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Posted by: nprev Jul 22 2020, 06:29 PM

Word today that the MMRTG has been installed on the rover, so seems like a good time to start the launch thread. Launch currently scheduled for 30 Jul, 2-hr window opening at 1150 GMT.

GO PERSEVERANCE!!!

Posted by: Antdoghalo Jul 22 2020, 10:49 PM

I'll try and catch the launch but it will be a pain since it's at sunrise. Eclipse glasses should hopefully help with that for the 7:50 AM EST launch.
Here is the Google Earth placemark if anyone is interested. I like how there's an upside down "Mickey Mouse" crater to the northwest.
Let the UAE/China/US Mars races commence!!!

Posted by: nprev Jul 23 2020, 02:57 AM

Flight Readiness Review cleared https://www.jpl.nasa.gov/news/news.php?feature=7710&utm_source=iContact&utm_medium=email&utm_campaign=nasajpl&utm_content=daily-20200722-2&fbclid=IwAR1fkN2gHJ-WiOpiX8EjfVEuT0jMYcURVGKU9_62ORMMrmmmc90Sr46zmrA.

Posted by: scalbers Jul 23 2020, 11:42 PM

Glad they apparently fixed the oxygen sensor launch rocket issue I recall from a couple of weeks ago.

Posted by: nprev Jul 28 2020, 09:05 PM

She's on the pad.

T-0 now planned for 30 Jul/1150 GMT. Live coverage with text updates available at https://spaceflightnow.com/2020/07/28/atlas-5-av-088-mission-status-center/.

Posted by: Tom Tamlyn Jul 29 2020, 09:15 PM

Greetings, I'm soliciting suggestions for additional twitter accounts to follow for the Perseverance launch tomorrow.

My own twitter list for planetary science, which I haven't updated in years, is set out below.

Also, I have a question about good-luck peanuts. It's my understanding that these are generally considered mandatory for events like landings and orbital insertions following a cruise. I don't recall hearing so much about them for launches.

I've got some peanuts ready for tomorrow in any event, but then, I'm very fond of peanuts. I'd be curious to hear other views.

******** Twitter List for Planetary Science *******
Emily Lakdawalla @elakdawalla

Dr./Prof. Sarah Hörst @PlanetDr

Shannon Stirone @shannonmstirone

James Tuttle Keane @jtuttlekeane

Doug Ellison @doug_ellison

Dr Pamela L Gay @starstryder

Nadia Drake @nadiamdrake

Elizabeth Tasker @girlandkat

Alexandra Witze @alexwitze

Planetary Society @exploreplanets

Scott Maxwell@marsroverdriver

Kimberly Maxwell @marssciencegrad

Dr. Julie Rathbun @LokiVolcano

Morgan Cable @starsarecalling

Katie Stack Morgan @kstackmorgan

Dr. Sarah Milkovich @milkysa

Stephanie [Stephanie L. Schierholz] @schierholz


ADMIN: Topic merged into launch & cruise thread. Also, as I understand it, peanuts are only appropriate for landings in accordance with the start of the custom with Ranger 7.

[Edited to reformat list items as single lines]

Posted by: mcaplinger Jul 29 2020, 10:38 PM

Not clear, though I don't pretend to understand the specifics of the JPL usage. https://solarsystem.nasa.gov/news/10022/lucky-peanuts/

I'm pretty sure they can't actually hurt, though.

Posted by: Antdoghalo Jul 30 2020, 11:37 AM

12 minutes to launch. Small 4.3 earthquake rattled some of the Team in California. Luckily no ill effects from the terrestrial temblor and the countdown goes on. Luckily Mars doesn't appear to be as geologically active.

Posted by: nprev Jul 30 2020, 12:02 PM

In parking orbit. So far so good.

Posted by: Antdoghalo Jul 30 2020, 12:34 PM

That was a good launch. Good thing it was today or else terrestrial weather may have put off launch until 2022.

