Proton & ExoMars

[Star One]

Does anyone know what the proposed configurations will be for the Proton rockets that will be used to launch ExoMars and is there likely to be a variation in the configuration for the one launching the orbiter and the one launching the rover?

Also on the recent BBC Horizon programme about Curiosity it talked about ExoMars as well and it was mentioned in passing that they were having to shrink the rover as the Russian launcher could not deliver as much payload to Mars. Is there really that much variation in this aspect between the Proton and Atlas V?

[spectre9]

Upper stage throw mass.

This is where cryogenic LH2 stages come into their own.

Centaur beats Briz-M easily.

The cost is another matter entirely.

[Star One]

Upper stage throw mass.

This is where cryogenic LH2 stages come into their own.

Centaur beats Briz-M easily.

The cost is another matter entirely.

From the programme & maybe I misheard this but I think they were talking about having to reduce the rover's weight by 50%, is there that large a gap between the Centaur & Briz-M & if there is is there any way the Briz-M could be upgraded in any way for a flight to Mars?

[baldusi]

Among other issues, the Proton only has a 4.1m fairing, so the maximum internal diameter of a heat shield would be 3.7m. The Atlas V has 5.2m fairing, with an internal diameter of 4.65m. Keeping everything else the same, they have 35% less mass if you keep the heat shield surface to payload mass constant.

[Star One]

Among other issues, the Proton only has a 4.1m fairing, so the maximum internal diameter of a heat shield would be 3.7m. The Atlas V has 5.2m fairing, with an internal diameter of 4.65m. Keeping everything else the same, they have 35% less mass if you keep the heat shield surface to payload mass constant.

The Proton/Briz-M combination will also be untested in interplanetary use as well which must be a concern to the ExoMars programme. I know we are talking about four years down the road for the orbiter & hopefully they will have sorted the Briz_M out by then, but failures such as yesterday's with this combination must raise some concerns?

[GClark]

I was under the impression (according to Anatoly Zak, at least) that the ExoMars launches would be using the Blok DM-03.  Have I missed something?

[Star One]

I was under the impression (according to Anatoly Zak, at least) that the ExoMars launches would be using the Blok DM-03.  Have I missed something?

I would have thought it would have been phased out by then or is one not a direct replacement for the other?

[GClark]

According to

http://forum.nasaspaceflight.com/index.php?topic=26990.135,

there are at least three future launches of the Proton-Blok DM planned out through 2015.

IIRC, one of the initial Russian objections was that they themselves no longer used this vehicle for Lunar & Planetary missions.

[Star One]

According to

http://forum.nasaspaceflight.com/index.php?topic=26990.135,

there are at least three future launches of the Proton-Blok DM planned out through 2015.

IIRC, one of the initial Russian objections was that they themselves no longer used this vehicle for Lunar & Planetary missions.

So it's ESA that want them to use it on these missions rather than the Russian side?

[Stan Black]

Three DM-03 already exist
http://forum.nasaspaceflight.com/index.php?topic=27417.msg852838#msg852838

Proton is now the choice for Spektr-UF though with Briz-M
http://forum.nasaspaceflight.com/index.php?topic=26990.msg891784#msg891784

[GClark]

So it's ESA that want them to use it on these missions rather than the Russian side?

AIUI, it was ESA that proposed the barter.

See here:

http://russianspaceweb.com/exomars_2016.html#turin

[GClark]

Proton is now the choice for Spektr-UF though with Briz-M
http://forum.nasaspaceflight.com/index.php?topic=26990.msg891784#msg891784

I had missed that.  Thank you, sir.

[Danderman]

AFAIK, Proton-M/Briz-M is rated at 5500 kg capability for lunar missions, whereas the old Proton-K/Block-D was used to send 5800 kg Zonds to the Moon; Proton-M should be much more capable for these missions, but I don't know why the official capability is less.

[Star One]

AFAIK, Proton-M/Briz-M is rated at 5500 kg capability for lunar missions, whereas the old Proton-K/Block-D was used to send 5800 kg Zonds to the Moon; Proton-M should be much more capable for these missions, but I don't know why the official capability is less.

Thanks. How much does that payload capacity drop when the flight is to Mars rather than the Moon, is it a fairly steep drop off of in payload capacity or is it less of a steep drop would you think?

[Dalhousie]

This is bit of a beat up I think.  Atlas was supposed to carry both MAX-C and ExoMars, Proton, which can send ~4 tonnes to Mars should be able to handle ExoMars, which has a rover mass of ~300 kg.
The statement may apply to the 2016 mission, with an orbiter of ~3 tonnes, a 600 kg test lander, and an unknown Russian lander, together this would be getting near the limit.

[Star One]

This is bit of a beat up I think.  Atlas was supposed to carry both MAX-C and ExoMars, Proton, which can send ~4 tonnes to Mars should be able to handle ExoMars, which has a rover mass of ~300 kg.
The statement may apply to the 2016 mission, with an orbiter of ~3 tonnes, a 600 kg test lander, and an unknown Russian lander, together this would be getting near the limit.

I am fairly sure the rover engineer they had did say it was 300kg now but had been shrunk because of the change of launcher.

Also there is this quote from Wikipedia.

In February 2012, following NASA's withrawal,the ESA went back to previous designs for a smaller rover,[3] once calculated to be 207 kg. Instrumentation will consist of the exobiology laboratory suite, known as "Pasteur analytical laboratory" to look for signs of past or present life - or biosignatures.[1][4][5][6] Among other instruments, the rover will also carry a 2 metres (6.6 ft) sub-surface drill to pull up samples for its on-board laboratory.[7]

http://en.wikipedia.org/wiki/ExoMars_rover

[Dalhousie]

A redesign (the fifth?) will be necessary of course, but in the Wikipedia article reference (3), which is the basis to the claim that the rover has shrunk from 207 kg,  says nothing of the kind, either it is from an uncited source or was simply made up.

[stone]

It is not a real re-design, it is only going back to the drawings before the joint rover time. The rover design is now very similar to the one in 2009. I know this from some TAS-I meetings to accommodate instruments in the ALD.
 

[Star One]

It is not a real re-design, it is only going back to the drawings before the joint rover time. The rover design is now very similar to the one in 2009. I know this from some TAS-I meetings to accommodate instruments in the ALD.
 

Thanks for that. Has there been any particular loss of science through returning to this 2009 design?

[stone]

It is not a real re-design, it is only going back to the drawings before the joint rover time. The rover design is now very similar to the one in 2009. I know this from some TAS-I meetings to accommodate instruments in the ALD.
 

Thanks for that. Has there been any particular loss of science through returning to this 2009 design?

We lost two instruments and all their science. Rover payload is smaller now.
We lost 400 or 500 days of science. The mission is 180 days and not two years.
We lost all the instruments on the US side of the ExoMars-MaxC rover.
We got in real trouble because there is still instrument participation of Goddard and everything called Exomars should have been canceled.

There is still changes within Exomars because the contracts with Russia are still under negotiation.