Community Missions (Early Access)

A Community Mission pools imaging time from many ARIS rigs onto one target. Everyone shoots the same object on their own nights, each rig sends its good frames, and the frames are stacked into one master, deeper than one rig can build in a season. The master then goes back to the people whose frames went into it.

How it works

You join a mission and choose which of your rigs take part.
You shoot the mission’s target on your normal nights, in any sequence and any project.
After a run ends, and once a day in daylight, each joined rig finds that target’s frames, vets them, and sends copies of the good ones. Each copy keeps only a short list of header cards.
ARIS checks every frame again. Each accepted frame is credited to the name you joined under.
After the mission closes, ARIS stacks the accepted frames, a person at ARIS reviews the result and finishes the image, and the master is shared with everyone who fed it.

Joining is free on every ARIS plan.

Where to find missions

Settings → Sky Data & Missions → Community Missions opens the Missions list. Running lists the missions you can join. Closed lists the closed missions you are in, and those you left after their master was shared with you.
On the Plan screen, the Missions pill in the BEST TONIGHT strip shows each running mission as a card, with Join and the badge of the rig Plan is showing.
A target in one of your Target Lists gets a Mission running chip, and a target you saved with the heart gets a Mission chip, when a mission is running on it and at least one of your rigs can feed that mission.

Tap a mission to open its page.

Joining a mission

Tap Join on a mission’s card or its page. The join sheet has three parts:

Rigs: each of your rigs, with the role its frames would play in this mission. Rigs that fit start ticked. Only ticked rigs send frames; a rig you leave unticked sends nothing.
Credited as: the name your accepted frames are credited under. It starts as your account’s name. If your account has no name, type one. Under the field: “Shown in the credits. Never your location or rig names.”
Terms: the contributor terms, with a Full terms link.

The button names how many rigs join: Join with 1 rig, Join with 2 rigs. Pressing it is your agreement to the terms, and your join records which version of the terms you agreed to.

After your first join, ARIS adds the mission’s target to your draft on the Sequencing screen.

Your rigs send frames from the night you joined onward, and only from nights inside the mission’s window. Frames from earlier nights stay on the rig. A night runs from noon to noon, so if you join the morning after a night, that night still counts.

To change which rigs take part, open the mission’s page and choose ⋮ → Choose rigs…. A rig you add later sends frames from your original join night onward.

What a rig needs

An identity ARIS knows. A rig without one reads “ARIS doesn’t know this rig’s identity yet. Reconnect it from the array to join.” and cannot be ticked. The in-app simulator is never offered.
To be paired to your account, to send. The rig proves who it is with the secret it got when you paired it, and the cloud takes its frames only when the rig belongs to the account that joined. An unpaired rig’s row on the mission page reads “Not claimed · claim it to send”, with Claim the rig ›. See Pair for Remote Access.
To be connected, for its fit to be checked. A rig that is not connected shows Offline and “ARIS checks its fit when it connects.”

The role each rig would play

Each mission has a reference: a pixel scale, and a mission frame, which is the area of sky every contributor shares. Your rig grades itself against it and the sheet shows the answer as a badge:

Badge	What it means
Detail	The rig’s pixel scale is at most 2× the mission’s. Its frames can carry fine structure. A rig with a finer pixel scale than the mission’s is always Detail.
Color & depth	The rig’s pixel scale is more than 2× and at most 4× the mission’s. The row reads “Your wider field feeds color and depth”.
Not a fit	The rig’s pixel scale is more than 4× the mission’s, or its field covers too little of the mission frame (less than 80%, unless the mission sets another share).
Profile incomplete	The rig does not know its own optics yet. The row reads “Set the focal length and pixel size to check the fit.”, with Set up ›.

These ratios are the defaults; a mission can set its own.

A rig knows its optics from its last real plate solve: every Center & Solve records the solved pixel scale, field and angle. Without one, it uses the focal length, pixel size and resolution in its equipment profile. For the framing check, the rig’s field and the mission frame are both centered on the mission’s center. A rig with a rotator is graded at the mission frame’s angle. A rig without one is graded at its own measured angle, or at the mission frame’s angle when it does not know its own.

A rig graded Not a fit or Profile incomplete cannot be ticked. Its row says why, for example “Too coarse: 4.40″/px is 4.2× this mission’s 1.05″/px.” or “Its 0.7° × 0.5° field takes in 18% of the mission frame.” If the rig fits another running mission, the row links to it, for example “M31 Broadband fits it ›”.

