satellites for the United States, GOES-S follows in the footsteps of GOES-East, now renamed to GOES-16. A huge jump in satellite capability, the new set of satellites cover from eastern Japan all the way over to west Africa, as well as parts of the Arctic and Antarctic. They can detect storms faster, see lightning and even have sensors to detect solar storms. The satellites were commissioned by the National Environmental Satellite, Data and Information Service (NESDIS) who manage the National Oceanographic and Atmospheric Administration (NOAA) constellation of environmental satellites. For more images and information follow them on twitter @NOAASatellites.
There are versions of the livestream on Youtube, and a highlight reel on the ULA Youtube page. They are definitely worth a watch if you want more information from the engineers themselves.
At 20:45 UTC on the 6th of February 2018 the long awaited Falcon Heavy soared up into the sky. Watching the livestream, there was something slightly different. Instead of the usual single commentator, they had four. Behind them, hundreds of SpaceX employees cheering all the way through the launch, with bigger cheers at each milestone. It was definitely long anticipated, and I even felt the impact at university. Students were going round making sure people knew that tonight was the night that the Falcon Heavy was launching. The stream didn’t disappoint space lovers, and I highly recommend watching it on the SpaceX Youtube page.
So what actually happened, why was this flight so important? The demo mission was the first firing of the full Falcon Heavy configuration. Although all the rockets had been previously fired and tested at SpaceX’s rocket test facility in McGregor, TX. Consisting of “Block 2” variant side boosters (B1023.2 and B1025.2) and a “Block 3” variant core stage (B1033.1). Both the boosters had been flown before and refurbished in Hawthorne, CA. B1023.2 was flown May 27th, 2016 for Thaicom 8 launch, landing on SpaceX’s autonomous drone ship “Of Course I Still Love You”. B1025.2 flew on July 18th, 2016 for the CRS-9 mission, landing at Landing Zone (now landing zone 1). It is noted that future Falcon Heavies will likely use the “Block 5” variant. Elon Musk Claims that the development of the Falcon Heavy project has cost $500 million to get to this stage.
At 20:45 UTC, the Falcon Heavy lifted off of pad 39A at Kennedy Space Centre. It weighed roughly 1,400 tonnes and was 70m tall. with 2,128 pounds of thrust, the triple barreled rocket lifted off the pad with its 27 Merlin 1D engines (9 on each booster). At the time of writing it is the largest and most powerful operational rocket in use today by a factor of 2. Elon Musk gave the launch a 50-50 chance of success, but it continued through almost all of the milestones. Through Max-Q, release of boosters, and release of the main engine. The second stage performed 3 burns during the 6 hour mission to accelerate the cargo to into a heliocentric orbit. The orbit ranges from earth orbit to beyond mars (0.99 x 1.71AU). The concept of this burn was to demonstrate long coasts between the second and third burns. This ability is needed for some DoD EELV Heavy class missions, a market that SpaceX wants to compete in.
Usually on these types of initial flights they put some sort of simulated weight in the fairing (the bit that holds the payload on top) usually a block of concrete. Elon Musk being Elon saw this as a marketing opportunity, and instead used his personal 2008 cherry red Roadster, weighing in at 1,250kg. In the driver’s seat sat a full scale human mannequin named “Starman”, wearing a SpaceX branded pressure spacesuit. The person who timed the release of the fairing showing the Tesla against the backdrop of the earth, to the music of “Life of Mars” by David Bowie, deserves a medal. Although perfectly timed, it is sometimes incorrectly attributed as “Starman” by Bowie, which would make more sense when you think about it. On the dashboard of the car is the immortal words of “don’t panic”, a tribute to A Hitchhiker’s Guide to the Galaxy, that was a clever addition. There is a livestream of the first 5 hours of Starmans trip, at which time it probably lost signal, or ran out of battery. There has been mixed reviews of this stunt. Some call it art, whereas others call it “space littering”. Some commentators such as Burnie Burns on the Roosterteeth Podcast simply don’t like the use of space for marketing purposes. Scientists at Purdue University called it “the dirtiest man-made object ever to be sent to space” due to its use driving in Los Angeles.
For me personally the most impressive part of the entire video was near to the end. SpaceX have had some famous problems with the landing of their reusable rockets, but during this mission they planned to land all three. The best shot of the entire livestream was the two boosters coming down at the same time, with the Cape in shot. Both boosters opening their landing legs, and coming down to land on Landing Zone 1 and 2. It was a truly epic sight, and from an engineers point of view, very impressive. The second pad was installed for these Falcon Heavy missions, and the boosters worked just as planned. The core was a slightly different story. It attempted to land on the autonomous drone ship “Of Course I Still Love You”. It completed its boost-back and reentry burn, but for the three-engine landing burn, two engines failed to ignite. The core ended up in the Atlantic. Smoothly brushed over, this was not mentioned on the Livestream, and not until a few hours later on Twitter. Even so, the things that did land correctly were impressive.
There has been a huge amount of excitement and skepticism about the Falcon Heavy. Some have heralded it the way Elon Musk wants to get to Mars, others just love the idea that the car will be out there for “billions of years”. Although very impressive, the Falcon heavy is really designed to be a beefier version of the Falcon 9, and will probably do the same job. SpaceX are aiming in the coming years to get more contracts from the Department of Defence, and aim to get more up into space at the same time. The Falcon Heavy is all about making it cheaper for big payloads to get to space. Although it has the capability to get to Mars, and carry people, Musk has said that there are bigger plans in the pipeline for those jobs. As for the car, according to chemist William Carroll, solar and cosmic radiation will break down most of the car within a year, leaving just the aluminium frame and maybe some glass that isn’t shattered by meteorites.
This is a big moment for SpaceX, and the space community, and shows that there are big things coming in the sector. There are big launches aimed from the big companies this year, and new rockets being unveiled in the near future. SpaceX may have just started a new space race. For all the excessive marketing that Elon Musk does, SpaceX have definitely got their marketing message right.