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Palomar

Member

From: USA

Registered: 2002-05-30

Posts: 9,734

Re: Signals - ...serious question

*Okay, I'm pressed for time, will hammer this out:

IIRC (may be totally wrong) the lunar landing modules of the Apollo missions relied on a signal from Earth to jettison themselves back up to the command modules...?

We have this current communication problem with Spirit, including factoring in the orbiters.  A signal from Beagle 2 couldn't be detected even though Mars Express passed directly over it (of course, maybe Beagle 2 was unfortunately smashed to smithereens upon landing or did roll deep down into that crater...but we don't know exactly what happened, right?).

Will Mars Direct vehicles have to rely on a signal from Earth in order take off and head back home when the mission is over (2-way mission of course)?  The way things are going, I sure hope not!  I went through portions of _The Case for Mars_ I thought might answer that; I probably missed something.

This really has me concerned (especially when orbiters can't "crack the nut").  I'm rusty on the finer details of certain (precise) matters, so input would be appreciated.

--Cindy

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We all know [i]those[/i] Venusians: Doing their hair in shock waves, smoking electrical coronas, wearing Van Allen belts and resting their tiny elbows on a Geiger counter...

--John Sladek (The New Apocrypha)

Byron

Member

From: Florida, USA

Registered: 2002-05-16

Posts: 844

Re: Signals - ...serious question

Will Mars Direct vehicles have to rely on a signal from Earth in order take off and head back home when the mission is over (2-way mission of course)?  The way things are going, I sure hope not!  I went through portions of _The Case for Mars_ I thought might answer that; I probably missed something.

I would certainly hope not as well.  Having people running the show on Mars *should* eliminate the need for control commands sent from Earth...I have no idea of what the deal about the lunar modules.  That's the huge advantage of manned vs unmanned missions...if there's a glitch, there's someone on-site to fix the problem, make repairs, etc.  Pretty hard to do when the nearest person is millions of miles away

B

RobertDyck

Moderator

From: Winnipeg, Canada

Registered: 2002-08-20

Posts: 7,813

Website

Re: Signals - ...serious question

The Apollo Lunar Module had a launch button, and an abort button. The abort button was used on landing; if it appeared something was going wrong an astronaut could hit the abort button causing it to jettison the lower stage and use the ascent engine in the upper stage to go back into orbit. Then the command and service module could rendezvous to pick them up for their ride home. Mission control just watched the pretty pictures, monitored telemetry of on-board instruments, and had experts ready to solve any technical problems. But the astronauts and on-board computer flew the ship. We have better computers now so we can send radio commands to activate complex programs, or radio updated programs, but one of the points of a manned mission is to have someone on-site to solve problems or fly when conditions are beyond any pre-programmed flight software.