2015 Discovery mission selection

[AngelLestat]

NO, Atsakusi is 517.6 Kg. Plenty for a relay station, when the Mars relay station, Mars Odyessy, is only 376 Kg. Its orbit is not that elliptical either.

The mass is not my main point about why it would not work as relay, but let me point that the payload of the spacecraft is 35 kg, then you have like 300 kg of fuel, +tanks, PV, engine, etc.

The main reason is that was not designed for that, neither the anteena, the frequency, the orbit, power, etc.

It may act as relay if you find an emergency and the japaneses are willing to change some of their procedures and software to allow this. But lets be realistic, it would not be used as relay, it can be used as support.

Kala Lumpur's multitasking also increased the complexity enormously- the tunnel needed to support so much more weight in water.

Is already buiilded and working since 2009, the real cost is the tunnel, the extra support is just steel bars.

There is only "enormously complexity" when you lack of talent (or good guidance) in your team.

NASA should encourage to try new approaches to reduce the cost of missions, but it seems they dont have problem wasting always the double in each mission leaving so many others behind, we can not continue with this approach for always.

Areocapture is never done anyways by NASA- considered too risky. Aerobraking is done instead, which doesn't need heat shields.

You already need a heatshield for the lander (and for a floating probe if is included), so why it can not shield the orbiter too? After the first pass, when you reach your apo, you detach the orbiter, this execute a circularization, and the other 2 proceed with reentry.

Or you can do it in many pass as aerobraking (which is not risk because you have a heatshield anyway)

This is the easier planet to practice this (more than earth or any gas giant), It is a maneuver very needed to reduce the cost of any kind of mission, an inflated heatshield with many pass is not risky at all.. is a lot more safe than when the magallan did it without heatshield in 1989!!! What is the excuse now? How much we need to wait to make these manuvers that are totally necesary for manned missions?

Davinci is an atmospheric probe, not a lander.

I like your 3rd probe, but then the mission would be in New Frontiers, not Discovery.

Is an atmospheric probe, but it land and will transmit from ground, that is what I remember.

I dont understand the new frontiers or discovery point, can you elaborate?

Edited October 1, 2015 by AngelLestat

[Kibble]

I love all these missions! And glad to finally see news for the next Discovery <3

[fredinno]

The mass is not my main point about why it would not work as relay, but let me point that the payload of the spacecraft is 35 kg, then you have like 300 kg of fuel, +tanks, PV, engine, etc.

The main reason is that was not designed for that, neither the anteena, the frequency, the orbit, power, etc.

It may act as relay if you find an emergency and the japaneses are willing to change some of their procedures and software to allow this. But lets be realistic, it would not be used as relay, it can be used as support.

Is already buiilded and working since 2009, the real cost is the tunnel, the extra support is just steel bars.

There is only "enormously complexity" when you lack of talent (or good guidance) in your team.

NASA should encourage to try new approaches to reduce the cost of missions, but it seems they dont have problem wasting always the double in each mission leaving so many others behind, we can not continue with this approach for always.

You already need a heatshield for the lander (and for a floating probe if is included), so why it can not shield the orbiter too? After the first pass, when you reach your apo, you detach the orbiter, this execute a circularization, and the other 2 proceed with reentry.

Or you can do it in many pass as aerobraking (which is not risk because you have a heatshield anyway)

This is the easier planet to practice this (more than earth or any gas giant), It is a maneuver very needed to reduce the cost of any kind of mission, an inflated heatshield with many pass is not risky at all.. is a lot more safe than when the magallan did it without heatshield in 1989!!! What is the excuse now? How much we need to wait to make these manuvers that are totally necesary for manned missions?

Is an atmospheric probe, but it land and will transmit from ground, that is what I remember.

I dont understand the new frontiers or discovery point, can you elaborate?

Here we go again with the inefficiency...

Yes NASA should develop new ways to reduce mission costs and increase capability, but they do not 'waste double'.

Also, the extra support for the water in the timnel is not just 'steel bars'. A lot else goes into that- how are you going to integrate the supporting structure? How do you make sure there is no damage to the tunnel done by the water- more reinforcements needed to prevent excessive erosion.

Shielding the orbiter would need more mass. Aerobraking is Not Aerocapture- aerobraking is to reduce the size of an already existing orbit, and involves less heat over many months, not neededing heat shieds- Aerocapture needs sheilds to put the probe into an orbit in the first place, which no missions have done so far.