Posted by: Explorer1 Jul 30 2020, 12:43 PM

Engine cutoff! Spacecraft separation upcoming!

EDIT: SEP confirmed! Mars, here we come!

Posted by: Ron Hobbs Jul 30 2020, 12:49 PM

Go Perseverance!!

Posted by: Explorer1 Jul 30 2020, 01:17 PM

AOS! (Acquisition of Signal)
It's showing up on the DSN Now page too.

Posted by: Explorer1 Jul 30 2020, 03:34 PM

DSN stills shows signal (Carrier wave only): press conference starting now.

Posted by: Tom Tamlyn Jul 30 2020, 04:15 PM

From Shannon Stirone @shannonmstirone:

https://twitter.com/shannonmstirone/status/1288862886710743041

I assume that this is a problem with every launch, and that sometimes DSN solves it it a couple of minutes, other times it takes longer.

Posted by: Explorer1 Jul 30 2020, 04:21 PM

At the press conference, they said it seems to have been solved and they have good telemetry!
Presumably it is not worth the trouble to use another Earth-based array for such a brief period, in terms of complexity?

Posted by: Tom Tamlyn Jul 30 2020, 04:27 PM

Emily Lakdawalla has noted that she has not yet been able to get detailed information about Perseverance’s additional EDL cameras.

https://twitter.com/elakdawalla/status/1288650896495144960

Matt Wallace just said that the new EDL cameras are ruggedized versions of standard 1080p cameras, and that they will capture, among other things, images of the parachute filling and of the descent engines blasting. He also mentioned that JPL was goaded into increasing the number of EDL cameras from watching beautiful videos of boosters separating from launch vehicles.

Posted by: mcaplinger Jul 30 2020, 04:39 PM

There's a paper about them all for the upcoming M2020 Space Science Reviews issue. I've seen some stuff in the media about them: https://www.businessinsider.com.au/nasa-mars-perseverance-rover-seven-minutes-terror-landing-video-2020-7

Posted by: mcaplinger Jul 30 2020, 04:41 PM

At 39 bits/sec. DSN Now shows uplink from Canberra DSS-34, they are probably trying to get the rate up to some normal value.

I have no source of information better than anyone else's.

Posted by: Steve G Jul 30 2020, 05:07 PM

That's a big stress gone. Launches always terrify me. I'll never forget checking the papers to see how Mariner 8 fared, and the Montreal Gazette wrote: MARTIANS SAFE AS ROCKET GOES ASTRAY. That totally ruined my day!

Posted by: vjkane Jul 30 2020, 06:05 PM

Been wondering when that issue was going to come out. Those special issues for missions have been my go to place for instrument descriptions for, I think, decades now.

Posted by: mcaplinger Jul 30 2020, 09:47 PM

The MSL special issue didn't come out until a month or so after MSL landed, and I wouldn't expect anything faster with this one.

Posted by: Explorer1 Jul 30 2020, 11:39 PM

A thorough explanation of everything that happened: https://blogs.nasa.gov/mars2020/2020/07/30/mars-2020-perseverance-healthy-and-on-its-way/

Tl;dr: Conservative safe mode parameters and an excessively strong signal; all is well now. (DSN shows 10 kb/s download rate!)

Posted by: dlilb200 Jul 31 2020, 02:56 AM

Can anyone point me to a solar system simulator that shows the relative positions of Tianwen, Hope and Perserverance? I found Perserverance on NASA’s Eyes not the other two. Tried googling around but no luck. Would be much appreciated!

Posted by: pioneer Aug 9 2020, 02:48 AM

I'm not sure if this is the right thread to bring this up, but one question I have is what is the maximum weight that Perseverance can store in its sample return containers?

Posted by: nprev Aug 9 2020, 06:28 AM

Per https://mars.nasa.gov/mars2020/timeline/surface-operations/, each sample is max 15g & there are a max of 30 samples, so 450g...just shy of 1 pound in imperial units (454g).

