NASA - Europa Clipper updates and discussion

[flatpf]

Wasnt there no choice but to can the magnetometer? It was just too far behind and not gonna happen?

ICEMAG apparently had problems developing optical fibres for their scalar magnetometer that could withstand the temperature and radiation at Jupiter (JUICE also uses optical fibres for its scalar magnetometer but I don't know if their requirements are comparable).

With the 2 scalar magnetometers there would not be the need to rotate the spacecraft every few weeks to calibrate for the offset in the fluxgate magnetometers, you could calibrate in-flight. Which is the reason JUICE is using its setup because in orbit around Ganymede you can't calibrate like EC now has to during its orbits around Jupiter. And apparently that setup is an order of magnitude more precise, and of course without a scalar magnetometer you can only measure the flux but not the absolute strength of the field.

Here is a PP-presentation by Bob Pappalardo at OPAG in 2019 addressing the issue and problems with losing ICEMAG and comparing it to a magnetometer with 4 fluxgate sensors, EC now has 3.

I heard a recent talk held by a EC/JPL scientist who rather ambiguously said that the new magnetometer while keeping the instrument budget low came with big operational cost because of its requirements, things that were not clear when it was chosen over ICEMAG.

[FutureSpaceTourist]

Animation:

https://twitter.com/europaclipper/status/1861096088868135016

This story is really beginning to unfold: While zooming through space at 22 miles per second (35 kilometers per second), our spacecraft has deployed its solar arrays, magnetometer boom, and now the antennas for its ice-penetrating radar instrument

https://www.nasa.gov/missions/europa-clipper/nasas-europa-clipper-millions-of-miles-down-instruments-deploying/

NASA’s Europa Clipper: Millions of Miles Down, Instruments Deploying

Jet Propulsion Laboratory
NOV 25, 2024
ARTICLE

CONTENTS
Boom Times
On the Radar
Instrument Checkout
Mars-Bound
More About Europa Clipper

Headed to Jupiter’s moon Europa, the spacecraft is operating without a hitch and will reach Mars in just three months for a gravity assist.

NASA’s Europa Clipper, which launched Oct. 14 on a journey to Jupiter’s moon Europa, is already 13 million miles (20 million kilometers) from Earth. Two science instruments have deployed hardware that will remain at attention, extending out from the spacecraft, for the next decade — through the cruise to Jupiter and the entire prime mission.

A SpaceX Falcon Heavy rocket launched it away from Earth’s gravity, and now the spacecraft is zooming along at 22 miles per second (35 kilometers per second) relative to the Sun.

Europa Clipper is the largest spacecraft NASA has ever developed for a planetary mission. It will travel 1.8 billion miles (2.9 billion kilometers) to arrive at Jupiter in 2030 and in 2031 will begin a series of 49 flybys, using a suite of instruments to gather data that will tell scientists if the icy moon and its internal ocean have the conditions needed to harbor life.

For now, the information mission teams are receiving from the spacecraft is strictly engineering data (the science will come later), telling them how the hardware is operating. Things are looking good. The team has a checklist of actions the spacecraft needs to take as it travels deeper into space. Here’s a peek:

Boom Times

Shortly after launch, the spacecraft deployed its massive solar arrays, which extend the length of a basketball court. Next on the list was the magnetometer’s boom, which uncoiled from a canister mounted on the spacecraft body, extending a full 28 feet (8.5 meters).

To confirm that all went well with the boom deployment, the team relied on data from the magnetometer’s three sensors. Once the spacecraft is at Jupiter, these sensors will measure the magnetic field around Europa, both confirming the presence of the ocean thought to be under the moon’s icy crust and telling scientists about its depth and salinity.

On the Radar

After the magnetometer, the spacecraft deployed several antennas for the radar instrument. Now extending crosswise from the solar arrays, the four high-frequency antennas form what look like two long poles, each measuring 57.7 feet (17.6 meters) long. Eight rectangular very-high-frequency antennas, each 9 feet (2.76 meters) long, were also deployed — two on the two solar arrays.

“It’s an exciting time on the spacecraft, getting these key deployments done,” said Europa Clipper project manager Jordan Evans of NASA’s Jet Propulsion Laboratory in Southern California. “Most of what the team is focusing on now is understanding the small, interesting things in the data that help them understand the behavior of the spacecraft on a deeper level. That’s really good to see.”

Instrument Checkout

The remaining seven instruments will be powered on and off through December and January so that engineers can check their health. Several instruments, including the visible imager and the gas and dust mass spectrometers, will keep their protective covers closed for the next three or so years to guard against potential damage from the Sun during Europa Clipper’s time in the inner solar system.

Mars-Bound

Once all the instruments and engineering subsystems have been checked out, mission teams will shift their focus to Mars. On March 1, 2025, Europa Clipper will reach Mars’ orbit and begin to loop around the Red Planet, using the planet’s gravity to gain speed. (This effect is similar to how a ball thrown at a moving train will bounce off the train in another direction at a higher speed.) Mission navigators already have completed one trajectory correction maneuver, as planned, to get the spacecraft on the precise course.

