78 votes
Accepted

Did a flight controller ever answer Flight with a no-go?

One thing to note is that these polls of the room are largely for-the-record - in other words, if a flight controller was sitting on a problem that would prevent the accomplishment of a major ...
Organic Marble's user avatar
28 votes
Accepted

What does the Ariane 5 rocket use to turn?

Like most large modern launchers, Ariane uses gimbaled engines for attitude control during ascent. Both the Vulcain liquid-hydrogen engine and the nozzles of the solid rocket boosters on the Ariane ...
Russell Borogove's user avatar
23 votes
Accepted

How does “space weather” cause reaction wheel failure?

Ceramic bearings are a relatively new concept. They were a hot research topic in the late 1970s and didn't become commercially available until the mid 1990s. The Far Ultraviolet Spectroscopic ...
David Hammen's user avatar
  • 73.8k
21 votes

How were the pilots of the space shuttle able to operate the rudder after time in space?

Despite the many other (unsourced) answers stating the opposite, this is actually a very valid concern. Not from a physical weakness angle, but rather, even though a shuttle mission was a couple of ...
Organic Marble's user avatar
18 votes
Accepted

Could the Apollo Lunar Module be flown to a landing without the LEM Guidance Computer?

"Could be flown" is a clear yes, "could be flown to a landing" is another story. Most of the points you are listing can be accomplished using the backup system in the LM, the Abort Guidance System (...
indy91's user avatar
  • 1,991
18 votes

What caused the jitter in the DART video as it approached Dimorphos?

This is an extended comment to your self-answer, so I'm making it community. From your answer, As to why they weren't able to do a single, early course correction and just glide smoothly in for the ...
17 votes
Accepted

How can a rocket go straight up after ignition?

Rockets can use different systems for attitude control (control thrusters, fins, gyroscopes, TVC, ...). Since you ask for the seconds after liftoff, the relevant system is TVC (Thrust Vector Control). ...
DaGroove's user avatar
  • 1,334
13 votes

Why does spinning help stabilisation?

This answer answers the title "Why does spinning help stabilisation" rather than specifically for launches. Context Before jumping into the answer it is worth looking at the background. With rigid ...
Puffin's user avatar
  • 9,504
13 votes

High altitude stage separation

For all modern rockets (and as far as I know, for all rockets ever, since at least the V2), the rocket isn't controlled from the ground, but by electronics (computers, for modern rockets) on the ...
Wayne Conrad's user avatar
12 votes
Accepted

Does this kill vehicle contain momentum wheels? Watch how it moves!

The thruster configuration can be seen better in this image:(cropped from this document ). The attitude control thrusters are not in plane with the direction control thrusters. This Raytheon patent ...
Andreas's user avatar
  • 1,385
11 votes

High altitude stage separation

Human operators are generally not involved in separation, that's controlled by on-board computers according to the plan programmed into them. 2 way radio lets human controllers see what is going on ...
GdD's user avatar
  • 20.1k
11 votes
Accepted

How did the pilot lockout on Vostok 1 work?

For Vostok, the controls were really not all that impressive by today's standards. The picture below shows the control and information panels on Vostok spacecraft. Here, 1 is the information display (...
Mu3's user avatar
  • 703
10 votes
Accepted

Machine Learning and Classical Navigation, Guidance and Control in Space Exploration

This is an attempt at the first part of your question: "are classical control algorithms better than machine learning approaches". Since I am personally more interested in launch vehicles, the answer ...
Przemek D's user avatar
  • 375
10 votes

Is it possible to navigate space travel with no computer?

You can travel in space without any navigation devices or computers at all, establishing suborbital flight and orbital flight is done by the rocket, it's accuracy there that matters and early manned ...
GdD's user avatar
  • 20.1k
10 votes

Did a flight controller ever answer Flight with a no-go?

