66 votes
Accepted

Was the payload bay of the Space Shuttle depressurized before launch?

Not before launch, during launch. The structure of the payload bay (and the other Orbiter compartments except for the crew compartment) was not strong enough to withstand either crush loads from a ...
56 votes

ISS Structural Integrity

"Is that really all that holds it together?" Well, no. There are several different attach mechanisms used to hold the various parts of the ISS together. The mechanism used depends on what kind of ...
39 votes
Accepted

ISS Structural Integrity

The ISS is pressurized to nominally Earth sea-level atmospheric pressure - about 1013hPa (14.7 pounds per square inch). Docking rings look to be about 2.2 meters in diameter, so appear to have a cross-...
  • 17.2k
27 votes
Accepted

Docking in space

There were issues with the docking system so it possibly it needed to be more complex. Docking is always a trade off of mechanism simplicity VS event simplicity. Just using pipe flange with bolt holes ...
24 votes
Accepted

Can ISS fold its solar panels?

The long boom holding the panels can be retracted (the term used instead of "folding"). It is not done lightly, for fear of not being able to reverse it. It has only been done a few times, once ...
17 votes
Accepted

How do satellite motors keep themselves cool and lubricated?

There is only one regular car in space, but it doesn't have a piston engine — as leftroundabout pointed out so helpfully, it is a Tesla, an electric vehicle. Even without piston engines, however, ...
16 votes

How do satellite motors keep themselves cool and lubricated?

Satellites never use Internal combustion engines like in cars (obviously they do have propulsion engines that require combustion for station-keeping purposes) in them, they mostly use solar-power and ...
13 votes
Accepted

What types of decoupling mechanisms to separate spacecraft are used in spaceflight?

According to The Logic of Microspace: Technology and Management of Minimum-Cost Space Missions by Rick Fleeter (Microcosm & Kluwer, 2000), p.130, the de-facto standard mechanism for separating ...
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13 votes

How do satellite motors keep themselves cool and lubricated?

There are a few elements here that are worth considering. Part of the story is to do with the purpose of the engines you might find in a satellite, or space vehicle for that matter. While the other ...
12 votes
Accepted

How do the booms on ISS (and other spacecraft) extend and retract?

tl;dr - each bay of the mast collapses as it is pulled into the cylinder. The ISS solar array mast is a truly ingenious mechanical structure which can be retracted into a remarkably small canister. ...
12 votes

Connection between SM an CM

They were connected by an umbilical, that curved around the edge of the heat shield. Source
12 votes
Accepted

How are umbilical connectors held in place until their intended detachment?

This paper surveys a large number of umbilical designs. For the mechanical connections to the vehicle, it lists two types of detachable locking devices. The type of locking mechanism ...
11 votes
Accepted

Is there an equivalent of the Dragon 'claw' and Apollo umbilical fairing between the Soyuz crew and service modules?

There is an "intermodule umbilical" that is "shed" at module separation. In preparation for the split of the modules, external cable lines connecting the three main sections of ...
11 votes

How do satellite motors keep themselves cool and lubricated?

For a satellite you need something that functions in zero gravity for many years without any maintenance or repair. Therefore piston engines are not used. To produce electrical energy solar cells are ...
  • 47.8k
10 votes

What holds the Space Shuttle orbiter itself stable on the launch pad?

The only hold-downs are the eight SRB bolts. This leads to the "Shuttle twang" when the main engines start. They're pushing to one side of the SRB hold downs, so they bend the stack just a bit. ...
  • 12.4k
9 votes
Accepted

Help understanding this Apollo 11 docking probe image, what are we looking at, and from where?

That's the "probe and drogue". The complicated thing is the probe, the conical thing is the drogue. The docking between the Apollo command and lunar modules employed the use of a "probe and ...
9 votes

Transfer of astronauts from CSM to LM

After docking both the probe and the drogue were removed, extracted from the tunnel and stored somewhere. Here is the transcript from Apollo 11. Some excerpts: 055:19:49 Duke: Apollo 11, Houston. It'...
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8 votes
Accepted

What holds the Space Shuttle orbiter itself stable on the launch pad?

Prior to launch the Orbiter was mounted on the External Tank and the External Tank was mounted to the Solid Rocket Boosters. The entire assemblage was referred to as "the stack". The entire weight ...
8 votes
Accepted

What are joint systems used for mounting manipulators to spacecrafts?

The Space Station Remote Manipulator System (SSRMS) is a seven-jointed teleoperated manipulator used on the International Space Station (ISS). Each end of the manipulator is composed of a Latching ...
7 votes

Saturn V and STS holding to launch pad mechanism

The Saturn holddown arms were released pneumatically with a pyrotechnic backup. Source and Source Please refer to What holds the Space Shuttle orbiter itself stable on the launch pad? for details on ...
7 votes
Accepted

Exactly what was Surveyor 3 doing with a spring-loaded boxing glove-like device?

It's the soil sampling arm and scoop. This Surveyor mission was the first one that carried a surface-soil sampling-scoop, which can be seen on its extendable arm in the pictures. This mechanism ...
7 votes
Accepted

What do remotely-controlled bolts look like?

Maybe this cross section is more what you are looking for? From here.
7 votes

Fancy locomotion for rovers

The question is exploratory in nature and seems to allow for some degree of flexibility, so I will pick and choose words and address: fancy locomotion for rovers and How close do already launched ...
  • 148k
7 votes

Docking in space

The Soviets designed a super-simple docking mechanism for their failed lunar program. Of course, the price was that you had to EVA-transfer from craft to craft. It was never used. Source: https://...
7 votes

How do satellite motors keep themselves cool and lubricated?

The requirements on engines (really motors in my experience) in space are very different from the requirements on automobile engines on the ground. This leads to very different designs and very ...
6 votes

What do remotely-controlled bolts look like?

Their name seems to be "Motorized Bolt Assembly", this is what they look like: The servo is in the rectangular box marked BMA, the bolt extends through the fine guide cone. More about the BMA (PDF ...
  • 122k
6 votes
Accepted

Why was the APAS docking system developed?

Prior to ASTP, both Apollo and Soyuz spacecraft used a probe-and-drogue docking system, which requires different hardware at each end of the docking interface. This means that if you want two ...
6 votes
Accepted

How were the pins for Saturn V controlled release tested?

This page describes in some detail the design of the holddown mechanism: https://www.hq.nasa.gov/office/pao/History/SP-4204/ch13-4.html It doesn't say how they were tested but it says they were ...
6 votes

Connection between SM an CM

From CSM06 Command Module Overview page 49 and 50: CM-SM CONNECTION For most of an Apollo mission, the command and service modules are attached; they separate only a short time before the ...
  • 47.8k
5 votes
Accepted

How was APAS-89 chosen for Buran and Kristall?

The major claimed advantage of the APAS was that it can be applied to more massive vehicles because it incorporates a damping system. Buran was going to be much more massive than Soyuz. Source: ...

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