Strange details about rockets/missions

[GigaG]

What are strange things that you did not know about a rocket or specific mission upon first glance?

-The Titan rockets that used SRBs did not ignite their core stages until the boosters separated. Here's a forum thread on another website discsussing why they might appear to have ignited-

http://www.secretprojects.co.uk/forum/index.php?topic=4905.0

-Dnepr rockets pull the payload with the 3rd stage instead of pushing. After second stage separation, the third stage engines extend over the sides of the rocket and appear to face "backwards" before the entire nose assembly turns 180 degrees. This was originally so the R-36 missile (which Dnepr is based off of) could spread out its nuclear warheads one at a time, which I imagine involved jettisoning one and pulling the others further. Now, it is used to put distance between different payloads as they are ejected.

-Dnepr rocket silos use a black powder gas generator (I wonder how much black powder they use...?) to push the rocket out. Then, the "tray" that the gas pushed on is jettisoned, as are some o-rings around the rocket. (I don't know what those are for, but I would guess it is to protect the joints between stages and other sensitive areas from damage resulting from the gas generator. Also, the NigeriaSat animation seems to show 4, but another one of the sources says 5.)

http://www.spaceflight101.com/denpr-2013-cluster-launch-updates.html

http://www.spaceflight101.com/dnepr-launch-vehicle-information.html

Dnepr launch procedure-

http://www.spaceflight101.com/uploads/6/4/0/6/6406961/4606578_orig.jpg

-More well-known - Some Space Shuttle flights used their OMS engines during SSME firing.

-Also about the Shuttle - Some missions used their OMS engines to go from a suborbital trajectory to an orbit with a periapsis in the atmosphere, then from an orbit with a periapsis in the atmosphere to a stable orbit. Others went directly into an orbit with a periapsis in the atmosphere and only burned their OMS engines once.

http://forum.kerbalspaceprogram.com/threads/62638-STS-131-Shuttle-Ascent-OMS-Burn

http://forum.nasaspaceflight.com/index.php?topic=16930.0

Standard Insertion-

http://www.orbiterwiki.org/images/2/2f/ShuttleAscentOMS1.png

Orbiter goes suborbital, transfer, then final orbit. (I must note that this is an exaggerated picture vertically, and IDK how accurate the abort trajectories are, but it's to show the idea.)

I believe direct insertion would have used the SSMEs to put the orbiter directly onto its transfer orbit.

[magnemoe]

-Dnepr rockets pull the payload with the 3rd stage instead of pushing. After second stage separation, the third stage engines extend over the sides of the rocket and appear to face "backwards" before the entire nose assembly turns 180 degrees. This was originally so the R-36 missile (which Dnepr is based off of) could spread out its nuclear warheads one at a time, which I imagine involved jettisoning one and pulling the others further. Now, it is used to put distance between different payloads as they are ejected.

-Dnepr rocket silos use a black powder gas generator (I wonder how much black powder they use...?) to push the rocket out. Then, the "tray" that the gas pushed on is jettisoned, as are some o-rings around the rocket. (I don't know what those are for, but I would guess it is to protect the joints between stages and other sensitive areas from damage resulting from the gas generator. Also, the NigeriaSat animation seems to show 4, but another one of the sources says 5.)

http://www.spaceflight101.com/denpr-2013-cluster-launch-updates.html

http://www.spaceflight101.com/dnepr-launch-vehicle-information.html

Dnepr launch procedure-

http://www.spaceflight101.com/uploads/6/4/0/6/6406961/4606578_orig.jpg

The O rings is to keep the rocket away from the silo walls, if you use cold launch from silo, that is shoot the rocket out like an bullet then ignite rocket in the air you will need thigh fit and the rocket is not designed to hit the silo walls, the O rings might even have small wheels, then out of the silo all this is jettisoned. Not sure how the US solves it for submarine launches as the rocket don't drop anything going up, however it might be dropped in the water. And yes the 3rd stage system looks strange but makes sense for deployment.

[GigaG]

Makes sense. That picture at-

http://www.spaceflight101.com/uploads/6/4/0/6/6406961/4606578_orig.jpg

shows the silo being narrow, which in retrospect seems to make sense. That diagram calls them "sealing rings." . As you said, you need a tight fit, and I would imagine that one of the roles of these rings is to keep gas from escaping around the missile. And if you are using such a narrow tube, their use as bumpers makes sense too.

[Budgie]

Early shuttle missions were never scheduled over the Dec 31/Jan 1 period, as NASA was unsure that the onboard computers would perform correctly after the year change

I'll add more if I remember them

[Tex]

I didn't realize that the external fuel tank on the STS was actually orange underneath, and was painted white until about STS-4 (I think). They finally stopped painting it to save the roughly 400lbs of paint from the external tank.

