ICE / ISEE-3, First comet encounter September 1985 |
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ICE / ISEE-3, First comet encounter September 1985 |
 Jun 17 2014, 11:27 PM
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#76
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 Member  Group: Members Posts: 723 Joined: 13-June 04 Member No.: 82  |
ISEE-3 Status Report 16 June 2014 (afternoon)
 We have a very strong confirmation (correct number of commands accepted) that transponder A is in coherent ranging mode and we have reasonably strong confirmation that transponder B is also in coherent ranging mode. We are now set up and ready to go for our first ranging session with DSN on 18 June. Our first session will use DSS-24, a 34 meter dish with 20kW transmitter located at Goldstone in California. If this ranging session with DSN is successful then we will proceed with plans to briefly fire two of the spacecraft's thrusters on 21 June so as to spin it up from 19.16 rpm to the mission specification of 19.75 +/- 0.2 rpm. Our spin-up target is 19.733 rpm, which is an increase of 0.573 rpm from the currently observed 19.16 rpm. This burn would utilize spin-up thrusters A and B (see image above) at a 22.5 degree pulse-width. There would be 11 pulses, taking 34 seconds to complete, with a total fuel usage of 0.0418 pounds. This optimal spin rate is required in order to properly fire the axial thrusters during the much longer trajectory correction maneuver (TCM) we need to perform to adjust the spacecraft's course. That TCM burn is now scheduled to happen between 30 June and 2 July. |
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Jun 18 2014, 12:08 AM
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#77
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Founder Group: Chairman Posts: 14433 Joined: 8-February 04 Member No.: 1 |
ISEE3 should show up as ICE on DSN Now at http://eyes.nasa.gov/dsn
Currently it's scheduled from 1945 UTC tomorrow with 100 minutes of setup time. It may be 2045 until we therefore see a signal - but it might be earlier than that. |
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Jun 18 2014, 08:08 PM
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#78
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Member Group: Members Posts: 201 Joined: 16-December 13 Member No.: 7067 |
DSN activity!
http://i.imgur.com/MZtaG69.jpg Edit: Didn't notice the ISEE3Reboot twitter, which was covering this with more detail - https://twitter.com/ISEE3Reboot "@ISEE3Reboot: We think DSN comms issue has to do w/ #ISEE3 transmitter old age habits - it tends to fall out of ranging mode after a while. Easy to fix." |
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Jun 20 2014, 01:33 AM
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#79
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Member Group: Members Posts: 723 Joined: 13-June 04 Member No.: 82 |
ISEE-3 Status Report 19 June 2014 (afternoon)
In the mean time, due to some pulsar observations that need to be conducted at Arecibo, we have moved up our ISEE-3 Spin-up burn to tomorrow, Friday 20 June. Our window at Arecibo opens around 1:18 pm EDT. We'll be performing the burn during the following several hours. |
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Jun 20 2014, 06:44 PM
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#80
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Member Group: Members Posts: 723 Joined: 13-June 04 Member No.: 82 |
ISEE3 Reboot Project Twitter
ISEE3 Reboot Project @ISEE3Reboot 18m Now sending dummy command to find receiver's sweet spot. ISEE3 Reboot Project @ISEE3Reboot 13m Command counter incremented 21 out of 21 times from +5 kHz to 25 kHz. ISEE3 Reboot Project @ISEE3Reboot 7m We're going to have to scrub #ISEE3 spin-up burn for today. Can't confirm receipt of commands in real time by the spacecraft. ISEE3 Reboot Project @ISEE3Reboot 7m If we cannot confirm that proper commands were sent to propulsion system we cannot fire thrusters with full confidence ISEE3 Reboot Project @ISEE3Reboot 5m Real time telemetry is not working as expected on #ISEE3 today. Remember: this spacecraft does not have a computer. ISEE3 Reboot Project @ISEE3Reboot 2m All 21 dummy commands worked - that should NOT have happened. Next time we sent them only 3 were accepted. Investigating ... |
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Jun 20 2014, 07:29 PM
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#81
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Member Group: Members Posts: 723 Joined: 13-June 04 Member No.: 82 |
ISEE3 Reboot Project @ISEE3Reboot 33m
Next #ISEE3 spin-up burn attempt will likely be the middle of next week - after our next DSN session. SEE3 Reboot Project @ISEE3Reboot 15m We're still talking to #ISEE3 right now. |
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Jul 2 2014, 07:55 PM
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#83
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Member Group: Members Posts: 723 Joined: 13-June 04 Member No.: 82 |
ISEE-3 Engines Fired For Spin-Up
