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Questions tagged [entry-descent-landing]

Questions about the end-to-end process of landing a spacecraft on a target

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7 votes
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Why wasn't the MSL landing ellipse in Gale Crater placed further South?

This paper documents the final landing site selection process for the Mars Science Laboratory (MSL) mission. One of the cons associated with Gale Crater (as pointed out in Table 10 of the paper), was ...
olamarre's user avatar
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7 votes
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What are the rules for callouts during mission landings?

I remember hearing at one point that in the control room at JPL, only the GN&C Lead is allowed to make the announcement for touchdown. It's because they don't want someone prematurely (and ...
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Is Perseverance's heat shield's thickness radially symmetric?

I came across this video1 about the Mars 2020 Perseverance rover mission, especially the atmospheric entry phase. It says between about 03:50 and ...
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5 votes
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251 views

Lunar Descent and Landing Simulation

I am trying to simulate lunar descent and landing as a part of my undergraduate project. For time being, I have included gravity turn guidance scheme and used these equations Now, I can solve ...
Kuldeep Barad's user avatar
4 votes
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Atmospheric Entry Simulation: Numerical Inaccuracy

I am trying to make an atmospheric entry/aero-assist simulation. For the propagator, I have used conventional equations of motions in planet fixed reference frame: where the scalar states are- ...
Kuldeep Barad's user avatar
3 votes
0 answers
178 views

Why does the landing trajectory of a blunt body take an S shape in the lower atmosphere?

I coded some Matlab plots of altitude vs time for the re-entry of a point mass (so no aerothermo analysis included). In all the trajectories, there is an S shape closer to the ground. Why? Please ...
RNG's user avatar
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How to get MSL coordinates during EDL from SPICE kernel?

Upon trying to extract MSL position above surface by decoding a SPICE kernel, I am gettin this error: At epoch 3.9750216818313E+08 TDB (2012 AUG 06 05:16:08.183 TDB), there is insufficient ...
jumpjack's user avatar
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3 votes
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Atmospheric entry of asteroid mining products

This is a more general question than How to get processed asteroid metals back to Earth in a safe manner That question was actually a quick check to see if a particular idea was plausible. Instead, ...
Craeft's user avatar
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Atmospheric Entry Vehicle: Wind frame representation and Visualization

I am looking at entry dynamics for a convex blunt aeroshell. We use Heading angle, bank angle and flight path angle for description of attitude from local horizon axes system. While it is sufficiently ...
Kuldeep Barad's user avatar
2 votes
0 answers
108 views

Is it possible for fuselages to have a negative lift coefficient at positive angle of attacks?

Recently I was interested in the descent phase of the first stage of the falcon 9 launch vehicle. I assumed a long cylinder to represent the first stage. using DATCOM to predict aerodynamics ...
جامکلو حسن's user avatar
2 votes
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Apparent close encounter of Inspiration4: Is the airspace cleared for returning spacecraft?

In the recording of the SpaceX live-stream covering the return of the Inspiration4 crew one can see an aircraft cross path with the capsule at 22:59:58. This image is a frame grab of the scene seen ...
Peter - Reinstate Monica's user avatar
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How are Launch Ascent Trajectories and Reentry Constraints Being Implemented these days?

Historically, endoatmospheric guidance for launch ascent has been open loop and suboptimal. Recently, however, it seems as though there has been renewed interest in determining optimal endoatmospheric ...
phobos's user avatar
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How to approximate the force generated by Falcon 9 grid fins?

I'm interested in approximating the force generated by the grid fins on a Falcon 9 rocket during its descent phase. However, I currently lack specific data and equations for this calculation. Can ...
IsolatedSushi's user avatar
1 vote
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223 views

Defining overshoot and undershoot boundary of entry corridor

I have been reading up on the mathematic of atmospheric entry. I have found different methods to theoretically calculate the corridor width but I don't understand how to define the overshoot and ...
Starck's user avatar
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How to Model the Aerodynamics of Landing a Falcon 9

I'm currently working on a landing simulation for the Falcon 9. One of my primary tasks is to model both the environment and the rocket. In a previous rough simulation, aerodynamics were mostly ...
IsolatedSushi's user avatar
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80 views

How long to flip over stage 1 of Falcon 9?

Curious how fast stage 1 flips over. 180 degrees is a lot of turning. At a rate of 5 deg/s, it would take 36 seconds to flip. This seems very long for the maneuver. A more modest duration of 10 s ...
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