Author Topic: The Spaceflight Thread  (Read 3581 times)

0 Members and 1 Guest are viewing this topic.

Re: The Spaceflight Thread
« Reply #180 on: November 07, 2018, 11:36:58 AM »

* EROSION.jpg (315.05 kB)

Re: The Spaceflight Thread
« Reply #181 on: November 07, 2018, 11:48:35 AM »

Re: The Spaceflight Thread
« Reply #182 on: November 07, 2018, 12:26:45 PM »
Here's a shot showing the one side booster having an issue during separation from the Soyuz abort flight.  It's the one on the left in the photo.

Re: The Spaceflight Thread
« Reply #183 on: November 07, 2018, 12:38:12 PM »


What did he mean by this? lol

That she will be coming back home with really bad bone density? ::)

Re: The Spaceflight Thread
« Reply #184 on: November 07, 2018, 02:53:50 PM »
What did he mean by this? lol

Sounded like:

[...] I just, uh, congratulations, amazing, what an amazing achie--uh, thing that you've done [...]"

Seems legit.

Re: The Spaceflight Thread
« Reply #185 on: November 15, 2018, 06:00:06 PM »
ust over an hour ago, Development Engine(DE)0525 completed a 650 second hotfire test with 113% Rated Power Level.  Originally the RS25 engine ran at 100%, over the years upgrades to the engine have allowed the engine to be run at levels higher than before.  Instead of recalibrating for the new 100% its easier to simply say the power level is at 113%.  They are testing some additive manufacturing(3-d printed) engine components


Re: The Spaceflight Thread
« Reply #186 on: November 15, 2018, 06:27:02 PM »
ust over an hour ago, Development Engine(DE)0525 completed a 650 second hotfire test with 113% Rated Power Level.  Originally the RS25 engine ran at 100%, over the years upgrades to the engine have allowed the engine to be run at levels higher than before.  Instead of recalibrating for the new 100% its easier to simply say the power level is at 113%.  They are testing some additive manufacturing(3-d printed) engine components

I like that some Stoner/Rocker logic, coach and sales director motivation, and sales and marketing campaigns is being adopted by rocket scientists and engineers.... "but these goes to 11," "give 110% percent" etc.....

Re: The Spaceflight Thread
« Reply #187 on: December 03, 2018, 08:55:50 AM »
And the next 3 have made it to orbit safely. 

Hey, what do you get when you put a Russian, an American and a Canadian in a tin can?

Congrats to David St Jacques and Anne McLain representing the Americas on orbit.


Re: The Spaceflight Thread
« Reply #188 on: December 03, 2018, 12:26:00 PM »
Soyuz MS-11 has successfully docked to ISS.

Currently the crews are equalizing the air pressures between the Soyuz Orbital and Descent stages.
Next event is hatch opening.

Attached pic shows the ISS with all the different cargo and crew vehicles docked to ISS after Soyuz MS-11 docked.


Re: The Spaceflight Thread
« Reply #189 on: December 03, 2018, 12:32:01 PM »
The Cosmonauts and Astronauts have doffed their Russian Sokul space suits as they're safely docked to ISS.

Re: The Spaceflight Thread
« Reply #190 on: December 04, 2018, 12:29:14 PM »
And after a successful docking using the Soyuz automatic docking system, the Northrop-Grumman(formerly Orbital ATK) Cygnus and Space Exploration Tech Corp.'s Dragon cargo resupply vehicles BOTH do not dock to the ISS, they approach close-by and then are grappled via the CANADARM-2(SSRMS-Space Station Remote Manipulator System) and then berthed to the ISS under complete control of the SSRMS.  Here is the hatch opening of the ISS crew and Soyuz MS-11 spacecraft greeting each other.

