Questions tagged [flight-control]
Systems and software used to control a space craft's trajectory.
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1answer
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How was it commanded to Ingenuity to fly to 10 ft and land again?
Since Mars is multiple light minutes away from Earth, Ingenuity can't be controlled remotely like any drone. Was there a command given to Ingenuity to at a certain time rise to 10 feet and then land ...
8
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1answer
148 views
How did the pilot lockout on Vostok 1 work?
The entire mission would be controlled by either automatic systems or by ground control. This was because medical staff and spacecraft engineers were unsure how a human might react to weightlessness, ...
3
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0answers
55 views
During space shuttle reentry, why was the sign of GALR based on mach number rather than directly on alpha?
(My apologies if this should go in Aviation.SE instead - I'm not quite certain where questions regarding the behaviour of the shuttle's flight controls during reentry should go.)
For flight in ...
2
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0answers
35 views
Trim controls for Apollo RCS systems?
Did any of the Apollo-era spacecraft have any method of trimming the RCS jets? Due to variable mass placement (fuel tanks and sublimators emptying, astronauts moving, item stowage, location of moon ...
3
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0answers
86 views
Trying to modify a JPL guidance algorithm for the Mars Sky Crane and Mars 2020
I've been trying to implement a modification to the JPL guidance law that was used (or very similar to what was used) for the powered descent portion of the MSL mission and I'm struggling to figure ...
4
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0answers
87 views
What are the implications of North Korean black and white patterns on missiles?
Black and white patterns on rockets were originally intended as roll patterns. They helped as a visual back-up for acceleration sensors measuring the roll, as discussed in this previous question What ...
2
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0answers
99 views
Can ten (or more) rockets be used together to launch one massive object?
With computer flight controls where they are today, what would stop us from building a relatively large space station on earth, but then using 10 or 20 or even 100 falcon heavy or Starship or SLS ...
2
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0answers
76 views
Is steam a good gas to use for a small RCS thruster on a small rocket?
Is steam a reasonable tradeoff from other hot/cryogenic gases in order to have safety and have it easily obtainable?
Thanks
3
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1answer
133 views
How powerful do cold gas thrusters normally get?
Modern rockets like the Falcon 9 use cold gas thrusters for steering on landing approach when the engines are dead.
Cold gas thrusters are common in smaller satellites and spacecraft, which way a ...
5
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1answer
45 views
Attitude and orbit detection systems for solar sails
When a solar sailing craft is successfully getting force from solar photon pressure, that force applies a small torque to the craft because the center of pressure is never perfectly aligned with the ...
2
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2answers
102 views
Efficiency in Space Capsule Docking Process
I'm watching the first operational Crew Dragon Capsule proceed through the regimented, and VERY careful International Space Station (ISS) docking process, which was turned on after pausing another ...
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0answers
78 views
How are NASA flight control center computers setup?
How modern control center are designed in ISS flight control center or any NASA control center.
I meant, how each console (monitors) are connected to the server (zero client technology are used) and ...
5
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1answer
189 views
Can the grid fins affect the rotation of the Falcon 9 descent?
Can the grid fins control the rotation of the Falcon 9 on descent?
How would they have to be positioned to stop the rotation?
If used to rotate the ship, then how they would they have to be positioned ...
3
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0answers
63 views
Rocket Engine - Actuator in Loop Simulations
For Actuator-In-Loop simulations, why are the rocket engine nozzles along with the thrust vector control assembly (including the actuators) kept inverted on a platform like in the attached image or as ...
2
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1answer
127 views
Knowing when to stop burning
Navigating in orbit usually relies on firing engines for some amount of time to achieve a specific velocity. This answer, for example, mentions "closed-loop guidance" for the ISS boosting.
...
5
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1answer
251 views
How do Falcon 9 grid fins deploy?
Is it aerodynamic drag that flaps the grid fins open? Or is there a controlled mechanism for it? Pictures show the grid fins connect through a small link to something inside the rotating trunnion arm--...
2
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1answer
104 views
Who or what performs the throttle up?
During a Falcon 9 launch you hear the commands 'throttle up' and 'throttle down'. Who or what performs 'throttle up' and 'throttle down' (i.e. astronaut or computer)?
