Questions tagged [landing]
Questions regarding the specific part of flights, during which a spacecraft touches down on the solid ground of a celestial body.
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How did Chang'e-4 hover, rotate, and then descend so gracefully? (Video)
In this incredible video we can see Chang'e-4 in it's final approach and landing on the moon from the point of view of the spacecraft.
The view is horizontal as the spacecraft seems to stop and hover ...
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2answers
152 views
Is helium used to power the Falcon 9 grid fins?
Is helium used as a hydraulic fluid to power the grid fins? Or for engine gimbaling?
What are the pros and cons of using helium instead of hydraulic fluids?
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2answers
1k views
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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0answers
49 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 ...
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2answers
1k views
How many engines are restarted for landing the falcon boosters
For landing the boosters, it is clear that SpaceX is using the center engine, but I suspect that igniting one engine will not be helpful.
If they aren't igniting all the 9 engines, how are they ...
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0answers
46 views
Falcon 9: how much fuel is left on a booster after stage separation?
If the booster attempts either land or sea landing, how much fuel (RP-1 and LOX) is left in its tanks right after stage separation?
Recently, I have heard numbers as high as 30% of its total tank ...
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0answers
49 views
Why the big difference between NASA and ESA/Roscosmos in evaluating the Oxia Planum landing site?
In november 2018 ESA announced that the Oxia Planum region is favoured for the ExoMars surface mission.
The figure above from this answer about the 21 potential landing sites for the Mars 2020 ...
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1answer
132 views
Could SpaceX's grid fins be controlled by electric motors instead of hydraulics?
There have been a few instances of landing failures related to the grid fins and their hydraulic control - one where the hydraulic fluid ran out, and the latest one where a hydraulic pump stalled.
...
4
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1answer
136 views
Why did they not use the Flight Termination system on CRS16 booster?
All US boosters (I assume other nations as well) have flight termination systems. The goal is to try and stop an out of control booster (Big vehicle, full of explosives/fuel/oxidizer) from causing ...
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5answers
4k views
Falcon 9: engines stabilize spin
On CRS-16, the landing Falcon 9 booster entered a spin rotation due to a stalling grid fin hydraulic pump.
According to Musk, the engines stabilized the spin. How is this possible? The main engines ...
5
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2answers
214 views
If the CRS16 booster was out of control, how did it abort to water?
The CRS-16 missions first stage, seems to have had a stuck grid fin. Apparently a hydraulic pump failed.
It was spinning fairly wildly and clearly did not try to land at the pad as it was scheduled. ...
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2answers
85 views
Propellants used for different Mars landers [till 2018]
What propellants have been used by lander to land on Mars surface?
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0answers
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How was the landing site decided to land InSight?
From this article
The High-Resolution Imaging Science Experiment (HiRISE) camera on NASA's Mars Reconnaissance Orbiter plays an important role in evaluating candidate landing sites on Mars. HiRISE ...
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3answers
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Won't the heat sensor probe interfere with the seismometer?
I've read that the Mars InSight Seismometer will be deployed before the HP3 probe. Won't the digging interfere with the seismometer? Or the shock produced will be small enough to be dissipated by the ...
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3answers
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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 ...
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1answer
97 views
How do Mars spacecraft control attitude on final descent and landing?
When I watch videos of probes landing on Mars after cutting the parachutes off, they show the lander doing final orientation adjustments before touching down.
The engines don't seem to have a ...
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0answers
108 views
Details about the BFR abort procedures?
What kind of emergency procedures will the BFR have during landings? I can see an abort to an alternate landing zone but what about when you have a an emergency ten seconds after engine shutdown?
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6answers
599 views
Is it possible to navigate space travel with no computer?
From launch to land could a person travel in space with only mechanical devices like a sextant? With enough experience what would be the minimum devices needed? Which vehicle currently would be easier ...
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0answers
67 views
Purging process of a rocket engine
Does spacex purge Falcon 9 engines after landing ? If so, which gas is used for purging?
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1answer
63 views
Nadir sensor for a spacecraft attempting to land
Is it possible theoretically for a sensor to detect Nadir? This could actually be of extreme value as generally spacecraft attempting to land need to maintain certain heading w.r.t Nadir as a function ...
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1answer
168 views
Could an inflatable heat shield be used on the SpaceX Mars Lander?
Could light weight inflatable heat shields be used like parachutes from NASA to increase surface area for the SpaceX Mars lander further decreasing velocity? Where would be the best placement of them? ...
10
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1answer
661 views
Can Stratolaunch land with the rocket still attached?
Is the Stratolaunch plane able to land with the rocket still attached, if a malfunction is detected – and the plane has to return without having launched its load?
Is there a known emergency ...
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1answer
210 views
Could a reentry powered monorail and flywheel make a kinetic engine for lift?
On reentry could a flywheel spin on a magnetic bearing creating a centrifugal force to keep the ship level whilst creating a plasma air pocket from the pits in the rotating heat shield? This would ...
4
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1answer
250 views
Does deploying the parachute dehermetize Soyuz?
When watching the Year in Orbit documentary, one of cosmonauts points to the big bags stowed between/above the seats of Soyuz capsule, identifying them as the main and emergency parachutes. But they ...
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1answer
117 views
Is the atmosphere a positive or a negative for reusability?
Does the atmosphere provide a benefit or detriment in terms of fuel economy for rockets that take off and land back on Earth? We know that the atmosphere plays a large role in helping slow down ...
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0answers
106 views
Does the downrange position of an ASDS vary, depending on payload mass?