If you need to get away from the ISS in a hurry, you dont want your lifeboat to have to be brappled by a CANADARM and then released to safety.  You want top be able to get to your lifeboat, close the hatches and jettison your lifeboat away from the ISS as quickly as possible. Of course this would be necessary in the most dire of circumstances. eg ISS gets hit by a not so "micro",  micrometeroid and is losing pressure at a very high rate. Let's hope that your Soyuz lifeboat isnt the structure that has been breached.

Due to the fact that crews that fly up to ISS on Soyuz space craft, almost always return to Earth aboard the same Soyuz spacecraft the "couches" that crew lay down upon prior to launch and prior to undocking from ISS, are vacuum molded custom "liner" for each crewmember, while it is possible to swap out these custom "liners" it is infrequently performed for safety reasons. The Soyuz hits the ground hard, it fires retrograde rocket motors just a few feet from the ground in order to reduce the G loading upon touchdown. The movie Gravity emphasizes the Soyuz retrograde rockets and uses them for propulsion to get to the Chinese space station Shenzous.

The amount of time that a Soyuz craft can remain in space is about 200 days, any longer and its propellants begin to decompose, so 200 days was chosen as a safe on orbit time for Soyuz.  This is why the current ISS crew who rode up on Soyuz MS-09 had to leave on December 21st whether there was new crew aboard ISS or not. The Soyuz MS-09 was reaching the end of their safety net in regards to the Soyuz vehicles on-orbit time constraints related to propellant stability.  That would have been horrible if the Soyuz MS-11 crew weren't able to reach ISS before the 21st be it due to technical issues, another abort or some other issue.  The 18 year
The Soyuz vehicle takes up to 3 humans to orbit, docks with the ISS, then sits there for up to 200 days on orbit, with its hatches open, acting as a lifeboat waiting just in case the 3 crewmembers need to evacuate to their Soyuz lifeboats.  One scenario is that the crew evacuates to the Soyuz and awaits further instructions with the ISS/Soyuz hatches in the open positions. The other emergency scenario includes crew retreating to their respective Soyuz vehicles, get inside and close the hatches.  There has been a few times where  a predicted piece of space debris or asteroid may come within a few kilometers. The crew enters their Soyuz crafts leaving the hatches open.  Occasionally a Debris Avoidance Maneuver(DAM) may be completed, but the amount or speed at which you can actually increase or decrease the altitude of the ISS's almost 1 million pounds is very limited.  The stations own thrusters can be used, and depending on what cargo/crew vehicles are docked to the ISS, their own propulsion can be used to not only change the ISS's altitude for DAMs, but also to boost the ISS's continually decreasing altitude.  While orbiting at around 408 kilometers(253 miles) the ISS is almost completely out of the Earths atmosphere, but there is still sufficient molecules of atmosphere to induce drag upon the ISS which decreases its velocity, the slower it travels the lower its altitude becomes.  It likes to orbit at about approx 28163km/17500mph  which gives you an Earth orbit every 90 minutes.  Compare the ISS orbit to the Hubble Space Telescopes altitude which is 540kms(336miles) which is about as high as the Space Shuttle Orbiter Vehicles to could reach, both for the Telescopes initial deployment on April 25 1990 during STS-31 and also during its various servicing Missions
Servicing Mission #1 STS-61 Endeavour in December 1993,
Servicing Mission #2 STS-82 Discovery in Feb 1997
Servicing Mission #3A STS-103 Discovery in December 1999
Servicing Mission #3B STS-109 Columbia in march 2002
Servicing Mission #4 STS-125 Atlantis in May 2009.  Servicing Mission #4 almost didn't occur as NASA administrator Shaun O'Keefe in the wake of the STS-107 Columbia entry failure didn't want to risk human lives to extend the service life of HST.  Well a new NASA administrator was installed in March 2005 and he, Michael Griffin OK'd one final serving mission if it hadn't, the Hubble Space Telescope would NOT be performing science missions at this moment.

