Discussing Juno/JunoCam Mission and Jupiter Data

[Clever Penguin]

Finally ! Juno's about to go inbound for a practice run with the science payload operating,
http://www.nasa.gov/feature/jpl/five-years-post-launch-juno-is-at-a-turning-point
Juno's science instruments were turned off during orbit insertion, to simplify spacecraft
operations during that critical maneuver. In contrast, all the instruments will be collecting data
during the Aug. 27 pass, which serves as a trial run before the mission gets to work collecting
the precious data it came for.

I can't wait. I hope it takes the scenic route...

 

[1oldman2]

I hope it takes the scenic route...

The route is guaranteed "scenic" (and the science is going to be super)... just a thought, super science sounds like something on a McDonald's menu, probably not the dollar menu either.

 

[enorbet]

Oh yes the Science does indeed promise to be super-sized. Juno will hit ~260,000 kph (yes, 4 zeroes) fastest unmanned human made object ever and already there is apparently some evidence supporting the hypothesis that "some sort of sonic event" from the insane turbulence below (think mega thunder!) as a contributing factor to higher than accounted for temps in upper atmosphere.

Someone said they would be disappointed if Juno didn't gather moon data but I am pleased this is a very singularly focused mission. Lots of answers and new questions about how our Solar System and others with gas giants, formed. Just terribly exciting stuff!

 

[1oldman2]

New imaging data dump from juno here.
https://www.missionjuno.swri.edu/junocam/processing?id=40
https://www.missionjuno.swri.edu/junocam/processing

Every year there is a period of time that Jupiter is too close to the sun for earth-based astronomers to
observe. This year that time co-incides with Juno’s initial large orbits of Jupiter. Ordinarily we would not
take images with JunoCam during this time however in the absence of our amateur ground-based
support we are collecting RGB images 4 times per hour. We call this the "marble movie" because Jupiter
is so small in the image. We have enough resolution to see if something major happens, like the
disappearance of the Great Red Spot, or the fading of the South Equatorial Belt. We are also imaging
Jupiter through our methane filter.

 

[1oldman2]

Closest pass to Jupiter during the entire mission coming up, It seems likely a portion of the data will be useful modeling the formation and life of exo-planets such as Proxima B, as well as solar system dynamics in general.
From, http://www.nasa.gov/feature/jpl/nasas-juno-to-soar-closest-to-jupiter-this-saturday

This Saturday at 5:51 a.m. PDT, (8:51 a.m. EDT, 12:51 UTC) NASA's Juno spacecraft will get
closer to the cloud tops of Jupiter than at any other time during its prime mission. At the
moment of closest approach, Juno will be about 2,500 miles (4,200 kilometers) above Jupiter's
swirling clouds and traveling at 130,000 mph (208,000 kilometers per hour) with respect to the
planet. There are 35 more close flybys of Jupiter scheduled during its prime mission (scheduled
to end in February of 2018). The Aug. 27 flyby will be the first time Juno will have its entire suite
of science instruments activated and looking at the giant planet as the spacecraft zooms past.

While the science data from the pass should be downlinked to Earth within days, interpretation
and first results are not expected for some time.

"No other spacecraft has ever orbited Jupiter this closely, or over the poles in this fashion," said
Steve Levin, Juno project scientist from NASA's Jet Propulsion Laboratory in Pasadena,
California. "This is our first opportunity and there are bound to be surprises. We need to take
our time to make sure our conclusions are correct."

Not only will Juno's suite of eight science instruments be on, the spacecraft 's visible light imager
-- JunoCam will also be snapping some closeups. A handful of JunoCam images, including the
highest resolution imagery of the Jovian atmosphere and the first glimpse of Jupiter's north and
south poles, are expected to be released during the later part of next week.

This dual view of Jupiter was taken on August 23, when NASA's Juno
spacecraft was 2.8 million miles (4.4 million kilometers) from the gas giant
planet on the inbound leg of its initial 53.5-day capture orbit.

 

[1oldman2]

http://www.nasa.gov/feature/jpl/nasas-juno-successfully-completes-jupiter-flyby

From, http://www.planetary.org/blogs/emily-lakdawalla/2016/08271754-junos-first-jupiter-close.html
NASA announced this afternoon that Juno passed through its first perijove since entering orbit successfully, with science
instruments operating all the way. This is a huge relief, given all the unknowns about the effects of Jupiter's nasty
radiation environment on its brand-new orbiter.

