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Questions tagged [entry-descent-landing]

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6
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1answer
327 views

Did the manned NASA capsules rotate during descent?

Watching the NS-11 launch, I noticed that during descent when the main chutes were deployed, the capsule rotated quite a bit, and would rotate back. Was this an issue as well during the Mercury/...
-1
votes
1answer
157 views

Could a Rotary Rocket charge a super capacitor while descending on Mars?

Could a rotary rocket entering the atmosphere collect enough energy in a super capacitor through the rotors (along with auto rotation) while descending to have a controlled landing in the last few ...
1
vote
1answer
44 views

Pressure effect during atmospheric entry

Maybe this question has a very obvious answer (I'm no aero engineer though), but I'll appreciate the clarification! So, I was reading an old nasa paper that indicates that the dynamic pressure for ...
5
votes
1answer
254 views

What is crossrange and downrange for an entry vehicle?

I have been searching the terms online but still can't get a more intuitive understanding. If you could refer me to some website, book or if you could offer me an explanation I would really appreciate ...
2
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0answers
69 views

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 ...
2
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1answer
148 views

Manned entry to Mars

Did Insight have a ballistic entry? If so, does NASA plan a ballistic or skip-glide entry for manned missions to Mars?
35
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3answers
6k views

Why was it necessary to program InSight with an ability to land in dust storms?

If the entire event of EDL (Entry - Descent - Landing) is going to take only 7 minutes and if the command to begin could be signalled based on ground weather conditions, why was it necessary to take ...
14
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3answers
2k views

What happens to Insight's parachute on Mars?

All of the animations I see show the heat shield detaching and falling to the ground, then Insight detaching and landing. There is no information about what happens with the upper part of the heat ...
9
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1answer
831 views

Why is InSight's nylon parachute a “soft good”?

NBC News' Mars InSight's landing team leader is all 'nerves and excitement' ahead of risky touchdown includes a conversation with Rob Grover, "who leads the team in charge of InSight's landing at NASA'...
5
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2answers
105 views

How does a Mars lander reach a chosen landing site?

I see lots of questions how landing sites are chosen, but none so far how these landing sites are reached. It already looks like magic how the target planet can be reached at all, but when are ...
7
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1answer
148 views

How different was the Apollo LM descent trajectory from the most fuel-efficient?

In most diagrams of the Apollo Lunar Module descent profile (example at the start of this video), it looks like the LM turns over and points some of its thrust downward relatively early in the process....
6
votes
2answers
226 views

Drawbacks and advantages of two slidable & rotatable control surfaces for BFS sized spaceships

BFS (SpaceX's Big Falcon Spaceship) is in development and has seen between 2016 and 2018 three major design modifications. January 2018 I asked here how BFS planned to manoever during aerobraking. ...
10
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2answers
352 views

Why does in-flight mission abort often ends in ballistic high-g reentry?

I am seeing a lot of references to the “ballistic reentry” mode of the crew return vehicle in relation to the abort during the powered ascent stage. In partiulat, the recent crewed Soyuz MS-10 abort ...
10
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1answer
867 views

How does a gamma ray altimeter work? What kind of sensor is used?

The answers to the Space SE question Soyuz landing ground detection really surprised me. A gamma ray altimeter is used by the returning Soyuz capsule to detect the presence of solid ground immediately ...
3
votes
0answers
167 views

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- ...
3
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0answers
49 views

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 ...
2
votes
2answers
178 views

Maximum dynamic pressure upon Mars entry

I have a Mars landing simulation, and one of the things it calculates is the dynamic pressure as the spacecraft descends through Mars' thin atmosphere (given by $q=\frac{1}{2}\rho v^{2}$). I know it ...
0
votes
2answers
137 views

How would a landing escape system be designed? [duplicate]

Launch escape systems have been used for half a century and have worked great when tried. But entering Earth's atmosphere from orbit and landing is at least as dangerous to astronauts, and have cause ...
6
votes
3answers
279 views

Where can I find high quality “descent” photos at as many different altitudes as possible?

I'm working on a graphical simulation and I'd like to get the "look and feel" to seem as realistic as possible. Other than Apollo landing videos (which seem pretty limited and low quality obviously) ...
8
votes
1answer
278 views

Archimedean braking for low density Venus lander + subsidiary question

Subsidiary question: Imagine a sphere 10cm in diameter in low venusian orbit. Slow it down a little in order to deorbit it. What's the density of the sphere, in order to touch the ground at 0 vertical ...
4
votes
0answers
199 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 ...
6
votes
1answer
74 views

Meteor color hints at chemistry

This recent meteor over the midwest. Reports described it at blue / green. I have seen blue / white, red and yellow meteors. I presume red means iron, green means copper. Can meteoritics or meteor ...
4
votes
2answers
710 views

Can we significantly reduce entry velocity with this method by airbraking alone for interplanetary travel?

For example, can a space ship overshoot Mars in a reverse gravitational slingshot mixed with a little air breaking, steering to keep the spacecraft from orbit and then land on Mars with a near 0 ...
3
votes
1answer
681 views

Blimp on Earth, but a glider on Mars?

Could enough surface area be created with a blimp to shed speed using Mars' atmosphere to have a controlled soft landing to minimize the need for retrorockets? Runway would need to be in place. While ...
5
votes
2answers
205 views

Is there a way to recover any of the energy of reentry of a Mars lander?

Is there a way to recover any of the energy of reentry of a Mars lander? Tremendous energy is generated as a craft enters the atmosphere – admittedly over a fairly short time - and only one time. We ...
-7
votes
2answers
518 views

Can a reusable electric powered blimp stage for launch possible?

Originally this question asked about using blimps and electricity in replacement of boosters. As written then it was no good and got down votes. I had a few question marks and each question really ...
1
vote
4answers
771 views

Can a blimp dead drop on Mars or Earth this way?

I saw a space jump where someone had exceeded the speed of sound before the air slowed him down enough to deploy a parachute, because the air was not dense enough to tear him apart in the upper ...
2
votes
1answer
239 views

What are transonic oscillations (wrist mode) and would Schiaparelli have been transonic at 2 to 4 km altitude?

edit: Considering that the recent (23-Nov-2016) ESA update suggests that a saturation of the rotational sensors in the IMU may have set off a series of miscalculations leading to mission loss, the ...
31
votes
1answer
28k views

What is a “suicide burn”?

The term suicide burn occasionally comes up in answers and comments, usually without any real explanation or definition. What is meant by the term "suicide burn"?