STEM Talk – Engineering is Cool



Watch Ken Hardman, an aerospace engineer and author talk to a group of youth about the engineering of airplanes, rockets, and space vehicles. Learn about mechanical, electrical, civil, chemical, industrial, and computer engineering. Watch, listen, and learn about Science, Technology, Engineering, and Math (STEM).

 

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Valkyrie Painting (finally)


A lot of things have been limiting my art production. First, we had a baby. We didn’t really bother with anything but learning to be parents right after Halvor was born. Then Bethany went bac…

Source: Valkyrie Painting (finally)

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“Units” can make all the difference in the… Mars


Inches vs Meters

Engineers and yet to be engineers, see how using the wrong ‘units’ can make all the difference in whether a space probe hit’s the mark, crashes into a planet, or heads off back into space. “The Mars Climate Orbiter (MCO) Mishap Investigation Board (MIB) has determined that the root cause for the loss of the MCO spacecraft was the failure to use metric units in the coding of a ground software file, “Small Forces,” used in trajectory models.” See the whole report here.

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Engineering Family History Stories


JohnGriffinAge30

Dear Engineering Stories friends, Thank you so very much for your interest in these Engineering Stories. I have enjoyed writing them both because I enjoy engineering, and I enjoy writing in general. In fact, at my regular job, I see myself in part as a technical writer because I’m always writing specifications, requirements, plans, presentations, proposals, and procedures. I enjoy writing whether technical, creative, or, yes about my genealogy. I have taken on the task of trying to make my ancestors accessible to their busy posterity by writing very very short succinct summaries of a key time in their lives. May I encourage this exercise? Those who lived on this earth before us, gave us so much, and there is so much we can learn from them. Take a look! Each story can be read in 90 seconds or less. And from one engineer to another, try writing some of these yourself, about your ancestors; it’s good writing practice for any anyone in any vocation, including engineering, it takes skill to write in so few a words. And each story is uplifting. Besides, you might find and engineer in your family tree; I did! Click here and FOLLOW my #AncestorClips blog. To help you write a short short meaningful story about your ancestor, engineer or not, I prepared a worksheet for you. Click here and start writing. www.ancestorclips.com #familyhistory #genealogy

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Polaris Station – Novelette Conclusion


(Continued from Part 10)

“I, I’ll try, but Kendall.” Katya said.

Kendall could hear the fear in her voice.

“Dmitry,” Kendall said. “Do the best you can from the Quad, son.” He and A4 had a terrifying view of the incoming rogue. “Do it now. Program the peak of the lateral wave to be right at the time of rogue passing. Becca knows the dynamics. Team up. We need a miracle.”

“Houston concurs. We are notifying all emergency channels of your situation. Good luck, Polaris.”

“Dad,” Dmitry said. “Becca and I are refining the polar equations for the satellite matrix.

“Dmitry,” Becca said. “You’ll have to sacrifice some gain margin.”

“But, what about stability?”

“It’s margin,” she said. “It’s there for safety. It will all be for naught if we don’t push it, use a global edit to modify gain margin on all parameters for the string of M-Sat values.

“Dmitry? This is Flight. We are receiving your parameters. Connecting you through to station control system. Ready to execute control on your commands.”

“Executing lateral wave maneuver now,” Dmitry said.

Kendall and A4 discontinued their cable descent, wrapped arms and legs around the nanotube firmly as the constellation and wing moved almost undetectably in a lateral direction.

“Captain Parker,” Houston said. “34 seconds before rogue collision.”

“We see it. Oh my… Houston, lateral offset is increasing, but very slowly. We are holding on. Here it comes…here it comes…”

“We are entering the Quad now,” Katya said. “Enabling Quad controls.”

Kendall held tight to his life’s work, looked straight down toward the Earth, toward the space elevator base where his family would either save the station, it’s purpose, and their lives, or lose everything.

“It’s just not fast enough,” Dmitry’s voice was heard over the radio again. “The frequency response is too low. I need real-time…”

The radio from the Quad went dead.

“Good-bye.” Kendall looked down again, imagined Katya, Becca, and Dmitry looking intently through the Quad upper windows at the station straining to see the last of their husband and father. He reaffirmed his grip when the station lateral movement unexpectedly increased.

