Comments on: How often are the Mars space robots out of contact with the Earth? https://gregladen.com/blog/2011/01/24/how-often-are-the-mars-space-r/ Thu, 27 Jan 2011 00:23:26 +0000 hourly 1 https://wordpress.org/?v=6.4.8 By: Ralf Muschall https://gregladen.com/blog/2011/01/24/how-often-are-the-mars-space-r/#comment-498525 Thu, 27 Jan 2011 00:23:26 +0000 http://scienceblogs.com/gregladen/2011/01/24/how-often-are-the-mars-space-r/#comment-498525 I think having a relay station just “somewhere” out in space (between Earth and the planet being observed) is not going to help. It is easier to erect a 100-meter dish on earth and pump megawatts into it than to send even something tiny into deep space (where the antenna diameter is limited to a few meters and power is hard to obtain).

The exception might be to have one big relay satellite very close to a swarm of probes, so that each probe needs only to cover the distance up to the relay. But even that is not trivially useful – around Jupiter, this small distance would be a few million kilometers, and after increasing the antenna diameter by a factor of 100 (i.e. Arecibo vs. relay), the same combination of power and antenna on the probe suffices for a few hundred million km, which is the distance between Jupiter and Earth.

]]> By: Greg Laden https://gregladen.com/blog/2011/01/24/how-often-are-the-mars-space-r/#comment-498524 Tue, 25 Jan 2011 20:54:34 +0000 http://scienceblogs.com/gregladen/2011/01/24/how-often-are-the-mars-space-r/#comment-498524 There has been a “plan” for a deep space telecom relay for some years. I’m not sure it is an official mission. The idea is to lighten up the payload for deep space missions. Is this what you are talking about?

]]> By: Timberwoof https://gregladen.com/blog/2011/01/24/how-often-are-the-mars-space-r/#comment-498523 Tue, 25 Jan 2011 20:29:21 +0000 http://scienceblogs.com/gregladen/2011/01/24/how-often-are-the-mars-space-r/#comment-498523 Mu, really? I tried Googling for that but found nothing. Got link?

]]> By: 6EQUJ5 https://gregladen.com/blog/2011/01/24/how-often-are-the-mars-space-r/#comment-498522 Tue, 25 Jan 2011 14:09:09 +0000 http://scienceblogs.com/gregladen/2011/01/24/how-often-are-the-mars-space-r/#comment-498522 There is the further complication that when the SEP angle (Sun-Earth-Probe) becomes small enough, solar radiation begins feeding into the side lobes of the tracking station’s antenna, raising the SNT (system noise temperature) and thus degrading the SNR (signal to noise ratio) of the ground receiver.

]]> By: Mu https://gregladen.com/blog/2011/01/24/how-often-are-the-mars-space-r/#comment-498521 Mon, 24 Jan 2011 22:22:15 +0000 http://scienceblogs.com/gregladen/2011/01/24/how-often-are-the-mars-space-r/#comment-498521 Interestingly, NASA is planing on putting a football field size antenna between Mars and Jupiter to act as a permanent relay between (possible future manned) Mars missions and Earth.

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