NASA's Juno mission successfully executed its first of 36 orbital flybys of Jupiter today. The time of closest
approach with the gas-giant world was 6:44 a.m. PDT (9:44 a.m. EDT, 13:44 UTC) when Juno passed about 2,600
miles (4,200 kilometers) above Jupiter's swirling clouds. At the time, Juno was traveling at 130,000 mph (208,000
kilometers per hour) with respect to the planet. This flyby was the closest Juno will get to Jupiter during its primemission.

While results from the spacecraft 's suite of instruments will be released down the road, a handful of images from
Juno's visible light imager -- JunoCam -- are expected to be released the next couple of weeks. Those images will
include the highest-resolution views of the Jovian atmosphere and the first glimpse of Jupiter's north and south
poles.

 

[enorbet]

Thanks 1oldman2. Nice update. I wonder what all the secrecy is about?

 

[collinsmark]

Thanks 1oldman2. Nice update. I wonder what all the secrecy is about?

It's not so much about secrecy as it is about transmission time.

Imagine you are standing next to someone: you can tell them your thoughts pretty quickly; but the Juno probe is not right next to us, so that situation doesn't quite apply. Now imagine that the person to whom you are talking to is a block away. You could shout really loudly, but there are limits to how loud you can shout.

There is another approach: you could shout slowly. The listener can then integrate over time. Assuming all the noise around the listener is random, it allows your shout to rise above the noise around the listener if your shouting is slow enough.

Beyond that, if you add some redundancy to your shouts, adding repetition/redundancy in a pre-agreed upon manner ("repeating" things in an a priori fashion), it allows the listener to detect and correct communication errors that might happen during the transmission.

Simply put, in a power limited system (such as a probe far from Earth), communication takes a while.

 

[1oldman2]

At the time of Juno's capture orbit (7/5/16) the distance was 48 light minutes. There is processing time involved and of course important discoveries will likely have an embargo placed on them while the review/publication process takes place. As you can see the image I posted (taken at a distance of 703,000 km) was processed and released quickly, the good stuff, from as close as 4,200 km will be released within a couple of weeks. once the science mission gets fully established ( early November) the data should be released without the delay (at least within days rather than weeks). According to JPL this pass was intended as a trial phase to check out instrumentation. Patience, there's plenty of "good stuff" to come.

 

[enorbet]

Thanks guys but I was only commenting on remarks made in the linked planetary.org blog that made a comparison to similar flights and concluding "secrecy" specific to Juno. The site has been generally reputable so I wonder about that writer as well as the conclusion.

Also having studied this shot for some time I am very prepared with patience as I'm sure enough focused data will be retrieved for at least 5 years of study.

 

[1oldman2]

Thanks guys but I was only commenting on remarks made in the linked planetary.org blog that made a comparison to similar flights and concluding "secrecy" specific to Juno. The site has been generally reputable so I wonder about that writer as well as the conclusion.

I caught the gist of your comment in regards to the "secrecy" and the site mentioned does have very good coverage of the mission.
"I don't know what other images have been planned, because the mission has inexplicably chosen not to share
information with the public about those plans. This is really weird, because Cassini and New Horizons were both very
open about their plans for imaging with their science cameras. Juno's JunoCam is an instrument intended specifically for
public outreach, and yet they're keeping information about it close to the vest. Apart from the types of imaging mentioned
in the press release, there has been discussion of attempting 3D imaging of clouds by taking images closely spaced in
time as the spacecraft passes from north to south. There was also an opportunity to image Ganymede yesterday. We'll
have to wait and see!"
Any way one looks at it this mission has great potential and I can't wait to see it evolve.

 

[collinsmark]

Regarding the communication link, and for a bit more explanation as to why it can take a while, here's something from the wiki:

"Due to telecommunications constraints, Juno will only be able to return about 40 megabytes of camera data during each 11-day orbital period. This photography downlink average data rate of less than 337 bit/s will limit the number of images that are captured and transmitted during each orbit to somewhere between 10 and 100 depending on the compression level used."​

(link: https://en.wikipedia.org/wiki/Juno_( spacecraft )#Telecommunications)

which references this source:

http://planetary.org/blogs/emily-lakdawalla/2011/3133.html

 

[1oldman2]

Regarding the communication link, and for a bit more explanation as to why it can take a while,

Interesting reading! thanks for posting that info, I'm curious about how much data (imaging) will make it back to Earth, considering the Hi-Def nature of the cam the downlink seems like one heck of a bottleneck.

