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Thoughts on a Spacecraft’s Rebirth

According to a recent NASA news release, the agency has never before signed the kind of agreement it has made with Skycorp, Inc., a Los Gatos, CA-based firm that will now attempt contact with the International Sun-Earth Explorer-3 (ISEE-3) spacecraft. You’ll recall that this is the vehicle that scientists and space activists alike have been talking about resurrecting now that, having completed its studies of the solar wind in 1981 and later comet observations, it is making its closest approach to the Earth in more than thirty years (see ISEE-3: The Challenge of the Long Duration Flight).

According to its website, Skycorp is in the business of bringing “…new technologies, new approaches, and reduced cost to the manufacture of spacecraft and space systems.” Founded in 1998, the company signed a Space Act Agreement with NASA for the use of the International Space Station in 1999, and qualified the first commercial payload used in the filming of a television commercial (for Radio Shack) in 2001. In addition to its ISEE-3 involvement, Skycorp is now working on an orbit servicing system (for Orbital Recovery Corporation) and the design of lunar surface systems with NASA.

The document NASA has now signed is a Non-Reimbursable Space Act Agreement (NRSAA) with Skycorp that involves not just contact with the ISEE-3 spacecraft but, possibly, command and control over it. ISEE-3 will near the Earth this August, and the agreement lays out the variety of what NASA describes as “technical, safety, legal and proprietary issues” that will need to be addressed before contacting and re-purposing the spacecraft can be attempted.

“The intrepid ISEE-3 spacecraft was sent away from its primary mission to study the physics of the solar wind extending its mission of discovery to study two comets.” said John Grunsfeld, astronaut and associate administrator for the Science Mission Directorate at NASA headquarters in Washington. “We have a chance to engage a new generation of citizen scientists through this creative effort to recapture the ISEE-3 spacecraft as it zips by the Earth this summer.”

It’s hard not to get excited about the prospects here. The ISEE-3 Reboot Project works with a spacecraft that, although inactive for many years, still contains fuel and probably functional instruments. Of course, ISEE-3’s reactivation will be handled remotely, but in the 1960s this would have made a great scenario for a short story in one of the science fiction magazines. In that era, ideas like in-space repair of satellites and salvage and re-use of older equipment by human crews were concepts made fresh by the sudden progress of the manned space program. After all, we were doing space walks!


I’m remembering “The Trouble with Telstar,” a 1963 story by John Berryman (the SF writer, not the poet) that brought home to readers what would be involved in maintaining a space infrastructure. In the editorial squib introducing it, John Campbell wrote: “The real trouble with communications satellites is the enormous difficulty of repairing even the simplest little trouble. You need such a loooong screwdriver.” It was a lesson we’d learn again in spades with the Hubble repairs. Berryman, a writer and engineer who died in 1988, followed up with “Stuck,” another tale of space repair that inspired the gorgeous John Schoenherr cover at the right.

Fortunately, the reactivation of ISEE-3 isn’t a hands-on repair job and we can attempt to salvage this bird from Earth. Current thinking is to insert the spacecraft into an orbit at the L1 Lagrangian point, at which time the probe would be put back into operations. In this sense, ISEE-3 is an interesting measure of our ability to build long-term hardware. Like Voyager, the diminutive spacecraft was never intended for activities over this kind of time-frame, but new operations do appear possible. Everything depends, of course, upon the satellite’s close approach this summer, for if communications cannot be established, it will simply continue its orbit of the Sun.

So we have a “citizen science” program hard at work on a novel problem, with the help of the agency that put the spacecraft into motion all those years ago. Any new data from a re-born ISEE-3 is to be broadly shared within the science community and the public, offering a useful educational tool showing how we gather data in space and disseminate the results. We’ll also learn a good deal about how spacecraft endure the space environment over a span of decades, information that will contribute to our thinking about future probes on long missions and potentially extendable observation windows.

Not bad for a satellite sent out over three decades ago to study how the solar wind can affect satellites in Earth orbit and possibly disrupt our sensitive technological infrastructure. I’m now wondering whether there are other spacecraft out there that might be brought back to life, and reminded that when we build things to last, we can discover uses that the original designers may not have dreamed of. That’s a lesson we’ll want to remember as we create mission concepts around any new space hardware.


