52

Key data for the Columbia accident investigation was provided by recovery of the MADS (Modular Auxiliary Data System) recorder which amazingly survived reentry and was found largely intact. The MADS recorder captured crucial engineering data that wasn't sent to the ground through telemetry. As the first spaceworthy orbiter, Columbia was instrumented with ...


30

While there is onboard recording, the significant difference between launches of space craft and those of aircraft is the extensive realtime telemetry used in rocket launches. Every piece of data that can be sent live to the ground station is sent. This is essential in an endeavour which is still incredibly dangerous and with high odds of destruction or at ...


14

Avionics is short for "aviation electronics"; on an aircraft it can include computer equipment, communications, guidance and navigation, radar, etc. "Avionics power nominal" implies that the rocket's guidance computers were getting the right amount of electrical power. Presumably the Antares rocket's avionics power went off-nominal a short time later, ...


14

Never go to sea with two chronometers; take one or three. Dual redundancy presents a big problem. Suppose you bring two chronometers (or two computers, or two inertial measurement units). What do you do when the two devices disagree? Which do you trust? Triple redundancy solves that problem. Ignoring the possibility that two of the devices go whacko at the ...


13

No, it's not an inside joke -- though after the FDAI was named, the name may have contributed to jokes! In avionics, a "flight director" is: ...an instrument system consisting of electronic components that compute and indicate the aircraft attitude required to attain and maintain a preselected flight condition. A command bar on the aircraft’s ...


11

I have retrieved via FOIA request the "Space Launch System Program (SLSP), Flight Software Application, Software Assurance Plan (SAP)". It is the core document describing the software development processes for the Flight computer (the bit responsible for on-pad prelaunch, launch, and ascent of the SLS vehicle) and the Green Run Application Software (software ...


10

Another example: The Orion Ascent Abort-2 flight is going to be equipped with a series of Ejectable Data Recorders (EDR) to return telemetry on the flight in case the main telemetry downlink (a radio link) partially or completely fails.


9

Spacecraft thermal control analysis employs modelling programs that can analyze combinations of conduction, convection, and radiation heat transfer in complex structures. An example is Sinda by MCS Software. I have no association with MSC Software but I did work on thermal analysis problems for the Apollo Service Model in the early 1960s using primitive ...


8

No specific knowledge of Falcon, but a "string" in avionics terminology means a element of a redundant flight control system consisting of a flight computer and a data bus to a set of sensors and effectors. Here's a schematic from the Shuttle showing one flight computer (on the left, labled GPC for General Purpose Computer) interfacing to four ...


7

From an forum titled "The Wings of the Web" on Airliners.net I found a conversation asking the same thing and read this: Larger aircraft adopted 24/28 (battery/generator) reduce the weight of the wiring system and components. Since work relates to the Watts it consumes (electrical power) and Watts are a product of voltage and current, the higher ...


6

As far as autonomous control is concerned, much of this has already been developed. It had to be given the long time delays between Earth and even "nearby" destinations such as Mars. The Mars rovers, for example, are able to navigate to nearby locations on their own (Curiosity article). This is extremely limited in comparison to the autonomous vehicles ...


6

A good starting point is NASA Software Engineering Requirements NPR 7150.2B 3.6 Software Assurance and Software IV&V 3.6.1 The project manager shall plan and implement software assurance per NASA-STD-8739.8. [SWE-022] Note: Software assurance activities occur throughout the life of the project. Some of the actual analyses and activities may be ...


5

The hydraulic fluid used to steer the fins is actually rocket fuel. After performing the function of steering the fins, the fuel drains into the main tanks to be burned by the engines. This setup saves the weight of a hydraulic pump and dedicated fluid. Since the fins are useless at low airspeeds, i.e. at final landing, nitrogen (cold gas) thrusters are ...


5

One reason a technical standard can persist is the availability of off-the-shelf components designed with a given standard in mind, and the economics of developing and manufacturing components around a new standard. Having a catalog of components with established reliability records can be a big time and cost saver over having to accumulate test experience ...


5

Redundancy is implemented in various ways. Generally speaking, triple redundancy means that the system can withstand two failures without having the system fail. In greatly simplified terms, redundant avionic systems have multiple computers running and comparing results -- voting out a system that gives a different answer. This voting is then effectively ...


5

NASA was (and still is) a leading organization in the field of software engineering, even before the term "software engineering" existed. The kinds of software programs developed for NASA range from one-off scripts / spreadsheets meant to yield a rough approximation to a specific engineering question to programs / scripts / spreadsheets that contain ...


5

Ok - after a bit more research, I figured out what the readouts in question are: the attitude "ball", along with readouts 2, 6 and 7, are part of a spacecraft-specific instrument called Flight Director Attitude Indicator (or FDAI): The readouts 2, 6 and 7 are, respectively, Roll value and rate, Pitch value and rate and Yaw value and rate, with red bands ...


4

It's a rather old question, but let me clarify a bit: Rikki-Tikki-Tavi got confused by logic gates versus logic cells - A typical logic cell of a typical FPGA is much more complex than a single logic gate. Some rather rough conversion factor is about 100. Hence, these FPGA are much much more powerfull than needed for this rather purpose. A FPGA that most ...


4

I'll take a whack at it - like CourageousPotato said color code your power/data lines for easier differentiation, and I personally would like to see ground indicators (but may not be necessary). I think breaking out the sensors into a dashed assembly and saying what sensors would be useful. Why do you have a primary and redundant battery for each of your ...


3

The power supply can be simplified - the data processing / control module is currently supplied by 7.4v at 7.4 amps. Instead of dedicated batteries I'd consider connecting your larger 14v batteries to + and - DC bus bars and having that power the whole system. The control module's power can then come from a 2:1 step down DC transformer connected to that ...


3

Your question is very broad, since software is so important to everything NASA does. But I will try to answer to the best of my abilities. NASA has a rich history of advancing the state of software engineering. In fact, as Martin Schroder noted, Margaret Hamilton, a legendary Apollo program flight software engineer, coined the term "software engineer". ...


3

I am not an expert in electronics or FPGAs, but a couple of these would fit the bill, I think: http://www.xilinx.com/products/silicon-devices/fpga/kintex-7q.html These aerospace grade fpga-chips fit 480,000 in a tiny IC package. I don't think the physical size is much of an issue here, even if we consider that the rover was designed a few years ago, when ...


Only top voted, non community-wiki answers of a minimum length are eligible