SpaceX in its recovery attempts can either do a Return To Launch Site (RTLS) or land downrange on an ASDS landing barge.
The Telesat 19V and 18V payloads were some of the heaviest payloads on the ...
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1answer
269 views
Why doesn't SpaceX deploy some module to cover whole fairing like a rain coat just before sea landing? [duplicate]
In order to avoid fairing to get wet in water, why can't SpaceX just deploy something such that when fairings separate from the Falcon 9 then from inside some raincoat type waterproofing to just cover ...
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4answers
9k views
Why can't Falcon 9 fairings touch the water?
SpaceX is spending considerable effort to catch Falcon 9 fairings into a giant net on a ship. I am aware that salt water ruins almost everything in the long run, but the fairings are a composite ...
6
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1answer
545 views
What is the minimal TWR of Falcon 9 booster right before touchdown?
A big point about Falcon 9 booster landing is that they need to stick the landing on the first try; they can't just hover and adjust position because even fully throttled single Merlin engine provides ...
5
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1answer
310 views
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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2answers
3k views
Will SpaceX delay launches, if the landing site weather is unacceptable?
With the initial landing attempts, it was not a big deal, twas all an experiment and they only reused Block 1-4 boosters once at best. So holding a launch because of weather at the landing site ...
3
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1answer
139 views
Landing shock of Soyuz spacecraft?
Every astronaut launching on a Soyuz has a custom-made seat. The seat should prevent injuries from the very hard landing. Are there any numbers about the maximum decceleration when hitting the ground?
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0answers
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Transportation on the Mars I Air
Due to the thin atmosphere generating lift on Mars is difficult at a lower speed, Flying is hard until aircraft go supersonic and then it becomes difficult to control(Ref.). The landing would not be ...
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1answer
237 views
Could a shuttle be built for Mars?
Mars does have an atmosphere, but is there enough atmosphere to glide, shed speed and land if there was a runway? What would this require from the shuttle, in terms of aerodynamics?
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3answers
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Why is an airbag landing on the moon not viable?
In this related question, it was explained that the differences in design between a Mars rover and moon rover were too substantial to substitute one for another. One of the points made was that the ...
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1answer
343 views
Could Space Shuttle's wings be diminished?
From Wikipedia
The crucial factor in the size and shape of the Shuttle orbiter was the requirement that it be able to accommodate the largest planned commercial and military satellites, and have ...
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2answers
1k views
How does a landing spacecraft control main parachute inflation?
In a recent post from SpaceX about Crew Dragon parachute test you can see how the main parachutes are deployed in semi-folded state, after a while they inflate a bit and after another while they ...
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1answer
97 views
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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2answers
2k views
Why is the first stage from the Falcon 9 SES-12 mission not recovered?
Youtube video here
At 4:13 minutes into the Iridium-6/GRACE-FO NASA Launch, the commentator mentions:
The first stage is not going to be recovered, so there won't be any views from the drone ship ...
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1answer
295 views
Do Falcon 9/Heavy Block 5 boosters need landing legs? Or can they land back on their launch mounts?
At 2017's International Astronautical Congress, Elon Musk claimed that SpaceX could master propulsive landing without landing legs.
The assertion was that Falcon 9's ...
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3answers
177 views
Is Mid-Air Deployment of the Mars Helicopter Feasible?
According to a recent news announcement1, NASA is going to send a small helicopter to Mars for testing purposes. Future landers could carry more of these
future rotorcraft [that might] act as ...
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1answer
66 views
Would a large impactor on an ice moon cause a thinning of the ice surface?
While it has not been confirmed, Callisto (Jupiter IV) could potentially have a small subsurface ocean below a thick ~100 km ice layer, according to Wikipedia. A mission to explore that ocean might ...
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2answers
168 views
SpaceX May 11, 2018 Falcon 9 launch had no boostback burn
One of my questions regarding the May 11 launch is Why no boostback burn? I assume that without such a burn, Stage One would continue on at about 8,000 km/hr in an EASTWARD direction, away from the ...
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1answer
554 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 ...
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2answers
343 views
SpaceX Raptor engined first stage landing
Reusability is a key strategy for SpaceX to lower the cost of orbital and interplanetary launches. With the Falcon 9 they are using the powered landing approach to recover the first stage for reuse.
...
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1answer
157 views
How can one ensure safety of the crew capsule if the rocket blows up at max dynamic pressure?
In general, say the rocket like the Soyuz blows up any time during flight (not on the ground). Is there some way to ensure that the crew capsule can be returned safely back. If it is high enough but ...
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2answers
2k views
What is the cause of this Falcon 9 first stage “dance” after landing?
Recently I watched a video on YouTube by Scott Manley: How To Do A Hoverslam - Things Kerbal Space Program Doesn't Teach. It deals about landing burns of Falcon 9 first stages. It features short clips ...
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1answer
295 views
Which crewed spacecraft provides the gentlest decent and/or landing?
Landing with a Soyuz capsule is often compared to being in a car accident1, it's pretty violent on touch-down. On the other hand, I imagine the Space Shuttle's touch-down to be a little like a rough ...
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2answers
4k views
Could SpaceX land on the moon today?
Now that SpaceX has a bunch of flown Block 4 Falcon 9 rockets laying around, could they theoretically do a mission to the Moon with landing even if it's just a rocket with no payload? Does it work out ...
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1answer
3k views
Why the soot pattern on the nosecone of Falcon Heavy side booster?
When a SpaceX booster is landed, we are used to seeing soot deposited all over it, usually in a specific pattern.
You can read more about that in this question:
Why the strange bands of soot of the ...