Discover missions are missiobs less than 500 million in cost- New frontiers are 500million to a billion in cost. Flagship missions cost more than a billion.

[Zucal]

How much we need to wait to make these manuvers that are totally necesary for manned missions?

They're not necessary for manned missions. Most manned Mars concepts include propulsive capture. Aerocapture is an extremely risky maneuver, and obviously mission planners feel that: more fuel > more risk.

[AngelLestat]

Here we go again with the inefficiency...

Hard to find a better word to describe it.

By the way.. here some tips on quotes:

Once you have all the text quote ready to reply, start to reply just under the text you want to reply erasing the rest, you just need to add a [ /quote.] at the end, or use the quote botton (which add both quotes needed) for extra text.

Yes NASA should develop new ways to reduce mission costs and increase capability, but they do not 'waste double'.

Nasa should lead the way in technology, they also need to do all the missions and risky things that private entities cant do, they should be the first to try reusability, aerocapture, new tech approach or other things to lead the way and guide other companies how to do it, but they are doing all the opposite, they are freeze in time and only spacex is trying new things.

Also, the extra support for the water in the timnel is not just 'steel bars'. A lot else goes into that- how are you going to integrate the supporting structure? How do you make sure there is no damage to the tunnel done by the water- more reinforcements needed to prevent excessive erosion.

Erosion? That is concrete, the material used in dams, besides you only have a flood enoght to open the first way only 1 or 2 times by year, and you need a really strong flood to open the second way (1 every 5 years).

Also I was thinking, if you have some holes from the first level to the second, and the second to the third, you can let escape the air to the top of the tunnel, so there is not need to support all the water weight, because it will be submerged.

At least that is the way I will do it.

Shielding the orbiter would need more mass. Aerobraking is Not Aerocapture- aerobraking is to reduce the size of an already existing orbit, and involves less heat over many months, not neededing heat shieds- Aerocapture needs sheilds to put the probe into an orbit in the first place, which no missions have done so far.

If you use a heatshield, you can do an intermediate maneuver between Aerobraking and Aerocapture, without insertion burn.

This would be much more safe than both.

Discover missions are missiobs less than 500 million in cost- New frontiers are 500million to a billion in cost. Flagship missions cost more than a billion.

Veritas has 500 millions and davinci another 500 millions as max. If you merge both missions (you keep the different teams) you have 1 billions, you will tell me that add a simple ballon with a camera and some instruments that only needs to last 1 or 2 weeks (before it reach the hurricanes in the pole) will cost so much?

When you merge missions, you dont need to think so much how to deal with every single step of the mission (launch, insertion, capture, transmission, etc) for each probe.

They're not necessary for manned missions. Most manned Mars concepts include propulsive capture. Aerocapture is an extremely risky maneuver, and obviously mission planners feel that: more fuel > more risk.

Aerocapture too risky? We will see what NASA scientists have to say about this:

http://www.lpi.usra.edu/opag/archive_documents/aerocaptureRisks03_08.pdf

http://solarsystem.nasa.gov/docs/Concepts_Munk_Spilker.pdf

Aerobraking reliability = 0.984

Aerocapture reliability = 0.994

I love destroy some myths, especially when they are founded simply by what NASA does or not, as if there were a holy guide of what is correct or not. Not sure why is so hard to believe that NASA managment are terrible to take decisions.

An extra way to aerocapture or aerobraking:

http://www.parabolicarc.com/2009/04/22/global-aerospace-developing-ballutes/

The heatshield generates a shockwave, that shockwave can be intercepted by the ring ballon, which achieve extra drag with low area, you can detach it when you achieve the orbit needed.

By the way, you can also have manned missions to Venus.

Edited October 1, 2015 by AngelLestat

[fredinno]

On 9/30/2015, 2:59:14, fredinno said:

“NASA has selected five science investigations for refinement during the next year as a first step in choosing one or two missions for flight opportunities as early as 2020.â€Â

Which of the missions chosen do you guys prefer the most?

Update: If the choose 2 missions, the next call for Discovery missions in 2017 will be delayed. No idea when to- it might actually mean more missions overall, but that really depends on a lot of factors.

[Kryten]

 

[_Augustus_]

1 hour ago, Kryten said:

 

I hope they selected both Venus missions.

[Kryten]

 

[_Augustus_]

2 hours ago, Kryten said:

 

Much better than I expected! I thought they'd select the 2 Venus probes for sure.

[Jonfliesgoats]

Exciting!