"Alas, ISEE-3 spacecraft, we almost caught you. Attempts to move a 36-year-old NASA probe closer to Earth have failed, but only because the vintage spacecraft is simply out of gas, according to the team of volunteer engineers now controlling the spacecraft. The spacecraft, called the International Sun-Earth Explorer 3 (ISEE-3), has run out of vital nitrogen gas needed to pressurize its propulsion system, according the private team of engineers. The team, which calls itself the ISEE-3 Reboot Project, has spent recent weeks puzzling through an issue that shut down attempts to send the ISEE-3 spacecraft on a new trajectory on July 10. With all options exhausted, the team now plans to do science in a different location instead."
Recently in ISEE-3 Reboot Project Category
"The citizen science team wanted to execute burns to drop the craft back in its 1978 orbit, but the spacecraft disagreed. The original hope was to execute burns to blaze past the moon and drop the spacecraft puttering about in a L-1 halo orbit. Alas, although ISEE-3 had enough juice to do a power-up spin to reach its optimal rotation rate, the nitrogen propellant has bled away. The aging craft is willing, but after 30 billion miles, it just doesn't have enough gas to change its trajectory. Instead, it'll do a lunar flyby, and resume its heliocentric orbit, this time blazing a trail ahead of us instead of stalking the Earth. But here's the thing: this time, it'll be doing science."
ISEE-3 spacecraft presentation in Guildford Saturday, Southgate ARC
"Achim Vollhardt DH2VA and Mario Lorenz DL5MLO from AMSAT-DL Bochum will be giving a presentation on ISEE-3 (ICE) to the AMSAT-UK International Space Colloquium at the Holiday Inn, Guildford, GU2 7XZ. The event is open to all ."
After a successful reawakening the venerable ISEE-3 spacecraft is about to begin the first interplanetary citizen science mission.
In April 2014 our team set about bringing the 36 year old ISEE-3 (International Sun Earth Explorer 3) spacecraft back into science operations. Our plan was to contact the spacecraft, evaluate its health, command it to resume normal operations, fire its engines, and resume the orbit it originally occupied in 1978. Once science operations resumed, our plan was to make the data openly available to citizen scientists - in fact, anyone, anywhere - as soon as we received it from the spacecraft.
We had a session with ISEE-3 today via Arecibo with support from AMSAT-DL/Bochum team in Germany. We engaged in "hammer mode" wherein we tried to open and close all of the latch valves repeatedly with the hope that this might get the propulsion system working. It did not. We then began to transition the spacecraft to science mode by turning on two additional science instruments. We'll post a detailed update tomorrow.
Keith Cowing and the Outrageous ISEE-3 Rebooters , Planetary Radio
"They have generated excitement, enthusiasm and support throughout the world. The ISEE-3 Reboot Project has succeeded in gaining control over the 36-year old spacecraft, but will they be able to move it."
Any space mission worth doing should have an education and public outreach (EPO) component. An EPO effort helps to efficiently disseminate information to those with a specific interest in a particular mission. Done properly it also serves as a means to spur interest in space exploration in general amongst a much broader audience. With the use of various Internet and social media resources an effective EPO effort can now reach an audience in ways that were not possible a decade ago.
Lost and Found in Space: Rebooting ISEE-3: Space for All, op ed, Keith Cowing, New York Times
"NASA likes to say that "space is hard," but to make itself relevant to the people whose taxes fund it, it must get outside its comfort zone. To its credit, NASA saw the potential of our project to reach beyond the traditional audience. The interactions via social media with our supporters have borne this out. Imagine what feats of exploration might be possible if an empowered and engaged citizenry realized that exploring space is really something anyone can do."
"After refusing to fire its engines last week for a course correction, a vintage NASA spacecraft did produce a bit of thrust Wednesday (July 16), proving it still has at least some fuel left after 36 years in space."
Citizen Scientists Get ISEE-3 Satellite Engines to Fire!, The Mary Sue
"The amazing people behind the ISEE-3 reboot project have gotten its engines to fire! They previously had trouble due to a lack of nitrogen to push fuel through the old satellite's fuel lines and into the engines, but some creative use of the satellite's tank heaters seems to have paid off and gotten things working."
During our pass at Arecibo today we managed to get some propulsion out of thruster K. We're looking at how this was accomplished with an eye toward repeating it. We expect to do a DSN pass on 24 July so as to further refine the spacecraft's location. We are also working to start communicating with ISEE-3 from Morehead State University in the very near future. We also have one of many documentary teams at McMoons today to document our efforts.
Our window with Arecibo opens tomorrow (Friday) at 12:13 pm ET. We will continue with our plumbing and electrical testing and see if we can get the propulsion system operating again.
"No one on our team is an experienced hydrazine expert," he said. "After receiving a few e-mails from people who offered suggestions on what might have happened, [we] decided to throw the problem out to the world. I was astonished at the response."
The July 10 post on the ISEE-3 blog and NASA Watch (Cowing's website) generated many suggestions, including some from "the most qualified professionals in the world," Wingo said, while declining to name names due to privacy concerns."
Crowdsourced Know-How May Put Salvaged ISEE-3 Spacecraft Back on Track, NBC
"After a series of setbacks, the decades-old ISEE-3 spacecraft revived by a team of experts may be getting back on track -- following input from a global community of aerospace experts. Space College, the group that resurrected the International Sun-Earth Explorer probe, wrote in a blog post Tuesday that asking for help on the project resulted in a flood of input, some coming from "the most qualified professionals in the world ... literally, the very top tier of experts."
During our interaction with ISEE-3 today we tried a variety of valve and thruster selections using both sides of the propulsion system combined with tank and fuel line heating. Although we met with limited success we did get several instances of thrust (the main intent) and also a change in the Fine Sun Sensor angle of the spacecraft. So, something changed the trajectory of ISEE-3 albeit slightly. Also, the temperatures in the fuel tanks only rose a little bit which is what you'd expect of they were still full of fuel. This is good news since we were concerned for a while that there might have been a loss of fuel and/or pressurant. So ... we're analyzing the data and trying to sleuth out how we got the momentary thrust and then apply that to our next interaction with the spacecraft. We have applied for an extension to our license from NASA to transmit to the spacecraft and are awaiting their reply.
