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Questions tagged [reentry]

Questions related to the movement of human-made objects as they enter atmosphere of Earth or other planetary bodies with atmospheres from space after being successfully launched.

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Could inflating while decending for rentry be possible?

Could entry of Mars with balloons work by inflating to equalize with the atmopheric air pressure while establishing buoyancy before meeting the ground? Would a balloon pop if dropped from space? ...
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1answer
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Could a spacecraft produce lift using sublimating material?

Following this question, could a spacecraft approaching upper atmosphere from very low circular Earth orbit, produce lift to soar propulsively, bleeding speed at constant apoapsis, by sublimating ...
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Could ablative material sublimation slow down a spacecraft?

Thought experiment illustrated below: Suppose a weird spacecraft entering Earth's atmosphere from low Earth orbit, payload first. Behind it there is an inverted nozzle shaped structure, attached with ...
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1answer
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What's the minimium velocity for re-entry flames to start?

Considering a space shuttle re-entering Earth, what's the minimum velocity that would cause the vehicle to start burning? Is there an equation to calculate that? I presume it varies according to the ...
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1answer
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How does a Reentry Breakup Recorder survive reentry and then broadcast its data before impact?

Below are two cropped parts of File:ISS-28 Ron Garan prepares the Reentry Breakup Recorder.jpg In the Unity node of the International Space Station, NASA astronaut Ron Garan, Expedition 28 flight ...
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How much does the rotation of the Earth affect re-entry and could we go against it?

I was thinking about how many things are affected by the Earth's rotation, and was wondering how much more difficult a retrograde re-entry would be (where the Earth's rotation direction is assumed ...
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What is typical lifetime of GTO rocket stages before reentry?

Most of geostationary satellites are launched at geostationary transfer orbit (GTO) first by rocket's upper stage. Than satellites separate and circularize the orbit by own propulsion. The upper ...
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Can a Soyuz-MS still propel itself back to earth if all its Hydrogen Peroxide decomposed?

In this answer it is stated that: If the fuel fully decomposes then return to Earth is still possible but only via ballistic descent I find it a little bit surprising, but maybe there is enough Δv ...
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Was splashing down on the USSR-controlled territory a possibility for Apollo missions?

From what I understand, the planned landing areas for Apollo command modules were pre-programmed beforehand and happened in the South Pacific. Was there any remote possibility of an emergency ...
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What was the nature of the visible part of the viscous wake trailing the Apollo CM during reentry?

This diagram suggests a helix in the wake, was it a single-helix, a multiple helix, or a superhelix? Is there any other part of the wake that would be visible?
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Orion reentry plasma

Below are two screen shots from the video of the Orion reentry, Astronaut’s-Eye View of NASA’s Orion Spacecraft Re-entry, and a diagram. Is the plasma contained, or primarily within the viscous wake, ...
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Did the Apollo astronauts ever describe reentry deceleration?

Did the Apollo astronauts describe any differences in how it felt in the CM as it passed between the hypersonic, supersonic, transonic and the subsonic zone? Did the CM shake more or less in ...
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1answer
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What would happen if air hitting heatshield was ignited?

During Earth's atmospheric entry of an Apollo-like capsule, what would happen if oxygen hitting heatshield was mixed with fuel injected through heatshield, and ignited? Edit & addendum : During ...
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Apollo recovery zone(s)

For the Apollo missions that left Earth orbit, were there multiple recovery zones for each splashdown? How big was each zone?
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Atmospheric re-entry speed

What would be the difference in atmospheric re-entry speeds from LEO and GEO, assuming a Hohmman transfer orbit from GEO to re-entry? If I am getting the transfer orbit concept correct?
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1answer
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Hypersonic Inflatable Aerodynamic Decelerator entry to Mars' atmosphere

Is it known whether or not a Hypersonic Inflatable Aerodynamic Decelerator inflation and entry into Mars' atmosphere would produce more violent vibrations and lateral movements than was experienced by ...
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1answer
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What is the circular item that fell off of the returning booster during the CRS-16 mission?