Kendall’s space suit environmental pack hummed it’s moderate tone. The nanotube emitted its gentle fifteen Hertz vibration. The radio emitted static. His breath was silent. His heart stopped.

“It cleared,” Kendall yelled, his heart beating again. “It cleared. It passed so quick we couldn’t turn our heads fast enough. No debris, no impact, no shock, no sound.”

Kendall finally turned enough to see the departing M-Sats. “There! Look A4, 479’s reflection moving above the satellite stream and out into space.”

The radio suddenly saturated with cheering from Houston and the Quad.

When the applause died down, Flight broke in. “That was amazing, Dmitry, Becca, Katya. And you too, Kendall and A4.”

“Thank you, Houston,” Katya said, “Dmitry, give me that tissue box. NASA, you picked the right team for this mission.”

“Katya,” Flight said. “There must be a problem with your beacons. Telemetry shows the Quad still docked with the elevator.”

“Katya, Katya,” Kendall’s heart trying to get back to normal. “You came back to the elevator didn’t you?”

“We never left, Dad.” Kendall heard his daughter’s voice. “It was Dmitry. At the last moment, Dmitry went back into the elevator and connected with the station bus. It was just fast enough to…”

“Becca, Dmitry,” Kendall shouted. “You did it. You did it!”

Kendall then lowered his voice. “My Katya, you are the best. I love you. Now quickly, get up here so I can show you just how I feel, and show you what it’s like up here. It’s more phenomenal than we ever imagined. See you in three hours. Enjoy the ride up.”

“Sir,” A4 said.

“Yes, A4,” Kendall responded.

“We have a problem.

“You mean we had a problem,” Kendall said.

“On its current path,” A4 said, “by Newton’s laws, M-479 will reach Octans Station in 43 minutes.”

Kendall stopped. “I know A4, but one emergency at a time.”

“The Callahan’s are in danger,” A4 continued. “If it clears Octans Station, we will then be ‘running the gauntlet’ again forty-six minutes after that.”

“The gauntlet?” Kendall asked. “Where did you get that ‘idiom’?”

A4 promptly replied. “I found it in my latest download. A gauntlet is a…”

“No, wait, what was that message this morning… the gauntlet is thrown? SEPA? Grappler Sub?” Kendall resumed a more rapid dissension to the station. “Let’s go, A4. I don’t think 479 was not an isolated anomaly.”

“Dad.” Kendall heard Dmitry on his private family channel.

“Dmitry?”

“I’m getting an automated status log from the wing suspension system, specifically the maglev field intensity controls.”

“What are you talking about, and why are you on our private channel?” Kendall said. “Why would the maglev send you a message?”

“In all of my software systems, I code a back door input and reporting routine.”

“Of course you do.”

“It’s A4,” Dmitry said.

“What?” Kendall said.

“It’s A4. That station vibration you had this morning?”

“Yes. What about it.”

“The suspension software log indicates that A4 transmitted a half Hertz field calibration wave into the maintenance buffers several days ago. It has a 24 hour period. This would explain the periodic station oscillations you’ve been getting. And it looks like his protocols have been changed too. Possibly to hide the transmission.”

Kendall paused his descent and looked at A4 without speaking.

“Dad,” Dmitry continued. “Did someone modify A4’s protocols?”

“No,” Kendall replied. “At least not that I know of. Wait a minute. A4 asked me about that this morning. But, if you put a back door in the code, could someone else use that back door to insert commands?”

“Only if.” Dmitry said. “Only if they got my password.”

“Dmitry? Does your password have something to do with knights, and the middle ages?

THE END

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Polaris Station – Novelette Part 10


WorldOrbitStationImage.001(Continued from Part 9)

“Then what difference does it make. We’re out of time.”

Houston reported progress live. “Calculating tether launch vectors and timing for M-478 and M-480 to connect to M-479. “Vectors determined and locked in. Executing now.”

Radio silence for fifteen seconds.

“NASA, please report,” Captain Parker said.

“Confirmed!” Katya’s was heard by all. “My telescope confirms grapple by both tethers.”

“Confirmed!” Dmitry said. “Holograph from constellation telemetry confirms M-479 in tension by 78 and 80 and in relative motion outward.”

“On my mark,” Flight said. “Initiate grapple release and tether retraction by 478 and 479. Three, two, one, mark.”