Space Dream Revived in an Abandoned McDonald's, Bloomberg View
"Can a group of citizen scientists working out of an abandoned California McDonald's re-energize U.S. space exploration? Thirty years ago, that question would have been the basis for a science-fiction novel, at best. Today, however, not only are the scientists and the McDonald's real, but the group has also commandeered a 36-year-old NASA space probe bound for an August fly-by of the Earth and moon."
"The ISEE-3 Reboot Project, as these enthusiasts call themselves, exists to revive an old spacecraft. A very old one. It was launched in 1978, and has thus spent almost two-thirds of the entire space age, which began in 1957 with the launch of Sputnik, in orbit around the sun. But in 1997 NASA decided ISEE-3 had done its job as a solar observatory and comet-chaser, and shut it down. Just in case somebody in the future wanted to try to revive it, the shutdown left the craft in standby mode. And that, as their name suggests, is what the Rebooters are trying to do."
"Before reviving a zombie spacecraft, Dennis Wingo and Keith Cowing traveled to the past to rescue a trove of early moon photographs that otherwise would have been destined for oblivion. They did not actually time travel, but that might have been easier. Mr. Wingo, an entrepreneur and an engineer, and Mr. Cowing, the editor in chief of the NASA Watch website, had confidence that they could decipher decades-obsolete NASA equipment, because, as Mr. Cowing said, "we've done this before." ... The earlier project involved 1,500 magnetic tapes and a couple of old, broken tape drives. In 1966 and 1967, NASA sent five robotic spacecraft, the Lunar Orbiters, to photograph the moon's surface to help find safe landing sites for the Apollo astronauts. The tapes, which recorded the original high-resolution images, and the tape drives ended up in the garage of a former NASA employee, and Mr. Wingo and Mr. Cowing embarked on a quixotic mission to retrieve the images."
Dennis Wingo: 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.
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.
"I have been following your effort to revive ISSE-3 with great interest since I worked on this project as an employee of Fairchild Space Company. Attached is a picture of the satellite in Hanger AE at the Cape. I am the second person from the right end and Rich Kramer is standing next to me on my right hand. On my left hand is Dick Collingwood and the three of us were the last people to work on the satellite on the pad prior to launch. Wishing you the best of luck. Ed Grebenstein"
Images copyright and courtesy of Ed Grebenstein. Click on images to enlarge
More images below
These images were provided by Todd Kramer. His father, Richard Kramer, worked on the ISEE-3 project and took these pictures. These photos show the final assembly and testing at NASA GSFC in May 1978 after ISEE-3 was moved there from the Fairchild facility in Germantown, MD. We'll be posting more photos from Todd that show the spacecraft being transported to KSC, prepared for launch, and then launched. All photos are copyright Todd Kramer. Click on image to enlarge.
More images below
Less than two hours after sending out a distress signal for help, engineers who worked on exactly these types of propulsion systems emerged from the digital wilderness to offer their hard-won experience. What the team learned was a mix of good and bad: solubility probably wasn't the problem impeding the satellite's thrusters. Awesome, they don't need to fix that! Boo, they only have about two or three more options of things that are fixably bad to work on. And if none of those are the problem? Then this will be a glorious, exciting, exuberant failure, and ISEE-3 will continue on its orbit about the sun, leaving us behind once more. Good luck, team. We're cheering for you.
Volunteer engineers struggle to get ISEE-3 back in gear, The Space Reporter
Attempts to shift the craft's trajectory began on Tuesday, but ISEE-3 failed to accelerate. The team first thought that the craft suffered from a stuck valve, but after investigating further, they began to suspect that it did not have enough nitrogen left to provide pressure to its fuel system. If the team is unable to change ISEE-3's course, then the craft will fly around the moon on August 10 before resuming its orbit around the sun. The volunteer engineers look to gain more information about the craft's condition during Friday's radio communications session. Even if they fail to bring ISEE-3 into a stable orbit, the team still hopes to use it for scientific purposes while it is in the inner solar system.
So we're left with the question "Is it better to have tried and failed than not to have tried at all?" Cowing seems to think so. As he told SpaceNews on July 9, "We did stuff that was widely seen as impossible, improbable, and impractical. You need to focus on the absurd things that are possible." And it's focused minds on the usefulness of the past. The relentless advancement of technology is good for Mars rovers and Netflix streaming speeds, but it also means we abandon still-useful gadgets. And magnetic readings from the sun are magnetic readings from the sun, whether they come from a silicon-encrusted modern craft or a disco-era one.
The ISEE-3 Reboot Mission: a dream SDR application, Balint Seeber, Ettus Research
"Upon arriving at Arecibo, I knew I was in the right place when I walked outside the rear of the Visiting Science Quarters and found a dipole antenna in the backyard. This was in fact a riometer experiment, and the data acquisition board and laptop were left on my room's table. While exploring the main facility itself, one truly finds themselves in RF heaven. From the first glimpse of the top of one of the three towers supporting the platform that is suspended above the dish, to riding the cable car up to the platform itself with the dish appearing in a slow reveal, to jogging around the perimeter of the dish, the scale of the place is incredible. This, along with stories of birds being cooked by the S-band RADAR, and only 1 dB of loss across the RF waveguide that extends from the 2.5 MW (peak power) 430 MHz klystrons next to the control room, across the cat walk, and into the Gregorian Dome, conveys the seriously large (and tiny) numbers the science conducted at Arecibo deals with."
We spent all day yesterday with space propulsion experts. We have identified a series of options including hydrazine tank heating and a long series of pulse attempts to (possibly) clear the lines. We have most certainly not given up on this spacecraft yet. It is doing science and will continue to do so for years to come.
We have a crowdsourced research project for our ISEE-3 Reboot fans. One of our volunteers, Karl-Max Wagner from Germany has an interesting idea. Did the Nitrogen pressurizing gas dissolve in the Hydrazine in the tanks?
This is something that we would like to research and for efficiencies sake and to get the job done quicker, we would like our project fans out there to help us in this research. I am reading an old USAF document on this now and it may be nothing, but it also may be something. We need to research the following:
- What is the solubility of Nitrogen in Hydrazine?
- What is the temperature dependence?
- Most important, what is the time required to dissolve 1 kg of Nitrogen in 15 kg of Hydrazine? This is an approximation for both tank systems of course.
This is important. Don't just throw stuff on the wall, help us research this.
Send your thoughts to email@example.com or post them in the comments section below.
Even though they might not be able to capture the spacecraft, Mr. Cowing said they were devising an alternative in which ISEE-3 would collect scientific data and send it back to Earth. "There's a Plan B," he said. "We're going to listen to the spacecraft as long as it talks."
