Richard Stephenson

A passion for all things "Space"

[Richard Stephenson @nascom1]

After 15 Year of posting about my passion for NASA and specifically the DSN, I'm finding it harder posting as an individual within the new NASA media framework. Its been a pleasure sharing my experiences and hopefully people have enjoyed them. All the best 😀

[Richard Stephenson @nascom1]

Just before dawn in Canberra. DSS43 pointing towards Voyager 2 in our southern skies. A best lock downlink expected after being uplinked 39 hours 29 minutes ago.

[Richard Stephenson @nascom1]

Canberra's DSS43 tracking Artemis 2 with the moon in background. The DSN has done a brilliant job maintaining communications with Orion over the last week. I'm very proud of the Operations teams at Goldstone, Madrid and Canberra.

[Richard Stephenson @nascom1]

@Bernard1963 DSS43 will be covering only VGR 1/2 command supports for the next week or so

[Richard Stephenson @nascom1]

Thanks everyone 😢. I'll keep the account active, some of my posts will still be relevant into the future. I might start posting about my other passions... I just have to find one 😉

[Richard Stephenson @nascom1]

https://t.co/ReDPuGR6RU

[Richard Stephenson @nascom1]

@alpha_adhito We aim in between the two, both see a small loss. For Ka uplink/downlink supports we use an aberration table, which physically offsets the uplink pointing, so no lose.

[Richard Stephenson @nascom1]

@ea4gpz @jimlux Each spacecraft has a designated channel. So only one at a time.

[Richard Stephenson @nascom1]

@alpha_adhito Mars tends to be X-Band so for a 34M BWG antenna the beamwidth is 66mdeg. For our 70m antenna its 32mdeg

[Richard Stephenson @nascom1]

@VU3BIZ I can't say that rain has a nominal attenuation, but light rain like drizzle can drop the symbol SNR by around 2db, heavy rain 10db.

[Richard Stephenson @nascom1]

@VU3BIZ There are 4 bit rates generally used, increasing as the elevation increases and also dropping with elevation to maintain the 2db margin. The highest is 333,333b/s

[Richard Stephenson @nascom1]

@ka9q Correct Turbo 1/6. NRZ-L

[Richard Stephenson @nascom1]

Some nasty weather starting to hit the complex. Just made it back to the ops room before the rain started. Luckily only DSS36 SOHO so S-band which is OK but the DSS35 on Juno both X/ka Band will see an impact from the weather. DSS34,43 are on maintenance.

[Richard Stephenson @nascom1]

@xjamesmorris @NASAPersevere The round trip light time makes any real time ARQ impractical. Usually it's a repeat of the data on another support if it's science data. Engineering data is generally lost.

[Richard Stephenson @nascom1]

@dslsynth @NASAPersevere That's bits/sec

[Richard Stephenson @nascom1]

@VinzR87 @realstealthcow @NASAPersevere Nope, it normal operations for all current and previous rovers

[Richard Stephenson @nascom1]

@realstealthcow @NASAPersevere The DTE is for real time low level engineering, they don't have to wait for an orbiting spacecraft to be overhead. All science data goes via our relay spacecraft.

[NASA JPL @NASAJPL]

We’re celebrating two milestones for @CanberraDSN!

The complex, which operates four radio antennas for our Deep Space Network, recently marked its 60th anniversary. Now, preparations are underway for a fifth dish that will increase the network's capacity. https://t.co/9KYFN7muUt

[Richard Stephenson @nascom1]

No its not a DSN Now issue. Currently our network is down for mission net maintenance. Every man, women and their dogs are piggy backing on this time to get jobs done around the network that could have a mission impact if done at any other time.

[Richard Stephenson @nascom1]

@Tom1973_1 correct, same data on each polarization

[Richard Stephenson @nascom1]

Now fully "awake" after its little nap its back to its normal configuration for the DSN. Identical telemetry transmitted on both Right and Left polarization and combined on earth to provide a 3db (doubling) gain. New Horizon is still the only spacecraft configured this way.

[NASA New Horizons @NASANewHorizons]

Just roused from hibernation, New Horizons starts six months of active operations that will include long-distance looks at Kuiper Belt objects and close-up data gathering on the dust and radiation environment in this remote part of our Sun’s heliosphere. https://t.co/HropgUD74r