Nasa Establishes Contact with STEREO Mission
1–10 of 19 posts
Re: Nasa Establishes Contact with STEREO Mission
#2The linked article that gives the background on this mission and its recovery is definitely worth reading [0]. In particular, it's worth noting that the STEREO mission was only supposed to last until 2008 and part of the reason it was lost was due to NASA's attempts to reconfigure it to survive the unplanned period it would be out of contact from Earth as it passed behind the Sun. It would be pretty impressive if they were able to get it back in service so long after its planned end-of-life.
[0] http://www.nasa.gov/feature/goddard/saving-nasas-stereo-b-th...
Re: Nasa Establishes Contact with STEREO Mission
#3The linked article that gives the background on this mission and its recovery is definitely worth reading [0]. In particular, it's worth noting that the STEREO mission was only supposed to last until 2008 and part of the reason it was lost was due to NASA's attempts to reconfigure it to survive the unplanned period it would be out of contact from Earth as it passed behind the Sun. It would be pretty impressive if the…
I imagine this happens more often than most people realize.
I worked on a satellite that was launched in 2003 and had a lifetime of 3 years. It operated until at least 2012 when the Air Force decided it was done paying for the downlink, but the satellite itself was still in pretty good condition.
Re: Nasa Establishes Contact with STEREO Mission
#4The linked article that gives the background on this mission and its recovery is definitely worth reading [0]. In particular, it's worth noting that the STEREO mission was only supposed to last until 2008 and part of the reason it was lost was due to NASA's attempts to reconfigure it to survive the unplanned period it would be out of contact from Earth as it passed behind the Sun. It would be pretty impressive if the…
I imagine this happens more often than most people realize. I worked on a satellite that was launched in 2003 and had a lifetime of 3 years. It operated until at least 2012 when the Air Force decided it was done paying for the downlink, but the satellite itself was still in pretty good condition.
What is usually the cause to get them in a "bad condition"? Is it just that better technology is available or is it radiation, solar panel issues or other stuff? I'm asking because as far as I understand it's mostly electronics so I always wondered what is causing it to fail while nobody is touching it.
Re: Nasa Establishes Contact with STEREO Mission
#5The linked article that gives the background on this mission and its recovery is definitely worth reading [0]. In particular, it's worth noting that the STEREO mission was only supposed to last until 2008 and part of the reason it was lost was due to NASA's attempts to reconfigure it to survive the unplanned period it would be out of contact from Earth as it passed behind the Sun. It would be pretty impressive if the…
I imagine this happens more often than most people realize. I worked on a satellite that was launched in 2003 and had a lifetime of 3 years. It operated until at least 2012 when the Air Force decided it was done paying for the downlink, but the satellite itself was still in pretty good condition.
My laymen guess is that unless your satellite electronics get fried by the particle storm of a solar flare not much happen in space. As long as the power source (solar panels) works and you do not need much fuel for repositioning like in low earth orbit, what stops a well built satellite? (sorry if I am too naive/ignorant)
Re: Nasa Establishes Contact with STEREO Mission
#6Earlier quoted context omitted.
I imagine this happens more often than most people realize. I worked on a satellite that was launched in 2003 and had a lifetime of 3 years. It operated until at least 2012 when the Air Force decided it was done paying for the downlink, but the satellite itself was still in pretty good condition.
My laymen guess is that unless your satellite electronics get fried by the particle storm of a solar flare not much happen in space. As long as the power source (solar panels) works and you do not need much fuel for repositioning like in low earth orbit, what stops a well built satellite? (sorry if I am too naive/ignorant)
Batteries can only take so many charge cycles, PV cells get pelted by alpha particles and micrometeoroids. Essentially, "wear and tear" is what eventually kills most spacecraft.
Re: Nasa Establishes Contact with STEREO Mission
#7Earlier quoted context omitted.
I imagine this happens more often than most people realize. I worked on a satellite that was launched in 2003 and had a lifetime of 3 years. It operated until at least 2012 when the Air Force decided it was done paying for the downlink, but the satellite itself was still in pretty good condition.