On Wednesday, members of the ISEE-3 Reboot Project spent two hours attempting to diagnose and repair the problem by "jiggling" fuel valves on and off and instructing the 36-year-old craft to fire several of its 12 thrusters. When these attempts failed to work, engineers concluded that the satellite's fuel system had lost critical pressure. "We have exhaustively tested the propulsion system with no good results," Dennis Wingo, chief executive of Skycorp Inc., and leader of the privately run project, said on his Twitter account.
The ISEE-3 Reboot Project efforts were funded with $160,000 raised on the crowd-funding website RocketHub.com. Another fundraising drive likely would have been required for the citizen science campaign Cowing and Wingo were planning. "We did stuff that was widely seen as impossible, improbable, and impractical," said Cowing. "You need to focus on the absurd things that are possible."
Our troubleshooting today eliminated some suspected causes of propulsion system problems. We do not think any of the valves are malfuctioning. 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. That said, we still have a number of troubleshooting options yet to be explored. We have a DSN pass scheduled for Friday that will allow us to recalibrate our location information and trajectory plans for ISEE-3. Even if the L-1 halo orbit is no longer an option, we do have plans to use ISEE-3 for science in other locations within the inner solar system after the lunar flyby on 10 August.
Mike Loucks @Astrogator_Mike Symmetry baby! Outbound #ISEE3 trajectory (blue) from 1983 and Incoming (green) in 2014. Earth-Sun rotating frame.
These charts represent data recorded during our Trajectory Correction Maneuver (TCM) thruster firings yesterday. Thruster firings were planned to done in groupings - or "segments" - of 63 firings per segment. The first chart is annotated to show the three firing attempts. The first segment was full duration but only partially successful. The second and third attempts failed. Possible causes (under investigation) include valve malfunction and fuel supply issues. Click on images to enlarge.
NASA's Zombie Spacecraft Learns to Fire Its Engines, The Atlantic
"The quest to save the ISEE-3--a long-lost NASA probe launched in the disco era and abandoned in the dot-com boom--might just succeed. Late last week, the amateur scientists and engineers working to salvage the probe hit a major milestone: They coaxed the craft into firing its rotational thrusters."
"In the past month of working with the spacecraft, Cowing said they'd gotten used to its idiosyncrasies. ISEE-3 lacks an onboard computer, so commands must be fed to it one at a time. Cowing compared the process to rock-climbing: When it's time to move to the next outcrop, the movement has to happen quickly and definitively. "You just have to push through it and the data you get back isn't exactly what you want. As soon as it would take another command, you just rush through the next one and the next one," he said. "It's like telling an old dot-matrix printer from back in the day to do something."
In Effort to Shift Abandoned NASA Craft, a Hiccup (or Burp), New York Times
"The first part of the maneuver succeeded, a milestone in an effort to resurrect a zombie spacecraft that NASA abandoned 17 years ago. But then -- perhaps to be expected during work on a jalopy -- problems cropped up, and the thrusters failed to fire properly. Another attempt to complete the course correction will be made Wednesday. "I feel like it is taunting us sometimes," Keith Cowing, one of the leaders of the effort, said of the 36-year-old spacecraft, the International Sun-Earth Explorer-3, or ISEE-3. It is not NASA commanding the spacecraft now, but a group of civilians working in a former McDonald's in California taking advantage of technological goodies of the 21st century, including Skype, Twitter, laptop computers and crowdsourcing."
"Now, as of Tuesday, they've been sending commands for engine burns that will actually change the vehicle's course. "And the first burn went well, we thought," says Cowing, "and then it stopped and we got indications that the spacecraft had changed its speed, which is what you want." But the second attempt to fire the engines didn't go as smoothly. "It's a cranky old spacecraft that -- knock on wood -- does what we tell it to do most of the time," says Cowing. "We kind of knew we might be doing this over the course of a day or two, so this isn't surprising."
"An attempt to divert NASA's venerable International Earth/Sun Explorer (ISEE)-3 satellite back toward Earth was suspended due to technical issues early July 8, but the all-volunteer team seeking to resurrect the 1970's-era heliophysics mission expects to try again July 9."
We managed to conduct the first segment (composed of 63 thruster pulses) but encountered problems with the second and halted the remainder of segment firings. Today's burn was supposed to be 7.32987 m/s. We're looking at data and formulating a plan for tomorrow. Our window tomorrow (Wednesday) at Arecibo opens at 12:39 pm EDT and extends to 3:26 pm EDT.
You can see telemetry from ISEE-3 here at AMSAT-DL
The photos below are from Mission Control at McMoons.
As many of you know, last week we fired the thrusters on ISEE-3 to do a spin-up burn. Before the burn (actually 11 pulses on the spacecraft's hydrazine thrusters) the spin rate of ISEE-3 was 19.16 rpm. After spin-up burn it was 19.76 rpm. The original mission specifications for ISEE-3 called for a spin rate of 19.75 +/- 0.2 rpm. In other words: bullseye.
If all goes according to plan on Tuesday, 8 July, we will conduct the Trajectory Correction Maneuver (TCM). This will require a much longer firing of the spacecraft's thrusters. Our window at Arecibo opens at 12:42 pm EDT and extends until 3:29 pm EDT. If the burn is a success we will follow up with another ranging session using the DSN to get an exact measure of the spacecraft's position, trajectory, and speed. After that we should be good to go for our lunar flyby on 10 August.
After the last technical tag-up for today it looks like TCM will be 432-435 pulses fired in 7 segments with a total delta V of approximately 7 m/sec.
ISEE-3 Project Team Announces the Space Probes Engines are Fired Up, CrowdFund Insider
"Just a little over a month since the closing of their crowdfunding campaign on RocketHub campaign to the close, the team behind the ISEE-3 Reboot Project announced over the week that they have successfully fired up the space probe's engines."
"The volunteer team attempting to resurrect NASA's International Earth/Sun Explorer (ISEE)-3 observatory before it goes hurtling into orbit around the sun for thousands of years will attempt to boost the venerable spacecraft back into the Earth system July 8."
"On July 2, the Cold War-era satellite fired its first thrusts since 1987, according to team members of the ISEE-3 Reboot Project. "All in all, a very good day," co-leader Keith Cowing wrote in a blog post. Though made up largely of former NASA employees, ISEE-3 Reboot Project's private group also has some younger space-lovers on board. "Some of our team members were not even born yet the last time the engines fired," the team said via Twitter."