At Mars, scientists plan to turn on the spacecraft’s thermal imager to capture multicolored images of Mars as a test operation. They also plan to collect data with the radar instrument so engineers can be sure it’s operating as expected.

The spacecraft will perform another gravity assist in December 2026, swooping by Earth before making the remainder of the long journey to the Jupiter system. At that time, the magnetometer will measure Earth’s magnetic field, calibrating the instrument.

More About Europa Clipper

Europa Clipper’s three main science objectives are to determine the thickness of the moon’s icy shell and its interactions with the ocean below, to investigate its composition, and to characterize its geology. The mission’s detailed exploration of Europa will help scientists better understand the astrobiological potential for habitable worlds beyond our planet.

Managed by Caltech in Pasadena, California, JPL leads the development of the Europa Clipper mission in partnership with the Johns Hopkins Applied Physics Laboratory in Laurel, Maryland, for NASA’s Science Mission Directorate in Washington. APL designed the main spacecraft body in collaboration with JPL and NASA’s Goddard Space Flight Center in Greenbelt, Maryland, NASA’s Marshall Space Flight Center in Huntsville, Alabama, and Langley Research Center in Hampton, Virginia. The Planetary Missions Program Office at Marshall executes program management of the Europa Clipper mission. NASA’s Launch Services Program, based at Kennedy, managed the launch service for the Europa Clipper spacecraft.

Find more information about Europa Clipper here:

https://science.nasa.gov/mission/europa-clipper

Caption:

An artist’s concept of NASA’s Europa Clipper shows the spacecraft in silhouette against Europa’s surface, with the magnetometer boom fully deployed at top and the antennas for the radar instrument extending out from the solar arrays.
NASA/JPL-Caltech

[Targeteer]

Still no mention of the trajectory correction burn, at all.

[mn]

...

Mars-Bound

Once all the instruments and engineering subsystems have been checked out, mission teams will shift their focus to Mars. On March 1, 2025, Europa Clipper will reach Mars’ orbit and begin to loop around the Red Planet, using the planet’s gravity to gain speed. (This effect is similar to how a ball thrown at a moving train will bounce off the train in another direction at a higher speed.) Mission navigators already have completed one trajectory correction maneuver, as planned, to get the spacecraft on the precise course.

Still no mention of the trajectory correction burn, at all.

Perhaps you missed it, there's mention of the burn in the update, I bolded it for you, see above.

[Blackstar]

Wasnt there no choice but to can the magnetometer? It was just too far behind and not gonna happen?

There are three sides to every argument.

[deadman1204]

Wasnt there no choice but to can the magnetometer? It was just too far behind and not gonna happen?

There are three sides to every argument.

sides of an argument = n^2 + 1

[ccdengr]

Wasnt there no choice but to can the magnetometer? It was just too far behind and not gonna happen?

ICEMAG apparently had problems developing optical fibres for their scalar magnetometer that could withstand the temperature and radiation at Jupiter...

Certainly at the time the science community had a lot of questions about the decision to descope ICEMAG. https://www.lpi.usra.edu/opag/meetings/mar2019/Findings.pdf

On March 5, 2019, NASA Associate Administrator Thomas Zurbuchen released a letter to the
science community about his decision to terminate the Interior Characterization of Europa using
Magnetometry (ICEMAG) experiment on Europa Clipper, to be replaced by a facility
magnetometer investigation. The loss of ICEMAG will adversely affect the science return of the
Europa Clipper mission... The letter explained that the termination decision was the result of “… a process
to monitor resource usage of each Europa Clipper instrument. As part of the process, cost
triggers were defined for each instrument with the understanding that exceeding the trigger
would escalate the situation…until a resolution was found.” This appears to be a new process
for how NASA HQ makes PI-experiment termination decisions, which is not well-understood by
the science community. It would be helpful for NASA to provide a full explanation in writing
about this new process.

If that clarification ever happened, I don't know what it said.

[vjkane]

Wasnt there no choice but to can the magnetometer? It was just too far behind and not gonna happen?

ICEMAG apparently had problems developing optical fibres for their scalar magnetometer that could withstand the temperature and radiation at Jupiter...

Apparently the original instrument had serious development problems

The current instrument is a classic design. As I understand it, the mission needed to develop the capability for the spacecraft to roll periodically  to, I believe, calibrate the measurements.

[Blackstar]

https://www.nasa.gov/missions/europa-clipper/nasas-europa-clipper-millions-of-miles-down-instruments-deploying/

[StraumliBlight]

At the OPAG meeting yesterday, the Clipper team presented a mission update. All is well, and spacecraft commissioning continues on schedule. Here's one slide with status on two recent instrument deployments.