During reentry of the first stage booster on the Dragon Resupply Mission (CRS-16), there was a ring-looking item that floated away from the booster. I would imagine it is some sort of ice debris, but ...
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Are there any advantages to being a smaller spacecraft for reentry?

Could a ship drop its cargo or shed weight before reentry to lessen the strain on the ship during reentry? Would a ship breaking down to smaller parts before reentry have any advantages over being one ...
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1answer
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Slipstream re-entry. Is it possible in theory?

Slip-streaming in cycle races saves a lot of energy by shielding the follower from a head wind. A sacrificial meteoroid precedes the re-entering spacecraft. It directs the hot plasma away from it. As ...
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How do the dynamic pressure evolves during reentry?

During launcher ascent, dynamic pressure evolution is describe in this answer for the Saturn V. I suppose this is comparable from one launcher to another. Given the protections designed for reentry, ...
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1answer
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How does falcon-9 engine survive while re-entry burn without chilling ?

I've often seen that in launch sequence, "engine chilldown". I've learnt that chilling is done to avoid thermal cracking in plumbing lines and also to avoid cavitation. While re-entry, do they ...
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What are the three peaks in this Apollo reentry heating plot?

The question Challenging Karman line from above includes the following plots and cites an answer in Quora by Robert Frost, Instructor and Flight Controller at NASA who has provided many authoritative ...
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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. ...
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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 ...
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1answer
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What is the likely plan to deorbit the ISS given its size and shape?

The ISS is nearing its final years and this question spurred me to ask a follow up. Let's say that the various countries grab whatever equipment/modules they provided in assembly and the ISS is ...
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1answer
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Satellite retrieval, fix and deploy possible remotely?

Is there any satellites that are designed to come back to Earth for repairs or upgrades and then be deployed again? Would there be any benefits to creating a capsule or inflatable heat shield to go on ...
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What eliminates the velocity when occupants return from ISS to earth, and how much?

The ISS has an orbital velocity of ~28000 km/h; the velocity $v$ relative to the landing site of the descent module is probably even higher than that most of the time. Once the occupants have landed, ...
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Could I use a satellite as a vehicle for delivering airborne leaflets?

Assuming I have a satellite in a decaying orbit, could I gently release leaflets from my satellite so they were on a near-identical sub-orbital trajectory and have them touch-down safely on the ground ...
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1answer
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What does “Poisson's formula” refer to in this calculation?

I am not entirely sure if this question belongs to this forum, but I don't know where else to ask. I am following a Rocket Propulsion course. There is a section concerned with the Velocity ...
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Would the right shape dimple heat sheild create more wake? [closed]

In this question: Would a dimpled heat shield reduce heat transfer during reentry? the answer says no it would not help more or less. My new question is would reverse dimples or bumps or a ring/s ...
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4answers
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Why can't you just parachute down right from orbit?

This will surely seem, at least at first sight, a completely stupid idea, seeing the usual “space isn't high away, it's fast away”, and that the heat shields which actually are used need to withstand ...
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5answers
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Have Air-breathing Engines ever been used on a reentry vehicle, could they be?

For the purpose of this question I would like to assume there is no risk of life for the astronauts, or that the design would only be used for delivery of a non-ethically-sensitive payload. Looking at ...
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2answers
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Why didn’t the Spacecraft used for the Apollo 11 mission melt in the Earth’s Atmosphere?

My brother has recently been converted to a Flat Earther and is convinced that something that proves his theory is the moon landings being faked by NASA. I have managed to counter argue the majority ...
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Nature of “the silky black 'highly flame-resistant felt'” on Block 5 Falcon 9's, and its intended functions?