36-Year-Old NASA Probe's Engines Successfully Fired Up by Private Team, Scientific American
"ISEE-3 needs to be moved to put it in an advantageous position to communicate with Earth. In past interviews with Space.com, Cowing has said the group will focus on what to use the spacecraft for after rescuing it. Another priority will be seeing how well its 13 scientific instruments function. At least one instrument, the magnetometer, is working well enough to do science. "Recent magnetometer data shows recent solar event," the team said via Twitter on Wednesday (July 1)."
Our ISEE-3 Reboot Project store is now open and online at CafePress.
Source: JPL HORIZONS
Ephemeris Type: OBSERVER
Target Body: ICE Spacecraft (ISEE-3)
Observer Location: Geocentric 
Time Span : Start=2014-07-04, Stop=2014-08-03, Step=1 d
Table Settings: defaults
Object Data Page
UPDATE (2014-Jul-03): Trajectory update from ISEE-3 Reboot based on Arecibo angular data and DSN two-way Doppler.
ISEE-3 Propulsion System Awakens at 11th Hour, Space News
"If ISEE-3 makes it back to Earth-sun Lagrange Point 1, Cowing and Wingo plan to command the spacecraft from mission control McMoons: an abandoned McDonald's on the Campus of NASA's Ames Research Center in Mountain View, California. Besides raking in more heliophysics data, Cowing and Wingo want to give the general public, students in particular, a chance to learn firsthand about Earth-sun interactions, and spacecraft operations."
"An old NASA spacecraft under the control of a private team fired its thrusters on Thursday for the first time in a generation. NASA's International Sun-Earth Explorer 3 probe, or ISEE-3, which the agency retired in 1997, performed the maneuver in preparation for a larger trajectory correction next week. The spacecraft hadn't fired its engines since 1987, ISEE-3 Reboot Project team members said."
An old workhorse satellite spins back up, The Economist
"In the month since re-waking ISEE-3, and with the assistance of both Arecibo and the global Deep Space Network (DSN), that team has been testing command responses and poking gently at the instrumentation on board. Doing so is not easy. The original control code is long gone, so the team has had to improvise their own. The satellite lacks any program storage: each command to be executed must be sent one at a time and acknowledged for the group to be sure they can proceed to the next step."
Further confirmation of the ISEE-3 spin-up burn yesterday. Before the burn (actually 11 pulses on the spacecraft's hydrazine thrusters) the spin rate of ISEE-3 was 19.16 rpm. After spin-up burn it was 19.76 rpm. The original mission specifications for ISEE-3 called for a spin rate of 19.75 +/- 0.2 rpm. Bullseye.
From Pat Barthelow on Facebook: (translation): Hey Folks! Just heard from my Moonbounce friends (Jan, PA3FXB and team) in Dwingeloo Holland (PI9CAM) who have a 25 meter Moonbounce dish, that they are hearing ISEE-3 easily, including spin modulation (AM) They can do this with an SDR that just yesterday they tried for the first time, and almost fell of their chairs when they clearly heard it, the first try, and that was using wide bandwidth, SSB voice, about 2.3 kHz. tomorrow they will look again at narrow bandwidths, and anticipate a booming signal with very high S/N. this is incredible. see photo of their newly rebuilt history making dish that originally saw first light in the late 1950s.
Ed Smith, Original Original Principal Investigator on ISEE-3 Vector Helium Magnetometer: The effort to recapture the ISEE-/ ICE spacecraft has just achieved a notable scientific success. Data recovered from the spacecraft very recently show that the magnetometer is not only operating well but has observed a large rapid change in the Interplanetary Magnetic Field/IMF.
What makes this accomplishment so remarkable is that it is the first science data returned by the spacecraft after its long 29 -year voyage around the Sun (traveling ahead of and slightly faster than the Earth). That trip began shortly after ISEE carried out the first encounter with a comet, Giacobini- Zinner, in September 1985. Shortly afterward, the ISEE experiments continued to operate but were disconnected from the radio telemetry so that only a beacon was being transmitted. In the intervening years, no scientific data were received.
The ISEE-3 Reboot Project mission control team for today's engine firing: From left to right: Austin Epps - Lead Engineer, Jacob Gold - Systems Engineer; Cameron Woodman - Flight Director; Dennis Wingo - Mission Director, Project Co-lead; Marco Colleluori - Attitude & Orbit Control Systems Engineer; and Balint Seeber - Communications Engineer, SDR Guru (Ettus Research)
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.
We have a window at Arecibo that opens today around 1:00 pm EDT. If all goes according to plan we will attempt to do our spin-up burn today. Once we have reliable communications, ability to issue commands, and reliable telemetry we will command ISEE-3 to make one pulse of its thrusters. If that is successful then we'll command an additional 10 pulses. Keep an eye on @ISEE3reboot on Twitter for updates.
Update: We were able to use the B transmitter today for the first time but were unable to complete the various steps needed to command ISEE-3 to fire its engines. There is a chance of a window at Arecibo tomorrow.
Meanwhile the first scientific measurement by ISEE-3 in decades has been obtained. Recent magnetometer data from ISEE-3 shows clear evidence of a recent solar event. We will be releasing more information on these observations very soon.
This is a screen grab taken at Morehead State University during our second DSN pass with ISEE-3 on 27 June. Morehead was observing the session and recording data. If you look at the larger version of this image you can see the ranging tone bursts being sent to ISEE-3 by DSS-24 at Goldstone. DSS-24 was broadcasting at approximately 10 kW. Click on image to enlarge.
Presentation at DorkBotSF on 24 June 2014 by Balint Seeber, Austin Epps, and John Malsbury.
We had an even greater DSN pass today with ISEE-3. We managed to get ~30 minutes of data (11 range points) after achieving 2 way Doppler lock and ranging at a 47.5 kHz offset. Morehead State University was listening and recording during this session (more on that soon). Earlier today we had a pass at Arecibo. Today's task was to take some time to probe the way that ISEE-3 listens - and responds - to commands. It has some quirky behaviors that we are still trying to fully understand.
We also got permission from NASA to communicate with ISEE-3 through 16 July using both Transponder A and B. Our Spin-up and Trajectory Correction Maneuvers should be happening in the next week or so. Stay tuned for updates.