As far as Eyes, been some time since I been on there. Likely that it just tracks US spacecraft. If I recall correctly setting up & maintaining the models is not a trivial effort, plus it relies on near-real time state data which is probably not readily available to NASA for most non-US planetary missions.

Posted by: vjkane Aug 9 2020, 01:37 PM

Per the Perseverance press kit, the rover carries 43 sample tubes, 5 of which are reserved as witness tubes.

I've read that the team designing the Mars assent vehicle (MAV) is finding it challenging to close a design that could return all the tubes. If memory serves me right (that's less and less reliable these days :<), the number returned might be as low as low 20s to 30ish. (Published presentations are vague on this as the MAV design matures.)

Posted by: mcaplinger Aug 9 2020, 03:47 PM

JPL Horizons had some early optically-derived elements for Tianwen-1 but I expect those will rapidly become inaccurate. Hope is being tracked by the DSN but I don't know who is doing their navigation [edit: KinetX is doing it] or if any information is being publicly shared. So any simulation would be fairly schematic.

[Oops, spoke too soon, Hope is on Horizons at EMM (spacecraft ID -62)]

Posted by: dlilb200 Aug 13 2020, 09:12 AM

Thanks very much - I did not know about Horizons - unfortunately I don’t know enough about orbital mechanics to use the data, but provides good motivation to learn!

Posted by: pioneer Aug 14 2020, 01:05 AM

An update from NASA's website:

https://www.nasa.gov/feature/jpl/nasas-ingenuity-mars-helicopter-recharges-its-batteries-in-flight

Does anyone know how Ingenuity will avoid having its landing legs land on a large rock and tilting it over? From what I understand, it doesn't have a hazard detection system. I'm guessing it will somehow know where it lifted off from and return there after the flight?

Posted by: pioneer Aug 14 2020, 01:08 AM

Thanks

Posted by: Explorer1 Aug 14 2020, 01:38 AM

Pages 16 and 17 of https://rotorcraft.arc.nasa.gov/Publications/files/Balaram_AIAA2018_0023.pdf give a good description of the plan:

Posted by: atomoid Aug 14 2020, 10:43 PM

With tip-prevention by careful reconnaissance to plan avoidance of such features in the flight plan seems effective enough given the other risks, in the https://www.nasa.gov/feature/jpl/nasas-ingenuity-mars-helicopter-recharges-its-batteries-in-flight it also states "If Ingenuity survives the cold Martian nights during its preflight checkout, the team will proceed with testing" a choice of words that didn't exactly fill me with confidence, but from the paper linked by Explorer1 shows in page 15-16 section 'H' seems the batteries should have more than adequate capacity to provide the 21Wh needed to keep above -15C at night, but does anyone know if the CO2 insulation was ever replaced by aerogel?

Posted by: pioneer Aug 14 2020, 11:14 PM

TCM-1 was supposed to be today, but I heard it was delayed according to https://www.reddit.com/r/PerseveranceRover/comments/i5miik/another_ula_bullseye_nasa_may_delay_the_1st_tcm/ due to the accuracy of the launch. I haven't heard anything official from JPL or NASA though.

Posted by: Marvin Aug 15 2020, 03:19 AM

TCM-1 was completed today:

https://twitter.com/NASAPersevere/status/1294450300095471616

Posted by: pioneer Nov 12 2020, 10:43 PM

Perseverance is now fewer than 100 days away from landing on Mars.

Posted by: Explorer1 Nov 19 2020, 12:23 AM

In addition to an EDL microphone recording of the heating system, one of the hazcams took some images during the cruise of some insulation and a cable:

https://www.jpl.nasa.gov/news/news.php?feature=7789

I am wondering about the lighting though: is that sunlight coming through the aeroshell, or something internal?

Posted by: antipode Nov 19 2020, 02:38 AM

I thought these cruise shots were illuminated by an LED, but I could be wrong.

