Posted on by Nancy Atkinson

Contact With 36-Year Old Spacecraft Results in Dancing, Hugs. Now Comes Even Bigger Challenge

A graphic illustrating the ISEE-3 spacecraft's history. Courtesy Tim Reyes.

What is it like to make contact with a 36-year old dormant spacecraft?

“The intellectual side of you systematically goes through all the procedures but you really end up doing a happy dance when it actually works,” Keith Cowing told Universe Today. Cowing, most notably from NASA Watch.com, and businessman Dennis Wingo are leading a group of volunteer engineers that are attempting to reboot the International Sun-Earth Explorer (ISEE-3) spacecraft after it has traveled 25 billion kilometers around the Solar System the past 30 years.

Its initial mission launched in 1978 to study Earth’s magnetosphere, and the spacecraft was later repurposed to study two comets. Now, on its final leg of a 30-plus year journey and heading back to the vicinity of Earth, the crowdfunding effort ISEE-3 Reboot has been working to reactivate the hibernating spacecraft since NASA wasn’t able to provide any funds to do so.

More Details: No turning back, NASA ISEE-3 Spacecraft Returning to Earth after a 36 Year Journey

The team awakened the spacecraft by communicating from the Arecibo radio telescope in Puerto Rico, using a donated transmitter. While most of the team has been in Puerto Rico, Cowing is back at home in the US manning the surge of media attention this unusual mission has brought.

Those at Arecibo are now methodically going through all the systems, figuring out what the spacecraft can and can’t do.

“We did determine the spin rate of spacecraft is slightly below what it should be,” Cowing said, “but the point there is that we’re now understanding the telemetry that we’re getting and its coming back crystal clear.”

For you tech-minded folks, the team determined the spacecraft 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,” Cowing wrote in an update on the website.

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.

“However, it’s not been totally ruled out, — as NASA would say it’s a not a non-zero chance,” Cowing said. “The fact that it was not where it was supposed to be shows there were changes in its position. But assuming we can fire the engines when we want to, it shouldn’t be a problem. As it stands now, if we didn’t do anything, the chance of it hitting the Moon is not zero. But it’s not that likely.”

But the fact that the predicted location of the spacecraft is only off by less than 30,000 km is actually pretty amazing.

Dennis Wingo wrote this on the team’s website:

Consider this, the spacecraft has completed almost 27 orbits of the sun since the last trajectory maneuver. That is 24.87 billion kilometers. They are off course by less than 30,000 km. I can’t even come up with an analogy to how darn good that is!! That is almost 1 part in ten million accuracy! We need to confirm this with a DSN ranging, but if this holds, the fuel needed to accomplish the trajectory change is only about 5.8 meters/sec, or less than 10% of what we thought last week!

We truly stand on the shoulders of steely eyed missile men giants..

Dennis Wingo and ISEE-3 Reboot engineers at Arecibo. Image courtesy ISEE-3 Reboot.
Dennis Wingo and ISEE-3 Reboot engineers at Arecibo. Image courtesy ISEE-3 Reboot.

In 1982, NASA engineers at Goddard Space Flight Center, led by Robert Farquhar devised the maneuvers needed to send the spacecraft ISEE-3 out of the Earth-Moon system. It was renamed the International Cometary Explorer (ICE) to rendezvous with two comets – Giacobini-Zinner in 1985 and Comet Halley in 1986.

“Bob Farquhar and his team initially did it with pencils on the back of envelopes,” Cowing said, “so it is pretty amazing. And we’re really happy with the trajectory because we’ll need less fuel – we have 150 meters per second of fuel available, and we’ll only need about 6 meters per second of maneuvering, so that will give us a lot of margin to do the other things in terms of the final orbit, so we’re happy with that. But we have to fire the engines first before we pat ourselves on the back.”

And that’s where the biggest challenge of this amateur endeavor lies.

ISEE-3 Reboot Project mission patch. Image courtesy ISEE-3 Reboot.
ISEE-3 Reboot Project mission patch. Image courtesy ISEE-3 Reboot.

“The biggest challenge will be getting the engines to fire,” Cowing said. “The party’s over if we can’t get it to do that. The rest will be gravy. So that’s what we’re focusing on now.”

After the June 17 TCM, the next big date is August 10, when the team will attempt to put the spacecraft in Earth orbit and then resume its original mission that began back in 1978 – all made possible by volunteers and crowdfunding.

We’ll keep you posted on this effort, but follow the ISEE-3 Reboot Twitter feed, which is updated frequently and immediately after anything happens with the spacecraft. Also, for more detailed updates, check out the SpaceCollege website.

Posted on by Tim Reyes

Guest Post: No turning back, NASA ISEE-3 Spacecraft Returning to Earth after a 36 Year Journey

A graphic illustrating the ISEE-3 spacecraft's history. Courtesy Tim Reyes.