What is usually the cause to get them in a "bad condition"? Is it just that better technology is available or is it radiation, solar panel issues or other stuff? I'm asking because as far as I understand it's mostly electronics so I always wondered what is causing it to fail while nobody is touching it.
Another aspect is that many spacecraft use thruster fuel over time, both for pointing and for station-keeping. Once you run out of fuel, the spacecraft may lose the ability to keep its high-gain antenna pointed at Earth, so you may lose touch with it completely, especially for deep space missions; but more seriously, it may also stop being able to keep its solar panels pointed towards the sun.
(Some spacecraft don't use thruster fuel for pointing, so they don't suffer from this so badly.)
In addition, if your vehicle is in Earth orbit, it may be assigned a position. For example, geostationary satellites must keep within their assigned slot or else you'll be very unpopular. (See, for example, the Galaxy 15 zombiesat, which went nuts and started drifting into other satellite's slots, while broadcasting hash.)
So if you run out of fuel, you won't be able to do this any more, and as a result some satellites are required to keep a fuel reserve so that they can be sent into a safe graveyard orbit at end-of-life.
Re: Nasa Establishes Contact with STEREO Mission
#8Earlier quoted context omitted.
I imagine this happens more often than most people realize. I worked on a satellite that was launched in 2003 and had a lifetime of 3 years. It operated until at least 2012 when the Air Force decided it was done paying for the downlink, but the satellite itself was still in pretty good condition.
What is usually the cause to get them in a "bad condition"? Is it just that better technology is available or is it radiation, solar panel issues or other stuff? I'm asking because as far as I understand it's mostly electronics so I always wondered what is causing it to fail while nobody is touching it.
Besides consumables like fuel, mentioned nearby, there are also mechanical parts like gyroscopes or reaction wheels (https://en.m.wikipedia.org/wiki/Reaction_wheel) which maintain pointing. If the s/c contains an imager, there will probably be a mechanical shutter, protective cover, and/or filter wheel.
There can also be higher power electronics, like signal amplifiers or radios, which tend to fail more often than computer electronics. Finally, there is cumulative radiation damage, and the possibility that a combination of single event upsets can get the s/c into an unrecoverable state.
From time to time, operational changes can force the s/c into new operating modes ("we need to flip the camera to take images to fit a new point spread function"). These new operating modes can cause unforeseen consequences ("when flipped, the antenna has to be pointed differently to target the ground station") that ripple through the system. As the mission wears on, the chance of a new operating condition tickling a latent problem increases, because there are a lot more latent problems.
Re: Nasa Establishes Contact with STEREO Mission
#9The linked article that gives the background on this mission and its recovery is definitely worth reading [0]. In particular, it's worth noting that the STEREO mission was only supposed to last until 2008 and part of the reason it was lost was due to NASA's attempts to reconfigure it to survive the unplanned period it would be out of contact from Earth as it passed behind the Sun. It would be pretty impressive if the…
Whoa, very cool. Waste not, want not. Well, science is kind of miss-and-hit (re: odds) so when they succeed and find additional use, that's inspirational I think.
Kind of had a funny mental image of the team wrapping up the shut-down process. Then, recently, all of them still at NASA get a calendar notification from the past: "SETERO-B about to return from behind the sun - go try and jump start it!" and they get back on the case.
Re: Nasa Establishes Contact with STEREO Mission
#10Earlier quoted context omitted.
My laymen guess is that unless your satellite electronics get fried by the particle storm of a solar flare not much happen in space. As long as the power source (solar panels) works and you do not need much fuel for repositioning like in low earth orbit, what stops a well built satellite? (sorry if I am too naive/ignorant)
Batteries can only take so many charge cycles, PV cells get pelted by alpha particles and micrometeoroids. Essentially, "wear and tear" is what eventually kills most spacecraft.
Any success by way of a giant Earth-based laser? Asking for a friend.