Comments on this entry are closed.

  • ljk May 22, 2014, 10:42

    Away Team Detects ISEE-3 at Arecibo

    By Keith Cowing on May 19, 2014 11:22 PM. 24 Comments

    ISEE-3 Reboot Project Hardware Detects ISEE-3 at Arecibo

    “The following are screenshots of data from the live receive session we did with our Ettus Research Software Defined Radio unit attached to the Arecibo antenna today (19 May).

    “Waterfalls” were generated by post-processing the recorded data. There are four recordings of various lengths as we were testing the setup, and this is the very, very initial result.”

    Details and more links here:


  • Jose May 22, 2014, 13:38


    do they try the same?:

    “ISEE-3 Reboot Project: Aiming for First Contact
    Date 5/13/14

    Today’s update regards the progress of the ISEE-3 Reboot Project team in our preparations to contact the spacecraft. We started this effort 32 days ago on on April 12 2014…”

  • Markham May 22, 2014, 23:59

    My brother and I contributed to this project over a month ago and are excited to see the progress.
    We both had been playing over the last few years with Linux based SDR (software defined radio) and now get see them use SDR to create their virtual communication hardware. We are now (as of 15 minutes ago) near the stretch goal of $150k (148k currently), the additional funds get them access to NASA’s DSN network.

  • NS May 23, 2014, 4:49

    Probably ISEE-3 space environment endurance information will be the most important gain, with the innovative engineering to regain control and the public participation as secondary benefits. The additional data (if any) collected by its instruments may be of little benefit. Per the International Sun-Earth Explorer-3 link:

    “…the S-band once used for ISEE-3 is outmoded. Solar wind data that ISEE-3 gathered at the rate of once every 40 minutes has been replaced by spacecraft with instruments that are 10,000 times faster.”

    It is these last sorts of things (rather than problems with building long-endurance devices) that set the more intractable limits to mission lengths. And the longer-term (and even less knowable) issue of whether science in (say) 500 years will even be interested in the types of data that we think are important.

  • mike shupp May 23, 2014, 6:12

    Same team. Cowling, a former NASA scientist, and Wingo, a long time engineer and entrepreneur, are the two guys behind the re-contact mission.

  • Dennis Wingo May 23, 2014, 8:55

    Thanks for the great article!

    We are here at Arecibo and we hope to get our newly arrived Power Amplifier installed today and we are getting ready to attempt our first commands!

  • ljk May 27, 2014, 9:27

    NASA Gives Citizen Scientists ‘Keys’ to Long-Decommissioned ISEE-3 Spacecraft

    By Emily Carney

    On Wednesday, May 21, it was announced that NASA gave a group of citizen scientists permission to contact the long-defunct International Sun-Earth Explorer-3 (ISEE-3) spacecraft in order to accomplish an extended science mission. In an unprecedented move, NASA signed a Non-Reimbursable Space Act Agreement with Skycorp, Inc., a company based in Los Gatos, Calif., which would allow them to “possibly command and control” the spacecraft, according to NASA. This is the first time the agency has signed such an agreement concerning a decommissioned spacecraft.

    ISEE-3′s story began nearly four decades ago, before space shuttles were even a reality. The spacecraft was launched on Aug. 12, 1978, by a Delta 2914 rocket from the Cape Canaveral Air Force Station. The spacecraft went on to accomplish many firsts in spaceflight history. It was the first satellite to be placed in a “halo orbit” at the L1 Sun-Earth Lagrangian point; this allowed the satellite to investigate our planet’s interactions with solar wind. (The L1 point is where gravitational forces of the Sun and the Earth-Moon system balance out.) The initial science mission was performed by NASA and ESRO/ESA, hence the “international” moniker; it had two “sister” spacecraft, ISEE-1 and ISEE-2.

