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Topics - ApolloGirl

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General Discussion / barbecue roll
« on: December 17, 2017, 07:00:23 PM »
The Passive Thermal Control maneuver, aka the barbecue roll, is a maneuver used by the Apollo spacecraft on its coast to the Moon. The CSM rotates along its x-axis (along the length of the body) of about one revolution per 10 minutes or slower. The in order to disperse heat from the Sun and heat up the spacecraft evenly.  




Active torquing was required to maintain the desired attitude because the moment of inertia principal axes were not precisely aligned with the spacecraft axes. This was accomplished by using the rotational hand controller to create a pure torque about the roll axis, instead of using the active attitude control mode.

This maneuver was first successfully tested in Apollo 7.
In Apollo 13, the crew performed a barbecue roll before powering down the spacecraft to avoid further thermal damage to the ship. 

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General Discussion / Saturn V fuel vapor
« on: December 14, 2017, 08:10:08 AM »
Ever wondered was that steam coming out of the side of the Saturn V rocket is? If you look closely, you'll see vapor steaming out of the top of the fuel tanks hours prior to launch.



All the three stages of the Saturn V use liquid oxygen (LOX) as oxidizer. The LOX is kept liquid at about -183 degrees Celsius. To main this temperature it continuously boils off and is replenished through the fill and drain line between loading and prepressurization.

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General Discussion / Early Access roadmap ahead
« on: December 11, 2017, 09:48:29 AM »
As many of you already know Space Simulator is coming soon to Steam Early Access. We plan to roll out the game in various stages through Early Access. 

Initial launch will include a detailed Apollo 8 mission. This includes launch, translunar injection, lunar orbits and return to Earth.

In the following months we plan to finish work on the Lunar Module to release Apollo 9, which was the first mission with the LM, then Apollo 10 and 11, etc. in successive months. 

Once all the Apollo missions are in place we'll start implementing the Steam Space Shuttle missions. This will likely be 6-12 months down the track from now.

Of course, if time permits we will enable VR to make this a truly immersive experience.

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General Discussion / apollo 8 earthrise
« on: December 11, 2017, 09:32:26 AM »
Many of us know that famous earthrise image showing a profound contrast between the gray of the Moon and blue of the Earth and the dark of space.




Although entrenched in the popular imagination, this image was in fact not the first photograph ever to be taken of the Earth by a human. 

The first ever picture taken of the Earth rising from the Moon was taken a minute before the above iconic image, but in black and white.

As Apollo 8 circled the Moon for the fourth time, LM pilot Bill Anders spots the Earth coming over the Moon's western horizon through window 5. Interestingly, the crew saw the horizon of the Moon running down vertically. The gap between the Earth and the horizon is much smaller than in the later pictures. 



Facing us is the Atlantic Ocean with the terminator running between South America and Western Africa.

Soon realizing the opportunity at hand, Anders quickly geared up a color roll to take that famous image through the rendezvous window.

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General Discussion / IMU, REFSMMAT and P52
« on: November 29, 2017, 06:49:53 PM »
A very brief intro of these essential concepts of the Apollo Guidance and Navigation system.
 
The attitude (orientation) of the Apollo spacecraft was measured by the inertial measurement unit (IMU). The IMU was a set of three nested gimbals that supported a platform at the center. The three gimbals separated the platform from the spacecraft so that the orientation of the platform remained the same while the spacecraft moved around it. The spacecraft's attitude could be calculated relative to the platform's orientation.



The IMU measurements only make sense if we know which way the platform was oriented in space. Here is where the REFSMMAT comes in. A REFSMMAT (reference to a stable member matrix) is a way to express orientationis. It is a set of numbers that describe the orientation of the IMU platform. Since the spacecraft moves substantially with respect to the Earth and Moon, an inertial reference is used. The REFSMMAT is defined with respect to the stars. 

The IMU drifted out of alignment with the REFSMMAT over time. Periodically, and prior to burns, the platform had to be realigned. This realignment is called a P52. A P52 is performed by sighting two stars with a sextant. The computer compares the star's actual position with where it thinks it should be to calculate the amount the platform has drifted.

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General Discussion / the burn PAD
« on: November 29, 2017, 02:06:27 PM »
How burns were actually performed in the Apollo missions?

In preparation for each burn, mission control would calculate the currently trajectory, and the magnitude and direction of the upcoming burn. Mission control then writes down the details of the required burn on a standard grid form called a pre-advisory data (PAD). 