""In October 2006 Griffin gave the final go-ahead, and the 11-day mission by Atlantis was scheduled for October 2008. Hubble's main data-handling unit failed in September 2008, halting all reporting of scientific data until its back-up was brought online on October 25, 2008. Since a failure of the backup unit would leave the HST helpless, the service mission was postponed to incorporate a replacement for the primary unit.""

While the Space Shuttle Program was up and running, the ISS was kept at a lower altitude than it's current 408 kilometers/254miles.  I remember the altitude being around 330-340kms(205-211 miles) when the US Space Shuttle was in operation.  This lower altitude was used in order to help the Space Shuttle get the heaviest payloads up to the ISS orbit.  For every degree above Florida Kennedy Space Centers 28.5 the Shuttle lost roughly 500 pounds of cargo capacity. Since the ISS orbits on a 51.6 inclination thats 23.1 higher for hHazakistan launches than KSC USA launches.  23.1 x 500 pounds=11,500 pounds.  So launching to the ISS 51.6 orbit automatically causes the payload capacity to take a hit of 11,500 pounds.
NASA's answer was to either to increase thrust, or to lighten the load(For each pound of weight reduction, the cargo-carrying capability of the shuttle spacecraft was increased almost one pound.), or both. 
In order to increase thrust the 5 segment solid rocket booster(SRB) which provided 3.6 million pounds of thrust was developed to make up that penalty, the usual SRBs were 4 segment units providing just over 3 million pounds of thrust each.  It should be noted that the new SLS super-rocket will use 2 of the new 5 segment SRBs, which have yet to fly. They have only been fired in full scale development firings.  Both the newer 5 segment and the 4 segment Solid Rocket Boosters fire for approx. 122-127 seconds.
In order to lighten the load, NASA decided to once again lighten up that massive aluminum External Tank(ET) which holds all the Liquid Oxygen(LOX and Liquid Hydrogen(LH2) that the 3 RS25 Space Shuttle Main Engines would require to fire at 104.5% for over 8-1/3 minutes or approx 500 seconds.

There have been 3 iterations of the External Tank(ET):

1) Standard Weight Tank (SWT)35,000 kg (77,000 lb) inert.  This tank was used for the test flights, STS-1 though STS-4 and for 2 operational missions, STS-5 and STS-7.  The first 2 tank for STS-1 and STS-2 were painted white in order to protect the Spray On Foam Insulation(SOFI) from UV damage as they weren't exactly sure how long these test launches would be sitting out on the pad exposed to the elements. As it turns out, the SOFI darkens in colour the more it is exposed to UV light.  Newly sprayed tanks will have a very light brown colour, while tanks exposed for some time will be darker in colour.  Often times you'll see dark brown acreage interspersed with very light brown sections.  This is where some foam has had to be removed in order to access some portion of the tank for repairs. Then once repairs/testing was completed, new SOFI would be applied and seeing that these portions or re-applied foam have not yet been exposed to UV light whereas the rest of the foam has already been exposed, large variations of light to dark brown colours are visible.
For STS-3 and 4 the ETs were NOT painted white, as such, 600 pounds were saved simply by the weight of the paint being absent. Another several hundred pounds were saved by removing the proven unnecessary anti-geyser lines that ran the length of the tank.

2) Light Weight Tank(LWT) each weighed approximately 30,000 kg (66,000 lb) inert. The first LWT was flown on STS-6 and the last LWT was used on the STS-107 Columbia flight which failed during the entry phase of the mission.
""The weight reduction from the SWT was accomplished by eliminating portions of stringers (structural stiffeners running the length of the hydrogen tank), using fewer stiffener rings and by modifying major frames in the hydrogen tank. Also, significant portions of the tank were milled differently so as to reduce thickness, and the weight of the ET's aft solid rocket booster attachments was reduced by using a stronger, yet lighter and less expensive titanium alloy.""