P

Posted by: rlorenz Nov 24 2020, 05:21 PM

This may be of interest re: sound propagation in the Mars atmosphere
http://www-mars.lmd.jussieu.fr/granada2017/abstracts/lorenz_granada2017.pdf

Posted by: djellison Nov 24 2020, 07:20 PM

There's no LED illumination out the back of the rover. That illumination is coming through gaps in the backshell

Posted by: vjkane Nov 25 2020, 12:50 AM

Obviously this isn't true, but I would have thought that gaps would allow super heated gasses to enter the backshell during entry.

Posted by: rlorenz Nov 25 2020, 04:04 AM

It's perhaps surprising, but there is a vent hole in the backshell - you have to let the air escape during launch to avoid a pressure differential that could cause structural failure. The same hole (the ~30cm dark circle you can see on backshell images, but there is some sort of wire mesh/filter, so the effective area is only 600cm2 or so) allows the aeroshell to repressurize during entry/descent, but this is slower. Attention is paid to avoid sensitive items being exposed to that repressurization flow, but it is relatively slow (effectively it just sips at the wake, it isnt exposed to the dynamic pressure on the heat shield).

I managed to put together some info on this sort of venting in a recent paper (email me if you can't access)
https://arc.aiaa.org/doi/abs/10.2514/1.A34861

Posted by: mcaplinger Dec 11 2020, 07:54 PM

New interactive Jezero geologic map at https://planetarymapping.wr.usgs.gov/interactive/sim3464

Posted by: Phil Stooke Dec 11 2020, 10:03 PM

Following on from that is a new paper in Space Science Reviews:

https://link.springer.com/article/10.1007/s11214-020-00739-x

If you have access to it. It's a description of this map and the geology of the site.

There is a supplementary file here (a c. 18 MB TIF file):

https://static-content.springer.com/esm/art%3A10.1007%2Fs11214-020-00739-x/MediaObjects/11214_2020_739_MOESM2_ESM.tif

which I think is open access (correct me if I'm wrong), and this gives the names of the nearly 200 quadrangles used for mapping the site. I really wanted to have this for Curiosity, but it was never released, as far as I know.

Phil

Posted by: mcaplinger Dec 22 2020, 06:58 PM

New EDL video: https://images.nasa.gov/details-JPL-20201221-M2020f-0002-EDL%20Full%20Version%20w%20SFX.html

My obligatory link to a comic on my office door: https://i.pinimg.com/originals/e0/32/a0/e032a09c7f71cfa162bc3c0a1fbc5f1f.jpg (Overlook the technical errors in the first two panels, it's still funny.)

Posted by: nprev Dec 23 2020, 07:21 AM

Great video, and superb obligatory comic.

Posted by: PaulH51 Dec 25 2020, 09:28 PM

Phil, wonderful stuff - does the paper provide a scale for this map, specifically the size of each of these quadrangles, also it would be good to know how to attribute it (I dont have access to the paper)
TIA

Posted by: Phil Stooke Dec 26 2020, 07:59 AM

Hi Paul - this abstract from LPSC earlier this year:

https://www.hou.usra.edu/meetings/lpsc2020/pdf/2254.pdf

says the quadrangles are 1200 m by 1200 m.

This is the paper citation:


Stack, K.M., Williams, N.R., Calef, F., Sun, V.Z., Williford, K.H., Farley, K.A., Eide, S., Flannery, D., Hughes, C., Jacob, S.R. and Kah, L.C., 2020. Photogeologic map of the perseverance rover field site in Jezero Crater constructed by the Mars 2020 Science Team. Space Science Reviews, 216(8), pp.1-47.

Phil

Posted by: PaulH51 Dec 26 2020, 08:15 AM

Many, many thanks Phil, much appreciated.

Posted by: climber Dec 28 2020, 10:08 PM

A lot of mountain regions from near my place including Pyrénées, Ordesa Y Monte Perdido, Pico de Europa...

