I have 4 questions about parachute-to-landing phase:
1) which is the maximum tilt any lander can tolerate for a safe landing?
2) which is the maximum transverse wind speed any lander can tolerate for a safe landing?
3) How can I determine the better direction for BAM if I don't know wind direction and speed?
4) How can we answer above questions without any method available to know lander tilt and wind speed and direction during landing? (or maybe there are methods, but I dind't find them in stuff I 've read).

The way EDL is validated is that many Monte Carlo runs are done with all of the parameters varied across their expected ranges and we see if the landing is successful.

Most of this is covered by ITAR so I wouldn't expect to see public information about the specifics.

The tilt at landing is well-known from looking at the gravity vector and the vehicle is actively controlling its attitude during powered descent. The tilt in the last 10 seconds of parachute descent, for example, is completely irrelevant to the tilt at landing.

Varying atmospheric conditions are the major reason that the landing ellipses are relatively large.

To "touch with your hand" Insight, or at least to get an idea of its real size, here it is the official NASA JPL app with ARCore support (i.e. no printed markers needed, just Android 7+ and a floor):
https://play.google.com/store/apps/details?...aftAR&hl=en

This file includes:
- same descent profile of my previous file (centered on Phoenix landing site)
- different images with transparency, representing lander in various configurations.

Unfortunately I can no more work on it till 2018-11-25 10:00 GMT, maybe you've best luck?

[Unfortunately I can no more work on it till 2018-11-25 10:00 GMT, maybe you've best luck?
[/quote]
Thank you so much for sharing. I'm afraid I won't be able to work on them until mid week...
Cheers

Fernando

Here's a useful timeline of EDL and post-landing events. If all goes well we may see a surface image as early as 1204 PDT (2004 GMT); however, this may not happen until the following day.

I don't know what the landing site local time will be.

They made a mistake, seem fixed now (at least the wrong day above)


It seems Horizons has flight data to entry interface, and from then on static, on the ground coordinates for 4 days. I.e. no EDL data in Horizons, which I dont think they ever had anyway. I suspect, however, they may have pasted the static data a tad too early over the flight data.

At :39:59 distance is about 20km greater than for nominal EI (125km above equator radius Mars, or 3522 from center), so that data infers EI at 19:40:16. I'll check back in 24 hours, will update my stuff then. The good thing is, Mars will be there, regardless :-)

https://mars.nasa.gov/insight/multimedia/raw-images/

This is where we will get to see the images as they come in.

Phil

Is the last TCM going to be used ?

The press kit says "mid afternoon on a winter day" (see page 13)
Fernando

Bit late, but press briefing live now. Appears that there will be a TCM-6 later today.

EDIT: Great brief. Lots of detail on MARCO and the seismometer thus far. The replay will be worth watching. Also just spotted Emily in the front row, and she's asking the first question!

EDIT2: TCM-6 will be "a few cm/sec" delta V, will offset current target point approx. 11 nm (yeah, I know) SE to avoid rougher terrain.

EDIT3: Forgot to mention that Emily's questions involved MARCO. Periapsis around 2500-3000 nm, imagery will be attempted but not guaranteed due to tech demo nature of mission. Was emphasized that the cams were off-the-shelf.

Here is a new version of the EDL simulation. Just a few tweaks, really, all I had time to do, but it includes the original ellipse and the new one that was presented at today's briefing. I could be wrong because I had just a few seconds to see it and it seemed to me its center was ENE and 11 km from the old. nprev says 11nm SE.
Anyway, here it is.
Fernando
Click to view attachment

<shrug> I could be wrong too about the direction. Think that what was said was that the terrain 11 (nautical?) miles (note the units!) NW of the original target point was potentially unsuitable so TCM-6 was gonna shift away from that.

The landing point before TCM 6 was in less suitable terrain, so it's been moved 11 miles SW to a better place with TCM 6.

One question I never heard was how accurate is the desired landing point to where they actually land, usually ?

MARCO-B image released during today's briefing.

https://www.nasa.gov/sites/default/files/th...pia22830-16.jpg

During the press briefing today, I just about fell out of my chair when they showed this example of one of the EDL status screens. Here's my best attempt at screenshotting it.
Click to view attachment

For those trying to figure out the geometry.......Martian north is basically 'down' in this image.