OPAG Presentation slides

Next Events:

• Implement the Europa-UVS low voltage check-out (December 7)
• Commission the remainder of the Europa-UVS instrument (January 8 – 25)

[redliox]

So they might do an asteroid flyby, but only if they find an archived one that'll flyby better than the Moon's orbit?

[Targeteer]

https://twitter.com/EuropaClipper/status/1863652504967536956

[Blackstar]

https://link.springer.com/article/10.1007/s11214-024-01115-9

The Europa Imaging System (EIS) Investigation

The Europa Imaging System (EIS) consists of a Narrow-Angle Camera (NAC) and a Wide-Angle Camera (WAC) that are designed to work together to address high-priority science objectives regarding Europa’s geology, composition, and the nature of its ice shell. EIS accommodates variable geometry and illumination during rapid, low-altitude flybys with both framing and pushbroom imaging capability using rapid-readout, 8-megapixel (4k × 2k) detectors. Color observations are acquired using pushbroom imaging with up to six broadband filters. The data processing units (DPUs) perform digital time delay integration (TDI) to enhance signal-to-noise ratios and use readout strategies to measure and correct spacecraft jitter. The NAC has a 2.3° × 1.2° field of view (FOV) with a 10-μrad instantaneous FOV (IFOV), thus achieving 0.5-m pixel scale over a swath that is 2 km wide and several km long from a range of 50 km. The NAC is mounted on a 2-axis gimbal, ±30° cross- and along-track, that enables independent targeting and near-global (≥90%) mapping of Europa at ≤100-m pixel scale (to date, only ∼15% of Europa has been imaged at ≤900 m/pixel), as well as stereo imaging from as close as 50-km altitude to generate digital terrain models (DTMs) with ≤4-m ground sample distance (GSD) and ≤0.5-m vertical precision. The NAC will also perform observations at long range to search for potential erupting plumes, achieving 10-km pixel scale at a distance of one million kilometers. The WAC has a 48° × 24° FOV with a 218-μrad IFOV, achieving 11-m pixel scale at the center of a 44-km-wide swath from a range of 50 km, and generating DTMs with 32-m GSD and ≤4-m vertical precision. The WAC is designed to acquire three-line pushbroom stereo and color swaths along flyby ground-tracks.

[deadman1204]

https://link.springer.com/article/10.1007/s11214-024-01115-9

The Europa Imaging System (EIS) Investigation

The Europa Imaging System (EIS) consists of a Narrow-Angle Camera (NAC) and a Wide-Angle Camera (WAC) that are designed to work together to address high-priority science objectives regarding Europa’s geology, composition, and the nature of its ice shell. EIS accommodates variable geometry and illumination during rapid, low-altitude flybys with both framing and pushbroom imaging capability using rapid-readout, 8-megapixel (4k × 2k) detectors. Color observations are acquired using pushbroom imaging with up to six broadband filters. The data processing units (DPUs) perform digital time delay integration (TDI) to enhance signal-to-noise ratios and use readout strategies to measure and correct spacecraft jitter. The NAC has a 2.3° × 1.2° field of view (FOV) with a 10-μrad instantaneous FOV (IFOV), thus achieving 0.5-m pixel scale over a swath that is 2 km wide and several km long from a range of 50 km. The NAC is mounted on a 2-axis gimbal, ±30° cross- and along-track, that enables independent targeting and near-global (≥90%) mapping of Europa at ≤100-m pixel scale (to date, only ∼15% of Europa has been imaged at ≤900 m/pixel), as well as stereo imaging from as close as 50-km altitude to generate digital terrain models (DTMs) with ≤4-m ground sample distance (GSD) and ≤0.5-m vertical precision. The NAC will also perform observations at long range to search for potential erupting plumes, achieving 10-km pixel scale at a distance of one million kilometers. The WAC has a 48° × 24° FOV with a 218-μrad IFOV, achieving 11-m pixel scale at the center of a 44-km-wide swath from a range of 50 km, and generating DTMs with 32-m GSD and ≤4-m vertical precision. The WAC is designed to acquire three-line pushbroom stereo and color swaths along flyby ground-tracks.

Wow, thats gonna be awesome. Its crazy to think that most of europa has only been mapped at about 1km resolution

[vjkane]

https://link.springer.com/article/10.1007/s11214-024-01115-9

The Europa Imaging System (EIS) Investigation

This is just one of a number of papers on the overall science goals, science goals by major investigation, and individual instruments.  I believe that all are open access.

https://link.springer.com/collections/bifafdigaj

There are similar paper collections for:

JUICE https://link.springer.com/collections/dficcaejhd
BepiColombo https://link.springer.com/collections/dciadahdfc
Lucy https://link.springer.com/collections/bgfdahhafc
Psyche https://link.springer.com/collections/fhhgidehgc
Perseverance https://link.springer.com/collections/dciddebiad