QUOTE Today we fired the A and B thrusters on ISEE-3 to perform a spin-up burn. Preliminary results confirm the burn and a change in rotation. Spin rate was originally 19.16 rpm. It is now at 19.76 rpm. The original mission specifications call for 19.75 +/- 0.2 rpm- so we are exactly where we wanted to be. We are now collecting telemetry in advance of our next DSN pass and our ATP-3 review with NASA. The earliest we expect to make our Trajectory Correction Maneuver is next week. All in all, a very good day. The rotation rate is now almost exactly right where they wanted it. A big step in preparing for the upcoming "Big Burn". I admit that I was starting to get worried about how long it was taking to get this done, the available time before it would be too late is limited. |
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Jul 5 2014, 05:39 PM
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#84
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Senior Member Group: Members Posts: 1585 Joined: 14-October 05 From: Vermont Member No.: 530 |
It's a fair bit later than some initial projections of when the big TCM had to be completed by, though the more recent blog posts appear to target June 30-July 2.
I wonder when the expected delta-V available truly falls short of the amount required. |
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Jul 7 2014, 11:17 PM
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#85
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 Senior Member Group: Members Posts: 2090 Joined: 13-February 10 From: Ontario Member No.: 5221 |
They've scheduled the TCM for tomorrow; Arecibo window from 12:42pm-3:29pm EDT .
https://twitter.com/ISEE3Reboot |
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Jul 8 2014, 05:08 PM
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#86
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 Senior Member Group: Members Posts: 1729 Joined: 3-August 06 From: 43° 35' 53" N 1° 26' 35" E Member No.: 1004 |
for today's TCM, AMSAT Germany is displaying real time telemetry
http://www.amsat-dl.org/index.html |
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Jul 8 2014, 05:52 PM
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#87
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Junior Member Group: Members Posts: 83 Joined: 19-April 05 Member No.: 251 |
First burn complete. Looks like it went well.
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Jul 9 2014, 12:38 AM
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#88
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Member Group: Members Posts: 723 Joined: 13-June 04 Member No.: 82 |
Mechanical 'hiccups' complicate satellite reboot mission
QUOTE Is NASA's forsaken ISEE-3 satellite finally headed home? On Tuesday a private team of engineers initiated a series of propulsive bursts intended to return the aging spacecraft to Earth orbit. However, several mechanical "hiccups" occurred that prevented the spacecraft from completing the maneuver and raised questions about the condition of the spacecraft's fuel system. The team will attempt to refire the spacecraft's thrusters on Wednesday. "The good news is the propulsion system works -- when it wants to," said Keith Cowing, a former NASA astrobiologist and a spokesman for the ISEE-3 Reboot Project. QUOTE On Tuesday, ISEE-3 completed the first of its seven burn sessions without a hitch. When engineers commanded the satellite to begin its second session however, it quickly became clear there was a problem.
"We could tell the valves and things were working, but we did not see that the spacecraft was changing its trajectory or speed, which told us something was going on," Cowing said. ISEE-3 is equipped with a dozen monopropellant hydrazine thrusters. Hydrazine, an extremely toxic substance, freezes at roughly the same temperature as water, so a series of heaters are used to liquefy the propellant before executing maneuvers. The hydrazine is kept in eight fuel tanks, which also contain pressurized gas. When the spacecraft receives a command to open a fuel valve, the pressurized gas forces the hydrazine through a fuel line and into a catalyst. The catalyst causes the hydrazine to break down, which produces a propulsive blast of hot gas. Unlike rockets taking off from Earth, the hydrazine blast is invisible to the human eye. Before executing the first burn on Tuesday, the reboot team turned off the fuel line heaters to save power, raising the possibility that the fuel had become frozen and thus unable to come in contact with the catalyst. "That's the first thing you think of," Cowing said. "But it could be something else. There may not be enough fuel for that to be an issue, or it's possible that the pressurant may have run out, or that there's a valve not doing its thing." Like most spacecraft, ISEE-3's propellant system contains numerous redundant elements, and Cowing said he was confident that the team would determine the cause of the firing failure and figure out a work-around solution. The window for ISEE-3's course alteration will remain open for several days. "Ideally, we would have done it today, but if we do it in the next day or two or three, we’re good to go," Cowing said. |
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Jul 10 2014, 05:18 AM
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#89
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Senior Member Group: Members Posts: 1729 Joined: 3-August 06 From: 43° 35' 53" N 1° 26' 35" E Member No.: 1004 |
latest update after the second TCM attempt
QUOTE Right now we think there is a chance that the Nitrogen used as a pressurant for the monopropellant Hydrazine propulsion system may have been depleted.
