SMAP failure

[Hcube]

So the radar dish on the Soil Moisture Active Passive (launched atop delta II january 2015) has stopped responding and transmitting data a few weeks ago and today the engineers gave up on trying to recover it... The satellite has seen its resolution go from a sharp 3km to about 40km now. (Because instruments are supposed to work in tandem). However the radio instrument is still online and the mission is still going on.

Source JPL

[Scotius]

Hmmm...Too bad we don't have a manned vessel that could reach it's ~700 km orbit and perform repairs and servicing.

[Nibb31]

Hmmm...Too bad we don't have a manned vessel that could reach it's ~700 km orbit and perform repairs and servicing.

It could only be serviced if it had been designed to be serviced, with a grapple point, hand railings, removable covers, and replaceable parts. You would only include those features if you anticipated that those parts will need replacing. If you anticipate the failure of that component, then you design it to remove that particular failure mode.

The whole problem of something like this happening means that is failure mode was unanticipated, which means that even if you had designed the satellite to be serviceable, this particular failure mode might not be repairable anyway.

[Elthy]

Wouldnt a manned mission be way more expensive than simply building another satellite?

[Hcube]

Wouldnt a manned mission be way more expensive than simply building another satellite?

I don't think so. The whole mission from design to end of mission (3 years initially but that's probably going to be shorter now) costs 916 million dollars. A manned mission would cost a few millions. Unless they built the exact same satellite, a new soil moisture program would likely cost another 900 million bucks...

[Kibble]

Unless they built the exact same satellite

If they are planning to replace it, this is probably what they'll do.

[PB666]

If you go to the GEWEX page and some of the other nasa pages you will see that this is one of many. The active radar is the problem, its electronics prolly overheated because of the problems of radiating heat in space. Even the gravity satellites are capable of detecting changes in ground water.

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It could only be serviced if it had been designed to be serviced, with a grapple point, hand railings, removable covers, and replaceable parts. You would only include those features if you anticipated that those parts will need replacing. If you anticipate the failure of that component, then you design it to remove that particular failure mode.

The whole problem of something like this happening means that is failure mode was unanticipated, which means that even if you had designed the satellite to be serviceable, this particular failure mode might not be repairable anyway.

Maybe a blown cap or resistor.

[Nibb31]

I don't think so. The whole mission from design to end of mission (3 years initially but that's probably going to be shorter now) costs 916 million dollars. A manned mission would cost a few millions. Unless they built the exact same satellite, a new soil moisture program would likely cost another 900 million bucks...

Just launching humans to the ISS on a routine crew rotation costs a lot more than "a few millions". You'd need a vehicle capable of supporting an EVA, which rules out Dragon, CST-100 or Soyuz, unless you heavily modify these vehicles for the new mission. Only Orion is planned to have that capability, and it won't cost "a few millions" to launch.

Unless the satellite was fitted with an IDSS docking ring, you would also need a device capable of grappling the satellite. This means an arm on the spacecraft side and a grappling fixture on the satellite. There are no spacecraft that are currently planned to have an arm, and SMAP obviously wasn't equipped with a grappling fixture or handrails, so you would have to design and build a specific mission module to grapple the vehicle allow the astronauts to hold onto it, and then figure out a way to launch that mission module.

Then of course, you would also need to spend several months planning the entire mission, training astronauts and the support team for the EVA, developing procedures and designing specific tools and fixtures that can be used in space.

Once you include all that, a manned mission costs much more than building a new satellite using the same design.

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Maybe a blown cap or resistor.

You won't be soldering a new component in space. You would just swap the board it was on, but unless the satellite was designed from scratch with access hatches and large parts that can be replaced wearing thick gloves and an EVA suit, that's impossible. Typically, electronics are buried inside satellites under several layers of shielding and insulation. There might be cutting edges that could damage an EVA suit, it might have coolant loops that cannot be disconnected without ground equipment, it might have thrusters that could be misfired while the astronaut is working on it.

I repeat, for a satellite to be serviced in space, it must have been designed for that purpose from scratch.

Edited September 7, 2015 by Nibb31

[Exoscientist]

Hmmm...Too bad we don't have a manned vessel that could reach it's ~700 km orbit and perform repairs and servicing.

Why I favor developing robonaut to a system that can do repairs remotely even to BEO space. This would be extremely important for the multi-billion dollar James Webb telescope. The Hubble telescope needed several service missions, and wouldn't have worked at all without the first. The Webb will have cost much more dollars and time to develop, yet as planned now will have no means to repair or service it.

Here's a demo mission for robonaut that could be launched now:

Let's Do Project M, Robonaut to the Moon.

http://exoscientist.blogspot.com/2014/06/lets-do-project-m-robonaut-to-moon.html

Bob Clark

[cryogen]

Just launching humans to the ISS on a routine crew rotation costs a lot more than "a few millions". You'd need a vehicle capable of supporting an EVA, which rules out Dragon, CST-100 or Soyuz, unless you heavily modify these vehicles for the new mission. Only Orion is planned to have that capability, and it won't cost "a few millions" to launch.

It's worse than that, we don't even have a human-rated rocket that can reach SSO (retrograde polar orbit). Wikipedia says Soyuz-FG gets 4,500 kg to 800 km SSO, which is a lot less than the 7,150 kg Soyuz TMA-M spacecraft.

Edited September 7, 2015 by cryogen
grammar

[K^2]

Why I favor developing robonaut to a system that can do repairs remotely even to BEO space.

Ugh. If we do this, we'll never go anywhere. We'll just keep sending better and better robots until they don't need us anymore. Call me a Luddite, but I wholeselfishly object to that course of progress.

[cryogen]

The Webb will have cost much more dollars and time to develop, yet as planned now will have no means to repair or service it.

What would be the additional cost of building and launching a 2nd JWST, having already built one?

[Steel]

a manned mission would cost a few millions

A quick Google search reveals a ULA launch (so that's just a rocket and some fuel) costs, on average $225 million. Then there's the cost of man-rating the rocket, capsule building & integration and the insurance costs of sending actual people into space. So I would say you're not going to be far off the $900 million or so of launching a brand new satellite.