A Detail rig’s row also lists the mission’s filter lanes its frames would land in, and its scale, for example “Dualband · 1.05″/px”.

If a rig cannot answer, its row reads “Its fit couldn’t be checked.” or, for older software, “Its software is too old to check the fit.”, with Update the rig ›. Such a rig, like an offline one, starts unticked; you can still tick it.

A mission without a reference

A mission can run before its reference is set. The sheet then says “This mission has no reference frame yet, so ARIS can’t check each rig’s fit. Every rig can join.” Every connected rig ARIS knows starts ticked. Until the reference is set, frames get no role, and the cloud check holds each frame to the mission’s detail budget alone.

Lanes and roles

A mission collects frames in lanes (its filters) and gives each accepted frame a role (Detail, or Color & depth). Lanes are about the light; roles are about the optics and the sharpness.

Lanes

Each lane is stacked into its own master, so a lane holds one kind of light.

Mono frames take their lane from the filter name in the file. The name must be one of these, in any case: L, Lum, Luminance, R, Red, G, Green, B, Blue, Ha, Halpha, H-alpha, H_alpha, OIII, O-III, O3, SII, S-II, S2 (or O III, S II and H a, with a space). Any other name, such as “Ha 7nm”, has no lane, and a mono frame with no filter name has none either. Those frames are not sent.
Color frames take their lane from the lines their filter passes. The rig reads them from the filter slot’s Passes setting (in the filter’s edit dialog on the Filter Wheel screen), or knows them from the filter’s name for an L-eXtreme, L-Ultimate, L-eNhance, L-Synergy or L-Pro:
- Dualband for a filter that passes Ha and OIII and no other line but Hβ, such as an L-eXtreme or L-eNhance;
- OSC for a filter that passes no emission line: no filter, a broadband filter, or a light-pollution filter such as an L-Pro;
- no lane for other narrowband light, such as an L-Synergy (OIII and SII) or a single-line filter. Those frames are not sent.
When neither says what a filter passes, or the rig has no filter wheel, the filter’s name decides: a name such as Dual, Duo, L-eNhance or L-eXtreme goes to Dualband, any other name to OSC. If ARIS does not know your filter, set its Passes. A color frame with no filter name goes to OSC.
A frame whose lane the mission does not collect is not sent.

While a rig’s filter wheel has not answered since its software started, the rig holds color frames back rather than guess their lane, and sends them once the wheel answers. The rig’s row on the mission page then says how many are waiting (“40 waiting for the filter wheel”), when the rig tries again, and offers Connect the filter wheel ›.

Roles

The badge you see before joining is your rig’s grade. The cloud check then gives each accepted frame two roles of its own, from that frame’s own plate solve:

its native role: Detail or Color & depth, from the frame’s own pixel scale and field, by the same rule as the badge;
the role it is used for: its native role while its stars are within the mission’s detail budget. A Detail frame whose stars are softer than the budget but within the mission’s color ceiling is used for color & depth. A frame softer than the ceiling is rejected. A Color & depth frame is never used for detail.

The budget and the ceiling are limits on the stars’ half-flux radius (HFR) in arcseconds. The rig and the cloud measure it the same way; a color frame is measured on its 2×2 superpixel.

My contributions counts the frames moved to color & depth: “6 used for color & depth (softer than the detail budget)”. When the mission is stacked, each lane gets one master per role.

What your rig sends

When it sends

A joined rig looks for frames to send:

after every run ends, whatever ended it, so a clouded-out or stopped night still sends what it got;
on a NINA rig, after each NINA run ends (see NINA rigs);
once a day in daylight at the rig’s site (the Sun above −6°; between 10:00 and 16:00 by the rig’s clock when the rig has no site);
a few minutes after the rig’s software starts.

It never gets in the way of capture. It waits while a sequence runs or is paused, while anything holds the camera, while the capture loop or a deep stack runs, and on a NINA rig while NINA images. It stops between two frames as soon as any of these starts, and carries on once the rig is idle. The rig’s row on the mission page then reads “Waiting until the camera is free”.