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Jul 15 2014, 09:27 PM
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#90
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Member Group: Members Posts: 723 Joined: 13-June 04 Member No.: 82 |
ISEE-3 Status Report 15 July 2014
QUOTE Our next window at Arecibo is tomorrow (Wednesday) between 12:19 pm and 3:03 pm ET. During that opportunity we intend to attempt a deep space plumbing repair on board ISEE-3 and then fire its engines. Right now we still only need approximately 10 m/sec of Delta V for the Trajectory Correction Maneuver (TCM) so we're looking good in terms of fuel reserves. Based on the number of thruster firings we achieve during that plumbing repair session we'll need to do some additional firings - possibly over the course of several days - all of which will constitute the TCM. If you have ever had to clean our your car's carburetor and fuel lines then you have an idea of what we will be attempting. More details to follow. We Are Borg: Crowdsourced ISEE-3 Engineering and the Collective Mind of the Internet QUOTE We are Now Living in a Science Fiction World. In the science fiction universe of Star Trek, set several hundred years in the future, when we are a spacefaring civilization, humanity encounters a species called the Borg. The Borg are a conglomeration of species who are assimilated into a collective mind numbering in the hundreds of billions. All of the Borg are connected to each other through a communications link that allows each of them to share each others thoughts, though in a manner that erases individuality. This week, with the call that our ISEE-3 reboot team put out to the internet for help in debugging our propulsion system problem, I have come to realize that a significant portion of humanity has reached a Borg like state, one where the internet has become a collective mind for communications and knowledge sharing. We still have our individuality, we can still decouple at will from the collective mind, but in a way that few philosophers or technologists have envisioned, we are connected in a way never before thought possible. The implications are staggering, and here is how our little ISEE-3 project is an example of the operation of the collective mind. [a lot of technical information deleted] There was a great article "Distributed Rocket Science is a Thing Now" on space.io9.com related to distributed engineering and our project, and how the people from the net came together to help us. I first saw the term distributed engineering in the late 1980s from the amateur radio community. It began through using ham radio to do this, then it migrated to email before the advent of web browsers, and then to the web. What happened with our call for help goes far beyond that as the distributed engineering meme begins with a pre organized group of people that collaborate in geographically disparate locations toward a common engineering goal. Before our call for help last week, I knew maybe one or two of the experts that came in and helped us. This goes well beyond distributed engineering to a collective consciousness. I often characterize the internet as the global extension of my brain, with vast stores of knowledge that the brain organizes through the interface of the browser. In the beginning of the net we used this to research information. With the rise of the ubiquitous internet among the professional class and beyond in the world, we now have something never before seen on this scale in the history of mankind, a near instantaneous way to not only research information, but to rapidly organize humans to do "things". We now have crowd funded efforts that bring people together of like interests to fund interesting projects like ours. We have crowdsourced collaboration in the arts, sciences, and engineering. There is a lot of talk about singularities in the technology world, and for the most part they are marketing myths from my experience. However, and this is what I leave the reader to ponder, we have reached a threshold where vast numbers of people can work together in a near real time manner to solve problems and do good and interesting (or evil) things. One wonders where this will go.... This reminds me of the SpaceX ocean landing video. The received rocket-cam video data stream of the touchdown was highly corrupted, and SpaceX was only able to get a couple of usable image frames out of it. So they threw the problem open to the wider community, and a group of volunteer experts (including some of the absolute top people in the world, in that field) formed a group that over several weeks, successfully extracted a high quality video of the Falcon 9 first stage landing on the ocean, developing some new tools along the way that will be useful in any similar problems in the future. |
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