IPB

Welcome Guest ( Log In | Register )

9 Pages V  « < 7 8 9  
Reply to this topicStart new topic
InSight Cruise Phase, Events during Mars transit prior to EDL
ollopa
post Nov 26 2018, 08:09 AM
Post #121


Member
***

Group: Members
Posts: 106
Joined: 25-November 04
From: Dublin, Ireland
Member No.: 113



QUOTE (nprev @ Nov 26 2018, 07:39 AM) *
TCM update:

[i]"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.

Source



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?
Go to the top of the page
 
+Quote Post
nprev
post Nov 26 2018, 08:15 AM
Post #122


Merciless Robot
****

Group: Admin
Posts: 8783
Joined: 8-December 05
From: Los Angeles
Member No.: 602



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!!!


--------------------
A few will take this knowledge and use this power of a dream realized as a force for change, an impetus for further discovery to make less ancient dreams real.
Go to the top of the page
 
+Quote Post
propguy
post Nov 26 2018, 08:23 AM
Post #123


Junior Member
**

Group: Members
Posts: 48
Joined: 8-August 12
Member No.: 6507



QUOTE (ollopa @ Nov 26 2018, 01:09 AM) *
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?


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).
Go to the top of the page
 
+Quote Post
dmuller
post Nov 26 2018, 08:26 AM
Post #124


Member
***

Group: Members
Posts: 340
Joined: 11-April 08
From: Sydney, Australia
Member No.: 4093



QUOTE (ollopa @ Nov 26 2018, 07:09 PM) *
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?

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 wheel.gif


--------------------
Go to the top of the page
 
+Quote Post
dmuller
post Nov 26 2018, 08:27 AM
Post #125


Member
***

Group: Members
Posts: 340
Joined: 11-April 08
From: Sydney, Australia
Member No.: 4093



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


--------------------
Go to the top of the page
 
+Quote Post
dmuller
post Nov 26 2018, 12:28 PM
Post #126


Member
***

Group: Members
Posts: 340
Joined: 11-April 08
From: Sydney, Australia
Member No.: 4093



I have MarCO closest approach numbers, inferred from what's in Horizons now:
CODE
MarCO-A 19:45:21 UTC SCET at 1,626km altitude
MarCO-B 19:47:45 UTC SCET at 1,750km altitude


--------------------
Go to the top of the page
 
+Quote Post
climber
post Nov 26 2018, 02:34 PM
Post #127


Senior Member
****

Group: Members
Posts: 2917
Joined: 14-February 06
From: Very close to the Pyrénées Mountains (France)
Member No.: 682



QUOTE (dmuller @ Nov 26 2018, 01:28 PM) *
I have MarCO closest approach numbers, inferred from what's in Horizons now:
CODE
MarCO-A 19:45:21 UTC SCET at 1,626km altitude
MarCO-B 19:47:45 UTC SCET at 1,750km altitude

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


--------------------
Go to the top of the page
 
+Quote Post
nogal
post Nov 26 2018, 03:09 PM
Post #128


Member
***

Group: Members
Posts: 870
Joined: 15-June 09
From: Lisbon, Portugal
Member No.: 4824



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!

Attached File  InSight_EDL_Sim.kmz ( 18.87K ) Number of downloads: 904

Go to the top of the page
 
+Quote Post
nprev
post Nov 26 2018, 04:01 PM
Post #129


Merciless Robot
****

Group: Admin
Posts: 8783
Joined: 8-December 05
From: Los Angeles
Member No.: 602



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


--------------------
A few will take this knowledge and use this power of a dream realized as a force for change, an impetus for further discovery to make less ancient dreams real.
Go to the top of the page
 
+Quote Post
Explorer1
post Feb 5 2019, 07:49 PM
Post #130


Senior Member
****

Group: Members
Posts: 2073
Joined: 13-February 10
From: Ontario
Member No.: 5221



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!
Go to the top of the page
 
+Quote Post

9 Pages V  « < 7 8 9
Reply to this topicStart new topic

 



RSS Lo-Fi Version Time is now: 19th March 2024 - 11:08 AM
RULES AND GUIDELINES
Please read the Forum Rules and Guidelines before posting.

IMAGE COPYRIGHT
Images posted on UnmannedSpaceflight.com may be copyrighted. Do not reproduce without permission. Read here for further information on space images and copyright.

OPINIONS AND MODERATION
Opinions expressed on UnmannedSpaceflight.com are those of the individual posters and do not necessarily reflect the opinions of UnmannedSpaceflight.com or The Planetary Society. The all-volunteer UnmannedSpaceflight.com moderation team is wholly independent of The Planetary Society. The Planetary Society has no influence over decisions made by the UnmannedSpaceflight.com moderators.
SUPPORT THE FORUM
Unmannedspaceflight.com is funded by the Planetary Society. Please consider supporting our work and many other projects by donating to the Society or becoming a member.