Posts: 1895 From: Cape Canaveral, FL Registered: Mar 2010
posted 03-01-2024 12:59 PM
quote:Originally posted by Axman: But a guidance system that doesn't know how high the craft it is guiding in is, isn't an optimal system.
And, your post above is the very first time I'd heard that three legs are now missing...
The vehicle was to have lidar to provide altitude and it couldn't turn on. They were trying to use the NASA experimental lidar, but in the end, it couldn't incorporate its data. In the end, the lander used comparative imaging to determine altitude, which worked crudely with the guidance system.
Only two legs came off, the third was damaged.
Glint Member
Posts: 1135 From: New Windsor, Maryland USA Registered: Jan 2004
posted 03-03-2024 01:07 PM
quote:Originally posted by Robert Pearlman: Do you really think a company capable of building a NASA-approved lander does not understand the physics and engineering behind their own vehicle?
Do you remember Perkin-Elmer? I seem to recall how they built a NASA approved space telescope mirror, which NASA launched and found its figure was non optimal. So the appeal to authority doesn't always work.
Robert Pearlman Editor
Posts: 52131 From: Houston, TX Registered: Nov 1999
posted 03-03-2024 01:21 PM
The point wasn't that companies cannot make errors — Intuitive Machines has admitted to its own, which was failing to remove the pin that would have enabled its laser altimeters — but rather, there is no reason to believe in this case that what they said occurred, did occur.
From what I recall and can find online, Perkin-Elmer did not put forth an alternate explanation after NASA found that the company's test instrument used to verify the mirror was faulty. There were disagreements over who was to blame (as NASA had earlier signed off on use of the test device) but it was not like Perkin-Elmer didn't understand or agree that the mirror was flawed.
randyc Member
Posts: 903 From: Denver, CO USA Registered: May 2003
posted 03-03-2024 03:50 PM
It's interesting that a pin that should have been removed wasn't removed before flight. Usually items such as the pin would have a red 'Remove Before Flight' banner attached to them that was clearly visible. If a banner couldn't be attached to the item there were other ways of indicating that it should be removed.
I worked at Cape Canaveral and, as the engineer-in-charge on tasks where items needed to be removed before flight, would verify, using a procedure, that the item(s) were removed. The step in the procedure would also need to be 'stamped' by the technician who removed the item and the inspector who witnessed the item being removed. The banner, with the item attached, would then be hung on a 'Remove Before Flight' board in the blockhouse so that the launch team could verify that every item that needed to be removed before flight was accounted for.
I don't know what process Intuitive Machines uses to ensure that all items that need to be removed before flight have been removed but the process we used on the Delta program worked well.
Robert Pearlman Editor
Posts: 52131 From: Houston, TX Registered: Nov 1999
posted 03-03-2024 04:57 PM
I misspoke (mis-wrote?), it was a switch, not a pin. As explained during the Feb. 29 press conference:
We have a difference between the engineering development units that we use on the ground for the laser rangefinders and the flight units that were on the vehicle. When we tested the laser rangefinders on the ground, the engineering units did not have that safety-enabled switch.
When we tested the flight lasers on the ground, we have ground support equipment feeding the power to those units. In those cables, there is a wire that pins into a connector that provides power to disable that safety enable and allow you to fire that laser rangefinder and we did that and it worked. The flight cables, however, did not have that wire lead in them.
There's a range safety requirement that you do not have an active laser with a potential to fire it and you need a limiter while you're on the launch pad getting ready to launch. That's why that safety enable is in that box, one for ground safety, one for range safety limits.
So there is a difference between how we test on the ground and the units we tested and the cables we use versus the cables we built for flight and that one wire in miles and miles and miles of wiring on the vehicle and different harnesses was an oversight and we missed it and we're not able to command that disabled switch on and therefore didn't have the laser rangefinders.
So there a couple of people beating themselves up pretty bad.
GACspaceguy Member
Posts: 3042 From: Guyton, GA Registered: Jan 2006
posted 03-03-2024 05:06 PM
Unlike a number of landing missions, this is just the first of a series. Looking forward to the next missions with this mission's lesson learned.
Jim Behling Member
Posts: 1895 From: Cape Canaveral, FL Registered: Mar 2010
posted 03-04-2024 08:39 AM
quote:Originally posted by randyc: Usually items such as the pin would have a red 'Remove Before Flight' banner attached to them that was clearly visible.
This would have been a "green tag"; something that would have be installed/performed before flight. Typically, it would be battery enable plugs or other types that enable circuits that have hazards associated with them.
Robert Pearlman Editor
Posts: 52131 From: Houston, TX Registered: Nov 1999
posted 03-15-2024 03:22 PM
Intuitive Machines video
Our official IM-1 mission ended on February 29th, as Odie was not designed to survive the moon's harsh temperatures without sunlight. While we wait for the possibility of hearing from Odie once the sun shines on the solar panels prior to the end of the month, watch our mission recap below, which includes a heartfelt farewell from Mission Director Jack Fischer, commemorating the lander's groundbreaking voyage and the wealth of knowledge delivered from the lunar surface.
Robert Pearlman Editor
Posts: 52131 From: Houston, TX Registered: Nov 1999
posted 03-25-2024 09:39 AM
Intuitive Machines update
As previously announced on February 29th, our IM-1 mission ended seven days after landing, as Odysseus' mission was not intended to survive the harsh temperatures of the lunar night. Before its batteries were depleted, flight controllers tucked Odie into a configuration that could call home if various systems outperformed manufacturer expectations.
Intuitive Machines started listening for Odie's wake-up signal on March 20, when we projected enough sunlight would potentially charge the lander's power system and turn on its radio.
As of March 23rd at 1030 A.M. Central Standard Time, flight controllers decided their projections were correct, and Odie's power system would not complete another call home. This confirms that Odie has permanently faded after cementing its legacy into history as the first commercial lunar lander to land on the Moon.
posted 03-01-2024 12:59 PM
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