    Full article here:


    To quote:

    However, some roadblocks remain for the ISEE-3 reboot team. On the crowd-sourcing website, the team announced: “ … During our listening sessions at Arecibo [Observatory, in Puerto Rico] the other day it became clear to us that the ISEE-3 spacecraft is not exactly where JPL’s database said it would be. After several decades, this is understandable. By adjusting the big dish we determined that the spacecraft is roughly 250,000 km from where is should be. Given that it is already on a lunar flyby trajectory – a close one at that – the error is such that there is a chance that it could hit the Moon – unless we fire the engines – and do so rather soon.”

  • ljk May 29, 2014, 16:39


    We Are Now In Command of the ISEE-3 Spacecraft

    By Keith Cowing on May 29, 2014 4:07 PM

    The ISEE-3 Reboot Project is pleased to announce that our team has established two-way communication with the ISEE-3 spacecraft and has begun commanding it to perform specific functions. Over the coming days and weeks our team will make an assessment of the spacecraft’s overall health and refine the techniques required to fire its engines and bring it back to an orbit near Earth.

    First Contact with ISEE-3 was achieved at the Arecibo Radio Observatory in Puerto Rico. We would not have been able to achieve this effort without the gracious assistance provided by the entire staff at Arecibo. In addition to the staff at Arecibo, our team included simultaneous listening and analysis support by AMSAT-DL at the Bochum Observatory in Germany, the Space Science Center at Morehead State University in Kentucky, and the SETI Institute’s Allen Telescope Array in California.

    Of course this effort would not have been possible without the assistance of NASA and the Space Act Agreement crafted by NASA Headquarters, NASA Ames Research center, and the System Solar System Exploration Research Virtual Institute (SSERVI).

    For further information on the ISEE-3 Reboot Project please visit our website at http://spacecollege.org/isee3 A much more detailed description of our First Contact efforts and future plans will be published on our website next week.

  • ljk May 30, 2014, 13:00

    A link to more links on news about reconnecting with ISEE-3 after 17 years:


    Includes a link to a scanned newspaper article from 1980 on the public efforts to keep the Viking 1 lander funded and operating through 1994. Sadly the historic machine was given faulty commands in late 1982, ironically while trying to help it last longer, causing Viking 1 to turn its antenna away and lose contact with Earth. Humanity would not have another working station on the surface of the Red Planet until Mars Pathfinder arrived there with its little rover Sojourner on July 4, 1996.

    Back to ISEE-3, its new masters have only until mid-June to command the probe to fire its thrusters for the first time so it can become a useful science tool again.

  • ljk June 2, 2014, 9:14
  • ljk June 3, 2014, 14:42

    Scientists Found a Way to Save a Long-Lost Spacecraft—Now It’s Facing Its Biggest Test Yet

    The craft’s celestial gauntlet includes a possible collision with the moon.


    JUN 3 2014, 7:06 AM ET


    To quote:

    According to Farquhar’s original programmed orbit, ISEE-3 will pass about 50 miles over the surface of the moon on August 10. The probe’s not quite where it was programmed to be, though, and—without changes to its trajectory—it might crash into the moon.

    “The odds of it hitting the moon are not that great, but they’re not zero,” said Cowling. There’s also a possibility that the half-ton craft could veer toward Earth. Only fine adjustments to ISEE-3’s orbit in the next few weeks will make those two unlikely scenarios impossible.

    But that pass doesn’t end the craft’s day. After it flies above the lunar surface, the ISEE-3 will swing behind the moon. That will lead to something of a problem. The probe’s battery expired decades ago, so it can now only run on solar power. For the half-hour it spends on the moon’s dark side, the ISEE-3 will be beyond the reach of solar rays. It will lose power.

    The ISEE-3 has lost power like this before, but it was years ago. Now with a couple extra decades of possibly frayed or fried circuitry, it’s less clear that the probe will survive the sudden darkness. (Cowler noted that the probe won’t “turn off.” It will instead lose power at once, like a lightbulb in a power outage.)

    If the craft neither crashes into the moon nor expires on its dark side, it will have endured August 10 and the most dire threats to its existence.

    And Then Where Does It Live?

