Hello, I have discussion board to be done . everything is explained below . 

Read the  Discussion Board Instructions before answering the following questions. 

this link is for discussion board just in case if it doesn’t open by you https://online.macomb.edu/courses/46220/pages/08-d… 

Your Initial Post:

As NASA’s newest capsule engineer, here are a few facts that you’re aware of:

1. Fuel is heavy. Getting a substantial amount up into orbit (the amount that would be required to land) is impractical, so we will have to operate our capsule with a minimal amount. Furthermore, it’s expensive and we have to stay within our budget.
2. Spacecraft stay in orbit partially due to their very large orbital speeds. If you slow down a little bit, then the radius of your orbit decreases. We will have enough fuel to change the radius of our orbit (but not to land).
3. Once the capsule slows down enough to reenter Earth’s atmosphere, you get the benefits (and drawbacks) of drag.
4. When the capsule is moving slow enough, you can deploy a parachute to cut its speed enough for a safe landing.

The deadline is coming up and the lead engineer asks for your written capsule proposal. Describe in words, in your initial post, the process of atmospheric reentry, starting from orbit, and ending with ground contact. Use the information in this post, as well as your own experience with friction, to discuss some of the effects that atmospheric drag may have during reentry and propose solutions to any challenges.

This proposal is meant to be your description of the effects of friction on a space capsule based on the above fact and your real-life experience with friction. You do not have to look up the process to make sure you are correct. Furthermore, DO NOT look up or use any equations for drag – this is eventually going to the budget committee, and they don’t like equations.

(This week’s post is more open-ended than usual, so to receive credit you must provide a thoughtful response, demonstrating that you have actually considered the situation presented. We’re not actually designing a spacecraft, so you don’t have to go into a great amount of detail, but low effort posts will get you fired and probably also cause you to lose points.)

Your Reply Post :

(I’ll send the class mate reply later, because i can’t see their post unless I post mine )

Select a classmate who does not have a reply and do not reply on the same day as your initial post.

You, the lead engineer, have just received the proposal from your new colleague (chosen classmate). Correct any errors or misconceptions in their proposal and add details that may be missing. Discuss the possibility of using our new capsule to land on the Moon and Venus (our closest cosmic neighbors). You may wish to use these webpages as reference:

https://en.wikipedia.org/wiki/Atmosphere_of_Venus (Links to an external site.)

https://en.wikipedia.org/wiki/Atmosphere_of_the_Moon (Links to an external site.)

HR reminds you that NASA wants to keep our new engineers, so be thoughtful and courteous in your response. Failure to do so will result in mandatory cooperation and sensitivity training (and loss of points).

first reply :

According to the first given fact, “fuel is heavy”. We know that the amount of fuel stored into orbit is impractical so, we have to calculate the amount of extra fuel needed to complete the spacecraft in order to life the heavy fuel. In order to stay within the budget, we need to consider the amount of fuel that is needed for the capsule. The budget committee will determine the costs and we will determine the amount of fuel needed. We also know that the spacecraft stays in orbit because of large orbital speeds. Therefore, a drop test will need to be performed. Once the capsule slows down enough to reenter the Earth’s atmosphere, we get the benefits of drag. Drag is a form of friction that occurs when an object moves through a fluid. When the fluid is air, this is often called air resistance. Unlike the kinetic friction that occurs when two surfaces rub together, drag depends on velocity. Friction is caused when two things in physical contact rub against each other. Friction doesn’t exist in space because space is empty so there isn’t any air resistance due to the fact that there is no air in space. When surfaces in space slide over each other in space, there is no friction.

second reply :

Friction is a very important factor in landing a spacecraft on a body with a noticeable atmosphere. Friction comes from the interactions between imperfections in two surfaces, fluids, or a combination of those, which apply forces on one another. This causes deceleration and heat to be generated. For the purposes of landing, static friction, the forces holding objects and fluids in place relative to one another, is irrelevant because the capsule will be in constant motion until it is on land. The kinetic friction, the forces applied to and by objects and fluids rubbing past each other, will need to be accounted for. In order to land a vessel on Earth with minimal fuel, the following steps will need to be taken. First, the vessel will need to be decelerated so that it begins to move toward the Earth’s surface. This must continue until the vessel is within the Earth’s atmosphere, and the vessel reaches a safe speed. The safe speed is determined by the drag caused by the kinetic friction between the air and the vessel, and the tolerance of the heat shielding. The vessel must go slow enough that it will not burn up in the atmosphere. Once at a safe speed, the thrusters can let up to allow drag to provide most of the vessel’s deceleration. Once at a sufficiently low speed, the parachute may be deployed. The parachute will apply an upward force on the vessel causing much greater deceleration. Once the capsule reaches the surface, it can safely fall into the ocean and be recovered by our marine counterparts and brought to land.