 

[enorbet]

40MB? In eleven days? Wow! How did I miss that? That is such a terrible constraint and I didn't even realize it existed these days. Thank you for the links. I can't help but wonder why such important exploration, particularly now when understanding planetary weather can be so... so... urgent! how NASA got such a "back seat". I suppose Crisis Management still rules most people. Foresight requires actual critical, abstract thinking. ; )

 

[glappkaeft]

While JunoCam is not entirely without a scientific mission it was designed to be a education/outreach tool and thus has low priority for the scarce bandwidth. Originally Juno would not have a camera at all.

https://www.missionjuno.swri.edu/pub/e/downloads/JunoCam_Junos_Outreach_Camera.pdf

 

[1oldman2]

https://www.missionjuno.swri.edu/pub/e/downloads/JunoCam_Junos_Outreach_Camera.pdf

Great link! thanks.

 

[rollete]

Can't wait for the pics. Waiting for Pluto's high resolution imagery was hard but worthwhile.

 

[Clever Penguin]

What's new from the Juno mission?

 

[1oldman2]

What's new from the Juno mission?

Just waiting on data release, should be something soon.

 

[rootone]

Orbit insertion and the first of the planned close fly-bys worked perfectly and was largely an exercise in calibrating instruments.
There will be have been useful data collected as well, although it'll take a while for all of it to be downloaded.
36 orbits are planned in total, ending in early 2018.
That could be extended as is frequently the case with probes that successfully complete their primary mission and are still functional..
https://www.nasa.gov/feature/jpl/nasas-juno-successfully-completes-jupiter-flyby

 

[Borg]

Just waiting on data release, should be something soon.

How about this?
Juno probe returns close up Jupiter pictures.

Aurora in infrared:

Southern hemisphere from 38,000 km:

 

[1oldman2]

How about this?

Yup, that's the stuff.





http://www.nasa.gov/feature/jpl/jupiter-s-north-pole-unlike-anything-encountered-in-solar-system

NASA's Juno spacecraft has sent back the first-ever images of Jupiter's north
pole, taken during the spacecraft 's first flyby of the planet with its instruments
switched on. The images show storm systems and weather activity unlike
anything previously seen on any of our solar system's gas-giant planets.

First glimpse of Jupiter’s north pole, and it looks like nothing we have seen
or imagined before," said Scott Bolton, principal investigator of Juno from the
Southwest Research Institute in San Antonio. "It’s bluer in color up there than
other parts of the planet, and there are a lot of storms. There is no sign
of the latitudinal bands or zone and belts that we are used to - this image is
hardly recognizable as Jupiter. We’re seeing signs that the clouds have shadows,
possibly indicating that the clouds are at a higher altitude than other features."

 

[1oldman2]

South pole from 78,000 km.

The best write up I have found so far.
http://www.planetary.org/blogs/emily-lakdawalla/2016/09021222-junos-instruments-return.html

 

[Clever Penguin]

Beautiful pictures!

 

[Jenab2]