A Retired Satellite Gets Back To Work, Here & Now (NPR)
"After 31 years in space, ISEE-3 is finally coming home. The International Sun-Earth Explorer 3 was a humble satellite launched in the late 1970s to monitor solar winds - until Robert Farquhar commandeered and reprogrammed it to help the United States become the first country to encounter a comet. Now, a team of scientists have come together in an unofficial effort to awaken the sleeping spacecraft and return it to its original spot -- and function -- by combining old technology with new. Next week, if all goes well, the team will command the satellite to fire its engines once again to orbit the Earth and monitor the Earth's weather. NPR's Nell Greenfieldboyce speaks with Here & Now's Jeremy Hobson about Farquhar's efforts in the 1970s and now."
Just as our DSN window closed today we were able to get 2 way Doppler lock and ranging at 47.5 kHz offset. DSN got the four ranging points needed from ISEE-3. This is the first time since 1999 that DSN has talked to the spacecraft. A follow up session tomorrow should get us a lot more recording time.
ISEE-3 Reboot Project: Critical Communications, The Mad Spaceball
"The ISEE-3 mission was launched in 1978. For those people that remember and who lived in that decade, computers and communications weren't near as sophisticated back then as they are now. Back then, Mattel's "Football," an electronic game using LED dashes representing the football and players, was considered pretty fancy (I was so happy to get one for my birthday). The "Speak & Spell" debuted in 1978 (how would ET ever have gotten home without one?). The Commodore PET, Apple II, and Radio Shack TRS-80 were some of the big names in computing during 1978 (a person could max out the Apple II's RAM with 48k)."
For him, satellite reboot is about reconnecting with an old friend, Los Angeles Times
"With ISEE-3 rebadged as the International Cometary Explorer, or ICE, Farquhar devised a flight path that rounded another libration point on the opposite side of the planet, boomeranged repeatedly around Earth and the moon, then used lunar gravity to sling the spacecraft through Giacobini-Zinner's plasma tail. From there, it would orbit the sun for eternity with a brief swing by Earth on Aug. 10 of this year. None other than science fiction author Arthur C. Clarke described the stunt as a mind-boggling feat. "ICE's track looks like a plate of spaghetti, dropped from a considerable height," Clarke wrote in his autobiography, "Astounding Days."
Our Arecibo pass today was a short one - only 40 minutes. We had some commanding issues again - so there was no spin-up burn attempt made. We did manage to shut off +28 volts and close the valves in the propulsion system. We are waiting to see when our next window will be at Arecibo.
Today was a double header. Our DSN pass for ranging started at 4:50 pm EDT. No luck there either although we think we have now narrowed the issues down to some rather straightforward fixes. This is an old spacecraft - so we, the DSN folks, and the people at Arecibo all need to pull out all of our magic tricks. Lucky for us everyone involved is really excited about this. We have another DSN pass tomorrow (Thursday).
During our session with Arecibo today we came very, very close to firing the thrusters on ISEE-3 for its spin-up maneuver. But we were not able to complete the process and fire the thrusters. The spacecraft was completely configured for a thruster firing during today's pass. We reduced the number of pulses from 11 to 1 to make certain that we had the proper commands in place. If that engine firing proceeded successfully we'd follow with the remaining 10 pulses so as to spin up the spacecraft to the required rotation rate. As it happened we were unable to get confirmation on the very last command and put a halt to the procedure.
Source: JPL Horizons
Ephemeris Type: OBSERVER
Target Body: ICE Spacecraft (ISEE-3) [-111]
Observer Location: Geocentric 
Time Span: Start=2014-06-05, Stop=2014-07-05, Step=1 d
Table Settings: defaults
Object Data Page
Revised: Jun 23, 2014 ISEE-3/ICE Spacecraft (Heliocentric)
Dennis Wingo: The DSN pass last week on 18 June that went from 1:45 to 2:45 Pacific Daylight time was not a success. Here is a recap of the pass activity. The DSN pass started at 1:45 pm PDT. Here is a graphic of the pass through a very nice DSN Now web app:
Figure 1: NASA DSN Now Web Interface Showing ISEE-3 (ICE) Pass Via DSS 24 Goldstone
The pass began with a +/- 3 KHz sweep across frequencies representing the input frequency of transponder A (2090.66) MHz + the Doppler offset + an additional 11.25 KHz that came from our most recent command session. The additional offset is due to thermal and or aging issues with the spacecraft transponder. The sweep is done with a carrier only, no modulation, to get the receiver on the spacecraft to lock to the DSN transmitted signal. The output of transponder A will start to vary in a 240/221 relationship when the carrier is locked. Then ranging can occur. The sweep was unsuccessful in establishing a coherent lock. The sweep rate was 60 Hz/sec. This conforms to the procedure used in 1985 by the DSN for the spacecraft during the ICE comet encounter.
Ani Vermeulen, Mike Guillemette, Ken Karalis, Hirose Naoyuki, Kris McCall, Luis Reyes, Daniel Carbone, Zach Shedd, Jonathan Crocker, Mark Laporte, Pierre Hugo, James Harrison, Wade Penner, Christopher P Sagovac, al, Jonty, Peter Mattisson, Steve Muenker, Lawrence N. Cosner Jr., Trevor Fisher, Bill Salina, Benoit Chamot, P L Carpenter, Alvin H. Belt, Saga Ingmarsson, Dale Perez, Marc Marshall, Alina Scholz, Brian Thurston, Thomas Swift, Christopher Stefan, Charles Broderick, Kristina Fedorenko, James Sinclair, Ewen Harrison, Diana Pisani, Alex Beattie, Andrew MacKinnon, Joe Britt, Jan Knutar, Anonymous, Paul Toben, Marcin Wlodarski, David Bennett, Greg Albrecht Kim, Christopher L. Freeze, Ken Meyer, Helen Shin, Frank Throckmorton, Richard King, Matthew Sutton, Caleb Rabinowitz, william glatfelter, Carlos Niederstrasser,
Are You Ready For Liftoff?, Forbes
"Once the ISEE-3 campaign was launched and promoted by Sky Corp and Space Ref Interactive, 2,238 supporters weighed in, raising $160, 000, $35,000 more than the project's goal. The project went from the improbable to the practical, and this is the transition on the forefront of every entrepreneurs mind. How can you do the same? ... Is this the path for you and your company? It could well be if you can meet the market with the thrust of the ISEE-3 campaign. If you can, your charity, reward or equity funding has a good chance of achieving liftoff."