3) Super Light Weight Tank (SLWT)
58,500 lb (26,500 kg) inert.
Length: 153.8 ft (46.9 m)
Diameter: 27.6 ft (8.4 m)
Gross Liftoff Weight: 1,680,000 lb (760,000 kg)

LOX Tank
Length: 54.6 ft (16.6 m)
Diameter: 27.6 ft (8.4 m)
Volume (at 22 psig): 19,541.66 cu ft (146,181.8 US gal; 553,358 l)
LOX mass (at 22 psig): 1,387,457 lb (629,340 kg)
Operation Pressure: 34.736.7 psi (239253 kPa) (gauge) (absolute)

Intertank (portion of the ET where the Liquid Oxygen Tank and the Liquid Hydrogen Tank came together.

Length: 22.6 ft (6.9 m)
Diameter: 27.6 ft (8.4 m)

LH2 Tank
Length: 97.0 ft (29.6 m)
Diameter: 27.6 ft (8.4 m)
Volume (at 29.3 psig): 52,881.61 cu ft (395,581.9 US gal; 1,497,440 l)
LH2 mass (at 29.3 psig): 234,265 lb (106,261 kg)
Operation Pressure: 3234 psi (220230 kPa) (absolute)
Operation Temperature: −423 F (−252.8 C)

The SLWT was first flown in 1998 on STS-91 and was used for all subsequent missions except for STS-99 Endeavour and STS-107 Columbia
""The SLWT had basically the same design as the LWT except that it used an aluminium-lithium alloy (Al 2195) for a large part of the tank structure. This alloy provided a significant reduction in tank weight (~3,175 kg/7,000 lb) over the LWT. Manufacture also included friction stir welding technology. Although all ETs produced after the introduction of the SLWT were of this configuration, one LWT remained in inventory to be used if requested until the end of the shuttle era. The SLWT provided 50% of the performance increase required for the shuttle to reach the International Space Station. The reduction in weight allowed the Orbiter to carry more payload to the highly inclined orbit of the ISS.""

The Core Stage of the new Space Launch System which uses 4 of the same engines as the Space Shuttle, in fact 14 of the 16 remaining RS25-D engines have in fact already flown to space on Space Shuttles. The other 2, Main Engine (ME) 2062 and ME-2063 were built in 2010 and 2014 respectively. Both ME-2062 and ME-2063 are due to fly on EM-2, the first crewed SLS mission which will fly 4 astronauts in a multi-trans-lunar injection (MTLI), or multiple departure burns, and includes a free return trajectory from the Moon. Basically, the spacecraft will orbit Earth twice while periodically firing its engines to build up enough velocity to push it toward the Moon before looping back to Earth.

1) fire burning in microgravity
2) Space Shuttle External Tank cutaway
3) Solid Rocket Booster segments for EM-1 there are 5 segments for each booster for SLS
4) External Tank from STS-1 Columbia just after being jettisoned and allowed to fall back to the Indian Ocean.  The black marks at about the shoulder level below the curvature of the nose are from the Booster Separation Motors which fire and actually push the SRBs away from the External Tank and Orbiter Vehicle. There are 3 Booster Separation Motors at the top of each Booster, their exhaust impinges against the ET and blackens it.  The very end of the ET is blackened as there is major heating and convection currents which burn the end of the ET.

5) A short clip which shows the forward Booster Separation Motors burning and pushing the SRBs away from the External Tank.  This happens at about 146,000 feet about 123 seconds after they first ignited.  They are only jettisoned after the thrust chamber pressure in each SRB is less than 50psi.  The front Reaction Control System is fired in order to keep most of all the soot and dirt from these Booster Separation Motors off of the front facing windows of the Orbiter.  See how toasty black the rear end of the ET gets. 
Here is the Booster Sep Motors video

Re: The Spaceflight Thread
« Reply #191 on: January 06, 2019, 07:55:19 PM »

Re: The Spaceflight Thread
« Reply #192 on: January 06, 2019, 08:17:38 PM »
Kewl video, tnx.