    After this celestial gauntlet, the ISEE-3 will have a calmer couple of months.

    “Once you come out from behind the moon, depending on where we are, we’re going to fire the engines a last few times,” said Cowler. The reboot team still hasn’t decided which direction they’ll fire them in. They could possibly pilot ISEE-3 back to where it began its mission in the 1970s: the first Lagrange point, a stable oasis between the Earth and the sun. But two more spacecraft, with more advanced sensors than ISEE-3, already inhabit that point, so it wouldn’t be of enormous scientific utility.

    “The problem [with a Lagrange point] is stopping once you get there,” added Dr. David Chenette, director of NASA’s heliophysics divisions. Maintaing a stable orbit in a Lagrange point requires extra fuel to both stop a craft and tailor its location.

    “We want to put it somewhere where we don’t have to spend as long tweaking it as we do running it,” Cowler said. The team is considering “a variety” of easy orbits between the Earth and the moon that would require less fuel but still provide interesting, useful data.

    He also raised another possibility: “We could also throw it at another comet in 2018.”

  • ljk June 5, 2014, 14:31


    ISEE-3 Status Report 5 June 2014

    By Keith Cowing on June 5, 2014 11:42 AM

    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 = 1 amp
    – transponder A RF power = 5 watts
    – transponder B RF power = 5.25 watts

  • ljk June 6, 2014, 14:44

    Technical details on how they communicated with ISEE-3 from several team members:


  • ljk June 10, 2014, 10:58

    Really Nice Words about ISEE-3 from Space News

    By Keith Cowing on June 9, 2014 1:37 PM. 5 Comments

    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.”


  • ljk June 16, 2014, 11:28

    Great, the New York Times called ISEE-3 a “zombie ship”, although it did make the front page of that newspaper, which still means something.


    “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 July.”

    All here:


  • ljk June 23, 2014, 10:23

    ISEE-3 Status Report 19 June 2014 (afternoon)

    By Keith Cowing on June 19, 2014 8:36 PM

    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, June 24, 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.

  • ljk June 30, 2014, 13:04


    By Keith Cowing on June 27, 2014 at 4:28 PM

    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 Greenfield Boyce speaks with Here & Now’s Jeremy Hobson about Farquhar’s efforts in the 1970s and now.”

  • ljk July 2, 2014, 10:49


    ISEE-3 Status Report 1 July 2014 (Update)

    By Keith Cowing on July 1, 2014 7:39 PM

    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.

  • ljk July 7, 2014, 10:23

    Notes on the ISEE-3 Vector Helium Magnetometer From the Original Principal Investigator

    By Keith Cowing on July 2, 2014 at 8:21 PM

    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.

    Full article here:


  • ljk July 9, 2014, 11:33


    In Effort to Shift Abandoned NASA Craft, a Hiccup (or Burp), New York Times


    JULY 8, 2014

    “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.”

  • ljk July 10, 2014, 14:23

    Vintage NASA Spacecraft May Be Out of Gas, Private Team Says

    By Elizabeth Howell, Space.com Contributor | July 10, 2014 10:11 am ET

    Attempts to move a vintage NASA spacecraft into a new orbit 36 years after the probe’s launch are in flux, with controllers fearing the spacecraft may have run out of fuel while performing maneuvers on Tuesday (July 9).

    The vintage International Sun-Earth Explorer 3 (ISEE-3) spacecraft, now under the control of a private group, was expected to fire its engines several times Tuesday to move into a more advantageous position to communicate with Earth. The first burn went off without a hitch, but the second engine burn halted for reasons that are still being investigated.

    “Our troubleshooting today eliminated some suspected causes of propulsion system problems. We do not think any of the valves are malfunctioning,” Keith Cowing with the ISEE-3 Reboot Project wrote in a statement Wednesday (July 9). “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.”

    If the spacecraft is not redirected soon, it will loop around the moon and be in an orbit that is less advantageous for communicating with Earth. But even if that scenario happens, the group plans to use it “for science in other location within the inner solar system” as at least some of the instruments are functioning, Cowing added.