We had to scrub ISEE-3 spin-up burn for today. We can't confirm receipt of commands in real time by the spacecraft. If we cannot confirm that proper commands were sent to propulsion system we cannot fire thrusters with full confidence. Remember: this spacecraft does not have a computer. All 21 dummy commands worked - that should NOT have happened. Next time we sent them only 3 were accepted. Investigating ...
"I am fascinated by all of this -- using new technology to impersonate old technology to rebuild communications with a spacecraft that would otherwise be space junk, finding private partnerships to pursue scientific curiosity, and getting to watch all of it in real-time. Thank you to everyone who helped make it happen, from the engineers working in their converted McDonald's to the people scrounging up abandoned technical documentation to everyone who chipped in funding to make this possible. This is a "We're living in the future." moment that fills me with glee every time I think about it."
Zombie Spacecraft Rescue Planned by Private Group, National Geographic
"A crew of NASA retirees, young hackers, and seasoned engineers has an audacious dream to rescue an abandoned spacecraft that has been coasting, unwanted and unloved, through the solar system since the mid-1990s. Originally known as the International Sun-Earth Explorer-3 (ISEE-3), the ship was launched in 1978 to study the stream of charged particles flowing from the sun. NASA retired the craft in 1997 and has pretty much ignored it ever since. But in May, fans of the zombie ship reestablished contact with it--the first time that a private group has ever controlled a spacecraft beyond Earth's orbit. On Saturday, the team, funded by nearly $160,000 from crowdsourcing, will test the spacecraft's steering jets."
After our first attempt to do DSN ranging yesterday we discovered that we need to put ISEE-3 into coherent ranging mode and then promptly issue commands. If we wait too long the spacecraft will drop out of coherent ranging mode. We've been suspecting that this has been an issue before. So, we are working with DSN to resolve this issue in advance of our next ranging attempt. As such, our Sunday DSN pass has been cancelled. The next opportunity will be on Wednesday from Canberra, Australia. Further information can be found at "ISEE-3 Reboot Project Scheduled for DSN Doppler and Ranging Activity".
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. For more information on this burn and the ISEE-3 pripulsion system check out these links.
If you go to the DSN NOW page at http://eyes.nasa.gov/dsn/dsn.html you will see ISEE-3 (ICE) lined up ready for ranging at DSS-24 at Goldstone. Our ranging session starts at 1:45 pm PDT and will last for an hour. We'll try and post real time updates on Twitter at @ISEE3Reboot
Update: We did not have any luck establishing two-way communication between ISEE-3 and DSN today. We'll regroup and try again on Sunday. This does not affect our plan to do a short series of engine burns on 21 June (Saturday) to spin up the spacecraft.
Tim Reyes (ISEE-3 team member): I sought someone to write a song. Local friends pointed to me and I was given a chance to contribute in this way to bring public awareness back to the long-lost spacecraft, ISEE-3.
We have now confirmed that both ISEE-3 transponders - A & B - are in coherent ranging mode. 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 - larger view) 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 scheudled to happen between 30 June and 2 July.
According to Viljo Allik in Estonia "I did another ISEE-3 receive test today. Results are added to the previous files here: http://184.108.40.206/public/p_DSN/ISEE3/ In the demodulated signal spectrum of the the last images it is possible to see the doppler shift caused by spacecraft rotation."
Detection of ISEE-3 With a 4.5 Meter Dish in Estonia, earlier post
ISEE-3 (ICE) Spacecraft Detected, USA-SATCOM.COM
"ISEE-3 (ICE) Spacecraft was detected today using a 1.2m dish at 2270.390831 MHz. The signal at this frequency was also simultaneously detected and confirmed by Paul over at UHF-Satcom. The detection was accomplished by integrating multiple FFTs with the spacecraft TX frequency corrected for Doppler. Without precise Doppler correction the signal would not be detectable - I confirmed by turning integration off. I also confirm target by off-pointing the dish confirming loss of signal in multiple directions."
Calling Back a Zombie Ship From the Graveyard of Space, New York Times (front page story!)
"Mr. Wingo has now persuaded NASA to use the Deep Space Network to pinpoint ISEE-3's trajectory, to calculate the rocket burn required to put it on a path to Earth orbit. Dr. Farquhar's 1986 calculations were close, but not exact. Slight errors are magnified over time, and now the uncertainty is 20,000 miles, which means the spacecraft could be on course to splat into the moon. "It is in the agency's best interest to find out, one way or the other," Mr. Wingo said. If everything goes as hoped, ISEE-3 will end up in its original location to observe solar wind, fulfilling Dr. Farquhar's promise to return the spacecraft."
"NASA has given approval so far for the ISEE-3 Reboot Project to speak to the spacecraft until June 25, but Cowing said he has every confidence the window will be extended. Then, when the spacecraft is ready, he has some big plans for outreach -- including a website where people can get near-real-time information on how the spacecraft is performing. "We will have an online presence on the spacecraft that rivals NASA's" or is even better, Cowing said, adding he will announce partners on the project when the time is right."
The ISEE-3 spacecraft is a 16-sided drum-shaped structure designed for spin-stabilized operation. [click on image to enlarge] It measures 161 centimeters in height and 174 centimeters in diameter and had a nominal mass of 457 kilograms at launch. The solar array covers the side of the spacecraft except for a band near its center from which various booms and antennas extend.
NASA has given us approval to fire the spin thrusters on ISEE-3 to increase its spin from 19.16 rpm up to the mission specification of 19.75 +/- 0.2 rpm. This 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. We do not yet have a specific target date for this spin-up burn. This will also serve as our initial test of the functionality of the ISEE-3 propulsion system in preparation for the much longer TCM burn between 30 June and 2 July.
Update: we are now targeting Saturday 21 June as the date for our spin-up maneuver.
See ISEE-3 Propulsion System Overview for a more detailed description of the ISEE-3 propulsion system.
We have received confirmation from NASA that we have been confirmed for time on the DSN (Deep Space Network) for two-way Doppler and ranging activities with the ISEE-3 spacecraft. This is being done so as to determine the location of ISEE-3 with great precision for navigation purposes. Based on this data we will conduct our course correction engine firing. We have moved that original firing date from 17 June to a window that currently covers 30 June and 2 Juy. As the DSN ranging data comes in that window will shrink. DSN ranging passes after the engine burn will help us calculate the result of that burn and the new trajectory that ISEE-3 is pursuing.
