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Space Shuttle: Meeting with Hubble at 300 Nm

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Space Shuttle: Meeting with Hubble at 300 Nm

Postby GinGin » Sun Sep 08, 2019 9:31 pm

A sum up of my last Journey in Space, meeting Hubble after 6 hours of phasing.

Night Launch Over Florida.
Midnight, clear sky and no moon.
All good for a launch towards Hubble.


Night Pad, getting ready to fire 7 millions of pounds.

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All procedures complete, Instructor global view from Mission Specialist seat

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Liftoff, rocket is in the air, safe journey.

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45 s into the flight, one of the most tricky phase here. Max Dynamical Pressure on the Orbiter and Max wing bending moment.
Negative Angle of attack and adaptative thrust reduction to allow the Shuttle to go through a thin safe hole in the flight envelop.

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Bye Bye Florida

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Almost at the end of stage 1, thinner atmosphere and 6 mn to go

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SRB separation on time

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Speed is rapdily increasing.
13000 Km/h of inertial speed and the 2 EO just blanked.
We can now safely endure a 2 engine failure without falling below 265 kfeet , safe external tank : Single Engine Droop boundary.

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Enjoying the sound of silence at 100 km above the Ocean, full darkness there

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MECO 00:08:29

MECO on time after 8 minutes and 30 seconds at 350 kfeet.
Orbit shape of 289 Nm by 58 Nm, Apogee in a big half hour. Hubble is 30 ° in front of us with a relative inclination of 0.17 °. A small burn and nodal precession will help to decrease that towards 0 for a close encounter of the shining satellite

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The usual work on pilot side then.
APU shutdown, Main engines Helium system and electrical controllers safing and ET door closure.

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Also reconfiguration of Cue cards for next burn

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Inertial orbital drift waiting for OMS 2 to start our phasing.
Some nice view from Commander window

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OMS 2 MET 00:53:26
1330 Nm behind and 72000 feet below


Let's work on OMS 2 burn.
Hubble will be 20 ° ahead of us at that time.
Our apogee is almost at the same height than her ( 289 for us and 300 for the target)

Goal is to be in three orbit 0.8 ° ish behind her ( 330 kfeet) to initiate final phase of rendez vous ( fine tunning to match our relative speeds)
Phasing is done by height difference.
The greater is the difference between the two orbit altitude, the greater will be the catch up rate .


Rule of thumbs: For every 13 Nm difference between ( target apogee plus perigee) and ( chaser apogee plus perigee), catch up rate is increase by a degree per orbit
Another version: 3500 feet of difference gives 17400 feet of catch up rate every orbit



Target at OMS2 is a difference in sum of 186 Nm for a catch up rate of 14.3 degrees
We will raise the Perigee then to 127 Nm with a 117 ft/s prograde burn

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Burn in progress

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Good burn and state vector coherent
LVLH holding overhead Australia

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Post Insertion


Time for Post Insertion actions now that we are safely in Orbit
Time consuming GPC reconfiguration done, Every bus are well assign.
3GPC still on, 2 for Guidance,control and navigation. 1 for system management.
I will let you guess which is what

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A bit of MEDS screens reconfiguration also

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Payload Bay doors opening and full Neon

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Planar Change ( PC) MET 01:19:46

A small burn on the - Y axis to reduce the relative inclination from 0.16 to 0.04 °
Purely state vector perpendicular burn at the descending node.
70 ft/s spent there





Phasing burn ( Nc-1) MET 01:40:00


Perigee there, 123 Nm above Earth, kinetical energy at its maximum.
We already catched up Hubble by 7 ° in half an Orbit, standing in front of us at just 800 Nm now.

A small burn to put our Apogee even closer to Hubble's one
From 291 Nm, we will raise it to 299 nm
15 ft/s of prograde burn

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Height Adjustment Burn ( NH) MET 02:25:30
440 Nm behind Hubble and 20 kfeet below



One Orbit after OMS 2
Apogee again and we are 6.8 degrees behind Hubble ( almost like forecasted with a 14 ° ish of catch up rate per orbit)
Time to really slow it down now.
We want to decrease the catch up rate from 14° to 4° per orbit.
Hence the perigee will be raised to 253 Nm to have a sum difference of 52 Nm, giving a 4 ° ish of catch up rate

Biggest burn here, of 230 ft/s prograde

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Nice visuals on it

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System Management

A bit on insight of the system management pages we can access to and we have to monitor for failure or incorrect tendency

First, a sum up of environment and main parameters ( like elec)
Environment page is interesting
Cabin pressure ( in Psia) and O2/H2 flow for cabin pressurization
Temperature of avionics bay ( water and air cooled )
Also, a look on Supply H2O tank ( water coming from fuel cell anod where H2 reacting with OH- will give electrons and water )

