Re: NASA moon trip video

Andrew Swallow (am.swallow@xxxxxxxxxxxxxxx) writes:
> Andre Lieven wrote:
>
>> Andrew Swallow (am.swallow@xxxxxxxxxxxxxxx) writes:
>>
>>>Andre Lieven wrote:
>>>
>>>>Wesley Struebing (strueb@xxxxxxxxxxxxxxxxx) writes:
>>>
>>>[snip]
>>>
>>>>>Don't think so - at least currently. Soyuz, but that means one can
>>>>>launch people or supplies (and not much; some pieces, I believe are
>>>>>too big/heavy for soyuz to carry) - but not both.
>>>>
>>>>Thats a no. The very first ever launched piece of ISS, Zarya, was
>>>>sent up on an unmanned Russian Proton rocket ( The same booster
>>>>type that used to loft the Salyut and Mir space station pieces ),
>>>>but modules to be launched by unmanned rocket need to be designed
>>>>and built to be so launched, as the loads that the modules
>>>>have to take, on a booster flight, V/ a shuttle flight, are
>>>>quite different.
>>>>
>>>>For one point, a shuttle lofted part, needs to be connected to
>>>>the orbiter payload bay at it's sides, not it's bottom, where
>>>>it would be connected to the upper stage of the unmanned rocket.
>>>
>>>Side connectors can be converted to bottom fasteners by adding a couple
>>>of pieces of metal shaped like a large tuning fork. However this does
>>>add unwanted width and weight.
>>
>> This isn't a simple matter of connectors. The modules built for shuttle
>> launch don't have to have fittings for aeroshells, and all thats
>> involved with jettisoning them at the right times. Mariner 3, the first
>> US probe to Mars, was lost just after launch, for want of a working
>> shroud jett system. Likewise the docking target sent up for Gemini 9.
>
> This is one of the reasons I restricted this suggestion to parts of the
> ISS.

This actually makes it worse. With the aforementioned planetary probes,
size was an issue, in certain dimensions, but with ISS modules stressing
is also a factor, with much higher flight loads during an expendable
booster launch. I believed that I had explained this.

If you doubt my comments, you could ask the knowledgable denizens
of sci.space.history, who could give you more precise data on this.

> It may be launched by a conventional rocket but the part will be
> fitted to the space station by a shuttle.

Then, whats the point of two separate launches to do one flight's job ?

> There are men on board the
> shuttle who can do things like operate the aeroshell's door handle.

No such aeroshell has ever been designed, much less tested and found
to be flight worthy. Indeed, the experience with the GT-9A's
extenporised docking target, replacing the Agena that blew up during
boost flight ( A risk that would be shared by an ISS module flying
on an expendable... ), suggests that trying a lash up in this area
is a near guarantee to failure.

> (Assuming that it takes more than 2 years to design a round metal box.)

Aeroshells are far more complicated than that. They have to not
only shield the payload, but they have to be *lightweight* ( Otherwise
they reduce the flight mass of the actual payload ), and built such
that they come off only at the right time.

>> Plus, launch loads on a shuttle flight are lighter than on an expendable
>> booster, so strcutures designed and built for flight inside the shuttle's
>> payload bay, may not be sufficiently stressed for flight on an
>> expendable booster.

I'll repeat: This is not a trivial issue in switching launchers.

>>>>Flight loads are also a factor, in the shuttle, the payload rides
>>>>well inside the payload bay, while a rocket lofted module would
>>>>just have an aeroshell covering it's front and all sides.
>>>
>>>If the load is not symmetrical ships, including rockets, do tend to via
>>>off course.
>>
>> As long as the exterior is symmetrical, then it works. There is often
>> more room for same inside the shuttle's payload bay, then on many
>> expendable boosters. At least, some design tolerances would be
>> different, and thats hard on already built major modules.
>>
>> Note that, in spite of multi year launch slips, due to the post
>> Challenger shuttle situation, the Galileo Jupiter orbiter was not
>> reassigned to a Titan rocket. Only the designed to fly on a Titan
>> rocket Casinni Saturn orbiter was so launched.
>
> Obitors need extra engines which causes problems, particularly when the
> engine is at 90 degrees to the main rocket.

Irrelevent. The mentioned probes needed such, no matter what launcher
sends them up. So, its not a variable. And, many orbiting planetary
probes with extra engines have successfully flown on expendable
boosters, that in no way is this an issue.

Rather, the designed in stressing of the modules, and their power
and attachment points ( Connection to power and command/info
routing busses within the modules ) are.

Andre

.

Relevant Pages

  • Re: staging, reliability, etc. (was Re: Towed Booster Stability)
    ... One D III failure was due to poor judgement by the company in not expending ... of the first flight. ... They appear to now have a mature design and operation. ... But launch ...
    (sci.space.policy)
  • Jonathans Space Report No. 536
    ... a flight duration of 23m56s from drop to touchdown. ... The other SpaceshipOne spaceflight was on Jun 21, with launch at 1450 ... the Russian Federal Space Agency launched Soyuz-FG rocket ... into a 165 x 358 km x 67.1 deg orbit. ...
    (sci.space.shuttle)
  • Re: Design Assistance
    ... especially when passing through Mach 1. ... I really need to make sure that this new design will be stable through the ... the rocket had several problems. ... about one caliber of stability at launch (one caliber between the static ...
    (sci.space.history)
  • Re: PlasterBlaster launch & aerial pics
    ... I was in CA two days after PB4, within one hour of the launch site! ... > rocket with 38mm strap-on boosters. ... and the main rocket had an I211. ... > My second flight was a 1.8" diameter rocket on a G80, ...
    (rec.models.rockets)
  • Re: Nightflights at UKRA?
    ... The window will be open from 15 minutes after the end of the pyro until 23:00. ... S& T must be notified of the launch happening in advance as a courtesy (a simple " I'm intending to night launch an illuminated rocket on a motor on the Saturday night at UKRA" should suffice unless S&T want more info). ... Pete & I must have full details of the flight a week beforehand - email them to me & I will pass them along to Pete. ...
    (uk.tech.rocketry)
Loading