Group items tagged

What ISEE-3 Really Looks Like

successfully

uplink commands to the space craft

accomplished through a lot of team work, strong leadership

and generous support from the community at large

designed a deep-space uplink modulator in a couple of days,

products like the Ettus Research USRP, the open source SDR framework GNU Radio have made this exceedingly easy.

12 June 2014

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

getting data back from the magentometer that indicates that science data is coming back

Just because an instrument is powered up doesn't mean that it is functioning normally

some of the ISEE-3 instruments had begun to fail or become partially functional as early as 1982

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

spin-up target is 19.733 rpm

This burn would utilize spin-up thrusters A and B

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

investigate motions of and mechanisms operating in the plasma sheets

continue the investigation of cosmic rays and solar flare emissions in the interplanetary region near 1 AU

Second mission: International Cometary Explorer

On June 10, 1982, after completing its original mission, ISEE-3 was repurposed. It was renamed the International Cometary Explorer (ICE)

The primary scientific objective of ICE was to study the interaction between the solar wind and a cometary atmosphere

a series of lunar orbits over the next 15 months. Its last and closest pass over the Moon, on December 22, 1983, was a mere 119.4 km above the Moon's surface. By the beginning of 1984, ICE was in heliocentric orbit

Giacobini-Zinner encounter

on a trajectory intercepting that of Comet Giacobini-Zinner.

On 11 September 1985, the craft passed through the plasma tail of Comet Giacobini-Zinner

ICE carried no cameras. It instead carried instruments for measurements of energetic particles, waves, plasmas, and fields

Halley encounter

transited between the Sun and Comet Halley in late March 1986, when other spacecraft

were in the vicinity of Comet Halley

ICE flew through the tail

Heliospheric mission

mission was approved by NASA in 1991

consisting of investigations of coronal mass ejections in coordination with ground-based observations

End of mission

On May 5, 1997, NASA ended the ICE mission, and ordered the probe shut down, with only a carrier signal left operating

Further contact

In 1999, NASA made brief contact with ICE to verify its carrier signal. On September 18, 2008

NASA, with the help of KinetX, located ICE using the Deep Space Network after discovering that it had not been powered off after the 1999 contact

status check revealed that all but one of its 13 experiments were still functioning, and it still has enough propellant

Reboot effort

A team webpage said, "We intend to contact the ISEE-3 (International Sun-Earth Explorer) spacecraft, command it to fire its engine and enter an orbit near Earth, and then resume its original mission...If we are successful we intend to facilitate the sharing and interpretation of all of the new data ISEE-3 sends back via crowd sourcing."

Sometime after NASA's interest in the ICE waned

A team of engineers, programmers, and scientists

realized that the spacecraft might be steered to pass close to another comet

began to study the feasibility and challenges involved

On May 15, 2014, the project reached its crowdfunding goal

which will cover the costs of writing the software to communicate with the probe, searching through the NASA archives for the information needed to control the spacecraft, and buying time on the dish antennas

The project then set a 'stretch' goal of $150,000

The project members are working on deadline: if they get the spacecraft to change its orbit by late May or early June 2014, it can use the Moon's gravity to get back into a useful halo orbit.

Earlier in 2014, officials with the Goddard Space Flight Center had said that the Deep Space Network equipment necessary to transmit signals to the spacecraft had been decommissioned in 1999, and that replacing it was not economically feasible

oject members obtained the needed hardware (power amplifier, modulator/demodulator[12]), and installed it on the 305-meter Arecibo dish antenna on May 19, 2014

Although NASA is not funding the project, it made advisors available and gave approval to try to establish contact

On May 21, 2014, NASA announced that it had signed a Non-Reimbursable Space Act Agreement with the ISEE-3 Reboot Project

"This is the first time NASA has worked such an agreement for use of a spacecraft the agency is no longer using or ever planned to use again," officials said

The final state of the spacecraft before was to have both of the transponders transmitters active and that is what people around the world have been tracking.

the spacecraft is set up with a lot of redundancy so you can use either transponder A or B to send telemetry or range

We tried several times to command the spacecraft's B transponder at 2041.9479 MHz into the mode where it normally sends engineering telemetry

did not work

Then we tried the same process on transponder A

modulation from the output of the telemetry system

The initial command was just to turn engineering telemetry on at 512 bits/second. This was successful.

successfully commanded the spacecraft into engineering telemetry mode.

initial verification

later

through the A transponder's receiver we commanded through the B transponder's command decoder to output engineering telemetry through transponder B's transmitter

verified so far the following systems on the spacecraft

1. Transponder A receiver

2. Transponder A's Command Decoder and Data Handling Unit

3. Transponder B's Command Decoder and Data Handling Unit

tried to command the spacecraft into 64 bits/second mode, which was a mode that is much more complicated to set up and we did not get working successfully during the limited time that the spacecraft is visible from Arecibo

need to do this so that the smaller dishes at Morehead State and Bochum will have a positive signal margin so that we can record several hours of data

neither of the ISEE-3/ICE receivers had met their specification in testing

for -120 dbm sensitivity

receiver A was tested at about -114 dbm, and Receiver B at -111 dbm

after our end to end systems test we had an earthquake

how observations could be affected by vibrations in the dome structure as it translates during an observation and then that happened

later processed our first day's data dump from the spacecraft and we received 49 full frames of data at a bit rate of 512 bits/second

there were no errors on the downlink

milestones related to commanding and receiving data

1. Successful commanding multiple times of ISEE-3/ICE

2. Received engineering telemetry from both data multiplexing units on the spacecraft

3. Successful demodulation on the ground of the received data, through the output of bits

4. Verification of good data at 512 bits/sec, including frame synchronization, correct number of bits/frame, and with no errors, showing a very strong 30+ db link margin through Arecibo

If we can maneuver the spacecraft by June 17th we get the very small delta V number

this starts to climb rapidly as the spacecraft gets closer to the moon

cannot at this time rule out a lunar impact.

have also obtained several documents from NASA as part of the development of our Space Act Agreement

Since there is no computer on board the ISEE-3 spacecraft our task is actually much easier since we are going to be directly commanding various subsystems

This is an ongoing process and we have, as usual, dug some of the pertinent information out of 35 year old IEEE or AIAA papers that are publicly available

The ISEE-3/ICE spacecraft was never really designed to be an interplanetary cruiser and thus the thrusters on board are very small

estimate that if we wait until mid-June to do the course correction that it will take 17 hours of thrusting to get the course change of about 40 meters/second that we will need at that time

recovering old imagery on magnetic tape reels from the first lunar orbiter missions),

operating outside the ranks and hallways of NASA

to accomplish a landmark achievement: to turn on, command and maneuver a NASA spacecraft long ago abandoned

Amateur radio operators now have technology sufficient to acquire the signal and through the internet are also a part of the recovery effort

without the original hardware transmitter, today’s high-speed electronics are able to emulate in software the hardware from 36 years ago

The mission required the spacecraft to leave the Earth/moon system and orbit around the sun instead

After encounters with comet Giacobini-Zinner in 1985 and the famous Halley’s comet in 1986 and the study of CME’s from the sun in 1991, the “plug” was pulled in the spacecraft on 5 May 1997

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.