Flight Question Shuttle reentery

[Rex]

hi everyone as im new to the orbiter program i have the concept of how to reenter and land with the shuttle but i dont know actually do it and land safely

 

[jinglesassy]

I suggest flying the default delta glider before attempting the shuttle its alot harder.

 

[Rex]

alright, will do

 

[jambooger]

hi everyone as im new to the orbiter program i have the concept of how to reenter and land with the shuttle but i dont know actually do it and land safely

Your in for a great and frustrating time. Give it a few months . Experiment over and over and over and over.

 

[Tommy]

The stock vessels like the stock Atlantis and DG are next to impossible to re-enter realistically. It's far too hard to hold the high AoA in these vessels. Since they don't burn, it's common to just lower the PeA to around groundlevel, then just "fly it down". You can control how fast you are braking by changing the altitude - less altitude means faster braking.

Some add-ons, including some shuttle add-ons, the DGIV or XR series, are designed for a more "realistic" entry. They are vulnerable to hull heating and include pilot aids to help maintain the high Angle of Attack used in real life. There are many threads on this forum detailing how to re-enter these vessels, simply search the forum for topics like "re-entry", "aerobrake" or "basesync".

 

[stealthstar]

It's pretty challenging mainly because in reality all the reentry of a space shuttle was done under computer control. But all I know is the reentry zone is somewhere over the Indian ocean at about 100km when a shuttle is flying to Kennedy Space Center. I wish I can get a working autopilot computer addon so that I can have it automatically do things like docking & reentry.

 

[IronRain]

It's pretty challenging mainly because in reality all the reentry of a space shuttle was done under computer control. But all I know is the reentry zone is somewhere over the Indian ocean at about 100km when a shuttle is flying to Kennedy Space Center. I wish I can get a working autopilot computer addon so that I can have it automatically do things like docking & reentry.

The great Space Shuttle Fleet has an autopilot for reentry and landing (you will need to read the documentation first!).
For other space planes we have:

• [ame="http://www.orbithangar.com/searchid.php?ID=2139"]AeroBrakeMFD[/ame]
• [ame="http://www.orbithangar.com/searchid.php?ID=5969"]Glideslope 2.3[/ame]

It requires some practice, but hé, what doesn't?

 

[Castor]

The great Space Shuttle Fleet has an autopilot for reentry and landing (you will need to read the documentation first!).

And if you are going to use that, just read this thread also :
http://orbiter-forum.com/showthread.php?t=26263 (post no. 8)

 

[IronRain]

And if you are going to use that, just read this thread also :
http://orbiter-forum.com/showthread.php?t=26263 (post no. 8)

Which is also documented in the documentation:thumbup:

 

[Castor]

Which is also documented in the documentation:thumbup:

Which documentation ? The one that comes with Shuttle Fleet says this:

Regarding AutoFCS - fear not, I have been in contact with the author of the original and he is working on an updated version that will work with Orbiter 2010 P1. Testing is on going at this time. Recent real-world commitments have delayed the release of the new AutoFCS, but development is not dead, just on hold.

 

[IronRain]

:facepalm: Excuse me, it is the file included with STS Payloads.

 

[wllmpeek]

@ Stealthstar. All the shuttle reentries were performed by the computers with the exception of STS-2. Joe Engle flew the Columbia in manually and nearly lost control demonstrating how difficult it is to reenter winged spacecraft when the CoG has been shifted aft causing negative stability. Computers are good for this job.

 

[Scav]

Joe Engle flew the Columbia in manually and nearly lost control demonstrating how difficult it is to reenter winged spacecraft when the CoG has been shifted aft causing negative stability. Computers are good for this job.

Source, please?

 

[Ripley]

Less than 1 minute Googling:

From http://www.jsc.nasa.gov/Bios/htmlbios/engle-jh.html

On 12 Nov 1981, General Engle commanded the second orbital test flight of the Space Shuttle “Columbia”, launched from Kennedy Space Center, FL. On this flight he became the first and only pilot to manually fly an aerospace vehicle from Mach 25 to landing.

From http://en.wikipedia.org/wiki/STS-2

The deorbit and reentry phase of this mission differed from STS-1, in that while the first shuttle entry was flown as a "middle of the road" test of the automatic guidance, the success of that mission allowed for the STS-2 crew to explore the stability margins of the vehicle's performance. Twenty-nine planned Programmed Test Inputs (PTIs) were manually flown in the Control Stick Steering (CSS) mode, with Engle making use of his past manual hypersonic flying experience in the X-15. These PTIs provided useful data for subsequent engineering modifications.[6]

Landing took place on Runway 23 at Edwards Air Force Base at 1:23 pm PST, November 14, after a 37-orbit flight which covered a total of 1,075,000 miles (1,730,000 km) over the course of 2 days, 6 hours, 13 minutes and 13 seconds.[1] Engle manually flew the re-entry from Mach 24 throughout the entire approach and landing – the only shuttle pilot to have done so – so as to test the limits of the shuttle's stability and controls.[6]

 

[Urwumpe]

Joe Engle flew the Columbia in manually and nearly lost control demonstrating how difficult it is to reenter winged spacecraft when the CoG has been shifted aft causing negative stability. Computers are good for this job.

