If the space station were left to its own devices, the living quarters would get incredibly hot. There are computers, hardware, and six crew members, all generating heat that must be gotten rid of. To do this, there are two heat exchangers inside the station that take warm water, dump that heat to ammonia, and send that ammonia out to panels outside the station. On December 11, 2013, Loop A of the thermal control system shut down, putting the station one failure away from evacuation. Plans for a spacewalk were tabled, but the ground crew managed to fix this hardware failure by telling the astronauts to push buttons, a metronome, and a software patch.
The problem with Loop A of the Internal Thermal Control System was a flow control valve that regulated the amount of ammonia flowing through the heat exchange. Too much ammonia, and the station would be far too cold. Too little, and it would be too hot. This valve is electronically controlled and takes exactly 13 seconds to move from open to closed. The first attempt at fixing the problem was having ground crew send the command to open the valve and cut the power halfway through. This involved using a metronome app on a phone to send two commands 6.5 seconds apart. It worked, but not quite well enough.
The failure of the metronome technique led [Todd Quasny] to write a script to turn the ‘on’ and ‘off’ commands from the ground to the ISS with millisecond resolution. This meant the commands to control the valve could be sent with the right delay, but they weren’t received with the right delay. This is a problem that had to be fixed from the station’s computers.
To finally solve the problem, ISS software engineer [Steve Joiner] was called in to write a software patch for the thermal control system. This is spaceflight and writing software is a long a laborious process of testing and code reviews. Nevertheless, the team managed to write and upload a patch in just two days.
This patch gave controllers the ability to control the valve with a resolution of 100 milliseconds, good enough for very fine control of the thermal system, and all without requiring the massive amount of planning that goes into a spacewalk or resupply mission.
Ups to [Ed Van Cise] for this tip. If you’re curious about the headline….
We are absolutely blown away by the level of detail that went into this amazing mission control panel that [Jeff Highsmith] made for his son.
His kid just started school and needed a desk to do homework on. They had recently visited the Kennedy Space Center, and his son found a new interest in all things space – So [Jeff] took the opportunity to make the desk into this mind-boggling control panel.
We saw a similar project recently, but this one seems to take it to the next level. The desk itself is hand-made from MDF sheet and with oak boards making up the structural members. He’s cut out over a dozen individual control panels, added switches, LEDs and potentiometers, and printed the labels on transparencies which give the whole thing a very professional and finished look. An iPad sits in the middle which plays a curated collection of space videos.
Continue reading “Ridiculously Accurate Mission Control Panel”
ISEE-3, one of America’s most dedicated space exploration vessels is on its way home. Unfortunately, when it gets here, no one will be talking to it. NASA decommissioned the equipment needed to communicate with the satellite nearly 15 years ago. [Emily Lakdawalla] at the planetary society has been following the long traveled probe for years. Her recent article on the topic includes the news that NASA essentially gave up the battle before it even started.
Originally named International Sun/Earth Explorer 3 (ISEE-3), the spacecraft was launched atop a Delta rocket on August 12, 1978. Its mission was to study interaction between the Earth’s magnetic field and solar wind. As part of this mission ISEE-3 became the first spacecraft to enter halo orbit. It did this by positioning itself at Lagrangian point L1, directly between the sun and the Earth. In 1982, scientists on earth were preparing for the 1986 flyby of Halley’s Comet. ISEE-3 was repurposed as a comet hunter, and renamed International Cometary Explorer (ICE). The craft flew back to Earth and entered lunar orbit, coming within 120km of the moon’s surface. It used this momentum to achieve a heliocentric orbit, on track for two comet encounters. ICE/ISEE-3 encountered Comet Giacobini-Zinner on September 11, 1985, collecting data and becoming the first spacecraft to fly through a comet’s plasma tail. While not considered part of the Halley Armada, ICE/ISEE-3 took measurements as it passed within 28 million km of Comet Halley’s nucleus. Since then, ICE/ISEE-3 has continued on its 355 day heliocentric orbit. It studied coronal mass ejections in the early 90’s, before being shut down in May of 1997. Follow us past the break to learn ICE/ISEE-3’s fate.
Continue reading “Call for Hams and Hackers: Welcome ICE/ISEE-3 Home”
Even though NASA’s Johnson Space Center’s impressive build for the upcoming DARPA Robotics Challenge is one of many entries, it has to be one of the coolest. The gang at IEEE Spectrum got a sneak peak of the robot dubbed “Valkyrie”, which at 1.9m and 125kg boasts 44 degrees of freedom while managing to look like a finished product ready to roll off the shelf. We can expect to see other custom robots at the challenge, but a number of teams will compete with a Boston Dynamics Atlas Robot, which we’ve covered a couple times this year.