Posted by: Mercure Jan 16 2021, 08:04 PM

Hi all,

Before February 18th I will be trying to get an article about Perseverance into one of the major newspapers of Denmark. I had https://politiken.dk/udland/art8013178/Kæmperaketten-Starship-skal-indfri-Elon-Musks-hede-drøm just before its December flight test.

Would you know of a good resource with a timeline of all EDL events? - I have been struggling a bit to find a source for all events with the precise Earth time as well as the expected altitude and speed at the time of the event. I'm sure the data is out there, but would like it from an authoritative source.

Thanks!

- Mercure

Posted by: mcaplinger Jan 16 2021, 08:42 PM

The EDL timeline is not precisely known in advance but can vary by as much as a minute or two at least.

https://mars.nasa.gov/mars2020/timeline/landing/entry-descent-landing/ is as good as we know. Predicted landing time is Feb. 18, 2021, at approximately 12:30 p.m. PST (that's 20:30 UT.)

Posted by: Mercure Jan 16 2021, 08:51 PM

Thanks mcaplinger!

Posted by: Phil Stooke Jan 22 2021, 04:16 AM

There was a Mars Sample Return sample caching workshop today with very interesting details about how Perseverance will go about its task of collecting and caching samples for later return. Here are the presentation slides:


https://drive.google.com/file/d/1fj5ZPFuieCzpJpWYaYDq2OQlq9v6TxN3/


https://drive.google.com/file/d/1nRoqv5vK_Kzyzu_JLfGpDb0tGYUnXlvo/


https://drive.google.com/file/d/1u19Svop3Ka3buHUyaemk2p2-7a1L-ZOC/


Phil

Posted by: vikingmars Jan 22 2021, 07:26 AM

Thanks so much Phil for the useful links.
I have already prepared a PPT presentation for our large Perseverance landing public event next February we (Planetary Society + Societe Astronomique de France/SAF) are organizing in Paris at our National Science Museum (Cite des Sciences).
It integrates the sample-return mission that follows the Perseverance mission.
=>> Now, thanks to you, I have a very good update to show about the latest sampling-cache strategy

Posted by: Antdoghalo Feb 11 2021, 04:02 PM

NASA's Eyes show Mars is now a barely resolved circle from the distance of Percy. Just a week away!!!
https://eyes.nasa.gov/apps/orrery/#/sc_perseverance?time=2021-02-11T15:51:36

Posted by: MahFL Feb 11 2021, 04:35 PM

I thought the sample tubes were dropped as each one was filled . Learnt something new...

Posted by: Phil Stooke Feb 12 2021, 07:34 AM

Not a great idea because they want to minimize the time it takes for the 'fetch' rover to pick up the cache. If the tubes are set down all along the traverse the fetch rover has to drive the whole traverse length to get them and then get back to the return vehicle. With the two cache system they decide which cache is best (almost certainly the second one) and go for that, land as close as possible and do a quick trip to collect it. In fact the only real reason for the first cache is insurance against a catastrophic failure of the rover before the second cache can be set down.

Phil

Posted by: JRehling Feb 15 2021, 06:18 PM

It's only as I read those excellent documents about the sampling plan that I absorb for the first time that, if all goes well, the scientific results from this mission will be far beyond what the instruments on Perseverance measure. This first occurred to me when I thought about absolute age dating, not from one rock or another, but from several rocks in the stratigraphy, and suddenly we'll have a specific, detailed timeline of Mars's early evolution.

We need a lot of successes to occur before this knowledge will be in hand, but it's awe-inspiring to consider the leap in understanding that this mission sequence is attempting.

Posted by: pbanholzer Feb 15 2021, 08:33 PM

I have a question about the current landing target. In two recent EDL animations (Eyes and the one about 3 minutes long), the landing is much nearer the delta face, maybe only several hundred meters away, instead of the earlier point near a 400 m crater more than a km away to the S. I'm answering some questions on YT threads and do not want to provide bad information. Thanks.