    Full article here:


    SpaceNews has even less happy news on the subject:

    Curtain Falls on ISEE-3 Reboot Project as Propulsion System Fails

    By Dan Leone | Jul. 9, 2014

    WASHINGTON — NASA’s International Earth/Sun Explorer (ISEE)-3 will not be resuming its original mission after all, now that citizen scientists and engineers striving to rescue it discovered July 9 that the old heliophysics observatory’s propulsion system is not working.

    “There was no burn and we detected no acceleration and nothing was coming out of the engines,” NASAWatch.com Editor Keith Cowing, who spearheaded the ISEE-3 Reboot Project along with entrepreneur Dennis Wingo, said in a July 9 phone interview.

    “We really can’t do anything,” Cowing said.

    The widely read blogger spoke to SpaceNews after a failed attempt to complete the remaining engine burns that project officials thought would be required to send the spacecraft, currently in a heliocentric orbit, back toward the gravitationally stable Earth-Sun Lagrange Point 1. From that position, the 1970s-vintage spacecraft was expected to be able to resume observations of solar winds breaking against Earth’s magnetosphere.

    “We’ve done our best, but we’re now looking at a flyby,” Cowing said. Controllers at the ISEE-3 Reboot Project’s main ground system at the Arecibo radio observatory in Puerto Rico have switched the craft over into science mode, which will allow its instrument to collect and beam data back to Earth for as long as anyone is willing to listen for it.

    Practically speaking, that will be about three more months, Cowing said. After that, the spacecraft will have traveled so far away from Earth that communicating with it will require receiving stations so large that the expense would simply not be worth it.

    Full article here:


    Though this very afternoon the ISEE-3 team was asking for technical help via their blog:


    My thoughts:

    Whatever may be the fate of ISEE-3, the fact that a group of people did retrieve it electronically and set it back to being a scientific satellite is triumph enough, in the very face of NASA’s initial lack of interest and later red tape bureaucracy, no less. This is overall good news for those wanting to operate spacecraft for decades at a time and longer. ISEE-3 may also have a few more things to reveal about space in its remaining time.

  • ljk July 10, 2014, 14:36

    This news piece has quotes from Bob Farquhar:


    Bob Farquhar, a former NASA mission designer who has always felt a close connection to the spacecraft, told NPR things don’t look good. “I don’t know what’s the matter, but it sounds like it’s pretty serious,” he says.

    Without the thrusters, Farquhar says, there’s no way to keep ISEE-3 around. Once it’s far enough away that we can’t really communicate with it, he says, “they should probably turn off all the transmitters this time and not have anything left on like they did before. I think we should let it have a good death.”

    Farquhar, who is 81, has long felt his own fate was connected to this spacecraft’s. Now, he says, he hopes they’re not that connected. “But I am getting pretty old also,” he says. “If you measure a spacecraft’s life, he’s probably about the same age I am.”

    He says his friend should pass close to Earth on Aug. 10. That’s when Farquhar plans to wave goodbye.

  • ljk July 14, 2014, 10:10

    Propulsion Issues Put Plans for ‘Vintage’ ISEE-3 Spacecraft on Ice

    By Emily Carney

    While the spacecraft may have been frozen in time, the excitement over its reawakening was brand new.

    But the effort to re-purpose the long-dormant International Sun-Earth Explorer-3 (ISEE-3) spacecraft for an extended science mission hit a snag this week when it was announced that issues with propulsion had developed during a scheduled burn.

    On the reboot mission’s website, it was theorized that a lack of pressurized nitrogen available in the hydrazine propulsion system may be the culprit. Plans to send the spacecraft back to a desired “halo orbit” at the L1 Sun-Earth Lagrangian point do not appear to be in the cards at this time (ISEE-3 was the first spacecraft to achieve this orbit).

    Despite this setback, the ISEE-3 Reboot Project’s website did state that following a lunar flyby on Aug. 10, there are scientific plans for the spacecraft in the works within the inner Solar System. A statement from the team on Facebook stated optimistically: “We have a plan B. We will be listening to ISEE-3 as long as it is transmitting regardless of where it is located in the inner solar system.”