Which frames

Light frames of the mission’s target, found by where each frame points: its RA and Dec must fall within a circle around the mission’s center, as wide as the mission frame’s diagonal (1° across for a mission with no reference). The project does not matter. A frame with no position counts when its target folder, file name or OBJECT names the mission’s target: M31_LRGB matches M31, never M3.
From the night you joined onward, inside the mission’s window.
In a lane the mission collects (see Lanes).

The rig’s checks

The rig measures each frame once and keeps the measurement. If live stacking already refused the frame for too few stars, for stars much softer than its earlier frames, or because it could not read the file, the rig takes that verdict instead. At each sweep the rig judges every frame again against the mission’s current limits, so a frame it held back can still go later if a limit changes.

A frame stays on the rig when:

the target was lower than the mission’s minimum altitude at mid-exposure;
the Moon was above the horizon and either more fully lit than the mission allows or closer to the target than the mission allows;
it has fewer usable stars than the mission asks (15 unless the mission sets another number, and never fewer than 3);
its stars are softer than the mission’s color ceiling, or than its detail budget when the mission has no ceiling;
its stars are more than 1.5× softer than the median of that night’s other passing frames in the same lane, once at least 3 frames pass;
the file cannot be read.

For the altitude and Moon checks the rig uses the frame’s own site, or else the rig’s site. The site never leaves the rig. If the rig cannot tell a frame’s pixel scale, it skips the softness check, and the cloud applies it after its own plate solve.

Frames the rig holds back are never sent, so they do not appear in My contributions. The rig’s row reads “Nothing to send” when it found frames but none passed.

The copy it sends

The rig sends a copy of each frame. Your original file stays where it is, unchanged.
The copy is compressed without loss and keeps only the header cards listed under What leaves your rig.
A copy may be at most 128 MiB (134 MB). A larger one is never sent, and the row reads, for example, “6 couldn’t be sent · too large”.
A rig sends at most 400 frames and 20 GB a day (by the UTC day). The rest wait for a later sweep, and the row reads “Stopped · the daily limit is reached”.
A failed upload is tried again at the next sweep, and the row reads “Failed · will retry at 7:40”.
A frame counts once per mission: the cloud refuses a second frame with the same pixels.

The rig’s row on the mission page also reads, for example, “Sending 12 of 40”, “Sent 40 last night”, “Nothing to send · no M31 frames last night”, or, before the rig has picked up a new join, “Joined · the rig picks it up at its next check”.

What leaves your rig

Before a frame leaves your rig, its header is cut down to an allow list. Every card that is not on the list is removed, whoever wrote it: the camera driver, NINA, or ARIS itself.

The cards that are kept:

Group	Cards
File structure	`SIMPLE`, `XTENSION`, `PCOUNT`, `GCOUNT`, `BITPIX`, `NAXIS`, `NAXIS1`, `NAXIS2`, `NAXIS3`, `EXTEND`, `BZERO`, `BSCALE`, `BUNIT`
When, in UTC only	`DATE-OBS`, `DATE-AVG`, `MJD-OBS`, `MJD-AVG`
Exposure and sensor	`EXPTIME`, `EXPOSURE`, `GAIN`, `OFFSET`, `EGAIN`, `READOUTM`, `XBINNING`, `YBINNING`, `XPIXSZ`, `YPIXSZ`, `PIXSIZE1`, `PIXSIZE2`, `CCD-TEMP`, `SET-TEMP`, `INSTRUME`
Color sensor layout	`BAYERPAT`, `XBAYROFF`, `YBAYROFF`, `ROWORDER`
Optics	`FOCALLEN`, `FOCRATIO`, `SCALE`, `PIXSCALE`
What the frame is	`IMAGETYP`, `FRAME`, `FILTER`
Where in the sky it points	`RA`, `DEC`, `OBJCTRA`, `OBJCTDEC`, `EQUINOX`, `EPOCH`, `RADESYS`
Plate solution	`WCSAXES`, `LONPOLE`, `LATPOLE`, `PLTSOLVD`, and every card whose name starts with `CRVAL`, `CRPIX`, `CDELT`, `CTYPE`, `CUNIT`, `CROTA`, `CD1_`, `CD2_`, `PC1_`, `PC2_`, `PV1_`, `PV2_`, `A_`, `B_`, `AP_` or `BP_`
Guiding quality	`GUIDRMS`, `GUIDRMSR`, `GUIDRMSD`, `GUIDPEAK`, `GUIDNSMP`

ARIS then adds one card, OBJECT, set to the mission’s target name. Your own OBJECT text is not kept. The compressed file also carries the cards that describe its compression, which say nothing about you.

