Goodnight, Venus Express

[Streetwind]

The European Space Agency's Venus Express probe is currently the only spacecraft orbiting Venus. It has been operating there since April 2006, an almost 6.5 times longer mission duration than originally planned.

Soon, however, Venus will no longer have a spacecraft in orbit around it. Venus Express has exhausted itself down to the last droplet of propellant, and will eventually be pulled in by the planet. Already, communication has been lost, as not even the RCS thrusters have anything left in them with which to keep the antenna pointed towards Earth. ESA has now officially declared end of operations.

Its final science experiment was performed earlier this year, when the probe was tasked to perform aerobraking at various heights to study the feasibility of such maneuvers in Venus' aggressive, highly turbulent atmosphere. This had never been done before, and offered a mountain of insightful data that will greatly assist future missions.

http://blogs.esa.int/rocketscience/2014/12/16/venus-express-goes-gently-into-the-night/

[Mazon Del]

Rest in peace faithful probe.

[m4rt14n]

May your circuits lay peacefully among the Veneras

[_Augustus_]

May future humans find your crumbled remains

[Skyler4856]

I wonder how viable an RCS type system that utilized a set of ion engines would be...

[Bill Phil]

Not very. The thrust is negligible. And RCS needs to be good for decently swift maneuvers.

[Streetwind]

Really depends on the application. Electric thrusters (particularly Russian hall thrusters) have been used for attitude control for a long time. In 2014, for the first time ever, more than 50% of all newly signed commsat contracts were "all-electric". It works well for commsats because those don't need to move much once they slot into their orbit.

[RainDreamer]

Maybe suddenly one day it will return from venus with a message from venusians!

"Hey, you drop this in our backyard. Now stop throwing trash over here!"

[Nibb31]

Not very. The thrust is negligible. And RCS needs to be good for decently swift maneuvers.

Tell that to Boeing.

http://www.boeing.com/boeing/defense-space/space/bss/factsheets/702/702SP.page?

[Bill Phil]

I wouldn't call that RCS. It's more a part if the main propulsion system.

[Nibb31]

I wouldn't call that RCS. It's more a part if the main propulsion system.

It's one and the same on satellite busses. The 4 ion thrusters are used for propulsion and station-keeping.

It typically takes the 702SP 5 months to reach its GEO orbit instead of 3 or 4 weeks for a bipropellant satellite, but it is much smaller and lighter, which cuts launch cost.

Edited January 3, 2015 by Nibb31

[Bill Phil]

Electric propulsion is generally more expensive, although there probably is a pint where it gets cheaper.

[technion]

Unlike cars and aircraft, spacecraft are not equipped with fuel gauges, so the time of propellant exhaustion for any satellite

This has me floored. Is there any reason you couldn't just fit such a gauge?

[Whirligig Girl]

Why is the probe in such a low orbit that it gets slowed down anyway?

EDIT: I can't read.

[Bill Phil]

This has me floored. Is there any reason you couldn't just fit such a gauge?

A better gauge would be DeltaV.

Plus, there's not an easy way to measure propellant in freefall very accurately. Although it would be nice to have a prop gauge AND a Dv gauge...

[Starwaster]

Maybe suddenly one day it will return from venus with a message from venusians!

"Hey, you drop this in our backyard. Now stop throwing trash over here!"

Do the Venusians look like this?

[PB666]

http://www.sci-news.com/space/planetaryscience/strong-electric-wind-terrestrial-planets-03966.html#.V2nN9GWfOt0.reddit

Little epitath for venus express