[GigaG]

^600lbs of paint (sorry, I kinda have to be nitpicky.)

Also, STS-2 was the last white tank mission. STS-4 is significant in being the Space Shuttle's last 2-man "test flight."

[magnemoe]

Early shuttle missions were never scheduled over the Dec 31/Jan 1 period, as NASA was unsure that the onboard computers would perform correctly after the year change

I'll add more if I remember them

In orbit this should be solvable with an reboot or other tricks. No I would not launch at midnight as an bonus firework.

You have run into computer issues then crossing the datum line or flying below sea level at death wally and death sea so it makes sense being careful.

[Bill Phil]

^600lbs of paint (sorry, I kinda have to be nitpicky.)

Also, STS-2 was the last white tank mission. STS-4 is significant in being the Space Shuttle's last 2-man "test flight."

They made lighter and more improved versions of the external tank over time. Pretty cool.

Orbiters used to have ejection seats. Same with Gemini.

[The Yellow Dart]

As part of the Vostok 1 mission plan, Yuri Gagarin had to bail out of his capsule after reentry and parachute to the ground rather than stay in the spacecraft. The USSR kept this information secret for many years after, for fears that it would not be accepted as the first space flight due to the pilot not returning to earth with his ship.

Edited March 23, 2015 by The Yellow Dart

[GreenWolf]

Every single Soviet/Russian rocket for launching manned spacecraft has been based off of the R7, the very first ICBM.

Zvezda, the core of the ROS of the ISS, was originally built in 1985 as part of the Salyut program, with the designation DOS-8, and was intended to be used in Mir-2. Its immediate predecessor, DOS-7, formed the core of Mir.

The Functional Cargo Block (FGB) modules on the ISS and Mir were derived from the FGB spacecraft, which was to be used as the service module for the TKS spacecraft. The TKS spacecraft was intended for use as crew transport and resupply craft for the Almaz military space stations. Almaz was eventually ended, and the TKS spacecraft never flew, but the FGB lives on.

[Kibble]

the TKS spacecraft never flew, but the FGB lives on.

TKS (with VA and such) actually did fly a couple times, but without any cosmonauts.

Also don't forget MLM! I bet DOS and FGB will fly for hundreds of years to come.

[GreenWolf]

TKS (with VA and such) actually did fly a couple times, but without any cosmonauts.

Also don't forget MLM! I bet DOS and FGB will fly for hundreds of years to come.

Huh, I thought they only flew separately. Guess you learn something new everyday.

And yeah, I would be very surprised if future Russian space stations aren't based off of the tried-and-true DOS/FGB combo. If it ain't broke, don't fix it, and all that.

[Kryten]

Also don't forget MLM! I bet DOS and FGB will fly for hundreds of years to come.

With current planning that's a bet you'll lose. After Krunichev's general incompetence with MLM, future modules are using Energia's new NEM design.

[Budgie]

I always love the story about switching "SCE to AUX" on Apollo 12. That was a near mission abort, until Mission Control and astronaut Alan Bean figured out an obscure fix:

http://en.wikipedia.org/wiki/Apollo_12#Launch_and_transfer

[Ten Key]

The Spirit and Opportunity Mars rovers both have aluminum from the World Trade Center built into them.

http://en.wikipedia.org/wiki/Rock_Abrasion_Tool

[GigaG]

I always love the story about switching "SCE to AUX" on Apollo 12. That was a near mission abort, until Mission Control and astronaut Alan Bean figured out an obscure fix:

http://en.wikipedia.org/wiki/Apollo_12#Launch_and_transfer

That reminds me - I saw in one documentary that the problems in the first stage of the partially failed Apollo 6 mission - severe resonance vibration - would have required a launch abort if the flight was manned.

As you may also know, that mission later suffered a double second stage engine failure (out of 5 engines total.) That documentary, along with Wikipedia, shows that the first failed engine had a broken hose in an ignition system if I remember correctly, and the computer was partly crosswired and shut down another engine. Wikipedia states that this was also vibration, and tests on the ground in the atmosphere covered up the issue.

Then the S-IVB underperformed due to a similar issue in its engine. Furthermore, it failed to reignite for a simulated trans-lunar injection, requiring the Apollo spacecraft to use its Service Module engine to get as close to the high-speed reentry as possible.