The No GO happens all the time. Many recent ULA and Spacex Launches get a NO GO - Most of the time its the Weather and the Range Telemetry guys. High Altitude winds , Range tracking failures , ...
Orrey's user avatar
  • 101
10 votes

What does the Ariane 5 rocket use to turn?

The first stage of Ariane V has in fact RCS thrusters, but only for roll control. While the solid boosters are burning, roll control of the whole stack is exercised by differential gimbaling of the ...
Peter Lichtenberger's user avatar
9 votes

How does “space weather” cause reaction wheel failure?

The study was specifically of ITHACO reaction-wheel assemblies that proved to be highly prone to failure in the space environment. These assemblies used steel bearings. Interference with electronics ...
Christopher James Huff's user avatar
8 votes
Accepted

An program that automatically generates a rocket guidance system?

You really have three separate problems to solve, though it sounds like you're talking about only one of them. The total package is known as GNC, or Guidance, Navigation, and Control. A little more ...
Tristan's user avatar
  • 17.3k
8 votes

How were the pilots of the space shuttle able to operate the rudder after time in space?

As others have pointed out, shuttle missions never lasted long enough to have serious concerns about the pilot or commander's physical abilities. Also note that the shuttle was a digital fly-by-wire ...
Bret Copeland's user avatar
8 votes
Accepted

Is aerodynamic lift ever useful in rocket flight?

Angling to get lift is going to increase the atmospheric cross-section of the rocket and so increase drag. For any reasonable angle of attack, the drag force is going to be much larger than the lift ...
Russell Borogove's user avatar
7 votes
Accepted

Does the Hubble telescope use a "simple" PID-controller for its pointing control system?

Yes. According to the NASA paper "Hubble Space Telescope Pointing Control System Design Improvement Study Results", in the first full paragraph on page 2, the author states The nominal control ...
Arthur Dent's user avatar
  • 1,135
7 votes

Is aerodynamic lift ever useful in rocket flight?

As far as I know, no. In order to make a cylindrical rocket as light as possible, they are flown to minimize the side loads to the structure -- as close to a zero angle of attack as possible. If they ...
Mark Adler's user avatar
  • 58.1k
7 votes
Accepted

Using what technology one can keep a spacecraft truly non rotating

This is the (attitude) lost in space problem. This problem arises, for example, when a spacecraft is first released from the upper stage after launch or when a spacecraft awakens after having been ...
David Hammen's user avatar
  • 73.8k
7 votes

Is it possible to navigate space travel with no computer?

Yes, as long as you don't care where you end up Early spacecraft used electrical controls, but had no computers: Six Vostok each carried one person to orbit. The first flight carried the first man ...
DrSheldon's user avatar
  • 47.9k
7 votes
Accepted

Can the grid fins affect the rotation of the Falcon 9 descent?

Yes, the grid fins can control the rotation of the stage -- and they're the primary mechanism for that during descent, since the cold-gas thrusters have little force and the engines are shut down for ...
FLHerne's user avatar
  • 183
7 votes

What caused the jitter in the DART video as it approached Dimorphos?

I'm revising my answer based on the comments and on the community answer started by David Herman. Corrections were not made right up until the end, but stopped with 500 miles to go. This is according ...
Mark Foskey's user avatar
  • 10.5k
7 votes

Understanding and breaking down pointing requirements

In my professional experience in writing spaceflight software requirements, reading them, implementing them, validating them, and verifying them, these "what does that mean" questions come ...
Erin Anne's user avatar
  • 10.8k
6 votes

How were the pilots of the space shuttle able to operate the rudder after time in space?

Shuttle missions were normally no more than about two weeks long, unlike many-month ISS missions; Chris Hadfield spent 5 months on-station. The muscular atrophy effects of zero gravity take a while to ...
Russell Borogove's user avatar
6 votes

SpaceX stage 1 reentry control?

I don't have any citation, but the first stage is doing all its own guidance and control; it would be insane to do it any other way. The "acquisition" called out at about 80km altitude is ...
Russell Borogove's user avatar

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