# Written by David Sims in Python 3.4.3, released to the public domain.
# Download Python 3.4.3 from https://www.python.org/downloads/release/python-343/
# This program is a modification of ephem, intended to track the Juno spacecraft in orbit around Jupiter.
import math
AU = 1.495978707e11
pi = 3.1415926535897932384626433832795
dr = pi/180.0
GM = 1.26686534e17
toi = 2457627.9966
# Update Juno's orbital elements relative to Jupiter Body Center (500@599)
# from JPL Horizons (http://ssd.jpl.nasa.gov/horizons.cgi)
# sma = semimajor axis, AU
sma = 0.02740009798134841
# ecc = eccentricity
ecc = 0.9816687162279770
# tpp = time of perjove passage, Julian date
tpp = 2457628.036427238025
sma = sma*AU
# The results will be vectors in the orbit's canonical coordinate system.
# There will be no conversion to ecliptic coordinates.
P = (pi/43200)*math.sqrt(sma**3/GM)
m0 = (toi-tpp)/P
m = 2*pi*(m0-int(m0))
u = m + (ecc-ecc**3/8+ecc**5/192)*math.sin(m)
u = u + (ecc*ecc/2-ecc**4/6)*math.sin(2*m)
u = u + (3*ecc**3/8-27*ecc**5/128)*math.sin(3*m)
u = u + (ecc**4/3)*math.sin(4*m)
U = 999.9
# Replace the four underscores with four spaces, where necessary.
while abs(u-U)>1.0e-14:
____U = u
____F0 = U-ecc*math.sin(U)-m
____F1 = 1-ecc*math.cos(U)
____F2 = ecc*math.sin(U)
____F3 = ecc*math.cos(U)
____D1 = -F0/F1
____D2 = -F0/(F1+D1*F2/2)
____D3 = -F0/(F1+D1*F2/2+D2*D2*F3/6)
____u = U+D3
if u<0:
____u = u+2*pi
x = sma*(math.cos(u)-ecc)
y = sma*math.sin(u)*math.sqrt(1-ecc*ecc)
r = math.sqrt(x*x+y*y)
q = math.atan(y/x)
if x<0:
____q=q+pi
if x>0 and y<0:
____q=q+2.0*pi
k = math.sqrt(GM/(sma*(1-ecc*ecc)))
Vx = -k*math.sin(q)
Vy = k*(ecc+math.cos(q))
V = math.sqrt(Vx*Vx+Vy*Vy)
print('toi {:15.7f}'.format(toi),'JD')
print('x {:15.3f}'.format(x),'meters')
print('y {:15.3f}'.format(y),'meters')
print('r {:15.3f}'.format(r),'meters')
print('Vx {:15.9f}'.format(Vx),'m/s')
print('Vy {:15.9f}'.format(Vy),'m/s')
print('V {:15.9f}'.format(V),'m/s')
print('T.A. {:15.11f}'.format(q/dr),'degrees')
print('E.A. {:15.11f}'.format(u/dr),'degrees')
print('P {:15.11f}'.format(P),'days')
keypress = input('Press return to exit program.')

 

[Jenab2]

I'll use the equations coded in the program to find the position of Juno in its orbit around Jupiter at noon on 5 September 2016.

First, let's convert the calendar date into a Julian date.

year = 2016
month = 9
day = 5
hour = 12.0

A = integer[(M−4)/12]
B = integer{[1461(Y+4800+A)]/4}
C = integer{[367(M−2−12A)]/12}
D = integer[(Y+4900+A)/100]
E = integer(3D/4)
t = B + C − E − 32075.5 + day + hour/24

A = 0
B = 2489544
C = 214
D = 69
E = 51
t = 2457637.0 (Julian date)

In the program this t would be the time-of-interest variable, toi. Next, we get updated orbital elements for Juno relative to Jupiter from JPL.

semimajor axis
a = 0.02727221357504968 AU = 4.07986508e+9 meters

eccentricity
e = 0.9815748160068685

time of perijove passage
T = 2457628.034514271654

The period of Juno's orbit around Jupiter (in days).

GM = 1.266694832e+17 m³ sec⁻²
P = (π/43200) √[a³/(GM)]
P = 53.2475 days

Mean anomaly of Juno at time of interest, t.

m' = (t−T)/P
m = 2π [m' − integer(m')]
m = 1.057924 radians

Initial approximation for the eccentric anomaly at time t.

u₀ = m
+ (e − e³/8 + e⁵/192) sin(m)
+ (e²/2 − e⁴/6) sin(2m)
+ (3e³/8 − 27e⁵/128) sin(3m)
+ (e⁴/3) sin(4m)

u₀ = 1.057924 + 0.756412 + 0.279640 − 0.005226 − 0.274370
u₀ = 1.814380 radians

i = 0

Repeat...

i = i+1
F₀ = uᵢ−e sin(uᵢ)−m
F₁ = 1−e cos(uᵢ)
F₂ = e sin(uᵢ)
F₃ = e cos(uᵢ)
D₁ = −F₀ / F₁
D₂ = −F₀ / (F₁ + ½ D₁F₂)
D₃ = −F₀ / (F₁ + ½ D₁F₂ + ⅙ D₂²F₃)
uᵢ₊₁ = uᵢ+D₃

...Until |uᵢ₊₁−uᵢ| < 1e-12

Eccentric anomaly at time t.

u = uᵢ₊₁
u = 1.964430 radians

Canonical position vector from Jupiter's center at time t.

x = a [cos(u)−e]
y = a sin(u) √(1−e²)

x = −5.569513e+9 meters
y = +7.199526e+8 meters

Distance from Jupiter at time t.

r = √(x²+y²)
r = 5.615853e+9 meters

True anomaly at time t.

