Tag: ISEE-3

ISEE-3 engine restart fails but the private effort continues

11:57 am

After numerous tries, the private effort to put ISEE-3 back into its original orbit has failed.

We have completely accomplished all of our original goals except for one: firing the ISEE-3 propulsion system in a sufficient fashion to alter its trajectory. We did operate the propulsion system briefly so as to correct the spin of the spacecraft, and to start the trajectory correction maneuver. The propulsion system works fine. The problem is that there is no longer any Nitrogen pressurant left in its tanks to allow it to work.

36 years and more than 30 billion miles have taken its toll on the spacecraft’s propulsion system. We have exhausted every option to bring the engines online so as to conduct the correction maneuver required to place it in its planned orbit. Without the pressurant it just won’t work.

Have they given up? No! Though the spacecraft will remain in a solar orbit where maintaining communications will be difficult if not impossible, they are going to try anyway, and are even going to run another crowd-sourcing campaign to finance it.

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Another ISEE-3 update

2:24 pm

The team trying to resurrect ISEE-3 had very mixed results in its attempt today to get the spacecraft’s propulsion system working.

They managed to get “several instances of thrust,” which suggests there is fuel, the system can function, and that their strategy is on the right track. They did not however get full thrust as hoped, and are not quite sure why the spacecraft only partly responded. They are analyzing the data while they apply to NASA for an extension of their license to transmit to the spacecraft.

This last point is merely a formality. What can NASA do if they continue anyway? Nothing. NASA will say yes, partly because it is good public relations and partly because most of the people at NASA are also fans of this effort.

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ISEE-3 might still be saved

3:39 pm

It ain’t dead yet: The private group trying to resurrect ISEE-3 has not yet given up.

[T]he reboot team, led by editor Keith Cowing and entrepreneur Dennis Wingo, CEO of California-based Skycorp Incorporated, isn’t quite ready to give up. One of the project volunteers has suggested that perhaps the nitrogen isn’t actually gone. It may in fact still be there, but dissolved in with the hydrazine.

If that’s the case, Wingo says, ISEE-3 could potentially repressurize the propellant by powering up the tank heaters, raising the temperature up perhaps 10 degrees from the roughly 25 degrees C where it stands now. “If [the idea] has any merit, then we could turn the heaters on and drive at least some of the nitrogen out of solution. That would give us more pressure that just heating the tanks themselves,” Wingo says. “It’s not desperation,” he adds. “There is some good physics behind this.”

Their big problem is that they need to know more about how the nitrogen was stored on the spacecraft. They are asking for help from anyone who is willing to research the problem.

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The effort to resurrect ISEE-3’s is over

9:42 am

The private effort to resurrect the 1980s research probe ISEE-3 has been stymied by a non-working propulsion system.

Before the July 9 attempt, the ISEE-3 Reboot Project thought it had a chance of completing its planned trajectory correction maneuver. The spacecraft’s small hydrazine thrusters were spun up July 3, and systems appeared nominal, Cowing said. On July 8, the spacecraft even managed to perform one of the six multipulse burns that would have set it up for a return to the orbit into which it was launched in 1978.

But further attempts to activate the thrusters July 8 proved unsuccessful, as were all attempts the following day. After eliminating a malfunctioning valve as the cause of the problem, the ISEE-3 Reboot Project was forced to conclude that the satellite’s hydrazine fuel simply was not being pushed through its plumbing at the right pressure to conduct a burn.

The spacecraft is in science mode and will gather data as long as it is in communication range, which will only be for another three months.

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ISEE-3 effort aborted?

4:07 pm

The engineers trying to resurrect ISEE-3 think their engine burn yesterday ended prematurely because the spacecraft’s supply of nitrogen needed for such a burn has been depleted.

They have still not given up hope, but it sounds like it is increasingly unlikely that they will be able to shift the spacecraft’s orbit as needed.

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An update on ISEE-3’s resurrection

9:45 am

The engineers trying to resurrect the 1980s ISEE-3 spacecraft have posted an update describing what happened with yesterday’s partly successful engine burn.

The bottom line:

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.

This doesn’t sound hopeful, but stay tuned as they continue to assess the situation.

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ISEE-3 engine burn

9:33 pm

The major course correction burn for ISEE-3 was only partially successful today.

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.

