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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Falcon 9: transonic attitude control on reentry

Attitude control on the falcon 9 is done with engine thrust vectoring, cold gas thrusters, and grid fins. After the reentry burn, when the rocket stage is in the atmosphere, there is a short period ...
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Would it be possible to avoid the heat-from-friction problem when re-entering the atmosphere by performing (vertical) “U-turns”?

If you lift a swing at a children's playground and release it will swing back and forth for a while, losing some altitude in each swing, mostly (?) due to drag. Eventually it has lost all energy and ...
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State vector update on reentry

The integration errors from IMU state measurements would seem very problematic when you're coming in for a landing, where error tolerances would probably be as small as they could get. This must mean ...
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Falcon 9 landing speed estimate?

How fast is a Falcon 9 stage 1 going when it touches ground? Rough estimates are OK. An upper limit would be helpful too. I'm getting 5.5 m/s (12 mph) in simulation and wondering how reasonable this ...
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Falcon 9 Reentry Burn Duration?

The videos and simulations I've seen suggest the reentry burn lasts 30 seconds. This is followed by the final landing burn and it may be preceded by a boostback burn. I'm interested only in the ...
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Help understanding vectors in diagram from “Magnetohydrodynamic flow control during reentry” and the actual goal of this research

A link to the ESA Advanced Concepts Team page Magnetohydrodynamic flow control during reentry was recently shared under Re-entry Heat Shield Alternative. It says: During the reentry phase, spacecraft ...
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ISS battery “de-orbit” burnup?

In reading these two questions: How many kilograms of nickel particles will be dispersed in Earth's atmosphere by dumping old ISS batteries overboard? and Why does it take so long for ISS garbage ...
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Why does it take so long for ISS garbage to fall out of orbit?

The ISS recently jettison some garbage and expects it to take 2-4 years to de-orbit and burn up. From Gizmodo's ISS Ditches 2.9-Ton Pallet of Batteries, Creating Its Most Massive Piece of Space Trash: ...
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How many kilograms of nickel particles will be dispersed in Earth's atmosphere by dumping old ISS batteries overboard?

Weighing 2.9 tons... this heap of old batteries is now the heaviest single piece of garbage to be jettisoned from the International Space Station. begins Gizmodo's ISS Ditches 2.9-Ton Pallet of ...
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This ISS trash deployment looks more like 2 feet than 2 inches per second, was it too fast or are these articles incorrect?

Digital Trends' Watch a NASA astronaut jettison part of the ISS into space which was linked in says: Writing in Air & Space last year about the process of jettisoning objects, veteran NASA ...
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Regulations for cubesats designed to survive reentry and be retrieved?

I'm currently thinking about the potential of manufacturing certain items (ZBLAN, Semiconductors, Organs, Drugs, etc.) in LEO and I want to know whether it would be possible/legal to design a cubesat ...
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During space shuttle reentry, why was the sign of GALR based on mach number rather than directly on alpha?

(My apologies if this should go in Aviation.SE instead - I'm not quite certain where questions regarding the behaviour of the shuttle's flight controls during reentry should go.) For flight in ...
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151 views

How fast was NASA Perseverance flying at when it hit Mars' atmosphere?

Do we know how fast Perseverance was flying at relative to Mars when it hit its atmosphere? The closest figure I could get to was "over 12,000mph" according to this article: https://www....
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During reentry, does the flux stay laminar? Should become turbulent the capsule could not mantain attitude

This a thing that, instinctively, I find it hard to grasp. The capsules are designed with a centre of gravity slightly to the direction of the thermal shield, this assures the right attitude, but how ...
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Why did Mars Pathfinder have such a high atmospheric entry velocity?

I was wondering what the highest atmospheric entry velocity of any lander was at Mars, for direct-entry landers (as opposed to those released from an orbiter), the atmospheric entry velocity tends to ...
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How long is Falcon 9 suicide burn?