θ = arctan( y , x )
θ = 3.013039 radians

Canonical velocity vector from Jupiter's center at time t.

Vx = −√{GM/[a(1−e²)]} sin θ
Vy = +√{GM/[a(1−e²)]} (e+cos θ)

Vx = −3738.4 m/s
Vy = −296.7 m/s

Speed relative to Jupiter's center at time t.

V = √(Vx²+Vy²)
V = 3750.2 m/s

 

[Jenab2]

I just noticed that I have the i=i+1 in the wrong place. I should have paid more attention when I replaced the while loop with the repeat-until loop.

 

[Dotini]

This infrared image from Juno provides an unprecedented view of Jupiter's southern aurora. Such views are not possible from Earth.
Credits: NASA/JPL-Caltech/SwRI/MSSS
http://www.jpl.nasa.gov/spaceimages/details.php?id=PIA21033

'"While we knew that the flyby of Jupiter's south pole might reveal the planet's southern aurora, we were still amazed to see it for the first time," says Alberto Adriani from the Istituto di Astrofisica e Planetologia Spaziali in Rome. Adriani is a co-investigator on the Jovian Infrared Auroral Mapper (JIRAM), the instrument that took the picture.

Unlike Earth, which lights up in response to solar activity, Jupiter makes its own auroras. The power source is the giant planet's own rotation. Although Jupiter is ten times wider than Earth, it manages to spin around 2.5 times as fast as our little planet. As any freshman engineering student knows, if you spin a magnet you've got an electric generator. And Jupiter is a very big magnet. Induced electric fields accelerate particles toward Jupiter's poles where the aurora action takes place. Remarkably, many of the particles that rain down on Jupiter's poles appear to be ejecta from volcanoes on Io. How this complicated system actually works is a puzzle.'
- from today's edition of spaceweather.com

 

[rollete]

Yumy. Was hoping to see closer pics of the surface, though. Maybe it didn't orbit around the sun-lit side.

 

[1oldman2]

Yumy. Was hoping to see closer pics of the surface, though. Maybe it didn't orbit around the sun-lit side.

I'm still hoping for a little more from this pass, although it was basically a calibration/test run I'm sure they have a lot of unreleased data. I'm also curious about what the other science instruments have sent back.

 

[1oldman2]

Minor set back to contingency mode, hoping all ends up well.

http://spaceflight101.com/juno-prm-postponed/
Instead of spiraling down into a two-week science orbit around Jupiter, NASA’s Juno spacecraft will have to remain in a highly elliptical orbit for at least one more lap around the gaseous world due to a suspect signature seen in the preparatory steps for the critical main engine burn originally planned for next week.

After operating all its instruments for the ‘perijove’ passage, Juno was outbound again, set for a routine Orbital Trim Maneuver ahead of passing the high point of its orbit on September 23 and starting the inbound leg to what was known as ‘Period Reduction Maneuver’ - a rocket-powered braking maneuver to bring down the apojove distance and place the spacecraft into its two-week science orbit.

The engine firing was planned to begin around 18 UTC on October 19, eleven minutes before Juno passed only 4,180 Kilometers above Jupiter’s cloud tops. This maneuver is the final scheduled use of Juno’s LEROS-1B main engine that was responsible for a pair of Deep Space Maneuvers in 2012 and the Jupiter Orbit Insertion maneuver on July 4.

"Telemetry indicates that two helium check valves that play an important role in the firing of the spacecraft ’s main engine did not operate as expected during a command sequence that was initiated yesterday," said Rick Nybakken, Juno project manager at NASA JPL. "The valves should have opened in a few seconds, but it took several minutes. We need to better understand this issue before moving forward with a burn of the main engine."

With a third Capture Orbit added to the mission, Juno is now looking forward to its second close pass by Jupiter that can be utilized for science data collection. Due to the mission’s orbital design, the close perijove passes of the Capture Orbits and the planned Science Orbit are very similar in terms of altitude and flight path - taking Juno from north to south with closest approach near the equator, offering excellent views of Jupiter’s polar regions.