    ISEE-3 has already encountered—and shattered—many roadblocks following the announcement of the project. The team responsible for this initiative, Skycorp, Inc., became interested in the spacecraft as it approached closer to Earth this past year. Due to budgetary constraints, NASA was unable to fund its “reawakening,” but the company began a crowd-sourcing initiative that raised $159,602. These funds were essential to write applicable software, for establishing first contact, and to further devise a science mission.

    Full article here:


    To quote:

    While ISEE-3 may not reach the intended glories of its past by chasing another comet, space watchers need not despair; the team does intend to use the spacecraft for science operations as long as contact is established, as stated earlier. In addition, ESA’s Rosetta spacecraft is expected to approach comet 67P/Churyumov–Gerasimenko in August, deploying its Philae lander in November. Rosetta owes its incredible journey in part to the legacy of one “vintage” spacecraft, launched in August 1978.

  • ljk July 14, 2014, 11:20

    Photos: An Insider’s Look at ISEE-3 – Volume 1

    By Keith Cowing on July 12, 2014 4:49 PM

    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.


  • ljk July 15, 2014, 11:28

    Photos: An Insider’s Look at ISEE-3 – Volume 2

    By Keith Cowing on July 14, 2014 8:21 PM

    “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”


  • ljk July 19, 2014, 11:53

    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.”


  • ljk July 19, 2014, 11:56

    Vintage NASA Probe, Once Abandoned in Space, Still Has Fuel, Space.com

    “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.”


  • ljk July 24, 2014, 13:31


    By Keith Cowing on July 24, 2014 12:51 PM.

    Announcing the ISEE-3 Interplanetary Citizen Science Mission

    “After a successful reawakening the venerable ISEE-3 spacecraft is about to begin the first interplanetary citizen science mission. We will be beginning the “ISEE-3 Interplanetary Citizen Science Mission” on 10 August 2014 as the spacecraft flies by the Moon.

    “We have a functional space craft that can do science and is already returning new data. All of our original citizen science objectives remain unchanged and are ready for implementation. In fact, we’ll be announcing some new partnerships shortly that will serve to turbocharge our efforts in this regard.”


  • ljk August 7, 2014, 13:22


    NASA’s Abandoned ISEE-3 Spacecraft To Fly Past Moon

    By Rachel Courtland

    Posted 7 Aug 2014 | 16:00 GMT

    In a few days time, ISEE-3 will begin its long goodbye, as it zips some 12,000 kilometers above the surface of the moon on Sunday before continuing on back into deep space.

    For the volunteers who have tried to bring the 35-year-old NASA spacecraft back home, it’s likely to be a bittersweet moment. A “reboot” team led by Dennis Wingo, CEO of California-based Skycorp Incorporated, and Keith Cowing, editor of the websites NASAWatch and SpaceRef, worked for months to return the spacecraft to an orbit close to the Earth’s, where it could resume its original mission observing the solar environment.

    The team raised nearly $160,000 in a crowd-funding campaign, redeveloped the capability to communicate with the spacecraft, obtained permission from NASA to command the spacecraft, and successfully took control.

    But attempts to fire the thrusters fizzled. Although there was some early hope that creative plumbing might fix the problem, in the end, the team determined that there wasn’t enough nitrogen pressurant left to force hydrazine fuel through the spacecraft’s thrusters. “It obviously leaked away, but the mechanism for how that happened is undetermined at this time,” Wingo says.

    The team is not yet done with ISEE-3, however. At least four of the spacecraft’s instruments are returning good data, Wingo says. That includes a magnetometer that can explore the front where the Earth’s magnetosphere meets the solar wind, and an experiment that can be used to measure the flux of protons coming from the sun.

    Radio dishes on the ground will be able to pick up ISEE-3’s science signals for months to come. The last to be able to do so—the Arecibo telescope in Puerto Rico—will likely lose contact with the spacecraft in about a year, Wingo says.