Capcom then reads the values on the PAD to the crew, which then writes down its own copy. The crew then reads it back to mission control to check the values have been copied correctly. Ultimately, the crew punches the numbers on the PAD into the DSKY, which then performs the required burn.

The PAD includes information on when the burn should occur, the amount by which it should change the spacecraft's velocity, and the direction in which the spacecraft should be pointing at the time of the burn.

So far we have sufficed with a throttle lever for firing up the engine. For the Steam version we are stepping up the game to include also simulation of burns performed with PAD numbers. 

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General Discussion / steam early access beta testers
« on: November 29, 2017, 01:36:06 PM »
Hi all,

As we approach the early access release date, we'd like to see if anyone's interested in beta testing in the coming weeks. Ideally we'd like to have an existing tester who is already a beta tester for the mobile version., just to keep things simple for now.

Anyone interested PM me for steam key.

Thanks!

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General Discussion / Apollo 13 facts
« on: July 28, 2017, 11:09:46 AM »
Events leading up to Apollo 13 incident. Much of this is already well known. Here is a brief summary:

* an oxygen tank with wrong voltage tolerance and faulty lining was installed in Apollo 13, leading to a series of damages including damaged powered fan wire insulation within the tank
* Apollo 13 was launched in a free return to Earth trajectory
* at 30 hours Apollo 13 made a midcourse correction taking it out of the free return trajectory
* at 56 hours into the flight as the fans were turned on, the wire shorted and oxygen tank no. 2 exploded, damaging also tank no. 1 and bay no. 4 cover. The crew lost electricity, light and water
* 5 hours after the explosion, Apollo 13 made a 35 second burn to put itself back in the free return trajectory
* on the far side of the Moon, another burn of 5 minutes was made to speed up the return journey
* 4 hours before landing the service module was discarded


Sources:
https://nssdc.gsfc.nasa.gov/planetary/lunar/ap13acc.html
https://www.nasa.gov/mission_pages/apollo/missions/apollo13.html

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General Discussion / new app icon
« on: May 07, 2017, 09:02:04 PM »
Space Simulator finally has a new app icon that does the game some justice.



It wasn't easy choosing one single image to convey all the things you can do in the game. In the end we decided to go with an orbit MFD which captures the spirit of the game well. Let us know if you like it!

10
General Discussion / NASA astronauts most searched questions
« on: April 28, 2017, 02:28:16 PM »
the most searched astronaut questions on Google are .... 
https://youtu.be/ZXvMARbZ5P8

11
General Discussion / windows close buttons (X)
« on: April 10, 2017, 04:17:38 PM »
Did you know that you can always show the close window buttons (X) by turning OFF "auto-hide windows" in the CONFIG menu. Currently, iOS users have AUTO-HIDE WINDOWS turned on by default to maximum screen space. If you are unable to find the close button (X) for the window you could try turning off auto-hide windows.

12
General Discussion / Steam keys up for grabs x10
« on: March 04, 2017, 05:33:43 PM »
Hey guys,

We had a great February with good sales a some really great reviews come through. To kick off March we have released another 10 steam keys for thoughtful reviews for the App Store. Same deal as last time, you will be rewarded with a free steam key for a copy of Space Simulator on Steam for a well-written review. 

Email me at info(at)brixtondynamics.co.uk or PM with your details.

First come first served!

13
General Discussion / GET YOUR FREE STEAM KEY HERE!!
« on: January 06, 2017, 03:20:39 PM »
Happy 2017 to all our dear forum members!

We closed 2016 with the successful release of v1.0.7 - our most stable release so far. In these coming months of the new year we are working hard to bring Space Simulator to Steam on Early Access.

To celebrate this milestone we are GIVING AWAY FREE steam keys!!!

Yes that right, we are giving away free steam keys (PC or MAC) for anyone who rates the game positively (5 stars) on the App Store with a genuine and thoughtful review (min 50 words). This offer is for v1.0.7 only so those who reviewed previously versions please update your reviews to qualify.

Those of you interested in claiming your key please email me at info[at]brixtondynamics.co.uk or PM with your review info. The key will give you FREE access to the game when it is released for Early Access on Steam later this year.

A big big thank you to those who have reviewed already (you'll get your free Steam Key too of course!)
 
Happy 2017!

14
General Discussion / Android v1.0.7 is out!
« on: December 14, 2016, 04:32:05 AM »
Space Simulator v1.0.7 is now available on Google Play!
Thank you for your patience. 

15
Betatest Area / beta iOS 1.35 ready
« on: November 15, 2016, 08:07:18 AM »
iOS beta 1.35 has been published for testing thanks!

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