Pages

Thursday, 22 June 2017

GB8SSD *Space Shuttle Discovery* Celebrating 33 years years since Launch

Space Shuttle Flight 12 (STS-41D) 

Launch attempts

AttemptPlannedResultTurnaroundReasonDecision pointWeather go (%)Notes
125 Jun 1984, 12:00:00 amscrubbed---Failure of Orbiter's back-up General Purpose Computer forced the scrub.[11] (T-9:00 minutes and holding)
226 Jun 1984, 12:00:00 amscrubbed1 day, 0 hours, 0 minutesPost-SSME start RSLS abort due to anomaly in number three main engine (T-0:06)Discovery returned to OPF for engine replacement; launch delayed over two months
329 Aug 1984, 12:00:00 amscrubbed64 days, 0 hours, 0 minutesDiscrepancy with master events controller relating to SRB fire commands
430 Aug 1984, 1:41:50 pmsuccessful1 day, 13 hours, 42 minutesdelayed 6 minutes, 50 seconds when private aircraft strayed into KSC airspace

June 26: Abort flight:



June launch attempt

During the 26 June launch attempt, there was a launch abort at T-6 seconds, followed by a pad fire about ten minutes later.[3][4]
Commentary: "We have a cut off."
"NTD we have a RSLS (Redundant Set Launch Sequencer) abort."
Commentary: "We have an abort by the onboard computers of the orbiter Discovery."
"Break break, break break, DLS shows engine one not shut down."
"OK, PLT?"
"CSME verify engine one."
"You want me to shut down engine one?"
"We do not show engine start on one."
"OTC I can verify shutdown on verify on engine one, we haven't start prepped engine one."
"All engines shut down I can verify that."
Commentary: "We can now verify all three engines have been shut down."
"We have red lights on engines two and three in the cockpit, not on one."
"All right, CSME verify engine one safe for APU shutdown."
"If I can verify that?"
"OTC GPC go for APU shutdown."[5]
Mission Specialist Steve Hawley was reported as saying following the abort: "Gee, I thought we'd be a lot higher at MECO (Main Engine Cut-Off)!".[6] About ten minutes later, the following was heard on live TV coverage:
"We have indication two of our fire detectors on the zero level; no response. They're side by side right next to the engine area. The engineer requested that we turn on the heat shield fire water which is what could be seen spraying up in the vicinity of the engine engine bells of Discovery's three main engines."
While evacuating the shuttle, the crew was doused with water from the pad deluge system, which was activated due to a hydrogen fire on the launch pad caused by the free hydrogen (fuel) that had collected around the engine nozzles following the shutdown and engine anomaly.[7] Because the fire was invisible to humans, had the astronauts used the normal emergency escape procedure across the service arm to the slidewire escape baskets, they would have run into the fire.[8]
Changes to procedures resulting from the abort included more practicing of "safeing" the orbiter following aborts at various points, the use of the fire suppression system in all pad aborts, and the testing of the slidewire escape system with a real person (Charles F. Bolden, Jr.). It emerged that launch controllers were reluctant to order the crew to evacuate during the STS-41-D abort, as the slidewire had not been ridden by a human.[6]
Examination of telemetry data indicated that the engine malfunction had been caused by a stuck valve that prevented proper flow of LOX into the combustion chamber.



About the mission

Tuesday, 20 June 2017

Trying out satellite video's

XW-2F TM17USA and G0ABI XW-2F TM17USA and G0ABI XW-2A

XW-2A Morse heard

AO-73 Funcube1 tenementary

Nayif-1 Funcube3 telemetry


AO-73 telemetry

AO-73 funcube1 telemetry

 FO-29

Ukube1 funcube2

Ukube1

XW-2D

FO-29 2M0SQL

XW-2a beacon

XW-2A heard G7LJA Peter

Thursday, 15 June 2017

Virtual buildathon is back





We will be starting the #vbuildathon with the small diplexer kit by HA8LFK, kits will no more than £20 depending on shipping and import tax, as always you pay what we pay, no additional costs.



Lilacsat 1 and 2 decoder now available on Raspberry Pi (3) image

We spent some time installing and testing out fitting all the GNU radio and demodulators onto a pi image.

Results you need 2 pi's to make this work well.

The image is available here



So we build GNU radio and gr-satellites and gr-lilacsat from scratch along with all dependencies



GNU radio loads and iports the lilacsat modules (detects funcube / airspy dongles)



The proxy loads and run OK



The front end module loads and displays the graphs just fine



Then we hit a resource issue, the pi-3 cannot handle running the second GNU radio module to decode the digital voice.

We think the answer is to build a second pi-3 to run just the decoder, and change the front-end gnu radio block to pipe the audio to the second pi.

We will continue to test and let you know how we get on, anyone who wants to test and give us feedback please do.

Twitter: @chertseyrc