Citation needed.

 

[wllmpeek]

Citation needed.

I've studied space history as a near fulltime hobby for over 30yrs. I've corrected two Apollo astronauts who later contact me with much thanks, "They had been been telling the story wrong for several years."

I hope I don't have to cite everything I share that I've learned over the years. It's all just a mass jumble from decades of space history study and I've forgotten half the places information came from.

Regarding Joe Engle, I ???THINK??? I read that in a book called At the Edge of Space The X-15 Flight Program by Milt Thompson. (What page and paragraph? Who knows?) I can't imagine I read it anywhere else as Joe Engle is not an astronaut I care to research...

 

[Urwumpe]

I've... research...

As already cited, no Space Shuttle ever got out of control or close to it during reentry except STS-107.

The Space Shuttle is not designed for manual flight at all, it requires computers at all times, and CSS is not manual flight, but just manual guidances inputs. And during STS-2, this CSS was only used for short phases.

One non-technical book source for the topic is this one:

http://books.google.de/books?id=8QL...ved=0CGcQ6AEwBg#v=onepage&q=STS-2 PTI&f=false

I would say, it is pretty much a good summary what did really happen. The full original is here: http://history.nasa.gov/SP-4109.pdf

And no, I don't self-study spaceflight for 30 years now, I am just interested in spaceflight for 32 years now... when its about the Shuttle and I feel unsure, I ask DaveS.

 

[DaveS]

During the early missions of Columbia a series of so called Program Test Inputs (PTIs) were executed during the hypersonic phase of entry. One of these were the so called Push Over/Pull Up (POPU) maneuvers done by the CDR. The POPUs involved first pushing over the AoA to 35°s and then pulling up to an AoA of 45°s before returning to the standard entry AoA of 40°s.

I believe that's where the confusion comes from, the POPUs. Somewhere along the line it morphed into the myth that the STS-2 entry and landing was flown entirely on CSS by the CDR, Joe Engle.

 

[wllmpeek]

As already cited, no Space Shuttle ever got out of control or close to it during reentry except STS-107.

The Space Shuttle is not designed for manual flight at all, it requires computers at all times, and CSS is not manual flight, but just manual guidances inputs. And during STS-2, this CSS was only used for short phases.

Perhaps there is a translation barrier when we say in America, "Manual Control"? I just assumed everyone understood there is no such thing in NASA space flight. Nasa space craft as far as I know, have been fly-by-wire. When I said Engle flew manually, I meant he removed the computers ability to follow the prescribed flight path. The computer was still enabled to maintain the attitude inputs from the pilot.

I'm pretty sure if you read "At the Edge of Space" or "Digital Apollo" you'll see where these authors claim the space shuttle not only on STS-2 but STS-1 as well, flew outside the prescribed reentry bank angle parameters. (Maybe this isn't almost out of control as I cited earlier but still outside flight parameters) I Don't know where I saw it (Please don't ask to cite) but I know I've seen a documentary with both John Young and Robert Crippen stating as much. Young I believe said, "It had his attention." Crippen said, "It scared the hell out of me." This also occurred on STS-2 as mentioned in the afore mentioned books.

David Mindell, the author of Digital Apollo is a bastion of historical knowledge regarding these issues. He can be contacted at his email on the MIT website.

David A. Mindell is Dibner Professor of the History of Engineering and Manufacturing, Professor of Engineering Systems, and Director of the Program in Science, Technology, and Society at MIT. He is the author of Between Human and Machine: Feedback, Control, and Computing before Cybernetics and War, Technology, and Experience aboard the USS Monitor.

 

[Urwumpe]

No translation error to America. Maybe a translation error between "layman's terms" and "dry and boring engineering". I have an engineering background, I read things with some different eyes than the layman.

STS-1 had a cross talking of the yaw jets with the airflow, resulting in unexpected aileron motion to compensate a banking moment. Thats not out of control, the Space Shuttle FCS had been designed for it. It didn't even saturate a FCS channel (which is "out of control" for flight-by-wire aircraft, it means that the control surfaces are at the limit of travel without being able to reduce the attitude error). They tested this on STS-2 further and confirmed on that flight, that the RCS jets energized the airflow and caused the Shuttle to produce more lift on one side.

Again, this wasn't "outside prescribed reentry bank angle parameters". There are no such things, there is a prediction how the shuttle will fly the reentry and an envelope of energy and altitude, which the shuttle must not leave at all costs. There are safe regions in the envelope and not so safe. And avoid at all costs zones. Every Space shuttle reentry differenced from the prediction by a small degree, since the high altitude winds and other phenomena can't be predicted over 5000 NM distance.

And don't get me started with "I remember that x said y". That is where I prefer solid references and second opinions.

And just checked: What scared the hell out of Crippen was the sight of Columbia after the flight. Not only did it loose some feathers...I mean tiles during lift-off, it also it had really bad damage to the right landing gear door, because plasma crept into a gap between tiles during reentry.