microsatellites

[bearnard66]

Does anybody have a piece of information about microsatellites? I wanna know the capability they have, what kind of mission they have, will microsatellites be able to substitute the satellites we have now?

 

[bearnard66]

Have you ever heard about satellites that observe collecting agricultural data and tracking environmental changes? Personally, I`ve recently heard about such kinds of microsatellites that been manufactured by the space company from South Africa.

 

[Funkworks]

Well yes, those are basically weather satellites. They are used to measure weather parameters. That data is what can be used to predict short-term weather forecasts as well as long-term climate trends or changes. Important numbers for farmers of course.

South Africa is definitely not the only country doing this. Everyone with a space program is and its quite natural that satellites, just like computers, become smaller as the years go by. It’s about efficiency, “having the most bang for your buck“, or “technological progress”.

 

[RFMan]

That's quite an open-ended question, but one way to kick off a discussion

Some musings and thoughts:

• Capabilities - This is quite mission-dependent.
• Longevity - Smaller sats tend to be in lower orbits (a generalization) which means shorter missions (drag brings them down sooner).
• Reliability - Since microsats are usually in lower orbits with shorter duration missions, less reliability is acceptable. One practical implication is that components that are less rad-hard and less long-lived (i.e., not necessarily formally space-qualified) can be used. That means that significantly more widely available and more capable (denser, more complex) electronics are flyable. First, radiation is typically less at lower altitudes (though if they pass regularly through the South Atlantic Anomaly or use a polar orbit, that's not so); second, the extremely long lifetime that derives from high-reliability would likely be wasted due to the short mission duration (again, a generalization; if you REALLY can't afford to lose the spacecraft early in the mission, then the calculus changes back to higher rel).
• Volume - Microsats are typically classified by mass, and since they are small, volume is usually small also (there are always exceptions - the Echo birds are an outlying example).
• Power - Microsat just can't provide much, either in battery or in solar array area. But a lot of missions don't need much.
• Attitude control - This is much easier for microsats on the high end of the mass definition.

Many people think of cubesats as a specific example of microsats, but the larger cubesats are on the low end of the microsat mass definition, which spans an order of magnitude.

The smaller ones are quite useful for relatively inexpensive testing the feasibility of specific concepts - performance of a specific sensor or antenna or deployment method or operational approach (e.g., swarming or short-range intrasat comms techniques or electric thrust or...). On the upper end, a microsat can technically mass ~500 kg; that's half a ton. Such a vehicle can carry larger batteries, solar arrays, multiple instruments, even active attitude control or a small propulsion system. Now you're talking longer, more intricate missions, perhaps higher altitudes - and noticeably more money.

 

[Peartree]

All good information so far, but as to the question of whether microsats will be able to substitute for, or replace the satellites we have now, in a word, no. Even though electronics have enabled sats to become smaller and still be quite useful for many things, there are still a lot of reasons to build bigger, more capable, more long-lived, and higher altitude satellites. Notice that despite the rapid miniaturization of many electronics, there is still a market for rockets like the Falcon Heavy that can loft even larger payloads and greater mass because nations and corporations still have reason to want to launch even *bigger* satellites than are currently in orbit.

 

[bearnard66]

All good information so far, but as to the question of whether microsats will be able to substitute for, or replace the satellites we have now, in a word, no. Even though electronics have enabled sats to become smaller and still be quite useful for many things, there are still a lot of reasons to build bigger, more capable, more long-lived, and higher altitude satellites. Notice that despite the rapid miniaturization of many electronics, there is still a market for rockets like the Falcon Heavy that can loft even larger payloads and greater mass because nations and corporations still have reason to want to launch even *bigger* satellites than are currently in orbit.

As far as I know, modern microsatellites are so advanced that they can easily substitute ordinary satellites and they have such capability as ordinary satellites. I don`t know that for sure, but now as we can see microsatellites are frequently used in different areas.

 

[Ronz Rocketz]

There’s a dozen or more videos on YouTube that will answer your questions. Three months ago, ESA launched the Vega after the rocket failed to ignite the 2nd stage a year ago. To prove they fixed it, they launched microsatellites to prove the rocket is reliable. Then a month ago, they tried again with a larger satellite but failed to reach orbit because they crossed the wires when they assembled the rocket so the thrusters went in the opposite direction. Will they launch more microsatellites again?

 

[Peartree]

As far as I know, modern microsatellites are so advanced that they can easily substitute ordinary satellites and they have such capability as ordinary satellites. I don`t know that for sure, but now as we can see microsatellites are frequently used in different areas.

Please read my earlier reply again. I didn't say that micro-satellites were not useful, I said that, in every case, they would not completely replace larger satellites. There are a myriad of things to be done in space just as there are on earth, and one size does not fit all.

 

[bearnard66]

That's quite an open-ended question, but one way to kick off a discussion

Some musings and thoughts:

• Capabilities - This is quite mission-dependent.
• Longevity - Smaller sats tend to be in lower orbits (a generalization) which means shorter missions (drag brings them down sooner).
• Reliability - Since microsats are usually in lower orbits with shorter duration missions, less reliability is acceptable. One practical implication is that components that are less rad-hard and less long-lived (i.e., not necessarily formally space-qualified) can be used. That means that significantly more widely available and more capable (denser, more complex) electronics are flyable. First, radiation is typically less at lower altitudes (though if they pass regularly through the South Atlantic Anomaly or use a polar orbit, that's not so); second, the extremely long lifetime that derives from high-reliability would likely be wasted due to the short mission duration (again, a generalization; if you REALLY can't afford to lose the spacecraft early in the mission, then the calculus changes back to higher rel).
• Volume - Microsats are typically classified by mass, and since they are small, volume is usually small also (there are always exceptions - the Echo birds are an outlying example).
• Power - Microsat just can't provide much, either in battery or in solar array area. But a lot of missions don't need much.
• Attitude control - This is much easier for microsats on the high end of the mass definition.

Many people think of cubesats as a specific example of microsats, but the larger cubesats are on the low end of the microsat mass definition, which spans an order of magnitude.

The smaller ones are quite useful for relatively inexpensive testing the feasibility of specific concepts - performance of a specific sensor or antenna or deployment method or operational approach (e.g., swarming or short-range intrasat comms techniques or electric thrust or...). On the upper end, a microsat can technically mass ~500 kg; that's half a ton. Such a vehicle can carry larger batteries, solar arrays, multiple instruments, even active attitude control or a small propulsion system. Now you're talking longer, more intricate missions, perhaps higher altitudes - and noticeably more money.

According to the information I found on the website of this new space company from South Africa that manufactures this type of satellite, these satellites have a bit different characteristics but still, you are quite right in most of the statements you brought.