Posted by: Explorer1 Feb 15 2021, 08:51 PM

I think it is just a generic point near the centre of the ellipse. The real landing will deviate somewhat in both entry point and trajectory through the atmosphere, as well as the direction onboard navigation takes it when firing the thrusters. Definitely smart enough not to land on a giant slope!

P.S. my own question for anyone in the know: any plans on MRO attempting imaging like MSL, or does the bent-pipe relay attitude preclude it this time around?
I could really use a new avatar....

Posted by: Art Martin Feb 15 2021, 09:21 PM

PlanetFest 21 happened this weekend (run by the Planetary Society) and there was an amazing talk by Rob Manning of the details of the landing. The ellipse (which this time is really a circle) they could come down in is about the size of Manhattan but the expectations are that the lander would emerge in powered descent somewhere near the center of it which is somewhat near the delta but below it in the crater. The onboard navigation system is designed to locate the closest safe spot to where it figures out it is and aim for that. He said that they determined there were safe spots to be found at all parts of the ellipse within close proximity. Eventually that talk will be posted to the Planetary Society's Youtube page so watch for it. The engineering he described is amazing.

He also said that MRO will be tasked with not only going after a shot of the lander on the parachute but also during the actual powered landing as well if they can get lucky.

Posted by: djellison Feb 15 2021, 11:46 PM

At the L-30 briefing they said yes - infact, they're going to try and do it a little later during EDL - so you'll have the powered descent vehicle flying below the parachute and backshell.

Fingers crossed.

Posted by: Greenish Feb 16 2021, 03:13 AM

I was curious:

Posted by: MahFL Feb 17 2021, 12:41 AM

Can someone give any more detailed insight on how exactly does the TRN work ? Are they aiming for a safe spot at the center of the landing ellipse, or any safe spot ?

Posted by: mcaplinger Feb 17 2021, 02:00 AM

It has a catalog of multiple safe spots within the ellipse and guides toward the closest one based on imaging. See https://www.jpl.nasa.gov/news/a-neil-armstrong-for-mars-landing-the-mars-2020-rover and https://trs.jpl.nasa.gov/handle/2014/46186

Posted by: MahFL Feb 17 2021, 03:35 AM

Thank you for the links, now I have a good understanding.

Less than 2M miles to go now....

Posted by: MahFL Feb 18 2021, 12:41 AM

Less than 1M miles to go now.

Posted by: pioneer Feb 18 2021, 12:49 AM

I know MRO will be able to act as a relay for Perseverance during landing. Will Mars Odyssey or MAVEN be available as well?

Posted by: MahFL Feb 18 2021, 01:00 AM

I think TGO is recording during the landing, later other orbiters are making passes, there are 5 orbiters that can relay rover data.

Posted by: djellison Feb 18 2021, 02:50 AM

MRO will be doing bent-pipe realtime relay ( which is a new feature on MRO thanks to a software update )
MAVEN will be doing canister mode recording for later return to Earth.

See pages 23 and 43 of the Landing Press Kit
https://www.jpl.nasa.gov/news/press_kits/mars_2020/download/mars_2020_landing_press_kit.pdf

Posted by: fredk Feb 18 2021, 03:01 AM

Does anyone know of a Jezero map using the same coordinates as this landing zone map that was presented today:

Knowing the origin of those coords we could probably translate into lat,long...

Posted by: djellison Feb 18 2021, 03:49 AM

That's not a map of the surface - that's a map of a plan through deep space. The spacecraft actively flies its way through entry to target the center of the ellipse. You can't translate that entry mapping image onto a surface map.

Posted by: Phil Stooke Feb 18 2021, 04:34 AM

Right - it's showing where the entry target point is on a plane perpendicular to the approach vector.

Phil

Posted by: fredk Feb 18 2021, 05:21 AM

I see; thanks.

Posted by: Antdoghalo Feb 18 2021, 03:24 PM

EDIT:---Wrong Topic---