Another thing - while Apollo 13 is known for its Service Module oxygen tank failure, it experienced problems similar to Apollo 6 on a less severe scale. Due to vibrations and combustion instability (again, Wikipedia is providing this info), the center engine of the second stage failed. This is shown in the Apollo 13 movie. Nevertheless, Apollo 13 was able to get onto its planned trajectory towards the Moon (the more famous oxygen tank failure is unrelated.)

The Spirit and Opportunity Mars rovers both have aluminum from the World Trade Center built into them.

http://en.wikipedia.org/wiki/Rock_Abrasion_Tool

I've heard of this before. The US also incorporated a few tons of WTC steel into the USS New York battleship (yet again, fact-checking from Wikipedia, but I knew about this before.)

Edited March 23, 2015 by GigaG

[Frida Space]

Maybe most of you knew this already, but I think it's still worth sharing: the Atlas 2 rocket that brought John Glenn into orbit had an aluminum skin which was extremely thin in order to reduce the rocket's body weight. In fact, it was so thin that it had to be constantly pressurized in order to maintain its structural integrity. If it lost pressure, the whole rocket would just have collapsed.

[Armchair Rocket Scientist]

Maybe most of you knew this already, but I think it's still worth sharing: the Atlas 2 rocket that brought John Glenn into orbit had an aluminum skin which was extremely thin in order to reduce the rocket's body weight. In fact, it was so thin that it had to be constantly pressurized in order to maintain its structural integrity. If it lost pressure, the whole rocket would just have collapsed.

Doesn't the Centaur still use this technology?

[magnemoe]

Doesn't the Centaur still use this technology?

Possible, however it will be simpler as centaur would need more structural strength under first stage and booster burns, then itself is burning it would be far more gentle.

[Bill Phil]

Maybe most of you knew this already, but I think it's still worth sharing: the Atlas 2 rocket that brought John Glenn into orbit had an aluminum skin which was extremely thin in order to reduce the rocket's body weight. In fact, it was so thin that it had to be constantly pressurized in order to maintain its structural integrity. If it lost pressure, the whole rocket would just have collapsed.

You mean the LV-3B?

And yes, Centaur still uses this technology. Atlas V doesn't use it anymore. It uses an isogrid structure. Atlas III was the last Atlas rocket to use balloon tanks, as they are called.

[Frida Space]

You mean the LV-3B?

And yes, Centaur still uses this technology. Atlas V doesn't use it anymore. It uses an isogrid structure. Atlas III was the last Atlas rocket to use balloon tanks, as they are called.

Where I read it it says Atlas 2, however I'm guessing all Atlases at the time were built in a similar fashion (at least the aluminium skin)

Do correct me if I'm wrong though, I love vintage space stuff and I'd like to get my facts right!

[GigaG]

That happened once during a fueling operation (or some fueling test) for an Atlas-Agena. The result can be seen here at 0:23.

Another video (the video misidentifies the rocket as a Thor-Agena)-

Despite spilling the fuel (you can see it spill out as the rocket collapses), there was no fire AFAIK. I would imagine that the Agena stage either wasn't fueled or stayed intact, as if it had ruptured, it would have exploded, as it used hypergolic fuel and oxidizer.)

[Hasegawa]

Where I read it it says Atlas 2, however I'm guessing all Atlases at the time were built in a similar fashion (at least the aluminium skin)

Do correct me if I'm wrong though, I love vintage space stuff and I'd like to get my facts right!

I believe the tanks for the pre-Atlas V were built out of stainless steel, and the Centaur tanks are still are.

[Bill Phil]

Where I read it it says Atlas 2, however I'm guessing all Atlases at the time were built in a similar fashion (at least the aluminium skin)

Do correct me if I'm wrong though, I love vintage space stuff and I'd like to get my facts right!

With or without Roman numerals? The Atlas II flew in the 90s...

I just looked it up. I think it is in fact the LV-3B.

What source are you using?

I like vintage space stuff, too. I guess that's why I like the soyuz rocket so much... Derivatives of the original still fly today.

[Frida Space]

What source are you using?

I'm following an online course on spaceflight over at edX, given by MIT teacher and ex-astronaut Jeff Hoffman. The course is really well done, however it's designed to be very basic (thanks to KSP I knew most of the stuff already), so it could be that he was mentioning it just as a side thing, a fun fact, and he didn't really care about the exactness of the statement. From my extensive 2-minute google research, I think you might be right. Thanks!

Btw, in the transcript it says Delta 2. But again, maybe they just wrote it down without paying too much attention, I'm guessing the guys that wrote down the transcripts probably aren't rocket scientists and didn't even think there could be a difference between 2 and II. Just guessing.