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How did omission of command to Huygens lander not get caught by anybody at ESA nor anybody at JPL? Procedures in place to avoid in future?
In this answer to Prior to putting spacecraft on a trajectory going a significant fraction of the speed of light, would some things need to be tested on Earth? I wrote:
As far as communications is ...
12
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3answers
2k views
How does “space weather” cause reaction wheel failure?
Failure of reaction wheels often causes premature mission ending or failure to achieve the goal because spacecrafts are no longer able to maintain orientation and have to rely on chemical propellants. ...
2
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0answers
77 views
Why were hot-stick downmoding to CSS, and the ability to use CSS for some control axes but not others, disabled during space-shuttle powered flight?
During ascent, if need be, a space shuttle’s flight controls could be switched from the normal, automatic control mode over to manual1 control (known as control-stick steering, or CSS), allowing the ...
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4answers
1k views
High altitude stage separation
Normally, at high altitude above Earth's surface, there are stage separation of a rocket. If we consider unmanned rockets, at high altitudes, how does human operators of a rocket who are here on Earth ...
12
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1answer
902 views
Could the Apollo Lunar Module be flown to a landing without the LEM Guidance Computer?
Inspired by answers to Could the lunar module have moved to a different spot? question but not talking about that specific relaunch scenario:
Could the LEM stack (descent configuration) be flown ...
1
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0answers
67 views
Control torque to a Reaction wheel that compensates for friction - need help understanding a working code
Reaction wheel in a s/c is driven by controller torque. However, since there is friction torque in RW, less than the reqd momentum change is achieved. Hence the control torque must be increased by ...
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0answers
109 views
How do single-nozzle staged combustion rockets control roll?
Related: How do single engine rockets control roll?
While many single-nozzle motors are gas generators & can deflect the pump exhaust asymmetrically to produce a torque, staged combustion motors ...
7
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0answers
84 views
Time scale separation and cascading control loops
The typical approach to designing flight control systems is to design an inner control loop to stabilize vehicle attitude and angular rates, while an outer loop tracks vehicle position. The reason ...
5
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1answer
133 views
Would astronauts have been able to save the CST-100 mission?
The Boeing CST-100 Starliner failed an unmanned test because the timer on the spacecraft was off by 11 hours. This caused the spacecraft computer to think it was ahead in mission timing by 11 hours, ...
16
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1answer
702 views
Why are there advertisements in the Russian ISS flight control room?
I found a photograph of the Russian ISS flight control room:
Source: NASA https://commons.wikimedia.org/wiki/File:Russian_ISS_Flight_Control_Room.jpg
Below the large screen are several ...
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0answers
179 views
How to filter a white noise or random noise in Matlab Simulink?
I am working on a sun-synchronous satellite Simulink model wich determines its attitude from a Sun sensor and a star sensor whom measure the sun and star direction in the satellite body reference ...
46
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3answers
8k views
Did a flight controller ever answer Flight with a no-go?
OK, all flight controllers, I'm going around the horn
Retro? Go
FIDO? Go
Guidance? Go
Control? Go
TELCOM? Go
GNC? Go
EECOM? Go
Surgeon? Go
Are there any recorded instances of a No-Go?
5
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2answers
256 views
Can a spacecraft use an accelerometer to determine its orientation?
I know that almost every spacecraft uses a gyroscope to determine its orientation, but I don't know if an accelerometer could also be used in addition to a magnetometer to calculate it.
I have been ...
2
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1answer
136 views
How do small, spin stabilized launchers follow a rhumb line?
This concise answer to What exactly is rhumb-line control in the context of a launch trajectory? explains the concept in the context of the SS-520 nanosatellite launch vehicle (which "doesn't exist"). ...
3
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1answer
562 views
What exactly is rhumb-line control in the context of a launch trajectory?
The conference paper SS-520 Nano satellite launcher and its flight result SSC18-IX-03 from the 32nd Annual AIAA/USU Conference on Small Satellites linked in this answer describes the use of rhumb-line ...
4
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1answer
306 views
Where are these historical IBM + Apollo related locations within NASA? What do these computers do?
In the Fortune Magazine video IBM's Moonshot: Past and Future with the notes
BM’s John Kelly reflects on Apollo 11’s historic mission and looks forward to what future technology will accomplish.