“Based on the perturbation on the two pulling satellites before release,” Dmitry said, “M-479 must be in motion radially outward.”

“Katya,” Flight said. “Can you confirm on your scope monitor the motion of M-479? It appears that…”

“Yes.” Katya said. “The rogue is moving back in line, and…stand by.” Katya adjusted the angle of her monitor to avoid sun glare.

“How much time till station intercept?” Kendall asked.

“Three minutes, 10 seconds,” Flight reported.

“Is it moving outward fast enough?” Kendall was sweating in his suit. “And have M-478 and 480 corrected themselves from the grapple impulse and retract?”

“The rogue is now in line and continuing to drift outward,” Dmitry examined his holographic data. “78 and 80 have nearly recovered.”

Kendall and A4 paused their descent and glared out toward the incoming stream of satellites, looking for an anomalous reflection in the strand of beads reflecting in the sunlight.

“There she is,” Kendall raised his right arm and pointed with his space glove. “A4, see that little break in the stream of reflections?”

“Yes, sir,” A4 responded. “M-479 is approaching about a satellite diameter above the stream.”

“Is she still moving outward?” Kendall said. “Will she clear the wing?”

A4 used his visual and electromagnetic sensors to triangulate the position, velocity and direction of the rogue, extrapolating forward to determine if it would impact or clear the wing.

“A4?” Dmitry asked over the radio. “What are your calculations?”

“M-479, at current trajectory will clear the wing, but only by 2.94 meters. That is insufficient to clear the first array of solar panels.”

“Drat! Flight, did you get that,” Kendall said. “We may still have an impact.”

“Captain Parker, this is Houston. You need immediate shelter. If the rogue takes out a few solar panels, you and the platform will be showered by debris. Some of that debris, even at 0.8 ‘g’ will rain down on you like . . .”

“Will the station survive?” Katya called out. “What if debris gets on the maglevs.”

“Not good, Katya,” Kendall and Flight replied, “Not good at all.”

“Kendall, descend as fast as you can,” Flight said. “Get to the escape pods. Katya, get you and your kids out of there.”

Kendall and A4 descended the nanotube as fast as they could, but with less than three minutes to impact, there was no way, especially with all the condensation in his helmet.

“We can’t make it,” Kendall said.

“Let’s go Becca and Dmitry.” Katya’s command was heard over the radio.

“But mom,” Dmitry said. “I’m still running simulations on satellite movements. The wire-less isn’t fast enough. I need the hard port connection.”

“Now,” Katya insisted.

Kendall knew exactly what his son was doing. He could imagine Dmitry waving his fingers over the holographic sensors on his portable, moving the satellites up and down.

“Option four!” Dmitry called out.

“I heard that,” Kendall felt a glimmer of hope. “Everyone, give your attention to Dmitry. Okay son, do we lower the stream of satellites, to lower the station, to clear the solar panels?”

“No, neither; lowering the constellation that far in two minutes will shear the station and maglevs too much. We need a lateral, out of plane wave.”

“But without the station thrusters?” Flight said.

“All we need,” Dmitry continued, “is to move the solar panels one or two meters to the left or right to clear the rogue. Right A4?”

“Of course,” Becca called out before A4 responded. “Use the M-Sat lateral transfer-functions to perform a coordinated out-of-plane wave.”

“Yes, It’ll cause the station to sway a bit,” Dmitry said, “but still within allowable’s. The maglevs can handle it.”

“I agree,” Becca said. “The dynamics are reasonable.”

Kendall looked at A4.

“Insufficient data for probability calculations within acceptable confidence levels.”

“Guess A4, guess,” Kendall demanded.

“To avoid maglev failure and maintain…” A4 said.

“Fuzzy logic, A4, what is your estimate?”

“Twenty-five percent. Zero-point-two-five probability of success.”

Kendall thought for a moment then said, “That’s not good enough. Katya, get everyone into the Quad and clear the area, now.”

“But dad,” Dmitry said. “I need full bandwidth, full data rate by plugging directly into the Station Bus at the elevator terminal so that the station can re-transmit rapidly along the M-Sat network. From the Quad, I can’t close the feedback control loop tight enough to manage perturbations. The low frequency vibrations may become unstable.”

Kendall looked at A4.