My question is How long is a Falcon 9 suicide burn? I assume the answer might vary between rides, depending on the payload lifted and its destination orbit so the time might not be the same for a ...
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57 views

What were the Shuttle TPS repair patches made of?

Following the incident on STS-107, three methods of dealing with damaged tiles were developed. The method for large tile damage involved screwing a very thin plate over the hole, after loosely filling ...
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How large can heatshield holes be?

The tiles on the underside of the STS Orbiter had gaps between them to allow for the frame underneath to shift slightly. However, if the gaps were too large fillers were used. What controls the ...
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How many solar system bodies have “knees” in their atmospheres?

Discussion lead to citing Why does Earth's atmospheric density have a big "knee" around 100 km? Is there a good analytical approximation? who's answer is "monatomic oxygen". ...
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How did the Space Shuttle prevent flying up when reentering the atmosphere?

Always when reentering the atmosphere, the shuttle was pitched up, right? When gliding through the mesosphere, how was it that it didn't fly up again then? Was it due to a certain distribution of ...
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Did the Apollo Command module really “skip” within, or off of the atmosphere as a part of it's reentry program?

This answer to a question about the Shuttle reentry begins: Skipping reentries aren't unheard of. The Apollo command module performed a single skip when returning from lunar missions. but Wikipedia'...
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How will SpaceX land its rockets on the unleveled surface of Mars?

SpaceX plans to send the Starship to Mars and to land it there, tail first in a vertical position. Unlike the Perseverance rover, which seems to be able to land on uneven terrain without the need for ...
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How will NASA set Perseverance to enter the atmosphere of Mars at the right location after traveling 7 months in space?

The Perseverance rover is set to land on Jezero crater on Mars, in February 2021. It is clear that if you want to land in location X you need to enter the atmosphere at point Y. From the animated ...
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How is PICA different from other heat shielding materials?

What are the differences and why did SpaceX prefer to use PICA?
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Can the Space Shuttle land on Mars assuming there is a paved surface for landing?

Can the Space Shuttle land on Mars if it had a paved runway? Can the Space Shuttle use aerobraking and will its control surfaces provide attitude control? Can the parachute and braking systems stop ...
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Why did Columbia disintegrate lower into the atmosphere, not during its peak heat phase?

Space Shuttle Columbia entered a period of peak heating at 46 mi (74 km) altitude. Before the contact got broken, the temperature on Columbia's wing leading-edges had sunk already (and the heat shield ...
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Does it count as orbital flight if one reentered the atmosphere due to its drag after about 1 revolution?

Imagine a spacecraft entered an orbit around the Earth whose perigee is low enough into the atmosphere so that it reenters and lands after a revolution, without having to perform a reentry burn. While ...
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Chance of ceramic board surviving re-entry on 3U CubeSat?

We're building a 3U CubeSat and have concerns about a ceramic PCB used in one of our experiments. Since ceramics have such a high melting temperature, we're not sure if the heat transfer during re-...
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Could an electrically pumped rocket stage position its batteries to enable it to re-enter stably nose-first?

Are the batteries in existing or planned electrically pumped rocket stages massive enough to change the centre of mass of the empty stage such that new re-entry strategies are available? e.g. Could ...
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What if a Space Shuttle entered the atmosphere of Venus?

How would a U.S. Space Shuttle's atmospheric entry on Venus differ from reentry on Earth? Say there's a Space Shuttle in a low Venus orbit performing a (re-)entry burn. How would the following ...
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What is the terminal velocity of SpaceX Starship?

What is the terminal velocity of starship on earth and mars during descent? Has SpaceX revealed or hinted the values of projected surface area and drag coefficient of the vehicle?
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How does Hayabusa2's return capsule orient and stabilize after separation and before and during reentry?

How does Hayabusa2's return capsule orient and stabilize after separation and before and during reentry? Have it some onboard system like RCS or reaction wheels, or does it rotate around longitudinal ...
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Starship surface heating on Mars landing

Mars atmosphere is much thiner than Earth's And then how much will Starship heat on a Mars landing comparing to a landing on Earth?
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Testing of rocket heat shield on Earth

One Space Shuttle was destroyed due to failure of the insulation tiles. SpaceX is reportedly using another technology, which replicates sweating , for wearing off the reentry heat. How is the ...
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Do aeroshells really get hotter than the surface of the sun?