The first close pass of Juno already revealed tantalizing new views of Jupiter provided by the spacecraft ’s sole camera instrument, JunoCam. Data captured by the other instruments was by no means less spectacular, but scientists needed time to fully dive in and analyze the first close-up data peering below Jupiter’s dense cloud tops.

Passing Jupiter on Wednesday, Juno will be outbound again with its next close pass of the planet on December 11 which will be the next opportunity for the Period Reduction Maneuver - pending evaluations of the suspect check valve signature.

The option of a third Capture Orbit has be prepared as part of numerous contingency scenarios worked out for this mission, however, there is some urgency in getting Juno down into the science orbit due to the limited lifetime of the spacecraft in the extreme radiation environment of Jupiter.

Juno was set for a total of 36 orbits around Jupiter with its science phase lasting until February 6, 2018. Pending reviews of the spacecraft ’s performance in the harsh radiation environment, a short mission extension will be assessed when the time comes.

Here is what JPL says.
http://www.nasa.gov/feature/jpl/mission-prepares-for-next-jupiter-pass
JUNO MISSION STATUS

Mission managers for NASA’s Juno mission to Jupiter have decided to postpone the upcoming burn of its main rocket motor originally scheduled for Oct. 19. This burn, called the period reduction maneuver (PRM), was to reduce Juno’s orbital period around Jupiter from 53.4 to 14 days. The decision was made in order to further study the performance of a set of valves that are part of the spacecraft ’s fuel pressurization system. The period reduction maneuver was the final scheduled burn of Juno’s main engine.

"Telemetry indicates that two helium check valves that play an important role in the firing of the spacecraft ’s main engine did not operate as expected during a command sequence that was initiated yesterday," said Rick Nybakken, Juno project manager at NASA's Jet Propulsion Laboratory in Pasadena, California. "The valves should have opened in a few seconds, but it took several minutes. We need to better understand this issue before moving forward with a burn of the main engine."

After consulting with Lockheed Martin Space Systems of Denver and NASA Headquarters, Washington, the project decided to delay the PRM maneuver at least one orbit. The most efficient time to perform such a burn is when the spacecraft is at the part of its orbit which is closest to the planet. The next opportunity for the burn would be during its close flyby of Jupiter on Dec. 11.

Mission designers had originally planned to limit the number of science instruments on during Juno’s Oct. 19 close flyby of Jupiter. Now, with the period reduction maneuver postponed, all of the spacecraft ’s science instruments will be gathering data during the upcoming flyby.

"It is important to note that the orbital period does not affect the quality of the science that takes place during one of Juno’s close flybys of Jupiter," said Scott Bolton, principal investigator of Juno from the Southwest Research Institute in San Antonio. "The mission is very flexible that way. The data we collected during our first flyby on August 27th was a revelation, and I fully anticipate a similar result from Juno’s October 19th flyby."

 

[1oldman2]

I'm looking forward to Wednesday,
From, http://www.nasa.gov/press-release/n...jupiter-mission-status-latest-science-results

Team members of NASA’s Juno mission to Jupiter will discuss the latest science results, an amateur imaging processing campaign, and the recent decision to postpone a scheduled burn of its main engine, during a media briefing at 4 p.m. EDT Wednesday, Oct. 19. The briefing will air live on NASA Television and stream on the agency’s website.

Emily at planetary.com had an interesting take on things
http://www.planetary.org/blogs/emily-lakdawalla/2016/10161412-juno-to-delay-planned-burn.html

While it's true that the mission does have the flexibility to delay this orbit burn without affecting the quality of the science at periapsis or reducing the number of orbits Juno can eventually make, I am sure that the science teams are scrambling this weekend. They didn't have a plan in place to do science on this orbit periapsis; now they will have to put something together very fast (I imagine it will have many similarities to what they did on perijove 2). And delaying the period reduction maneuver also means a delay in the start of the science mission, and the calendar of future events will be changing a lot. Ground-based observers who planned to observe Jupiter at times corresponding to Juno periapses will have to try to change dates. Among the less important consequences of the calendar change is that all the moon science opportunities that Candy Hansen wrote about in her earlier guest post will now not happen, because any close approaches between Juno and the moons will be on different, as-yet-undetermined dates and different distances. It will take some time to determine when the observation opportunities are with the new orbit, and to plan those observations.