“Ten percent. Zero-point-one probability of success from the Quad.”

“I’m sorry everyone,” Kendall said. “It was a great ride, but if we’re going to save anyone, it’s going to be my family. Katya, get them out of there.”

(Click here for Conclusion)

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Polaris Station – Novelette Part 9


(Continued from Part 8)

“That’s not gonna’ happen,” Kendall insisted. “I haven’t had an asymmetrical collapse in all my years of para-gliding, and I’m sure not going to have one now.”

“Kendall?”

Kendall heard a sniffle. “Yes, Katya.”

“I can see you,” Katya said slowly and quietly, “I can see the station, through the top window of the elevator. The station is so small. I’m worried.

“Captain Parker,” Flight said. “Twelve minutes until impact. How much time will it take you and A4 to get to the reserves; to the emergency escape pods?”

“Look,” Kendall continued. “We’ve got the satellites re-distributing, now we just have to do something with M-479. Flight, what are all our options? Let’s get the smart people talking.”

“Okay Kendall,” Flight said. “We’ve been working on it. Houston has the following options so far.”

“Option One. Re-align M-479 back inline with the M-Sats.”

“Option Two. Re-align the stream of satellites downward in line with 479.”

“Is that realistic?” Kendall said.

“Option Three. Move M-479 laterally out of orbital plane so it passes harmlessly by the station.”

“Option Four. Move the satellite stream and the station out of plane so M-479 still passes harmlessly by the station.”

Five seconds passed.

“Is that all you’ve got?” Kendall said.

“Okay, Option Five. Destroy M-479.”

“How do we do that?”

“We can use the Station’s shape-able parabolic reflector to track and concentrate the sun’s energy on 479. The intense heating will cause the pressure vessel to explode.”

Silence for ten seconds.

“Well,” Kendall said. “There’s no way to move M-479 so options one and three are out and I’m not going to be a sitting duck for option five’s shotgun approach; one rogue bullet is better than a million pieces of shrapnel. The odd numbers are out and with station thrusters off line, option four is out. So it’s up to option two? How much time is needed to move the constellation and the station downward enough to align with 479?”

“We can’t move the station,” Dmitry called out. “At least not very fast. The axial and station keeping thrusters are still in calibration. If we lower too fast, the station might oscillate and cause a satellite maglev crash.”

“But what if we move slowly?” Kendall said. “Lower the station by lowering the constellation slowly.”

“Dad, do you think it will be in time?”

“We’re out of options, son. Make your calculations.”

“Okay,” Dmitry said. “But, it will require closed-loop control of the entire M-Sat constellation with feedback from all station and wing rail sensors. The bandwidth will be critical.“

“Okay, everyone,” Captain Parker commanded. “Option two it is. Flight, do you concur? How much time do we have left?”

“8 minutes, 30 seconds to collision.”

“Katya, are you getting telescope images yet? Can you lock on to the rogue trajectory?”

“Affirmative, M-479 clearly coming in low, but still within the orbital plane.”

“How could it still be in the orbital plane?” Kendall said.

“I don’t think this was caused by debris,” Katya said. “It would require an exact vertical impact.”

“If we can’t bump the sat, what about the M-Sat tethers?” Becca said. “Can M-478 and M-480, now that they are closer to M-479, launch their auxiliary tethers, lock onto M-479 from both sides and reel her in line?”

“Keep talking, Becca,” Becca’s father insisted.

“Affirmative,” Flight broke in. “Great idea Becca, but all we need is a nudge. We grapple M-479 with 478 and 480, then using M-Sat thrusters we play tug-a-war, to get M-479 moving outward till she’s in line with the others…”

“Negative,” Dmitry interrupted while preparing his M-Sat maneuver calculations. “Once you get M-479 moving outward, release the grapples and let her continue to move outward, moving higher than the M-Sat constellation and fly right by Polaris Station above, not below the wing.”

Again there was silence for a few seconds.

“Let’s do it, Houston,” Kendall ordered. “Execute the Becca/Dmitry maneuver now.”

“Sir,” A4 spoke up as he and Kendall continued descending down cord sixteen to the station’s main platform.

“Yes, A4?”

“There is a problem with this plan?”

“Do you have a better way to keep this thing from killing us?”

“No sir, but…”

(Continued at Part 10)

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