    Although ISEE-3’s nitrogen leaked away, the spacecraft has shown incredible longevity otherwise. Its solar arrays draw more than 90 percent of the power they did in 1980—about 150 W—and the spacecraft’s 1970’s CMOS circuitry—which consists of 4000-series RCA state logic—is still largely functional. When it comes to the solar arrays, Wingo says, it’s possible that some low-temperature self-annealing process might have helped repair radiation damage.

    The spacecraft will have to hold up even longer if we’re to make contact once more. It will be another 15 years before ISEE-3 gets this close to Earth again.

  • ljk August 13, 2014, 13:19

    ISEE-3 Makes Lunar Flyby, Waves ‘Goodbye’ Days Before Launch Anniversary

    By Emily Carney

    Only a few days after one of its successors approached a comet in deep space, the International Sun-Earth Explorer (ISEE-3) spacecraft made its closest approach to Earth, shortly followed by a lunar flyby this past weekend. ISEE-3 recently made the news because it was successfully “rebooted,” after being defunct for 17 years, by a group of citizen scientists. This milestone came days before the spacecraft celebrated its launch “birthday.”

    On Saturday, Aug. 9, ISEE-3 made its closest approach to Earth. On the following day, the spacecraft came within 9,700 miles (15,600 kilometers) of the Moon. This flyby comes after unsuccessful attempts to fire the spacecraft’s thrusters in July; it is believed vital nitrogen gas has been depleted in the spacecraft’s propulsion system (this gas pressurized the system). The ISEE-3 Reboot Project citizen scientists intended to restore the vintage spacecraft to a “halo orbit” at the Sun-Earth Lagrangian Point; ISEE-3 was the first spacecraft to enter such an orbit after its initial commissioning.

    While a return to its desired orbit was not reached, the scientists still intend to pull data from ISEE-3, as long as it continues to communicate with Earth. The team announced the “ISEE-3 Interplanetary Science Mission” on July 24; thus far the spacecraft has detected solar data. Five of its 13 experiments are still functioning—no mean feat after nearly four decades in space.

    Full article here:


    To quote:

    In addition, days after scientists and engineers waved “goodbye” to ISEE-3 as it made its closest approach to Earth, the spacecraft celebrated its 36th birthday. ISEE-3 was launched on Aug. 12, 1978, by a Delta 2914 rocket from Florida’s Cape Canaveral Air Force Station. To show perspective, this spacecraft outlived the space shuttle program, which was in service from April 1981 to July 2011.

    The daily activities of ISEE-3 can still be monitored through a Google project called “A Spacecraft for All.” At present time, the spacecraft is more than 430,000 miles from Earth (over 700,000 kilometers). In another 16 years, ISEE-3 will once again be on our cosmic doorstep as it approaches Earth again. Who knows, maybe it will be possible to once again raise a dormant spacecraft from “the dead.”

  • ljk August 14, 2014, 12:39

    After Moon Flyby, Vintage NASA Spacecraft to Study the Sun

    By Elizabeth Howell, Space.com Contributor | August 14, 2014 10:15 am ET

    As a vintage spacecraft soars out of Earth’s vicinity, the private teamworking with it plans to use the probe for solar science for as long as they can stay in touch with the satellite.

    The minds behind the so-called ISEE-3 Reboot Project have been controlling the 36-year-old International Sun-Earth Explorer (ISEE-3) for the past few weeks. At first they planned to park it close to Earth, but they abandoned that plan after finding out that the probe was out of the pressurant needed to move the craft.

    At least some of the 13 science instruments are still working, however. So the old spacecraft will do one of the things it was originally tasked to do: studysolar weather. Its measurements will be compared with those taken by the network of satellites that are closer to Earth’s vicinity like NASA’s Solar TErrestrial RElations Observatory (STEREO).

    Full article here:


    To quote:

    During the Sunday broadcast, co-leader of the project Keith Cowing said that most donations were only in the $10 to $50 range, and mostly from contributors who are not self-described space people.

    “I tweeted a joke about disco once and I suddenly got donations from people saying, ‘Hey, I heard your comment about disco,'” Cowing said.