But it's always better to have a safe and healthy spacecraft whose science you need to replan, than to have an out-of-control spacecraft . I know that Juno is in good hands, and hope the engineering team will be able to get to the bottom of the check valve problem quickly. Best of luck to the Juno team!

 

[1oldman2]

Today's Juno news...
http://www.nasa.gov/feature/jpl/juno- spacecraft -in-safe-mode-for-latest-jupiter-flyby

NASA’s Juno spacecraft entered safe mode Tuesday, Oct. 18 at about 10:47 p.m. PDT (Oct. 19 at 1:47 a.m. EDT). Early indications are a software performance monitor induced a reboot of the spacecraft ’s onboard computer. The spacecraft acted as expected during the transition into safe mode, restarted successfully and is healthy. High-rate data has been restored, and the spacecraft is conducting flight software diagnostics. All instruments are off, and the planned science data collection for today’s close flyby of Jupiter (perijove 2), did not occur.

"At the time safe mode was entered, the spacecraft was more than 13 hours from its closest approach to Jupiter," said Rick Nybakken, Juno project manager from NASA’s Jet Propulsion Laboratory in Pasadena, Calif. "We were still quite a ways from the planet’s more intense radiation belts and magnetic fields. The spacecraft is healthy and we are working our standard recovery procedure."

The spacecraft is designed to enter safe mode if its onboard computer perceives conditions are not as expected. In this case, the safe mode turned off instruments and a few non-critical spacecraft components, and it confirmed the spacecraft was pointed toward the sun to ensure the solar arrays received power.

Mission managers are continuing to study an unrelated issue with the performance of a pair of valves that are part of the spacecraft ’s propulsion system. Last week the decision was made to postpone a burn of the spacecraft ’s main engine that would have reduced Juno’s orbital period from 53.4 to 14 days.

The next close flyby is scheduled on Dec. 11, with all science instruments on.

The Juno science team continues to analyze returns from the first close flyby on Aug. 27. Revelations from that flyby include that Jupiter’s magnetic fields and aurora are bigger and more powerful than originally thought. Juno’s Microwave Radiometer instrument (MWR) also provided data that give mission scientists their first glimpse below the planet’s swirling cloud deck. The radiometer instrument can peer about 215 to 250 miles (350 to 400 kilometers) below Jupiter’s clouds.

"With the MWR data, it is as if we took an onion and began to peel the layers off to see the structure and processes going on below," said Bolton. "We are seeing that those beautiful belts and bands of orange and white we see at Jupiter’s cloud tops extend in some version as far down as our instruments can see, but seem to change with each layer."

The JunoCam public outreach camera also was operating during the Aug. 27 flyby. The raw images from that flyby (and all future flybys) were made available on the JunoCam website (www.missionjuno.swri.edu/junocam) for the public to not only peruse but to process into final image products. JunoCam is the first outreach camera to venture beyond the asteroid belt.

"JunoCam has a small operations team and no image processing team, so we took a leap of faith that the public would step up and help us generate images of Jupiter from the raw data," said Candy Hansen, JunoCam imaging scientist from the Planetary Science Institute in Tucson, Arizona. "All sorts of people are coming to the JunoCam site and providing their own aesthetic. We have volunteers from all over the world, and they are doing beautiful work. So far all our expectations for JunoCam have not only been met but are being exceeded, and we’re just getting started."

The final image products include straightforward images of the solar system’s largest world, but also some with a certain artistic license, including a variation on Vincent Van Gogh’s Starry Night painting and even a "smiley face" made from an image of Jupiter’s south pole. These amateur-generated JunoCam images are not only being used to help interest the media and public in this mission to the most massive planet in the solar system, but are engaging Juno’s science team as well.

"The amateurs are giving us a different perspective on how to process images," said Hansen. "They are experimenting with different color enhancements, different highlights or annotations than we would normally expect. They are identifying storms tracked from Earth to connect our images to the historical record. This is citizen science at its best."

 

[1oldman2]

While we are waiting for the bugs to get worked out of Juno, here are some of the Junocam images.

 

[DennisN]

Beautiful photos, @1oldman2!