39

It's just the aerodynamics. There is high pressure where the air spills out the side that tends to push them apart more than the forces that you mention that pulls them together. Good thing too. A giant parachute with the same drag would take too long to open. Clustering is very commonly used for cargo.


38

There is an atmosphere on Mars. An atmosphere ~1% as thick as Earth's sounds like it ought to 'basically not count as an atmosphere' but 1% earth's atmosphere is still quite a lot of gas! The pressure of Mars's atmosphere is about ten million times larger than outer space. I can't find it right now, but there's a quote about the Martian atmosphere, that says ...


36

Would you even be able to open the door? It would depend on the capsule, but since the Apollo 1 fire, one expects crewed American capsules to have explosively-jettisoned hatches that can be activated by the crew. If you had a regular skydiving parachute with you, is there any way you could skydive and survive? Yes. Terminal velocity for falling ...


26

I'm pretty sure that by "soft good" he means it's an element of the system that can't be completely constrained from a simulation or engineering standpoint, in this case fabric. If you're working with static systems or systems with a limited amount of degrees of freedom, it's possible to calculate and analyse every possible state the system can be in. For ...


24

The test they were doing didn’t require parachutes. Data-taking ended right after the capsule separated from the tower. Since the capsule’s behavior after that was not part of the test, it could be an inert item. To extend the test through parachute deployment, the capsule would have to be much more complex with the parachutes, deployment system, and a ...


23

If you're just looking at it as a mass trade, then yes, you will definitely get a mass savings by replacing a portion of your propellant with a bag full of nylon. Depending on your speed, the nylon can have a much higher "Isp" than the rockets. However at the system level, there are other things to consider besides mass. First, parachutes are not "hyper-...


17

I don't know what Dragon uses, but large air-drop parachutes use a "reefing" technique. There's a "reefing line" around the circumference of the parachute that controls its expansion: The (significant) forces trying to inflate the parachute pull the line through, but it takes some time during which the parachute is only partially inflated and the ...


17

It's quite simple. The new Mars Science Laboratory rover is too heavy to survive an airbag landing. The airbags themselves are made from fabric and had to be strengthened for the Mars Exploration Rovers project. There are some nice videos on-line of JPL in the vacuum chamber at Plum Brook shredding up some Sojourner-era airbags when testing them at MER entry ...


17

Thanks to the paper linked by Jan Doggen in the comments we can say that it is a natural outcome of the shape of the parachute. In particular, the shape, together with the near absence of wind and the fact that the craft is descending near vertically determines that pulsating motion. In the words of the paper: The studies of [1, 2] demonstrated that ...


17

An atmosphere does not need to be very thick to heat up a reentry vehicle significantly. And it should be noted that reentry vehicles entering the Earth's atmosphere get heated up at a pretty high altitude with thin air as well. The point of maximum heating is also not necessarily the same as the point of maximum acceleration. At near-orbital speeds, two ...


16

Note that this answer refers to the final flight version of the Dragon V2. The first powered landings will be using parachutes before the system is validated for powered-only landing (see this article, thanks to Mark Adler for pointing this out). Parachutes are passive devices that slow the vehicle but do not steer it (some parachutes can steer a bit, ...


16

Those dark objects are the deployment bags which contained the main parachutes prior to inflation. Source: The Apollo Parachute Landing System Also from Apollo 15 Main Parachute Failure Anomaly Report Two 16.5-foot diameter conical ribbon~type drogue parachutes are mortar-deployed 1.6 seconds after forward heat shield jettison. The drogue parachutes ...


15

E. Musk has answered this multiple times in interviews. This comes down to the economics of it. They are putting this entire system together to haul cargo, and the reusable portion is there to increase profits. They are putting in place a reusable restartable engine in order to have the maximum duplication of function for the components onboard. Previously ...


15

From the article: Tuesday’s launch was more focused on testing the launch abort system itself. The parachutes on Orion have been tested 47 times.


15

The Red Bull Stratos jump was done from about 39km up (high altitude balloon). It was fairly straightforward, in that he jumped and opened a parachute. His max speed was just above mach 1 (800mph/1300kpm roughly) and when he moved himself from the freefall to a more traditional skydive position, he was at a more tolerable 500mph/700kph. By the time he ...