Everything else is removed. On the frames ARIS writes, that includes:

the site’s latitude, longitude and elevation (SITELAT, SITELONG, SITEELEV);
the target’s altitude and azimuth (CENTALT, CENTAZ) and the airmass (AIRMASS), since with the time and the pointing they would give the site back;
the local time (DATE-LOC), which gives away your time zone;
the telescope name (TELESCOP), your project name (PROJECT) and the sequence ids (SEQID, SAVEDSEQ);
the focuser position and temperature (FOCPOS, FOCTEMP), the rotator angle (ROTATANG), the ambient temperature (AMBTEMP) and the software name (SWCREATE);
every COMMENT and HISTORY card.

Beside each file, the rig sends a short record that only you can read in the ledger: the frame’s id (made from the night’s date, part of the rig’s id and a hash of the pixels), its lane, its exposure time, the night’s date, the pixel hash, its star count and star size, the center and scale of its plate solve when it has one, and a tag saying the rig passed it.

The cloud checks the list again. The cloud check cuts its own copy down to the same list, sets OBJECT again, and never publishes a copy that carries any other card.

The master’s header is built from nothing. A published master carries only its structure, the plate solution of the shared grid, and OBJECT (the target), FILTER (the lane), ARISROLE (the role), STACKCNT (frames stacked), TOTEXP (total exposure), NCONTRIB (contributors) and LICENSE. It carries no camera, gain, date or site card from any contributor. The finished JPEG has its EXIF (with any GPS block), XMP, ICC profile, IPTC, comments and thumbnail removed, without changing a pixel.

The cloud check never learns where you are. It tests a frame’s time only against what is possible somewhere on Earth.

The cloud check

Every frame you send is checked again in the cloud before it counts. In this order, a frame is rejected when:

The check	Words in My contributions
The image the file declares is too big (over 120 megapixels, or over 480 MB uncompressed)	the file was too large
The file cannot be read	the file could not be read
Its pixels are not the ones the rig sent	the file changed after it was sent
Its capture time is missing, later than its arrival, or at a time when no place on Earth had the target above 20° with the Sun below −12°	the capture time does not add up
No night it could belong to falls inside the mission’s window	taken outside the mission window
More than 0.5% of its pixels are at or above 90% of full scale	saturated
It says it is a flat, or it is lit like one and has too few stars	looks like a flat, not the sky
It has fewer usable stars than the mission asks	too few stars
It does not plate solve near the mission’s center	could not be plate solved
The mission’s center is not inside its solved field	not on the target
Its own solved pixel scale or field does not fit the mission	pixel scale too coarse for this mission, or field takes in too little of the mission frame
Its stars are softer than the mission allows (see Roles)	stars too soft for this mission

A frame the check fails to finish five times is rejected as “could not be checked”.

When a frame is rejected, ARIS deletes its stored copy, and its row in My contributions keeps the reason. When a frame is accepted, ARIS keeps its cleaned copy for the stack and credits you.

Ledger and credit

Each accepted frame credits its exposure time to you. A mission’s page shows:

Accepted: each lane’s accepted hours against its goal, and the number of contributors. It counts accepted hours only.
Credits: each contributor’s credited name and accepted hours, and nothing else (“names and accepted hours only”). Anyone using the ARIS app can read these names and hours.
Your rigs: each of your rigs with its badge, and, for a joined rig, what it sent and is sending.
My contributions, once you have joined: one row per night and rig, with Sent, Accepted and Credited. “Pending check” means the frames are waiting for the cloud check. Under a row: how many still wait for the check, how many were used for color & depth, and how many were rejected, with the reasons. Only you can see your rows.

Your credited name is the one you gave when you joined. ARIS can hide a credited name; it then reads “Hidden”. A member with no name reads “Anonymous”.

When a mission closes

A mission’s window ends on its last night. Two days later the mission closes: rigs stop sending, and the cloud check finishes the frames already sent. On the Missions list, a closed mission’s card shows its progress as Collect · Stack · Finish · Ready.