The Teslarati article SpaceX Falcon 9 Block 5 rocket’s drone ship return captured in stunning detail [gallery] and accompanying photo spread shows many interesting details of "SpaceX’s first West ...
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Have spacecraft ever dipped below the Karman line and then safely continued spaceflight?

The item in Science Alert's A Harvard Astrophysicist Says Outer Space Is Actually Closer Than We Think (see also Science; Outer space may have just gotten a bit closer) talks about the recent Acta ...
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1answer
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How was/Was Kalam-sat Recovered from the Ocean?

I was reading this article about Kalam-SAT and it states that: "Kalamsat fell into the sea. It will be recovered and NASA will be sending it back to us for decoding the data," [Srimathy Kesan, ...
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6answers
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Dangle a cable down to earth - fundamental Physics question

If I had the material that had the tensile strength, would it be possible to have it dangle from the lowest most practically possible geostationary object down into the atmosphere? Would it not ...
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1answer
379 views

Can a reentry be done slowly?

The usual approach to reentry is fast and hot. There's a lot of energy to be lost, and doing it quickly has some advantages: You can dump energy into hypersonic air, and then leave that heat behind ...
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How would the space shuttle fare without payload doors? [duplicate]

If the space shuttle had the doors locked open, blown off, or otherwise unable to close, would it be able to re-enter and land somewhat intact? Was there any procedures in place on the off chance this ...
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1answer
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Would landing on mars during a storm considerably increase atmospheric drag?

Any chance we could harvest all those dust particles for an significant improvement in aero-breaking capabilities or would it destroy most heat-shields?
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With what attitude does Soyuz reenter, and in what way might this angled pattern on Exp. 53's return a result of attitude?

The BBC article Soyuz space capsule brings ISS crew back after five month mission describes the return of ISS Expedition 55's "Russian Anton Shkaplerov, American Scott Tingle and Japan's Norishige ...
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Looking for atmospheric density models of various planets and moons

Looking for atmospheric density models of various planets and moons, any sort of data/resources/database of this information would be extremely useful as I am working on recreating these models for ...
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Why will the BFS reenter broadside rather than engine first?

Musk has stated that they added the delta wing to the BFS design because; from one flight to the next the ship may have differing payloads and differing fuel loads. These changes shift the center of ...
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1answer
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Is this smoke from Expedition 53 returning Soyuz capsule?

I was clicking through YouTubes and came across the NASA Video ISS Expedition 53 Landing in Kazakhstan (also here). I don't recall seeing such prominent and continuous smoke from returning Soyuz ...
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1answer
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How to calculate the stagnation temperature at the tip of the nose of a reentry module?

A re-entry module flies with Mach 10 at an ambient temperature of –27°C with. CP = 840 J/kg-K, gas constant R = 140 J/kg-K. What is the stagnation temperature at the tip of the nose of the re-entry ...
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Is there real footage of Tiangong 1 reentry?

There are a couple of videos on the net showing some reentries and claiming them to be Tiangong 1. Is any of them authentic? I could not find any footage on the websites of the major space agencies (...
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Why are Tiangong-1's Apogee and Perigee Graphs Wobbly?

The apogee and perigee graph of the Tiangong-1 space station, about to re-enter and break up Real Soon Now, is depicted in this graph (source: Wikipedia): Why are the graphs wobbly? Is it because the ...
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1answer
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Why is there a need for getting rid of ISS trash using the empty ATV and similar vehicles

Why is trash from the ISS sent down in some of the cargo vehicles. Would it not make more sense to dump it overboard in the downward + retrograde direction (as described here) and use reusable cargo ...
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How are impact probability maps rigorously calculated?

This is one example of an impact probability map. It was posted in this question and is from Aerospace Corporation. But My question is about the process, not this particular map, although it is a good ...
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Nano spacecraft reentry

Suppose if one designs a Small size reentry capsule. What will be the typical deacceleration achieved by atmosphere. More precisely, what is the relationship of the size and drag by atmosphere. I am ...