  • ljk August 29, 2014, 10:58

    ISEE-3 Post-Lunar Flyby Status and Modification of Mission Goals

    By Keith Cowing on August 28, 2014 7:04 PM

    Communication with the ISEE-3 satellite was successfully re-established with the goal of commanding the satellite to change its trajectory with the goal of putting it into a libration point orbit that would allow it to resume its original mission goals of collecting data for solar physics research. The trajectory change goal unfortunately could not be completed due to the failure of the onboard thrusters. This failure was apparently the result of the loss of nitrogen pressurant in the Hydrazine fuel system.

    This inability to change the spacecraft’s orbit rules out the original reboot mission goals which would have provided long-term data collection from the satellite instrumentation package using modest antennas. After the orbit change attempt, the ISEE-3 Reboot Team powered on the instrumentation package and began data collection from the instruments to assess their current physical status and usefulness for any ongoing scientific mission. We are now redefining our mission goals to obtain the maximum scientific usefulness of ISEE-3 in its new interplanetary orbit. Figure 1 shows the flyby orbit and the long-term sun centered (heliocentric) orbit.

    The rendering in Figure 1 shows the projected position of ISEE-3 through August of 2016. The flyby of the Moon increased the orbital energy of the spacecraft. The original orbit, from 1983 through August 10th 2014 was interior to the Earth’s orbit around the sun. The orbit of the Earth is the light blue ellipse. The red line is the new orbit, but with respect to the Earth. This is why there is the small red ellipse in the first year near the Earth/Sun L5 location. That the large and small ellipse represents is the eccentricity of the orbit. The top of the large ellipse represents the maximum distance from the sun, which is about 1.2 astronomical units or about 180,000 kilometers.

    The ISEE-3 spacecraft is traveling slower than the Earth during this time. The top of the small ellipse is the closet point to the sun, which touches the orbit of the Earth, which is about 146 million kilometers from the sun. Figure 2 shows the orbit for the next 15 years, until the return of the spacecraft for another encounter in seven years at about 30 million km and then back to Earth orbit in 15 years in August of 2029.

    Full article here:


  • ljk September 29, 2014, 10:03

    ISEE-3 is in Safe Mode

    By Keith Cowing on September 25, 2014 2:26 PM

    Since the lunar flyby on August 10th the ISEE-3 Reboot team has continued to work with Google Creative Lab to bring to full fruition the http://www.spacecraftforall.com website to provide real time data from ISEE-3. We have been working with the various dishes that have supported us until now, including Arecibo, Bochum, the SETI Institute, Morehead State and others. We now have a problem.

    The ground stations listening to ISEE-3 have not been able to obtain a signal since Tuesday the 16th. Arecibo, Morehead, Bochum, SETI, as well as the Usuda 64 meter dish in Japan and the Algonquin 45 meter dish in Canada have all pointed at the spacecraft with no positive results. So, at this time we are assuming that the spacecraft has gone into safe mode.

    What This Means

    Safe mode on ISEE three can basically only occur from one problem, loss of power. Before the lunar flyby ISEE-3 orbited closer to the sun than the Earth. This resulted in a very good power profile for the spacecraft. However, as seen in the figure 1 here, since the flyby the spacecraft is traveling much farther away from the sun than it has been before:

    We have not had many opportunities to get data from the spacecraft since the flyby as the antenna configuration has also been much worse from an attitude perspective. Also, we no longer have propellant to change the attitude of the spacecraft to improve this configuration. We can change the antenna pointing a bit but the first time we tried it, it did not work.

    Next Steps

    When ISEE-3 goes into safe mode it turns off all of the experiments and it turns off both transmitters and waits for help. Due to some uncertainty in the trajectory this may end up being a bit more of a problem than otherwise. We are working now to put together the commands to turn the transponders back on and obtain engineering telemetry. The last telemetry we have looked ok, but the spacecraft is still traveling farther away from the sun, and thus it is probable that last week the voltage on the power bus dropped enough to trigger the safe mode event. There is no functioning battery on the spacecraft now as it failed in 1981.

    So, stay tuned for more information.

    Dennis Wingo
    ISEE-3 Project Co-Lead