Editor’s note: This guest post was written by Tim Reyes, a former NASA software engineer and analyst who has supported development of orbital and lander missions to the planet Mars since 1992.

The International Sun-Earth Explorer spacecraft (ISEE-3) is phoning home and will be returning whether we are ready or not. Launched in 1978 to study Earth’s magnetosphere, the spacecraft was later repurposed to study two comets. Now, on its final leg of a 30-plus year journey to return to Earth, there’s a crowdfunding effort called ISEE-3 Reboot aimed at reactivating the hibernating spacecraft since NASA is not offering any funding to do so.

Interestingly, on May 14th, the spacecraft will be in conjunction with the planet Jupiter, passing only 2 arc minutes from the giant gas planet. While the spacecraft is not visible to the human eye or optical telescopes, Jupiter on the 14th marks the spot where ISEE-3 resides in our night sky.

ISEE-3 Jupiter conjunction on May 14, 2014. Graphic courtesy of Tim Reyes.
ISEE-3 Jupiter conjunction on May 14, 2014. Graphic courtesy of Tim Reyes.

Here’s a bit of history on the program and this spacecraft in particular: The International Sun-Earth Explorers 1, 2 and 3 were the vanguard of what became an ongoing NASA program to monitor and understand the Sun-Earth relationship. ISEE-3 was part of a 3 spacecraft international effort to study the interaction of the Solar Wind with the Earth’s magnetosphere.

In 1982, NASA engineers at Goddard Space Flight Center, led by Robert Farquhar devised an unprecedented sequence of propulsion maneuvers including Earth and Moon gravitational assists to send the spacecraft ISEE-3 out of the Earth-Moon system. It was rechristened as the International Cometary Explorer (ICE) to rendezvous with two comets – Giacobini-Zinner in 1985 and Comet Halley in 1986.

The trajectory given ISEE-3 to escape the Earth-Moon system and flyby comets included returning to Earth on August 10, 2014. Final tweaks to the trajectory were completed in 1987 to assure a flyby of the Moon which Farquhar knew could be used to return ISEE-3 to an Earth orbit.

ISEE-3 Reboot Project mission patch. Image courtesy ISEE-3 Reboot.
ISEE-3 Reboot Project mission patch. Image courtesy ISEE-3 Reboot.

Enter the 21st Century, 30 years later and documents and magnetic tapes have predictably disappeared. The software and hardware to program, command and transmit to ISEE-3 are long gone. An independent team of engineers, led by Dennis Wingo and Keith Cowing (the same leaders of the Lunar Orbiter Image Recovery Project (LOIRP) — recovering old imagery on magnetic tape reels from the first lunar orbiter missions), operating outside the ranks and hallways of NASA are now racing against the clock to accomplish a landmark achievement: to turn on, command and maneuver a NASA spacecraft long ago abandoned, its primary missions completed in the 1980s. There are no funds, no remaining hardware or mission software to execute but this is the 21st century.

As of this writing there are five days left to contribute to this project, which is at 92% of its goal.

“ISEE-3 Reboot” team leader Dennis Wingo, says that if the efforts to contact the spacecraft are successful, plans are to return the spacecraft to the Sun-Earth L1 Point. Wingo emphasizes that Farquhar remains as instrumental to the spacecraft’s recovery today as he was to its departure, providing critical insight into the spacecraft systems.

While ISEE-3 has been on its long journey to return to Earth, remarkable technological and social events have unfolded. The personal computer arrived and matured; visionaries such as Steve Jobs have come and gone. With the Internet — non-existent when ISEE-3 launched – now a RocketHub crowdfunding effort was started to raise funds. Teleconferencing, more limited to board rooms in the days ISEE-3’s launch-date have brought retired NASA engineers and Wingo’s band of engineers together.

Amateur radio operators now have technology sufficient to acquire the signal and through the internet are also a part of the recovery effort. These events have conspired to give the band of engineers a small window of opportunity to recover the spacecraft. Additionally, without the original hardware transmitter, today’s high-speed electronics are able to emulate in software the hardware from 36 years ago.

While budget woes and shortfalls have plagued NASA since the 1960s, the 1980s were especially difficult. Recall that it included a decade void of any missions to Mars. Additionally, Congress refused to fund a US led mission to flyby Comet Halley. NASA was left out in the comet’s return while European, the Soviets and Japanese all had spacecraft planned. Repurposing ISEE-3 filled this gap and it became the first spacecraft to ever fly through the tail of a comet.

Now 36 years after launch, a spacecraft that time forgot, ISEE-3 has become a time traveler. It is the twin astronaut returning home from his long journey to find his twin, now aged and the World transformed. Wingo and his engineers, by recovering ISEE-3 create a link from the past to the present new generations of engineers. Wingo’s Skycorp will make ISEE-3 scientific data open to the public and to researchers and present a system for training engineers in mission management and spacecraft systems.