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Electrical then.
A sum up of DC voltage on the three fuel cells and Main bus ( A, B 1 C)
AC voltage also, three phased coming from inverter changing DC fuel cells current to AC current for motors for example, that need to work in one way or the other ( payload bay doors, ET umbilical doors, etc)
CNTL for controllers, which are buses giving feed back on switch positions, etc
And Amperage on each fuell cell, with a total of 477 there

Fuel Cells page to have insight on what is going on in each fuel cells ( Stack temperature, and several check points like Exit temperature giving temperature after the H2 flow exits a condenser in order to separate a first time water from H2 before being re injected in the fuell cell)
Any fuel cells voltage below 28 V with a high O2 flow would be a sign of contamination and fuell cell performance degradation , leading to a purge to recover full voltage capacity.
We can see that the fuel cell 3 is almost at its maximum of 31 V with a low O2 flow, meaning it is not actively used.
We have some spare performance in case of a fuel cell failure, triple redundance there.

Cryo page for insight on how well is the cryo O2/H2 storage
Heaters are there to slighly heat the tanks when they are depleting, in order to keep the pressure constant for a maximum storage performance

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Finally, Thermal Management
Hydraulic for recicrulation of hydraulics fluid via recirculaiton pumps
I forgot the heaters to keep the lines heated, which can be seen by negative temperatures for elevon, rudder, bodyflap etc

Propellant thermal in order to keep RCS and OMS lines/pods heated to avoid cold ergols into the lines ( degradated performance for subsequent burns)

APU/Environment thermal for heating of APU lines and Flash evaporators feelindes and parts
A very intersting parameters there is the rad in Temp and evap out T
It will give the temperature of Freon before entering the cooling loop via radiators and/or Flash evap
98 ° before, 43 ° ( 39 ° nominally ) after.
Everything nominal there.

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Phasing Burn 2 (Nc-2) MET 03:59:30
200 Nm behin and 3000 feet below



One more Orbit done, we are now 3.1 ° behind Hubble.
We want to be in another orbit ( third one since OMS 2) at 0.8 ° behind her.
Hence, we will decrease the catch up rate around 2 ° per orbit ( halved it)
Perigee will be increase to 277 Nm, for a 28 ft/s prograde burn
Orbit is slowly matching Hubble one.

Approaching to our apogee

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NC-2 burn parameters, 3 mn before the burn

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Good burn and here we go for another orbit, gaining speed while falling to our 277 Nm perigee

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Phasing is almost done.
I really like that motion plot, giving a strong idea of what is going on, and what is our relative displacement regarding the target.
Final part of rendez vous is coming alive

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Final Phasing burn ( Nc-3) MET 05:33:00


We are where we wanted to be since OMS 2 after three orbits.
322 kfeet behind Hubble, a tad above her and almost in the same plane.
We will now reduce even more the catch up rate for our close encounter

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A nice overhead view of the Earth Clouds

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Sunset and Neon

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Lambert Targeting

Rendez vous in 45 Mn
After some star tracker pass and Rendez vous radar switched on, it is time for Lambert equations to pinpoint the rendez vous with the Spec 34 page
A quite fast rendez vous final phase there.
Phasing was well done, hence no need for big speed adjustment close to the target.

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Hubble finally in sight, quietly waiting for us

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Ready for an R bar intercept and a long and fastidious grapple and inspection procedure

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After 7 hours of space travel and with 54 % of propellant reamining, we can safely say that we meet up there our shining lady :)
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Re: Space Shuttle: Meeting with Hubble at 300 Nm

Postby wlbragg » Sun Sep 08, 2019 11:04 pm

Fascinating, that is a considerable amount of time and a real testament to the validity and realism of the simulation.
Kansas(2-27-15)/Ohio/Midwest scenery development.
KEQA (2-27-15), 3AU, KRCP Airport Layout
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Re: Space Shuttle: Meeting with Hubble at 300 Nm

Postby GinGin » Mon Sep 09, 2019 12:18 pm

And not a single game crash :)
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Re: Space Shuttle: Meeting with Hubble at 300 Nm

Postby V12 » Wed Sep 11, 2019 12:38 pm

Perfect !
Fly high, fly fast - fly Concorde !
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Re: Space Shuttle: Meeting with Hubble at 300 Nm

Postby amalahama » Wed Sep 11, 2019 6:53 pm

Hey GinGin,

Have you thought of publishing one of your spaceflights in YouTube, with written/spoken notes? It would totally rock and would become a priceless training aid
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Re: Space Shuttle: Meeting with Hubble at 300 Nm

Postby F_D2760 » Wed Sep 11, 2019 7:21 pm

Hi,
Amazing.
Regards
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Re: Space Shuttle: Meeting with Hubble at 300 Nm

Postby GinGin » Thu Sep 12, 2019 5:08 pm

Thanks guys

@Amalahama: Eventually yes :)
There is already tons of tuto and docs. But a video one might be a good complement indeed.
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