14

It is called parachute "breathing", and is quite common. It is a natural consequence of the flexibility of the parachute shape. It is initiated in the initial inflation, where the parachute will always over-inflate, and then oscillate around a mean inflation state. Hopefully with decreasing amplitude. If the breathing amplitude would be too large or growing,...


14

The apollo command module had three parachutes and two of the three would have been sufficient to slow the capsule sufficiently for a survivable landing. However, this redundancy would not have protected against certain failure scenarios where the parachutes failed to deploy properly or multiple chutes failed due to a common cause, such as collision with ...


13

The X-38 (based on the outer mold line of the X-24 lifting body) was planning to use the largest parafoil parachute in history for its final deceleration. Alas, she only flew as a test. This parafoil was actually designed to autonomously deliver light armor to forward operating locations for the military.


13

I'm pretty sure it will be like the Phoenix lander. Collectively that part of the lander is referred to as the "Backshell". This is the image of Phoenix of the hardware on the surface. This is mentioned in the official timeline. Powered Descent - Once the lander separates from its backshell and parachute, 12 descent engines on the lander begin firing and ...


12

The fairing itself is large, (a pair can enclose a school bus sized payload) and is very light, and not very aerodynamic when split into two halves. When joined together it is very aerodynamic, when split apart, dramatically less so. Thus the parachute has to overcome a very oddly shaped, unoptimized for gliding shape. It is fairly large, ungainly, and ...


12

First, there's a lot that can go wrong with a parachute + air bag landing system. Second, the Mars Pathfinder / Mars Exploration Rover systems also required rockets to fire just before reaching the ground. In that case they were solid rocket motors as compared to the throttled liquid monopropellant engines used by Mars Science Laboratory. Third, all of ...


12

This is not a complete answer as I do not know the status of the parachute development, but here are some reasons a parachute is not needed: Ejected Data Recorders: These ~20 data recorders, literally Raspberry Pis with parachutes and waterproofing, all get the complete telemetry data from the test. This is made up of accelerometer, gyroscope, magnetometer ...


11

All round parachutes have many suspension lines, and they're needed to distribute the load on the canopy, keep its shape, and their hooking (or even re-hooking) geometry during deployment can help with reefing and keeping its shape. It's not because we can't make suspension lines strong enough. Fewer suspension lines would require stronger canopy that would ...


11

During the parachute descent, InSight's trajectory is at an angle to the vertical. After the backshell and parachute separate, the engines fire, leveling the craft. This allows some horizontal separation between the parachute and the craft: 11:52 a.m. PST (2:52 p.m. EST) — Activation of the radar that will sense the distance to the ground 11:53 a.m....


11

I found a diagram that explains it better than words. The landing rocket module was at the base of the parachute lines, not above them: The linkage appears to be hinged, but I'm guessing it's a solid piece of metal rather than easily-burned fiber. According to Space Biology & Medicine: Space and its Exploration, the capsule would be falling at 7-8 m/s ...


11

Here's an official response: NASA has already fully qualified the parachute system for flights with crew through an extensive series of 17 developmental tests and 8 qualification tests completed at the end of 2018. Test data from 890 sensors was sent in real-time to ground sites as well as recorded on board by 12 data recorders. The 12 data recorders ...


10

Another factor: Acme delivers you an unobtanium chute that can take all the forces involved. What happens? Your objective is hard braking at high altitude. You slow down, you're not in orbit anymore, you start falling. You have to shed your velocity before you get too deep in the atmosphere. How much time do you have to do this? Very little! You need ...


10

Already a lot of good answers, so just one additional aspect to the explanation: When orbiting Mars, the vehicle has a lot of kinetic energy that has to be reduced to zero before landing. Coming from a low orbit, you have to somehow slow down from 3.5 km/s (8000 mph) to zero. Over non-atmosphere bodies like the moon, the only chance to slow down is firing ...


9

In addition to Erik's answer I might be able to give you some insights on some disadvantages. I've been growing up around parachutes and until about 10 - 15 years ago you would often see people having a parafoil as a main canopy and a round one as a reserve (today it's very different, but that's not really relevant). Round canopies are much simpler than ...


9

According to spaceflight101: [The Soyuz capsule] is outfitted with the spacecraft's fully redundant parachute system [...] I would assume that the designers needed to keep a certain precision for the landing. If they deployed the main parachute and the backup simultaneously, the decent speed may be lowered to the point that they could no longer satisfy ...


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