TCM update:

"At 1:47 p.m. PST (4:47 p.m. EST) engineers successfully conducted a last trajectory correction maneuver to steer the spacecraft within a few kilometers of its targeted entry point over Mars. Engineers still need to conduct a last trajectory correction maneuver to steer the spacecraft toward its entry point over Mars. About two hours before hitting the atmosphere, the entry, descent and landing (EDL) team might also upload some final tweaks to the algorithm that guides the spacecraft safely to the surface."

Source

That is a somewhat confusing report on activities. We did perform TCM6 today and it was very successful. We do not have any more TCM's to perform (that is the somewhat confusing portion of the report). Latest Navigation report show us very close to the entry corridor and estimates of the ground landing ellipse shows over 99% chance of landing on the perfect terrain for InSight (think Bonneville Salts Flat). The last portion is accurate in that the EDL tream is reviewing atmosphere models and entry location to set the last set of parameters for entry. Prop system preheats of the portions of the system used for EDL only (pressurization system and descent components) are well underway and looking good. Just about E-12 hrs and we are ready for EDL! Going to be a great day tomorrow! Go InSight and Go Marco!

This seems very ambiguous. Does anyone have authoritative information that would clarify? Does the press release mean there is to be a TCM-6x at 12:42:27 UTC, or did they just forget to remove the reference to a "last trajectory correction" when they updated the post?

Also, can anyone remember if MPL and PHX used a TCM-6 or TCM-6x?

Yeah, I don't know. Might be a bad edit on their part.

I don't really think that they have enough time left for another TCM because I'd assume that it'd take substantially more propellant to produce the same effect with every passing minute right now.

EDIT: Whups, missed Propguy's post above; much clearer. Thanks, man. Think it's all good, ollopa; no further TCMs, just entry parameter updates.

GO INSIGHT!!!

See my post on the end of page 8. No additional TCM's will be conducted. PHX did not do a TCM6, but we only did it to ensure we were right on the center of the ellipse (all trajectory values pre-TCM6 met entry requirements, just being extra safe, which is a great idea). Got to get to bed to be ready for EDL. Hope you all enjoy the day tomorrow (actually later today). I am sure I will get my track record above 50/50 (MPL and PHX being my previous landing missions).

Yeah, propguy clarified in post #120. From what I've read, TCM-6X wouldnt have been more of a alternate or part 2 of TCM6 rather than clean up a TCM6 gone wrong.

Also, I see you quote "12:42:27 UTC" ... if you've taken that from my website, thanks for the visit, and a note that it was just my best guess based on descriptions I had ("so-and-so many hours before landing" which I took as "before EI" based on EI info I had at the time). I havent coded functionality yet for events that are not known (to me) to the second precise. If it was the actual time considered, that'd be spooky

What time is Entry Interface, SpaceCraft Event Time, to the second precise? Does anybody here know

I have MarCO closest approach numbers, inferred from what's in Horizons now:

Daniel, one important information is missing in your simulation timeline: Start eating Peanuts.

It was already late (so I couldn't do an update) when I found in YouTube the press conference video. At about 9:30 minutes into the video Tom Hoffman describes how the successive TCMs adjusted the landing ellipse ever closer to the intended target and shows (at about 10:25) the ellipse after TCM 5, which (center) was about 11 miles (ENE) away from the desired target location. So it was decided to perform another TCM, which has already been discussed in this thread.

For what it is worth, here is the InSight EDL file again (I have merged the two files from posts #87 and #93) including the target, the landing ellipse after TCM 5, and the EDL path now leading to the target.

Less than 5 hours now... GO, GO INSIGHT!

Click to view attachment

Here we go! EDL thread is now live, please move discussion over there. NASA TV coverage will begin in three hours (1900 GMT).

Not sure if there's a more appropriate thread: the MarCO's have fallen silent: https://www.jpl.nasa.gov/news/news.php?feature=7327

They might try to contact them again next perihelion, but not very likely. Congrats to the team on a unique (and very helpful) experiment!