DSN opportunities have been identified for 18 & 22 June and 3, 4, 6 July. We will probably need to actually utilize less than half to a third of these opportunities. Among the dishes to be used will be DSS-24 at Goldstone, DSS-34 and DSS-45 at Canberra, and DSS-54 and DSS-65 at Madrid. You can watch live DSN activity at DSN Now. Over the next few days we will be configuring ISEE-3 via Arecibo so as to be able to interact with DSN during this ranging activity.
Here are the DSN windows that have been identified. Again, we'll only be using a fraction of them since the DSN has lots of other customers.
2014-169T19:45:00.000 2014-169T22:00:00.000 100 015 DSS-24 ICE N083 1A1 2014-173T02:00:00.000 2014-173T04:15:00.000 100 015 DSS-24 ICE N083 1A1 2014-175T18:45:00.000 2014-175T21:10:00.000 100 015 DSS-54 ICE N083 1A1 A 2014-176T05:05:00.000 2014-176T07:10:00.000 100 015 DSS-34 ICE N083 1A1 A 2014-179T16:55:00.000 2014-179T19:35:00.000 100 015 DSS-65 ICE N083 1A1 A 2014-181T09:15:00.000 2014-181T12:45:00.000 100 015 DSS-65 ICE N083 1A1 A 2014-184T17:15:00.000 2014-184T20:45:00.000 100 015 DSS-65 ICE N115 1A1 A 2014-185T02:00:00.000 2014-185T04:00:00.000 100 015 DSS-34 ICE N083 1A1 A 2014-187T07:30:00.000 2014-187T11:45:00.000 100 015 DSS-65 ICE N083 1A1 A 2014-187T22:20:00.000 2014-188T02:15:00.000 100 015 DSS-45 ICE N083 1A1 A
As we recently reported, we are getting telemetry from ISEE-3 indicating that its entire suite of science instruments is powered up and has been powered up since NASA last commanded the spacecraft many years ago. We are getting data back from the magentometer that indicates that science data is coming back. We now have a growing team of former ISEE-3 investigators, their colleagues, and successors working to make sense of what the spacecraft is sending back.
Just because an instrument is powered up doesn't mean that it is functioning normally - just that it is powered up. Based on some historical references, some of the ISEE-3 instruments had begun to fail or become partially functional as early as 1982. See "Data from ISEE-3 for the IMS Period", T.T. Rosenvinge, The IMS Source Book AGU, 1982. (click on image to enlarge) By 1993, the Cosmic Ray Isopes experiment was having significant issues according to "Cosmic Ray Composition Investigations using
ICE/ISEE-3", M.E. Wiedenbeck, Final Technical Report, NASA-CR-192808, 1993.
Given that so many other things on board ISEE-3 have been operating since 1978 and are still doing quite well, it would not be at all surprising if some of the science package remains operational as well. We'll be posting updates on the science instruments soon.
During our pass at Arecibo today (remotely conducted via laptop in McMoons in California) we switched ISEE-3's B transmittier to a data rate of 64 bps. We hope to eventually leave it this way so as to allow dishes smaller than Arecibo (such as the one at Morehead State University) to complete the link and have solid two-way communication with ISEE-3. Participants in today's pass: McMoons, Bochum Observatory in Germany, and Arecibo Observatory in Puerto Rico. Our next pass at Arecibo opens tomorrow (Tuesday) around 2:30 pm EDT.
ISEE-3 Reboot Project Is Already a Winner, editorial, Space News
"Inspiration is a word that gets bandied about a lot in the space business, often as justification for multibillion-dollar programs that never come to fruition, let alone inspire. ... Whatever the final outcome, the ISEE-3 Reboot Project has already succeeded in attracting an audience that the space community often has a hard time reaching. Credit the team, for having the vision and gumption to pull this off, and NASA, which hasn't always embraced these types of nontraditional endeavors. Together they have shown how prolific a little inspiration can be."
Viljo Allik, ES5PC, a member of ESTCube-1 student satellite team at Tartu Observatory, Estonia writes: "I did some receiving experiments today, both on 2217.5 MHz LHCP and 2270.4 MHz RHCP. The RHCP carrier is a few dB-s stronger than LHCP. Up to 10 dB carrier to noise can be seen in 1Hz bandwidth with my 4.5 m moonbounce dish at home and G4DDK preamp. Using Ettus Research USRP N210 as a receiver. Its reference frequency is locked to a high precision 10 MHz rubidium clock. If any help for a precise frequency measurement of ISEE-3 is needed, I can do it with even higher precision using the 3m dish setup at Tartu Observatory which has more precise GPS locked rubidium clock frequency available. Also I can make SDR I/Q data recordings of the signal and make them available on our webserver.Some SDR screenshots are available at: http://220.127.116.11/public/p_DSN/ISEE3/ Please note that times on SDR screenshots are UTC+3 hours except from the middle of the second 2270 waterfall image where I changed it to UTC. "
Click on image to enlarge.
According to our team "The frequency offset is ~18025 Hz on Spectravue, so it looks likely. He's tuned to XB, so just seeing the very tip of the PM carrier."
We already have telemetry that shows ISEE-3 to be spinning at 19.16 rpm (spec is 19.75 ±0.02 rpm). According to a tweet by @baudline (Erik) "This Doppler oscillation measurement shows that the ISEE-3 spacecraft is spinning at 19.163 ±0.02 RPM."
Erik used some of our raw data to make this calculation. The software he used is Baudline a time-frequency browser he makes that is used for scientific visualization of the spectral domain.
Click on image to enlarge.
After decades of silence, a vintage spacecraft says hello to Earth, Planetary Society
"A group of space enthusiasts and vintage hardware experts walk into a radio observatory. They contact a 36-year-old spacecraft to ask how it's doing. The spacecraft responds and says it's well. The group leaves and continues to stay in touch with the spacecraft from their laptops, working out of an old McDonald's building at the NASA Ames Research Center. It's no joke--that's the latest news coming from the ISEE-3 Reboot Project, a crowdfunded effort to repurpose NASA's International Sun-Earth Explorer (ISEE-3), launched in 1978 on a mission to study Earth's magnetosphere. In 1983, ISEE was sent on a new mission to study comets Giacobini-Zinner and Halley, and has been spent the past three decades circling the sun in roughly the same orbit as Earth."
Here is what 64bps telemetry looks like coming from ISEE-3 after our successful remote commanding today. Click on image to enlarge.