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ISEE-3 engine burn tomorrow

3:46 pm

The private effort to resurrect the 1970’s sun-observing space probe ISEE-3’s will attempt its first full engine burn on July 8.

They hope to get the spacecraft back into one of the Earth-Sun Lagrangian points where it can be controlled reliably from Earth and can thus resume its study the solar wind, as originally designed. They have most of July to make the burn that will shift the orbit appropriately, so if this first attempt fails they can still make it happen.

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ISEE-3 fires its thrusters for the first time since 1987.

4:57 pm

The private team resurrecting the 1970s space probe ISEE-3 successfully fired its thrusters for the first time since 1987.

It took several attempts and days to perform the roll maneuver because ISEE-3 was not responding to test commands. But this time, controllers got in touch. They increased the roll rate from 19.16 revolutions per minute to 19.76 RPM, putting it within mission specifications for trajectory corrections.

The spacecraft is now prepped for the big burn that will change its trajectory.

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The private effort to reactivate the 1970s ISEE-3 space probe has successfully re-established two way communications with the spacecraft.

2:34 pm

The private effort to reactivate the 1970s ISEE-3 space probe has successfully re-established two way communications with the spacecraft.

They will spend the next few days assessing ISEE-3’s overall health in order to plan the engine burns necessary to get it back to its original location orbiting the Sun near Earth.

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An summary of the past week’s private effort at Aceibo to reactivate ISEE-3.

9:59 am

A summary of the past week’s private effort at Aceibo to reactivate ISEE-3.

They have discovered that the spacecraft is approximately 150,000 miles away from its expected position. This complicates the rescue effort significantly, as all their course corrections have to be recalculated based on this new position and they don’t yet have it refined enough to do those recalculations.

This has become extremely important as there is a solid statistical chance that the spacecraft could impact the moon or even be off course enough to threaten other spacecraft in Earth orbit. We are working with Mike Loucks of Space Exploration Engineering (SEE) our trajectory guy on this issue. An east coast company, Applied Defense (ADS) has also offered their help and engineering support to derive a new ephemeris from our new position reports. ADS and SEE did the trajectories for NASA’s just completed LADEE mission.

Hopefully by the end of this weekend they will have more to report.

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The private effort to reactivate ISEE-3, a 1970s NASA spacecraft in orbit around the sun, has successfully detected the spacecraft.

9:00 am

The private effort to reactivate ISEE-3, a 1970s NASA spacecraft in orbit around the sun, has successfully detected the spacecraft.

Unfortunately the signal is a little weaker than we expected, and it’s also odd that it fades out toward the end of this capture (it returns and fades in subsequent ones too). Again, this is all very preliminary data done tonight on a rush basis. Much more detail to follow.

They don’t have a lot of time to detect, re-establish contact, and get the spacecraft into the necessary orbit for research. Orbital mechanics give them only through July to do this before it will be too late.

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Though they really don’t need it, a private effort to reactivate a 1970s spacecraft has now gotten NASA’s okay.

10:34 am

Though they really don’t need it, a private effort to reactivate a 1970s spacecraft has now gotten NASA’s okay.

This piece of paper from NASA is a definite nice-to-have, given that “a private entity cannot legally salvage U.S. government property in space,” according to Mike Gold, a space law expert and attorney who works full time as the head of Washington operations for Bigelow Aerospace, the North Las Vegas, Nevada, company developing inflatable space habitats with technology licensed from NASA.

But practically speaking, it appears NASA could have done little to stop the ISEE-3 Reboot project from moving ahead with its plan to take over the old spacecraft — an Earth-Sun observatory that launched to the gravitationally stable Earth-Sun Lagrange point 1 in 1978 and is now swinging back toward the home planet in the heliocentric orbit NASA nudged it into in 1982 to chase comets.

What is really more important is that their effort to raise the necessary private funds for this project has largely succeeded.

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Putting a spacecraft back in the orbit it was intended, thirty-one years later.

9:14 am

Putting a spacecraft back in the orbit it was intended, thirty-one years later.

The spacecraft, ISEE-3, was intended to study the solar wind and the connection between the Sun and the Earth. In 1986 it was diverted instead to take a look at Halley’s Comet. Now there is an opportunity to return it to its original task, assuming engineers can wake it up after three decades.

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