This might be a stupid question, but what's the point of a landing radar since the trajectory is pre-programmed and can't be changed mid-flight from the ground...
Is the AFTS re-armed for landings?
The ground radar gives the Stage much faster (readings per second) altitude above the landing surface for the last 1000' or so... Much more so then the GPS can do... More reads and more accurate... why it's there and kinda important... to stick the landing...
This might be a stupid question, but what's the point of a landing radar since the trajectory is pre-programmed and can't be changed mid-flight from the ground, or is it just the launch trajectory that can't [per Jim}? Is the AFTS re-armed for landings?
Quote from: CyndyC on 11/30/2017 04:30 pmThis might be a stupid question, but what's the point of a landing radar since the trajectory is pre-programmed and can't be changed mid-flight from the ground, or is it just the launch trajectory that can't [per Jim}? Is the AFTS re-armed for landings?One reason: GPS is much less accurate in Z than in X and Y. And Z really matters in the last few seconds of the landing.
Those are some very interesting characteristics & differences between GPS & radar, but my point was no matter how they watch, I didn't think the landing trajectory could be altered once it was programmed. There was a big discussion in an Iridium thread with Jim insisting no changes to a launch could be made from the ground, so I wrongly assumed changes couldn't be made at all, or couldn't be made to landings either. I take it the responses imply there are some "IF/THEN" scenarios built into the programming in the avionics inside the interstage, just nothing from the ground.
Quote from: Robotbeat on 10/21/2017 02:30 amAnd SpaceX is using some kind of special heat-resistant cement, I think. And a generous layer of radar-reflective paint.It doesn't seem it would matter whether or not the concrete itself is heat resistant if it's coated with reflective paint,
And SpaceX is using some kind of special heat-resistant cement, I think. And a generous layer of radar-reflective paint.
Quote from: CyndyC on 11/30/2017 03:47 pmQuote from: Robotbeat on 10/21/2017 02:30 amAnd SpaceX is using some kind of special heat-resistant cement, I think. And a generous layer of radar-reflective paint.It doesn't seem it would matter whether or not the concrete itself is heat resistant if it's coated with reflective paint, I hadn't heard about the heat-resistant cement, but if they are using it, it makes sense because any spalling/degredation of the concrete as it gets hit with the F9 exhaust on landing is going to create a lot of FOD getting blasted everywhere, including potentially back into the vehicle itself or a side core landing on the next pad.
The planned trajectory is not altered after launch. Because nothing's perfect, the vehicle can't and won't exactly follow the planned trajectory; instead, it needs to be able to continuously estimate how far away it is from the planned trajectory so it can correct its actual trajectory to approach the planned trajectory. Think "solving for [dx, dy, dz, z] = [0,0,0,0]" rather than "if/then".
In the future, the rockets may target another local landing site: a proposed pad at Kennedy Space Center that is the subject of early discussions between the Air Force, NASA and Space Florida.The goal is to lessen the burden landings impose on the Cape’s nearby industrial area, which workers must evacuate for hours during some missions....As outlined in KSC’s master plan, the new landing pad could be built near the northern end of the spaceport’s secure perimeter — north of pad 39B and south of State Road 402 leading to Canaveral National Seashore's Playalinda Beach....It was not immediately clear who would pay for the landing pad and if it would be exclusive to SpaceX or potentially available for other uses.
Quote from: MattMason on 12/15/2017 02:57 pmExcellent launch and landing!Anyone else think for a few seconds that the Falcon 9 was WAY off from the landing pad on final approach-- --until you realized that the second landing pad was now complete? Congratulations to SpaceX, CCAFS and NASA. Onward with the mission.For those that missed shot of second pad
Excellent launch and landing!Anyone else think for a few seconds that the Falcon 9 was WAY off from the landing pad on final approach-- --until you realized that the second landing pad was now complete? Congratulations to SpaceX, CCAFS and NASA. Onward with the mission.
FH landing pads.LZ-2 will be ready. It's right next to LZ-1. Center core to ASDS Of Course I Still Love You.
That shot is missing a circular feature north of LZ-1 and LZ-2, visible for a very few frames on the technical webcast. Any ideas? LZ-3 for a triple RTLS?
#DEIMOS2 captured new developments at Cape Canaveral's Landing Zone 1, where @SpaceX is expanding its facilities. #ChangeDetection #SpaceX #DragonSpacecraft
Latest image dated July 16:Quote#DEIMOS2 captured new developments at Cape Canaveral's Landing Zone 1, where @SpaceX is expanding its facilities. #ChangeDetection #SpaceX #DragonSpacecrafthttps://twitter.com/deimosimaging/status/1022745963734228992
Quote from: FutureSpaceTourist on 07/28/2018 06:08 amLatest image dated July 16:Quote#DEIMOS2 captured new developments at Cape Canaveral's Landing Zone 1, where @SpaceX is expanding its facilities. #ChangeDetection #SpaceX #DragonSpacecrafthttps://twitter.com/deimosimaging/status/1022745963734228992Looks like they are getting ready to build a third landing pad. Any guesses on which FH mission that would be for?