Stack. ARIS stacks the accepted frames into one 32-bit linear master per lane and role, all on one shared grid. A lane and role with fewer than 3 frames gets no master.
Finish. A person at ARIS reviews the masters, can leave out frames that would spoil them, and finishes the color image by hand. The card reads “Being finished by hand · a push tells you when it is ready”. Frames left out of a master still count toward your credit.
Ready. The master is shared: the lane masters (FITS), the finished image (a JPEG, with a FITS copy), and credits.txt, which lists every contributor by credited name and accepted hours under the CC BY 4.0 license.

The master is shared with every member who is still in the mission and had at least one frame accepted. A push, “Mission master ready”, tells you once, however many of your rigs fed it. If none of your frames were accepted, the mission’s card says “None of your frames were accepted, so it isn’t shared with you.” A mission that ends with no accepted frames makes no master.

Getting the master

In the app. On the mission’s page, the Ready step shows the finished image (tap it for full screen) and two downloads: Finished image · JPEG and Lane masters · N FITS.

The finished image goes to Photos on an iPhone, iPad or Android device, to the place you choose on a computer, and to your downloads in a browser.
The lane masters go to the app’s folder in the Files app on an iPhone or iPad (On My iPhone → ARIS, or On My iPad → ARIS), to a folder you pick on Android or a computer, and to your downloads in a browser. On a phone or tablet the app asks before it downloads them, and names their size.

On your rigs. Each of your rigs that fed the mission saves the master into its own Files, in a Missions project, at its next sweep. Under On your rigs, the mission’s page shows where each rig saved it.

A rig saves only while at least twice its free-space floor stays free afterwards (see Disk protection). Otherwise it waits and tries again at every sweep, and it deletes nothing to make room. The app download still works meanwhile.
A rig never writes over an existing file. A later version of the master is saved beside the first.
If you delete the files from Files, the rig does not bring them back by itself. The mission’s page offers Save it again ›.
A rig of yours whose frames were all rejected gets no copy (“Not sent to this rig”).

Leaving a mission

To leave, open the mission’s page and choose ⋮ → Leave mission, or tap Leave on its card. ARIS asks first, and says what leaving does at that point:

When you leave	What the dialog says
While the mission is running	”Your rigs stop sending, and the raw subs you sent are withdrawn.”
After it closes, before the master is shared	”The raw subs you sent are withdrawn, and the master is stacked again without them. You won’t get the master, and your name leaves the credits.”
After the master is shared with you	”Your raw subs are deleted from ARIS’s storage, and a later version of the master won’t use them. You keep the master, and your name stays in its credits.”
After a master that is not shared with you	”Your raw subs are deleted from ARIS’s storage.”

Withdrawing marks every frame you sent to that mission as withdrawn, takes its time off the leaderboards and the lane hours, and deletes the copies ARIS stored, both those waiting for the check and the accepted ones. A master cannot be shared with a withdrawn frame in it. A frame that was still uploading when you left can arrive afterwards; it is never added to the ledger or to a stack.

If you join the same mission again later, you start fresh: frames from nights before the new join do not count, and the frames you sent before stay withdrawn.

Deleting your ARIS account withdraws you from every mission in the same way. On a master that was already shared, your credit stays in the app’s credits as “Anonymous”. The credits.txt file published with that master keeps the name it was published with.

NINA rigs

The NINA plug-in itself does nothing for missions. On a NINA rig, the work is done by the ARIS backend that the plug-in starts beside NINA (see NINA): it sends frames after each NINA run ends and once a day in daylight, and it saves masters into the rig’s Files, as on any other rig. Without that backend, a NINA rig sends nothing.

The plug-in does not yet pass the app’s mission questions on to that backend, so the app cannot ask a NINA rig for its fit or for what it sent. On a NINA rig:

the join sheet reads “Its software is too old to check the fit.”, with Update the rig ›. Updating does not change this yet. The rig starts unticked, and you can still tick it and join;
a joined rig’s row on the mission page reads “Update this rig to send”, whether or not it is sending;
once a master is shared, its row reads “Update this rig to save the master”.

My contributions still shows the NINA rig’s nights once its frames reach the cloud.

Contributor terms

The join sheet shows these terms right above the Join button. This is the same text the app shows, word for word:

You keep your subs. ARIS and this mission’s contributors may stack them. The finished image goes to everyone who fed it, under CC BY 4.0, with your name in the credits. Leave any time and your raw subs are withdrawn.

Pressing Join is your agreement. Contributor terms says what each part means in practice.