Today's pass with ISEE-3 at Arecibo was under command from a laptop located at the offices of our team member Ettus Research. We commanded ISEE- 3 to switch Transmitter A into coherent ranging mode and sent tones to test it. This will help us better determine its exact location. We commanded Transmitter B into 64 bps mode on engineering telemetry and then switched it back to 512 bps. Our next session with ISEE-3 will be on Monday.
Source: JPL Horizons
Ephemeris Type: OBSERVER
Target Body: ICE Spacecraft (ISEE-3) [-111]
Observer Location: Geocentric 
Time Span: Start=2014-06-05, Stop=2014-07-05, Step=1 d
Table Settings: defaults
Object Data Page
Revised: Jun 05, 2014 ISEE-3/ICE Spacecraft -111 (Heliocentric)
UPDATE (2014-Jun-05): Trajectory updated to JPL solution #21 (s21), based on coarse Arecibo plane-of-sky angular measurements (not delay/Doppler).
Because uncertainties for s21 are large, predicts are currently available for tracking purposes only through Aug 01 and have these 3-sigma pointing uncertainties:
As many of you have probably read, the ISEE-3 Reboot Project was able to successfully send uplink commands to the space craft. This was accomplished through a lot of team work, strong leadership by Dennis Wingo, and generous support from the community at large. Balint Seeber and I were fortunate enough to work on the communications for this project. When you tell most people that you designed a deep-space uplink modulator in a couple of days, there is a good chance that they will be fairly impressed. In reality though, products like the Ettus Research USRP, the open source SDR framework GNU Radio have made this exceedingly easy. We're just building off the work of many people before us! Let's talk about how this "magic" works!
Свой космос: как спасают станцию ISEE-3 Компьютерра
У космоса есть нехорошая особенность: он быстро надоедает. И так же, как сорок лет назад «приелся» человек на Луне, сегодня мало кого восхищают гоняющие по Марсу роботы и парящий рядом с кольцами Сатурна зонд. Интерес подогревают новые яркие свершения -- но попробуйте-ка совершить что-нибудь из ряда вон, когда мы были почти везде и видели почти всё в Солнечной системе! Впрочем, как раз сейчас неподалёку от Земли (меряя в космических, конечно же, масштабах) разворачивается эксперимент, подобного которому ещё действительно не было: энтузиасты пытаются спасти космическую станцию ISEE-3 -- и это им почти удалось!
宇宙愛好家、放棄された宇宙探査機をクラウドファンディングで復活させる, Wired Japan
"宇宙愛好家のグループ「ISEE-3 Reboot Project」は5月29日、放棄されていた宇宙探査機International Sun-Earth Explorer 3（ISEE-3）との双方向通信を確立したと発表した。 ISEE-3は1978年に打ち上げられた衛星で、1980年代に太陽風の研究等に使われた。 ミッション完了後、NASAは月の引力を使い、ISEE-3を地球へと向かう太陽中心の軌道に放り込んだ。ISEE-3との通信は、1998年に正式に停止された"
"Wszystko zaczęło się od tego, że Robert Farquhar porwał satelitę. W 1982 roku był w NASA naukowcem zajmującym się planowaniem trajektorii lotu pojazdów kosmicznych tak, by wykorzystać przyciąganie Ziemi, Księżyca i innych obiektów do umieszczenia sondy tam, gdzie była potrzebna. Był w tym tak dobry, że potrafił - bez strat dla misji - tak zaplanować trasę lotu, by jego kluczowe momenty przypadały na przykład w czyjeś urodziny."
We are doing a receive run - NOW - from Arecibo controlled via laptop from ISEE-3 Mission Control at McMoons in northern California.
Taking data received on 29 May 2014, we have performed demodulation, error correction, and frame construction. Approximately 1,000 frames of telemetry have been received and processed. 773 Frames were received with no errors. More telemetry processing is currently underway.
Using the Arecibo 130 arc second beam width allowed our team to improve the ranging solution over the baseline JPL Horizons (2001 circa) data. Using Arecibo and asteroid-style orbit determination, this resulted in an improved ephemeris. It also reduced the Trajectory Correction Maneuver (TCM) burn from 50-60 m/s to <10 m/s. This reduces post-lunar flyby dV to <10 m/s for ESL-1 insertion.
We have received authorization from NASA to communicate with (and command) ISEE-3 until 25 June. Meanwhile, analysis of telemetry from ISEE- 3 shows that *ALL* of its science instruments are still powered on. Telemetry also shows that ISEE-3 has a power margin of +28 watts - after 36 years. It is important to note that ISEE-3 has not had a functioning battery for decades. Indeed, this power capacity is what was projected for the spacecraft to have had in 1982 after 4 years in space.
Power System Status
- main bus voltage >= 28 volts
- solar array current >= 5.2 amps
- essential bus current <= 0.25 amps
- non-essential bus current = 4 amps
- shunt dump current >= 1 amp
- transponder A RF power = 5 watts
- transponder B RF power = 5.25 watts
"The next task will be looking at the propulsion system and making sure they can actually fire the engines for a trajectory correction maneuver (TCM), currently targeted for June 17. One thing this TCM will do is to make sure the spacecraft doesn't hit the Moon. Initial interactions with the ISEE-3 from Arecibo showed the spacecraft was not where the JPL ephemeris predicted it was going to be. "That's a bit troublesome because if you look at the error bars, it could hit Moon, or even the Earth, which is not good," Cowing said, adding that they've since been able to refine the trajectory and found the ephemeris was not off as much as initially thought, and so such an impact is quite unlikely."
"What happens when you successfully gain control of an abandoned spacecraft after decades? Disbelief, a happy dance, and hugs, of course. The unedited video of the moment the engineering team realizes the craft is doing what they want is totally cute, even if the sound quality makes me want to apply a bandpass filter."
"Luckily for the group, their preparation worked: first contact went off without a hitch, with the spacecraft responding to a tone exactly as expected. "I'm doing my happy dance," Cowing said."
Telemetry we have received from ISEE-3 shows that it is spinning at 19.16 rpm. The mission specification is 19.75 +/- 0.2 rpm. We have also learned that the spacecraft's attitude relative to the ecliptic is 90.71 degrees - the specification is 90 +/- 1.5 degrees. In addition, we are now receiving information from the spacecraft's magnetometer.
ISEE-3 Experiment Summary (summaries of all the spacecraft's instuments)