A few readers are probably polishing their pitchforks in anticipation of shouting “Not a hack!” but before you do, take a look at the tasks for the robots in this challenge and consider how new this territory is. To that end, the NASA JSC crew seem to have prepared for resolving catastrophes, even if it means throwing together a solution. They’ve designed the limbs for quick removal and even reversibility: the arms are identical and only slight adjustments are required to turn a left arm into a right. Unlike the Atlas, which requires a tether, Valkyrie is battery-operated, and it can run for around an hour before someone needs to crack open the torso and swap in a new one, Iron Man film-style.
The team was also determined to make Valkyrie seem more human, so they added a soft fabric layer to serve as a kind of clothing. According to IEEE Spectrum, it’s even getting custom made footwear from DC Shoes.There are some utilitarian compromises, though: Valkyrie has adopted a shortcut taken by time-constrained animators in many a cartoon, choosing three fingers per hand instead of four. Make sure you watch the video after the break for a closer look.
Continue reading “Robot Battle for the Big Leagues: Valkyrie and the DARPA Challenge”
There is so much amazing technology that came out of the space race. For this week’s Retrotechtacular we’re looking at the guidance computer used in the Apollo program undertaken by NASA in the 1960’s.
One of the main components of this system is the Inertial Measurement Unit or IMU. That’s a familiar term for hackers who build quadcopters or other devices for which spacial awareness is paramount. In this case the IMU provided critical information about the motion and orientation of the capsule during it’s trip from the Earth to the Moon and back. But it wasn’t just high tech electronics along for the flight. To determine actual position a sextant was used for triangulating position. Yes, this is the same type of measuring device used for centuries. The method of using the sextant is displayed above. The spacecraft was turned until the sextant pointed at a landmark on Earth. The instrument was the adjusted to line up a star as a landmark, then the computer calculated position based on time and the angles of the two points being sighted. There’s a lot more shown in this thirty-minute film including in-depth assembly and testing of the computer components.
Before we point you to a few related articles we’d like to mention that our stash of really cool Retrotechtacular tips is running low. So if you know of some old footage that’s awesome to watch please send us a tip about it.
Now if you can’t get enough about NASA electronics you should check out the LVDC board which [Fran] got her hands on. Also, it’s worth checking out the unbelievable soldering techniques specified in the NASA manual. There’s a pretty good discussion about that going on in the Reddit thread.
Continue reading “Retrotechtacular: The Apollo Guidance Computer”
[Douglas Adams] will tell you not to forget your towel when it comes to space travel. But NASA may start mandating that astronauts always carry a toothbrush. That’s because when a recent repair on a critical International Space Station component went wrong it was a toothbrush hack that saved the day.
The culprit here is a bolt that wouldn’t re-seat after replacing a power transfer module that routes electricity from solar cells to the station’s electrical systems. About how many times have you had trouble with bolt threads? Now put yourself in a space suit in orbit for eight hours trying to get the thing to work. Yikes!
Just like in the movies there was a team of engineers at the ground center which gathered all the supplies available in the ISS. They figured out that metal shavings in the threaded hole needed to be cleaned out and the area lubed for the bolt. One of the two types of tooth brushes on hand would work for the lube, but needed to be stiffened. There was also a brush for cleaning the threads which was made out of a jumper cable. The images seen above are the step-by-step instructions the team uploaded to the astronauts who reproduced their hacked hardware to complete the repairs.
[Thanks G Mob]
After reading about an initiative between NASA and Boeing to develop lights for the International Space Station [Rasathus] decided to give it a go at building his own. The project uses RGB pixels to build a circadian rhythm light installation. Without the normal rise and fall of the sun the sleep wake schedule for the astronauts can be pretty rough. This uses color and intensity of light in a well-defined schedule to help alleviate that. [Rasathus] is trying to bring his project in well under the $11.1 million mark which was established for the ISS.
The light modules he’s using are from a strand of LEDs from Adafruit. Each is driven by a WS2801 controller, a common driver used for easy and complicated projects like this huge ball of light which our own [Jesse Congdon] tackled. The board above is the start of an adapter board for interfacing with the Raspberry Pi GPIO header. [Rasathus] wanted to make certain he didn’t fry the control electronics so he built some protection into this adapter. The control software is covered in the second portion of the write up. We’ve embedded the video from that post after the break.
Continue reading “NASA inspired circadian rhythm lights”