...
5
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2answers
145 views
Apollo CSM RCS maximum number of simultaneously active engines?
Reading the RCS subsystem manual, it seems like each RCS quad of the Apollo SM consisted of four hypergolic engines. Am I correct in saying that all four engines of each of the four quads could be ...
7
votes
1answer
147 views
Apollo CSM mass, inertia and RCS parameters?
Is there a document specifying the total mass, the 3-by-3 inertia tensor of the Apollo CSM assembly, as well as the geometry of the service module and command module RCS assemblies (in other words, ...
2
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1answer
121 views
Satellite mission design/performance requirements to attitude/orbit control design specifications
Are there any good sources that discuss: the steps involved in deriving attitude/orbit control design specifications, from satellite mission design/performance requirements?
2
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1answer
174 views
What are the top most used satellite control system, flight dynamics solution at the moment ? Approx costs?
I am looking for a list of top most used satellite control systems, flight dynamics solutions by space agencies, private companies etc. the moment? How much do they cost approx for use by 1 person? Is ...
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0answers
224 views
Analyzing Amateur Rocket Stability and Range Safety
I am working with a university bunch of other university students on building a very large amateur rocket. Our objective with this rocket is just to go very high, with no significant payload or ...
4
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2answers
201 views
Among Quantitative Feedback Theory and H infinity, which one is preferred for robust control of satellites esp. small satellites? And why?
I am interested in designing a robust controller for a small satellite with antenna, sloshing propellant and flexible panels on board. I am mostly interested in achieving arcsec precision pointing ...
11
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5answers
944 views
Is it possible to navigate space travel with no computer?
From launch to land could a person travel in space with only mechanical devices like a sextant? With enough experience what would be the minimum devices needed? Which vehicle currently would be easier ...
4
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0answers
734 views
Why would someone use Modified Rodrigues Parameters over Quaternions for spacecraft attitude estimation? And vice versa?
I see quite some papers on spacecraft attitude determination and control, that rely on quaternions. While some others rely on MRPs. The advantage that I see so far is that... for quaternions, the ...
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0answers
531 views
Avionics Systems on board Falcon 9 (Reusable)
What kind of control systems are active and how do they function on board a Falcon 9 booster while it's landing ?
13
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1answer
4k views
How can a rocket go straight up after ignition? [duplicate]
We have seen during rocket launches that the rocket goes straight up after the launch clamps have disconnected.
What ensures that it doesn't tilt because of the uneven mass distribution?
How does a ...
8
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1answer
1k views
Machine Learning and Classical Navigation, Guidance and Control in Space Exploration
Due to the increasing availability of large quantities of data and computational power, machine learning (ML) is providing increasingly better results in various fields. Much research has been done on ...
4
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4answers
379 views
Using what technology one can keep a spacecraft truly non rotating
Inspired by the question I thought maybe a photon thruster can be used for precisely giving thrust to maintain spacecraft attitude. But soon I realized that for high precision attitude control, one ...
1
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1answer
125 views
An program that automatically generates a rocket guidance system?
This is for a liquid propelled rocket that launches from earth. It could also perhaps be used for orbital maneuvers and landing on the Moon (not mars or earth).
The inputs for such a program would ...
17
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4answers
2k views
How were the pilots of the space shuttle able to operate the rudder after time in space?
I've just watched this video showing three astronauts who've returned from space. At around the 5:46 mark in the video we can see astronaut Chris Hadfield being carried out of the Soyuz capsule. I've ...
7
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2answers
192 views
Implementing control system to track position and velocity references simultaneously
I've been trying to implement a PI (proportional-integral) controller to allow a launch vehicle to track 2 reference states simultaneous, namely position and velocity, so that the launch vehicle will ...
3
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2answers
320 views
SpaceX stage 1 reentry control?
In watching today's BulgariaSat-1 broadcast:
It was mentioned that the drone ship had acquired the 1st stage as it was returning. I had always been under the ...
4
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2answers
631 views
Does the Hubble telescope use a “simple” PID-controller for its pointing control system?
I am wondering whether the Hubble Space Telescope uses a "simple" PID controller like this:
Or is it using another type of control system that may be much more complex?