This answer to How to design heatshield bluntness? says: Curiosity reentry dumped about 98% of its entry energy into the atmosphere, the aeroshell can still get to be temps greater than the surface ...
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g-forces entering and leaving atmospheres, how would they vary from one body to another?

I was wondering how launching from and returning into atmospheres of other bodies such as Mars, Venus, Titan, etc. would differ from Earth's. Specifically, I am wondering how many g's would be ...
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What is the use of the belly-flop maneuver?

Why the Starship needs a bellyflop maneuver? Why not to return vertically like Falcon 9? The term is used in articles like this one: During such a flight, experts believe SN8 will perform an unusual “...
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Lunar landing in cotton candy?

When spacecraft land on Earth, they use the atmosphere to slow down. On the Moon there's no atmosphere, so spacecraft must instead use rockets to slow down from orbital velocity. Would it be possible ...
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Is the Low-Density Supersonic Decelerator scheduled for any upcoming Mars mission? Is the program still active?

Back in 2014 and 2015, some tests of the Low-Density Supersonic Decelerator were performed. The LDSD is intended to land heavier payloads on Mars than is currently possible. Mark Adler (the project ...
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Why Falcon 9 doesn't need heat shield tiles? [duplicate]

The Space Shuttle and the Starship need tiles for termal Protection while reentry. Why Falcon 9 doesnt need them?
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Seeking Book about Aerodynamic Design of the Space Shuttle

a few years ago I found a book written by an engineer working on the aerodynamics of the shuttle during design, ALT, and early STS. I have since forgotten the title and author's name. Does that ...
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Soyuz/spacecraft deceleration speed for reentry

I recently saw a program by Prof. Brian Cox (Human Universe Ep.1) where he mentioned that just by using two equations - f=ma and the universal law of gravitation, you could calculate how much a ...
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What was the leeward surface temperature of the Apollo Command Module during reentry?

From the Apollo Experience Report: Thermal Protection System, there is a diagram that shows the surface temperatures of the Command Module at various points (image was obtained from this answer). It ...
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Which deorbit trajectory minimizes reentry heating?

Atmospheric reentry, as I understand it, is a balancing act between minimizing delta-v needed and not burning up or breaking up in the atmosphere. The higher the velocity on reentry, the greater the ...
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Falcon 9 landing stages

I know the first stage of Falcon 9 separates at about 2:30 min and it lands at about 8:30 min But what are the distinct stages of the descent? Like deorbit burns, grid fin deployment, leg deployment ...
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Why not bring a rocket to idle velocity for less violent and safer re-entry? [duplicate]

Since kinetic energy have to be converted into heat during re-entry, the re-entry into the earth's atmosphere seems very violent. Why most rockets or crew re-entry modules plunge into the earth's ...
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What impact will the deorbiting of thousands of satellites have on the atmosphere?

With the creation of mega satellite constellations like Starlink, there are several thousand satellites being launched each year. This means that as these satellites go out of order in a few years, ...
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Why will OGO-1 reenter from an elliptical orbit rather than circularize first?

According to all the sources cited in Why does OGO-1's trajectory and imminent reentry come from sky surveys and NEO tracking rather than normal satellite tracking? OGO-1 is in a highly ...
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Why does OGO-1's trajectory and imminent reentry come from sky surveys and NEO tracking rather than normal satellite tracking?

Space.com's 56-year-old NASA satellite expected to fall to Earth this weekend says: "OGO-1 is predicted to re-enter on one of its next three perigees, the points in the spacecraft's orbit ...
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How much do on-demand, artificial meteor showers cost these days?

On-demand, artificial meteor showers are discussed in Artificial Shooting Stars - how could this possibly work (economically/technologically)? Why would a box full of 1cm balls released into LEO be ...

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